HK1138710B - Using codewords in a wireless communication system - Google Patents

Description

Using codewords in a wireless communication system

Cross-referencing of related applications

This patent application claims priority from U.S. provisional application No.60/889,252, entitled "A METHOD AND DAPPARUTUS FOR EFFICIENT USE OF CODE AND IN A WIRELESS COMMUNICATION SYSTEM", filed on 9.2.2007, the entire contents of which are incorporated herein by reference.

Technical Field

The following description relates generally to wireless communications, and more specifically to efficiently using codewords in a wireless communication system.

Background

Wireless communication systems have been widely deployed to provide various types of communication such as voice and/or data through such wireless communication systems. A typical wireless communication system or network may provide one or more shared resources (e.g., bandwidth, transmit power) for multiple user accesses. For example, the system may employ a number of different access technologies such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), third generation partnership project (3GPP) Long Term Evolution (LTE) systems, Orthogonal Frequency Division Multiplexing (OFDM), and so forth.

Generally, wireless multiple-access communication systems can simultaneously support communication for multiple mobile devices. Each mobile device may communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations. The communication link may be established by a single-input single-output (SISO), multiple-input single-output (MISO), single-input multiple-output (SIMO), or multiple-input multiple-output (MIMO) system.

For example, a MIMO system may employ multiple (N)_T) Transmitting antenna and a plurality of (N)_R) And the receiving antenna is used for data transmission. From the N_TA transmitting antenna and N_RA MIMO channel composed of multiple receive antennas can be decomposed into N_SIndividual channels, which may also be referred to as spatial channels, where N_S≤min{N_T，N_R}. The N is_SEach of the individual channels corresponds to a dimension. The MIMO system may provide improved performance (e.g., higher throughput and/or greater reliability) if the additional dimensionalities created by the multiple transmit and receive antennas are utilized.

MIMO systems may support Time Division Duplex (TDD) and Frequency Division Duplex (FDD) systems. In a TDD system, the forward and reverse link transmissions may be on the same frequency range, thus enabling the estimation of the forward link channel from the reverse link channel by the reciprocity principle. This enables the access point to extract transmit beamforming gain on the forward link when multiple antennas are available at the access point.

Wireless communication systems often employ one or more base stations that provide a coverage area. A typical base station can transmit multiple data streams for broadcast, multicast, and/or unicast services, wherein a data stream can be a single data stream that an access device desires to receive. Mobile devices within the coverage area of that base station can be employed to receive one, more than one, or all of the data streams carried by the composite stream. Likewise, a mobile device can transmit data to the base station or another mobile device.

Transmissions between the mobile device and the base station can span both traffic channels and control channels. The transmission of traffic channels between mobile devices and base stations can be accomplished using complex orthogonal modulation. It may be desirable to utilize complex orthogonal modulation for uplink control channel transmissions, particularly when complex orthogonal transmissions are used for traffic channel transmissions. However, efficient single-carrier frequency division multiple access (SC-FDMA) or Orthogonal Frequency Division Multiple Access (OFDMA) uplink control channel design is challenging, in part, because of conflicting requirements (e.g., bandwidth limitations, etc.) to be considered for the design of the uplink control channel.

Disclosure of Invention

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all embodiments. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

Various aspects are described in connection with facilitating transmission of control channel information between communication devices in a communication environment (e.g., a wireless communication environment), in accordance with one or more embodiments of the invention and corresponding disclosure. The present invention can utilize a complex orthogonal codeword set that can be constructed and used for bandwidth-efficient non-coherent signaling associated with single-carrier frequency division multiple access (SC-FDMA) or Orthogonal Frequency Division Multiple Access (OFDMA) to transmit control channel information between communication devices. The complex orthogonal codeword set comprises a first subset of codewords having desired cross-correlation properties and another subset of codewords comprising deleted codewords (expurgated codewords) comprising discarded codewords (discarding such codewords in order to meet desired spectral efficiency), and/or pairs of codewords resulting in undesired cross-correlation properties, such as worst case cross-correlation properties. The set and subset of codewords may be determined based at least in part on predefined codeword criteria. Multi-mode operation associated with the composite codeword is employed to further improve bandwidth efficiency. In addition, the discarded codeword, or a portion thereof, may be used for other desired purposes, such as erasure decoding and/or interference level estimation, for example, to help improve bandwidth efficiency.

In accordance with related aspects, a method that facilitates information transfer (e.g., in a wireless communication environment) is described. The method includes generating a set of codewords that facilitate transmission of information including control channel information. Further, the method includes deleting the subset of codewords based at least in part on a predefined codeword criterion.

Another aspect relates to a wireless communications apparatus. The wireless communication apparatus includes: a memory for holding instructions related to transmitting information using a codeword generated at least in part according to a predefined codeword criterion. Further, the wireless communications apparatus can include a processor coupled to the memory and configured to execute the instructions retained in the memory.

Yet another aspect relates to an apparatus. The apparatus includes a codeword generator for generating a codeword based at least in part on a predefined codeword criteria to facilitate transmission of information including control channel information. The apparatus also includes a remover for removing codewords based at least in part on predefined codeword criteria.

Yet another aspect relates to a wireless communications apparatus that facilitates information transfer, such as in a wireless communication environment. The wireless communications apparatus can include means for generating a subset of codewords to facilitate transmission of information. Further, the wireless communications apparatus can include means for deleting the generated subset of codewords based at least in part on a predefined codeword criterion.

Yet another aspect relates to a machine-readable medium having stored thereon machine-executable instructions for generating a set of code words to facilitate information transfer; and deleting the subset of codewords based at least in part on a predefined codeword criterion.

In accordance with another aspect, an apparatus in a wireless communication system can include a processor, wherein the processor is configured to utilize a generated set of codewords, wherein the codewords are generated based at least in part on predefined codeword criteria. Further, the processor can be configured to utilize a portion of the generated set of codewords to facilitate transmission of a control channel message based at least in part upon the predefined codeword criteria.

In accordance with other aspects, a method that facilitates communicating information related to a communication environment is described. The method includes receiving a signal associated with a generated set of codewords that facilitate transmitting information including control channel information based at least in part on predefined codeword criteria. Further, the method includes decoding the received signal.

Yet another aspect relates to a wireless communications apparatus that includes a memory that retains instructions related to receiving and decoding a signal related to a generated codeword set for transmitting information including control channel information based at least in part on a predefined codeword criterion. Further, the wireless communications apparatus can include a processor coupled to the memory and configured to execute the instructions retained in the memory.

Another aspect relates to a wireless communications apparatus that facilitates information transfer in a wireless communication environment. The wireless communications apparatus can include means for receiving a signal related to a generated set of codewords that facilitate transmitting information including control channel information based at least in part upon predefined codeword criteria. Further, the wireless communications apparatus can include means for decoding the received signal.

Yet another aspect relates to a machine-readable medium having stored thereon machine-executable instructions for receiving a signal related to a generated set of codewords that facilitate transmitting information including control channel information based at least in part on predefined codeword criteria and decoding the received signal.

In accordance with another aspect, an apparatus in a wireless communication system includes a processor configured to receive a signal related to a generated set of codewords that facilitate transmitting information including control channel information based at least in part on predefined codeword criteria. Further, the processor is configured to decode the received signal. Moreover, the processor is configured to perform erasure decoding on the received signal using a subset of the generated set of codewords, the subset including the discarded codewords.

To the accomplishment of the foregoing and related ends, the one or more embodiments comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more embodiments. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed and the described aspects are intended to include all such aspects and their equivalents.

Drawings

Fig. 1 illustrates a wireless communication system in accordance with various aspects set forth herein.

Fig. 2 illustrates an example system that facilitates generating codewords to facilitate information transfer between communication devices in accordance with an embodiment of the present invention.

Fig. 3 illustrates an example methodology that facilitates communicating information in a wireless communication environment.

Fig. 4 illustrates an example methodology that facilitates generating codewords to facilitate transmitting information related to a wireless communication system.

Fig. 5 illustrates an example methodology that employs scrambling to facilitate transmitting information related to a wireless communication system.

Fig. 6 illustrates an example methodology that facilitates erasure-type decoding to facilitate transmission of information related to a wireless communication system.

Fig. 7 illustrates another example methodology that facilitates erasure decoding to facilitate transmission of information associated with a wireless communication system.

Fig. 8 illustrates an example mobile device that facilitates transmission or reception of information related to a wireless communication system.

Fig. 9 illustrates an example system that facilitates transmission or reception of information related to a wireless communication system.

Fig. 10 illustrates an example wireless network environment that can be employed in conjunction with the various systems and methods described herein.

Fig. 11 illustrates an example system that facilitates communication of information related to a wireless communication environment between communication devices.

Fig. 12 illustrates an example system that facilitates communication of information related to a wireless communication environment between communication devices.

Detailed Description

Various embodiments are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident, however, that such embodiment(s) may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more embodiments.

As used in this application, the terms "component," "module," "system," and the like are intended to include a computer-related entity, either hardware, firmware, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component can be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes in accordance with a signal comprising one or more data packets (e.g., data from one component coupled to another component in a local system, distributed system, and/or other system coupled via a signal over a network such as the internet).

Moreover, various aspects are described herein in connection with a mobile device. A mobile device can also be called a system, subscriber unit, subscriber station, mobile, remote station, remote terminal, access terminal, user terminal, wireless communication device, user agent, user device, or User Equipment (UE). The mobile device may be a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device having wireless connection capability, a computing device, or other processing device connected to a wireless modem. Moreover, various aspects are described herein in connection with a base station. A base station can be utilized for communicating with mobile device(s) and can also refer to an access point, a node B, or some other terminology.

Furthermore, aspects or features of the disclosed embodiments may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, etc.), optical disks (e.g., Compact Disk (CD), Digital Versatile Disk (DVD), etc.), smart cards, and flash memory devices (e.g., EPROM, card, stick, key drive, etc.). In addition, various storage media described herein can represent one or more devices and/or other machine-readable media that can be used to store information. The term "machine-readable medium" can include, without being limited to, wireless channels and various other media capable of storing, holding, and/or carrying instruction(s) and/or data.

Referring now to fig. 1, a wireless communication system 100 is illustrated in accordance with various embodiments herein. System 100 comprises a base station 102 that includes multiple antenna groups. For example, one antenna group can include antennas 104 and 106, another group can include antennas 108 and 110, and an additional group can include antennas 112 and 114. Although two antennas are shown in each antenna group, more or fewer antennas may be utilized in each group. Base station 102 can additionally include a transmitter chain and a receiver chain, each of which can in turn comprise a plurality of components associated with signal transmission and reception (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, antennas, etc.), as will be appreciated by one skilled in the art.

Base station 102 can communicate with one or more mobile devices (e.g., mobile device 116 and mobile device 122), although it is to be appreciated that base station 102 can communicate with substantially any number of mobile devices similar to mobile devices 116 and 122. Mobile devices 116 and 122 can be, for example, mobile phones, smart phones, laptops, handheld communication devices, handheld computing devices, satellite radios, global positioning systems, PDAs, and/or any other suitable device for communicating over wireless communication system 100. As described above, mobile device 116 is in communication with antennas 112 and 114, where antennas 112 and 114 transmit information to mobile device 116 over forward link 118 and receive information from mobile device 116 over reverse link 120. In addition, mobile device 122 is in communication with antennas 104 and 106, where antennas 104 and 106 transmit information to mobile device 122 over a forward link 124 and receive information from mobile device 122 over a reverse link 126. For example, in a Frequency Division Duplex (FDD) system, forward link 118 can utilize a different frequency band than that used by reverse link 120, and forward link 124 can employ a different frequency band than that employed by reverse link 126. Further, in a Time Division Duplex (TDD) system, forward link 118 and reverse link 120 can utilize a common frequency band and forward link 124 and reverse link 126 can utilize a common frequency band.

Each group of antennas and/or the area in which they communicate can be referred to as a sector of base station 102. For example, antenna groups can be designed to communicate to mobile devices (e.g., 116) in a sector of the areas covered by base station 102. In communication over forward links 118 and 124, the transmitting antennas of base station 102 can employ beamforming to improve signal-to-noise ratio of forward links 118 and 124 for mobile devices 116 and 122. Moreover, while base station 102 can employ beamforming to transmit to mobile devices 116 and 122 scattered randomly through an associated coverage, mobile devices in neighboring cells can be subject to less interference as compared to a base station transmitting through a single antenna to all its mobile devices.

It may be desirable to employ non-coherent signaling, such as orthogonal modulation, to transmit control channels between communication devices (e.g., mobile devices, base stations). For example, when orthogonal multiplexing is utilized for a traffic channel, such as single carrier frequency division multiplexing (SC-FDM) or Orthogonal Frequency Division Multiplexing (OFDM), it may be desirable to utilize orthogonal multiplexing for a control channel, such as a Channel Quality Indication Channel (CQICH) which may convey downlink channel signal-to-interference-plus-noise ratio (SINR) measurement information and may be used as an uplink power control reference, with the same or similar interference experienced between the traffic channel and the control channel in terms of channel measurement. For example, after decoding the control channel, channel conditions (e.g., interference conditions) for the control channel can be measured and applied to the traffic channel using the same type of multiplexing (e.g., orthogonal) to facilitate improved control and/or decoding of the traffic channel, which can improve signal transmission and reception on the traffic channel. Such channel condition information is not available if the control channel does not utilize the same multiplexing (e.g., orthogonal) as the traffic channel. Another reason for using orthogonal modulation based on non-coherent signaling is that coherent signaling suffers from pilot overhead, while orthogonal modulation with respect to non-coherent signaling may remove the uplink pilot overhead.

Conventionally, the inefficiency of the orthogonal code used for the control channel information transmission is undesirable. The present invention extends the quadrature modulation from binary modulation to complex modulation (e.g., quaternary), which can significantly improve bandwidth efficiency. The present invention also optimizes the efficiency of orthogonal control channels by designing a bandwidth efficient complex codeword set with significantly improved cross-correlation properties, which may help reduce the number of tones utilized for orthogonal multiplexing of uplink control channels, help interference level estimation, erasure detection, and/or help simultaneous or substantially simultaneous transmission of multiple types of control information (e.g., CQICH, Precoding Matrix Indicator Channel (PMICH), Scheduling Request Channel (SRCH), etc.). For example, the present invention may design a desired (e.g., large) set of complex orthogonal codewords, and the worst case codewords and/or additional codewords may be deleted from the complex orthogonal codes in order to create a bandwidth efficient non-coherent signaling codeword set with desired cross-correlation properties. In addition, multi-mode operation may be employed to use the designed composite codeword in order to further improve bandwidth efficiency.

For example, it is common to transmit 8 bits with binary orthogonal modulation (based on non-coherent signaling) to involve (256, 8) Hadamard codes, and such binary orthogonal signaling takes 256 tones, which is an undesirably high number because it exceeds the bandwidth budget of orthogonal multiplexing of uplink control channels and also provides very low code rates (e.g., 1/32). In accordance with various embodiments, the present invention may reduce the number of tones employed to a significantly smaller number of tones (e.g., 32 tones or less) to transmit for uplink8 bits of orthogonal multiplexing of the uplink control channel. For example, the present invention can employ complex orthogonal modulation (e.g., Quaternary Phase Shift Keying (QPSK)) for non-coherent signaling to reduce the number of tones used to transmit control channel information compared to binary orthogonal modulation to facilitate efficient bandwidth non-coherent signaling. The data that yields poor correlation (e.g., correlation is) This can improve the worst-case cross-correlation between the remaining pairs of codewords. Further, a predetermined number of the remaining codewords may be discarded in order to meet a desired spectral efficiency (e.g., a desired number of valid codewords for a given number of tones). The discarded codewords may be used for other purposes such as interference level estimation, erasure detection, and so on.

In accordance with one aspect, a communication device, such as a mobile device (e.g., 116) and/or base station 102, can be configured to utilize a composite sequence for bandwidth efficient non-coherent signaling of uplink control channels (e.g., CQICH, PMICH, SRCH, etc.) associated with, for example, SC-FDM or OFDM. The communication device may transmit a desired number of bits of control channel information, which may be transmitted using complex orthogonal modulation.

It should be appreciated that although the present invention is described herein with respect to mobile devices (e.g., 116) and base stations 102, the present invention is not so limited and various aspects of the present invention may be employed with virtually any communication device, whether communicating in a wireless environment or a wired environment.

In accordance with one embodiment, complex orthogonal modulation can be employed and utilized by a communication device (e.g., 102, 116), wherein higher order modulation (e.g., QPSK) can be employed for non-coherent signaling to facilitate reducing the number of tones employed to transmit control channel information. In an aspect, a plurality of bits of desired control channel information to be transmitted may be divided into a plurality of bit sets, and each bit set may be separately encoded (e.g., using a Hadamard code). For example, by dividing the bits of the control channel information into sets, the number of tones employed may be reduced to a specified number of tones based at least in part on the number of bits and/or groups of bits in each group of bits, as compared to the number of tones employed without dividing the bits. The constellation can be extended from binary to quaternary, one subset of bits can be transmitted for in-phase (I-phase) and another subset of bits for quadrature phase (Q-phase), so that each sequence of control channel information can be modulated with a higher order modulation (e.g., QPSK) and transmitted over a specified number of tones. In another aspect, the codeword may be scrambled by a particular complex pseudo-random noise (PN) sequence of a specified length (e.g., equal to the number of tones in each set) to provide better autocorrelation in the multipath channel.

For example, to transmit a desired number of bits (e.g., 8 bits) of control channel information with binary orthogonal modulation based on non-coherent signaling, the signaling may include a (256, 8) Hadamard code, which may take 2 for the binary orthogonal signaling⁸A number of tones (e.g., 256 tones). By employing complex orthogonal modulation, the number of tones used to transmit a desired number of bits of control channel information can be reduced to, for example, 16 tones to transmit 8 bits. In one aspect, the desired number of bits of the control channel information can be divided into a plurality of sets of bits (e.g., 2 sets of bits), and each set separately encoded with a suitable Hadamard code. The constellation can be extended from binary to quaternary, with 4 bits sent for I-phase and 4 bits sent for Q-phase, so that 2 can be used⁴Tone instead of using 2⁸A tone (e.g., as required by conventional binary quadrature modulation). For example, the 8 bits may be divided into two sets of 4 information bits, each set being encoded by a (16, 4) Hadamard code, respectively. The two length-16 real binary sequences may be formed of a pair (c)_I，m，c_Q，m) And (m ═ 0, 1.., 255). The binary sequence may be represented by s_m＝c_I，m+jc_Q，mPerforming QPSK modulated and transmitted over 16 tones.

In another aspect, the complex PN sequence of length 16, which is specific to the UE, scrambles the codeword to provide better autocorrelation over multiple channels. Despite the significant bandwidth reduction, it is difficult to apply the above QPSK codeword set to a specific non-coherent signaling, e.g.,

formula (1)

It is noted that the cross-correlation between codewords is an important parameter that controls the performance of non-coherent signaling. In general, a pair of different codewords will not have a consistent correlation value because of the difference in I-phase or Q-phase. In many cases there may be orthogonal I-phases but coincident Q-phases between a pair of codewords, or vice versa. The correlation value (e.g., correlation property) may be 0 as long as both the I-phase and the Q-phase are orthogonal, but may be 1/2 or 1/2 if the I-phase or the Q-phase of a first codeword coincides with the Q-phase of a second codeword while the Q-phase of the first codeword is orthogonal to the I-phase of the second codeword, or the I-phase of the first codeword coincides with the Q-phase of the second codeword while the Q-phase of the first codeword is orthogonal to the I-phase of the second codewordOne principle is that it is desirable to remove as many of these high correlation cases as possible (e.g., worst case cross-correlation values)) (to the extent that the desired spectral efficiency can be achieved) wherein the composite codeword is fully coincident at either the I-phase or the Q-phase-if it is fully coincident at the I-phase, there may be an undesirable correlation, and if it is fully coincident at the Q-phase, there may be an undesirable correlation. There may also be an undesired correlation with respect to one codeword if the I-phase of the codeword completely coincides with the Q-phase of another codeword. For example, in a flat fading channel, the receiver (e.g., base station 102) may observe a background noise vector z having a normalized variance after multiplying by a complex channel coefficient hThe best non-coherent receiver can then obtain the maximized codeword:

formula (2)

In the case of diversity reception in order L in a rayleigh fading channel (e.g., due to multiple receive antennas or multiple receive antennas), the best metric may instead be:

formula (3)

Wherein the content of the first and second substances,is the ith of the codewordDiversity reception, σ_l ²Is the long-term average power of the ith diversity channel, | s | | Y²Is the common energy of the valid codewords. When the channel profile cannot be measured, α can be measured_lIs set to alpha_l＝1。

In general, even if the codeword length is increased, the high cross-correlation does not degrade in the above orthogonal composite code design because it results from a complete collision of one dimension of a codeword with one dimension of another codeword, which may result in a correlation value of 1/2, or with two dimensions of another codeword, which may result in a correlation value of 1/2

In accordance with another embodiment, independent real scrambling codes can be applied to the I-phase and Q-phase of each codeword to help reduce peak cross-correlation of complex quadrature modulation in a non-coherent receiver (e.g., base station 102). For example, when two complex orthogonal codewords s_m＝c_I，m+jc_Q，mAnd s_n＝c_I，n+jc_Q，nTwo conditions are satisfied, and the two code words are not identical to each otherPeak cross correlation of (d):

[ Condition 1)]c_I，m＝c_Q，m＝c_Q，nOr c_I，m＝c_Q，m＝c_I，nAnd formula (4a)

[ Condition 2)]c_I，n≠c_Q，nEquation (4b)

To reduce peak cross-correlation of complex quadrature modulation in a non-coherent receiver, independent real scrambling codes may be applied to the I-phase and Q-phase of each codeword, wherein a first real scrambling code may be used for the I-phase of each codeword and a different real scrambling code may be used for each codewordA number scrambling code may be used for Q-phase. The two scrambling codes for I-phase and Q-phase respectively can be represented by a_IAnd a_QIt is shown that the resulting complex orthogonal code word can take the form:

s_m＝s_I，m+js_Q，m＝(a_Iоc_I，m)+j(a_Qоc_Q，m) 0,1,.., 255, formula (5)

Where the operators a o b may be defined as element-by-element multiplication of the vectors a and b. In another aspect, the codeword may also be scrambled by a UE-specific complex PN sequence having a specified length (e.g., length 16 in the above example) to provide better autocorrelation in multiple channels.

Two different codewords s_m=s_I,m+js_Q,mAnd s_n=s_I,n+js_Q,nCross-correlation between is likely to decrease because it can take

Formula (6)

Wherein the content of the first and second substances,andis a pseudo-random variable which depends on the codeword pair and a_IAnd a_QThe cross-correlation property of (a). Suppose a_IAnd a_QIs an independent random binary sequence, R_I,Q(m, n) and R_I,Q(N, m) may be approximated as a zero mean gaussian random variable with a variance of 1/4N for the sequence length N. Thus, with this random scrambling sequence, the peak correlation can be described statistically as:

formula (7)

When N is large, it is likely to be smaller than. In the example of N =16 (it is determined that N equals 16 according to the example above), a typical correlation value may be calculated as:

however, the worst case cross-correlation value may be greater than this typical correlation value (W)Lower limit of elch). By designing scrambling sequence pair a_IAnd a_QSo that the worst-case cross-correlation between I-phase and Q-phase can be minimized or reduced and the performance of non-coherent demodulation can be improved.

In accordance with another embodiment, the bits of the control channel information may be divided into subsets, which may be transmitted via separate Time Division Multiplexed (TDM) or Frequency Division Multiplexed (FDM) resources, wherein the division of the bits helps to reduce and/or control the worst case cross-correlation properties. In accordance with one aspect of the invention, binary orthogonal modulation may be employed to transmit a first subset of bits of control channel information to a receiver (e.g., base station 102) over a first subset of tones and to transmit another subset of bits of control channel information to the receiver over another subset of tones.

Therefore, the worst-case cross-correlation property is not encountered between codewordsIn this embodiment the worst case cross-correlation value generated is at most 1/2, since the first or second subset is fully linearly aligned with some other codeword. By using separate bandwidths for the first and further subsets of bits, the worst case cross-correlation value can be avoided compared to the complex orthogonal modulation example described above

For example, continuing with the previous example comprising 8 bits of control channel information, the 8 bits of control channel information may be divided into two subsets of 4 information bits, and each subset is separately encoded by a (16, 4) Hadamard code. The two real binary sequences of length 16, such as sub-codewords, may be modulated by Binary Phase Shift Keying (BPSK) and transmitted over two sets of 16 frequency tones each. Each sub-codeword may be scrambled by a UE-specific complex PN sequence of a specified length (e.g., length 16 in this example) to provide improved autocorrelation over multiple channels. At the receiver (e.g., base station 102), the information bits transmitted over the two sets of resources (e.g., 1 of 16 in this example) may be individually decoded by a peak energy detector and concatenated to recover the original information bits of 8-bit length.

In the example of transmitting 8 bits of control channel information, the 8 information bits are transmitted using 32 tones, which, although larger than the 16 tones used for complex orthogonal modulation, is much smaller than the 256 tones used for basic single binary orthogonal modulation. It is noted that when the information bit subsets are all successfully decoded, the decoding is successful. In terms of cross-correlation, the worst case cross-correlation value of the resulting criterion may be 1/2, which may occur when the first or second sub-codeword of the two codewords coincide. Thus, the worst case cross-correlation can be derived from the double time-bandwidth consumption (e.g., 32 tones instead of 16 tones) compared to complex quadrature modulationThe improvement was 1/2.

In addition, it may be desirable to allocate the two sub-codewords together in coherence time and coherence bandwidth because if the two resources experience different channels, the multi-real quadrature modulation is not efficient in terms of multi-path impedance performance due to the short length (e.g., 16 tones) of each sub-codeword (or despreading period). The normalized out-of-peak value of the autocorrelation of the random sequence can be approximatedWhere N is the spreading factor (or integration length). Thus, in the above example, two sets of 16 tones were each transmitted separately, as compared to approximately32 tonesTuned multi-path impedance which can be reduced to approximately

In accordance with another embodiment, the erasure-based complex orthogonal code can be designed and can be utilized by a communication device, such as a mobile device (e.g., 116) and/or base station 102, to facilitate transmission of control channel information to a receiver, such as another communication device. In one aspect, the erasure-based complex orthogonal code can be designed by a combination of two high-speed orthogonal modulation techniques as described in this application. A code is designed that facilitates bandwidth efficient transmission of control channel information, wherein undesired codewords (e.g., codeword pairs associated with worst case cross-correlation values) are removed from a set of available codewords. For example, deletion generation may be desiredOr at least remove as many such codeword pairs as possible. Thus, for example, it may be desirable to delete pairs of codewords in which both the I-phase and Q-phase of one codeword coincide with the I-phase or Q-phase of another codeword (e.g., pairs of codewords that satisfy conditions 1 and 2, respectively, associated with equations 4a and 4b described in this application).

In accordance with one aspect, complex orthogonal modulation (e.g., QPSK) can be employed and a set of codewords can be generated based at least in part on a predefined codeword criterion. Further, the subset of codewords can be deleted based at least in part on predefined codeword criteria, such as generating worst case cross modulation values (e.g.,) The code word of (1). Some codewords in the codeword set may also be deleted and discarded such that a desired number (e.g., a minimum) of codewords remain to facilitate a determination based at least in part onA predefined codeword criterion to transmit control channel information having a desired number of bits, wherein the discarded codewords or a portion thereof may be used for other purposes (e.g., interference level estimation, erasure detection, multi-mode control channel, etc.). The predefined codeword criteria may relate to, for example, available bandwidth, a number of codewords in a codeword set, a number of bits of control channel information to be transmitted at a given time, cross-correlation values for each pair of codewords, a type of orthogonal modulation transmission desired to be used, a worst-case cross-correlation value defined between codewords, a number of tones employed to facilitate transmission of control channel information, a number of codewords that are discarded and desired to be available for other purposes (e.g., interference level estimation, erasure detection, multi-mode control channel, etc.), and/or other factors.

In one aspect, a set of real binary orthogonal (e.g., Hadamard) sequences of a predetermined length may be generated. A different pair of sequences may be selected from the set of sequences, and a particular number of available codewords may be derived based at least in part on the selected sequences. The different sequences selected may be such that at least a required number of codewords are used to transmit control channel information (e.g., CQICH) having a desired number of bits. Further, one of the different sequences may be utilized for the I-phase and another different sequence may be utilized for the Q-phase to create a composite codeword. If there are additional codewords in addition to the number of codewords needed to facilitate transmission of the control channel information bits, these additional codewords can be deleted and discarded to meet a desired spectral efficiency (e.g., a desired number of valid codewords for a given number of tones). The discarded codewords may be used for other purposes such as interference level estimation, erasure detection, for multi-mode control channel operation, and so on.

For example, continuing with the example where it is desired to transmit 8 bits of control channel information, the pruned complex orthogonal code may be generated as follows. Generating a set of real binary orthogonal (e.g., Hadamard) sequences { c) of length 24_lI =0,1, ·,23 }. Selecting a pair of different sequences from the 24 binary orthogonal sequences { (c)_m,c_n) M ≠ n }, which provides₂₄C₂=276 available codewords (e.g., (24 · 23)/2=276 codewords). A 24Hadamard codeword is the smallest one that can yield at least the desired number of available codewords (e.g., 256 codewords) that can facilitate transmission of 8 bits of control channel information, because, for example, there are no 23Hadamard codewords, the next smallest available Hadamard codeword is 20, which cannot yield at least the desired number of available codewords. Since 256 codewords are expected to be suitable for transmitting 8 bits of control channel information, a subset of 256 codewords can be selected by applying a predefined design criterion (e.g., a predefined codeword criterion), and unselected codewords can be deleted and discarded. In an aspect, the 20 codewords that are discarded may be used for other purposes (e.g., interference level estimation, erasure detection, for multi-mode control channel operation, etc.). The k-th length-24 deleted complex orthogonal codeword may be generated as follows, s_k=(b_I+jb_Q)о(c_m(k)+jc_n(k)) K =0, 1.., 255, where a scrambling code b may be utilized_I+jb_QAnd may be a communication device specific normalized complex PN sequence that may be used to provide better autocorrelation in multiple channels. With respect to the above formula, the operator o represents an element-by-element multiplication of a vector (e.g. as defined in the present application), (c)_m(k),c_n{k)) May be a different pair of binary orthogonal sequences corresponding to the kth codeword. Since the designed codeword is a complex codeword and the complex codeword is multiplied with a common complex PN sequence, there is no change in the correlation structure, which is also desirable, and the autocorrelation properties of each codeword can be improved so that each codeword is more robust and can better suppress multipath interference.

The worst-case normalized cross-correlation between any two complex orthogonal sequences in the designed set becomes 1/2 through deletion because of the codeword deletion condition applied in the code designSo as not to satisfyCondition 1 and condition 2 (e.g., as discussed herein with respect to equation 4a and equation 4 b). It should be noted that the multi-real quadrature modulated or coherent order 2 RM code may also have a worst case cross-correlation of 1/2, believed to be due to the previous description in this application

In another aspect, a transmitting communication device (e.g., mobile device 116) can employ complex quadrature modulation based on erasure to facilitate sending 8 bits of control channel information to a receiver (e.g., base station 102) over 24 tones through non-coherent signaling, which is better in bandwidth efficiency than multi-real quadrature modulation, which utilizes 32 tones to transmit 8 bits of control channel information to the receiver. Furthermore, the erasure-based complex orthogonal modulation is better than the multi-real orthogonal modulation in terms of multi-path interference suppression efficiency, because the despreading length can be equal to the codeword length. For example, in an example utilizing 24 tones, the suppression capacity may be proportional to 1/24, which is improved over the exemplary use of 32 tones (divided into two sets of 16 tones with suppression capacity proportional to 1/16), because in the previous example (e.g., 24 tones), all of the spectrum allocated is used in one segment of the codeword, rather than in two separate segments of the codeword in the latter example (e.g., two sets of 16 tones).

In accordance with another aspect, a receiver (e.g., a communication device such as base station 102 or mobile device 116) can employ sub-optimal multi-peak non-coherent decoding instead of optimal decoding (e.g., as described herein with respect to equations (2) - (3)) in order to reduce receiver complexity, although the sub-optimal multi-peak non-coherent decoding can potentially reduce decoding performance. In this case, the receiver may evaluate the set of real orthogonal vectors { c }_iAnd the descrambled observation vector (b)_I-jb_Q) O a correlation between y, wherein (b)_I-jb_Q) Is a descrambling sequence and y is the received signal, in order to obtain the phaseRelevance metric

i is 0,1, 15. Formula (8)

Multiplying one real code word of the 24 binary code words by the descrambled composite received signal can achieve the I-phase and Q-phase of the correlation result in equation (8). For example, the decoding metric may be calculated and compared as follows:

L(s_k)＝|C(c_m(k))|²+|C(c_n(k))|²(energy combination) formula (9)

Or

L(s_k)＝Im[(C(c_m(k))^*C(c_n(k)))](differential combination) formula (10)

In another aspect, the number of tones used to transmit control channel information having a desired number of bits may be further reduced and/or the number of codewords discarded that may be used for other desired purposes may be increased by spreading the erasure-based complex orthogonal modulation. In accordance with one aspect, { s } can be obtained by exchanging the I-phase and Q-phase of each orthogonal codeword (in addition to the common scrambling code)_kCan be divided into { s }_kIs added to the complex orthogonal codeword set based on erasures in order to double the set size without degrading the cross-correlation properties between codewords, since s_k＝(b_I+jb_Q)о(c_m(k)+jc_n(k)) And s_k＝(b_I+jb_Q)о(c_n(k)+j_cm(k)) Quadrature, the result is true because c_m(k)And c_n(k)Orthogonal and vector c_m(k)、c_n(k)、b_I、b_QHas a constant amount (e.g., +1 or-1) of each element of (a). Assuming such an orthogonal relationship, { s }_kThe addition of the complex orthogonal codeword set to the erasure does not degrade the codeCross correlation properties between words, but as such will s_kThe addition of the complex orthogonal codeword set to the erasure doubles the set size.

When the number of available tones is N, the initial set of complex orthogonal codes based on erasures is of size_NC₂N (N-1)/2, and the extended set size is_NP₂N (N-1). Thus, in the example of 8-bit control channel information where 256 codewords are desired to facilitate the transmission of 8 bits from a transmitting communication device (e.g., mobile device 116) to a receiver (e.g., communication device such as base station 102), the minimum number of tones satisfying N (N-1) ≧ 256 is 17. Thus, a real binary Hadamard sequence { c } of length 20 may be employed_l: l 0, 1.. 19} instead of a real binary Hadamard sequence of length 24 as utilized in the previous example. The expanded set size may result in 380 codewords (e.g., 380 codewords 20 · 19). A subset of 256 codewords may be selected from the 380 extended deletion-based complex orthogonal codewords based at least in part on a predefined design criterion (e.g., a predefined codeword criterion). The other 124 codewords may be discarded and the 124 discarded codewords may be used for other purposes (e.g., interference level estimation, erasure detection, for multi-mode channel operation, etc.). The 124 dropped codewords that can be used for other desired purposes are significantly increased over the 20 dropped codewords used in the previous example. In addition, the spreading code transmits 8 bits of control channel information to the receiver using 20 QPSK tones while maintaining the normalized worst case cross-correlation value at 1/2. When using the extended erasure-based orthogonal codewords, a corresponding receiver (e.g., a communication device) can employ optimized non-coherent detection as described herein.

In accordance with yet another aspect, erasure decoding can be applied to non-coherent signaling to facilitate erasure detection and decoding of received signals during control channel information transmission. When employing erasure-based (or extended erasure-based) complex orthogonal modulation, the discarded codewords may be used for other purposes, such as erasure decoding, and when used for erasure decoding, the use of the discarded codewords helps control the threshold for erasure detection.

For example, because the discarded codewords are not used as part of the control channel signaling, the discarded codewords or a portion thereof can be used for erasure decoding or other purposes when the transmission is received. The discarded codewords are correlated with the input signal, which facilitates measuring or estimating an interference level (e.g., interference level estimation). It is beneficial to use these discarded codewords to measure the background noise level. These discarded codewords may also be used to fine tune the threshold level.

There are various techniques for applying erasure-type decoding. In an aspect, a receiver (e.g., a communication device such as base station 102 or mobile device 116) can employ erasure-type decoding for non-coherent signaling. The receiver receives a non-coherent signal during transmission of control channel information. For example, the receiver can be a base station 102 that receives control channel information from a mobile device (e.g., 116).

The receiver determines the codeword by Maximum Likelihood (ML) decoding, such as described in this application with respect to equations (2) - (3). The receiver may select codewords that are completely orthogonal (e.g., cross-correlation of 0) to the determined codeword. The receiver calculates an average of the decoder output energy values corresponding to the selected codeword. The receiver determines the difference (or alternatively the ratio) between the determined energy value of the codeword and the average value of the decoder output energy corresponding to the selected codeword. The receiver determines whether a measure of the difference (or alternatively, the ratio between) the determined energy value of the codeword and the average of the decoder output energies corresponding to the selected codeword is greater than or equal to a predetermined threshold level associated with the decoding result. If the metric is greater than or equal to the predetermined threshold level, the receiver determines that the decoding result is valid; and if the metric is less than the predetermined threshold level, the receiver determines that the decoding result is invalid and declares it erasable.

In accordance with yet another aspect, the determined codeword can be utilized as a known sequence to facilitate application of erasure decoding in non-coherent signaling to facilitate decoding of a received signal during transmission of control channel information. Assuming that the decoding is correct, a receiver (e.g., a communication device, such as base station 102) can estimate the propagation channel coefficients using the determined codeword. The determined or declared codeword may be used as a reference signal or pilot signal that facilitates construction of a control channel. After the channel is constructed, the channel power is measured. The receiver may remove (e.g., subtract) the signal component corresponding to the determined codeword from the received signal. The receiver calculates the average power of the residual signal (e.g., after removing signal components from the received signal) to estimate the background noise level. It should be noted that if the decoding is not correct, the background noise level may be high. The receiver calculates a signal-to-noise ratio (SNR) based at least in part on the channel estimate (e.g., estimates of propagation channel coefficients) and the noise level estimate.

It should be appreciated that the application of erasure decoding described in this application is one of a variety of techniques that may be used to perform erasure decoding, and the invention is not so limited, as the invention contemplates that a receiver or other component may employ other techniques to perform erasure decoding of a received incoherent signal. The receiver may determine whether the SNR is greater than or equal to a predetermined threshold level in order to determine a valid decoding result. If the receiver determines that the SNR is greater than or equal to the predetermined threshold level, the receiver may determine that the determined codeword is a valid decoding result. If the receiver determines that the SNR is less than a predetermined threshold level, the receiver may determine that the determined codeword is not a valid decoding result and the receiver may declare it to be erasable.

In accordance with another aspect of the subject invention, a communication device (e.g., mobile device 116, base station 102) can utilize a discarded codeword for a multi-mode control channel. For example, in addition to utilizing a selected number of codewords for transmission of a first type of control channel information (e.g., CQICH), the communication device can utilize other codewords (e.g., discarded codewords) to facilitate transmission of one or more other types of control channel information (e.g., PMICH, SRCH, etc.) to the receiving communication device. For example, a predetermined number of bits of CQICH and/or a predetermined number of bits of other control channel information (e.g., PMICH, SRCH, etc.) may be transmitted from a transmitting communication device (e.g., mobile device 116) to a receiving communication device (e.g., base station 102) based at least in part on predefined codeword criteria (relating to available bandwidth, available codewords, number of tones, orthogonal modulation type, and/or other factors as described herein).

For example, if the rate of change of the precoder is significantly lower than the rate of change of the channel SNR, then multi-mode operation of the designed code between CQICH and PMICH is desirable. In an aspect, a transmitting device (e.g., mobile device 116) may send a PMICH to a receiver (e.g., base station 102) when it is desired (e.g., needed) to update the precoder. Otherwise, the CQICH may be transmitted separately or with other control channel information (e.g., SRCH), as desired. The infrequent replacement of CQICH by PMICH does not significantly affect AMC operation. In accordance with another aspect of the invention, multi-mode operation for transmitting more than one type of control channel information may be performed in conjunction with using the deleted codeword for other purposes (e.g., erasure coding, interference level estimation, etc.).

For example, continuing with the previous example of transmitting 8 bits of control channel (e.g., CQICH) information, there may be 380 available codewords by employing the extended erasure-based complex orthogonal modulation and utilizing 20 QPSK tones. 256 codewords are selected from the 380 available codewords and used to facilitate CQICH transmission from a transmitting device (e.g., mobile device 116) to a receiving device (e.g., base station 102). The remaining 124 codewords may be discarded or deleted codewords, which may be used for other purposes, e.g., a portion of the discarded codewords may be used to facilitate transmission of other control information. If the designed code is used for both a CQICH and PMICH (and/or SRCH, etc.), then either an 8-bit CQICH or a 6-bit PMICH may be transmitted from the transmitting communication device to the receiving communication device, wherein with the 6-bit PMICH transmission, the PMICH may be transmitted with 64 of the 124 available dropped codewords, and the remaining 60 dropped codewords may be used for other purposes, such as to facilitate adjusting the threshold for erasure-type decoding or communicating a third control channel (e.g., SRCH, request related to uplink resource allocation), for example. Since the set of codewords is distinguishable between CQICH and PMICH, if decoding is successful, the receiving communication device (e.g., base station 102) can properly interpret the decoding result regardless of whether the received signal is for CQICH or PMICH.

In the same or similar manner, if a 7-bit CQICH is desired to be transmitted from a transmitting communication device to a receiving communication device, with extended erasure-based complex orthogonal modulation, 16 QPSK tones may be utilized and 240 available codewords may be designed based at least in part on the number of tones. The 7-bit CQICH or 6-bit PMICH may be transmitted using 192 codewords, with the remaining 48 discarded codewords being available for other desired purposes. Alternatively, 12 QPSK tones may be selected and 132 codewords designed and only available for transmitting a 7-bit CQICH. Depending in part on the bit width desired for PMICH and/or SRCH transmissions, additional QPSK tones may be desired for the latter design.

The present invention may use composite sequences for bandwidth efficient non-coherent signaling of control channel information from one communication device to another. In accordance with various aspects and embodiments, the present invention may employ complex orthogonal codes and remove the worst case codeword from the complex orthogonal codes to create a bandwidth efficient non-coherent signaling codeword set with desirable cross-correlation properties. Further, in accordance with various aspects and embodiments, the complex orthogonal code may be used for one or more control channels, such as CQICH, PMICH, and/or SRCH, by dividing the designed codeword into multiple subsets of codewords, in order to further improve bandwidth efficiency.

Referring to fig. 2, illustrated is a system 200 that facilitates designing and/or generating codewords to facilitate transmission of information between communication devices in accordance with an embodiment of the present invention. System 200 includes means 202 for facilitating designing and/or generating codewords that facilitate transmission of information, such as control channel information, erasure decoding information, interference level estimation information, and/or other information between a transmitting communication device (e.g., mobile device 116) and a receiving communication device (e.g., base station 102). According to one embodiment, apparatus 202 may be a computer or other computing device that facilitates designing and generating codewords. It is to be appreciated that apparatus 202 can include the same or similar functionality relating to designing and/or generating codewords, such as described in detail herein with respect to system 100, for example. For example, apparatus 202 facilitates constructing and/or generating codewords related to binary orthogonal modulation, complex orthogonal modulation, erasure-based complex orthogonal modulation, extended erasure-based complex orthogonal modulation, and/or the like to facilitate bandwidth-efficient transmission of information (e.g., control channel information, erasure-type decoding information, and/or the like) between communication devices with non-coherent signaling.

Apparatus 202 includes a codeword generator 204 for generating a codeword. The codeword may be generated based at least in part on predefined codeword criteria to obtain a codeword with a desired design. The predefined codeword criteria relates to, for example, available bandwidth, the number of codewords in a codeword set, the number of bits of control channel information to be transmitted at a given time, cross-correlation values for each pair of codewords, the type of orthogonal modulation transmission desired to be used (e.g., binary orthogonal modulation, complex orthogonal modulation, erasure-based complex orthogonal modulation, extended erasure-based complex orthogonal modulation, etc.), the worst-case cross-correlation values defined between codewords, the number of tones employed to facilitate control channel information transmission, the number of codewords discarded that are desired to be available for other purposes (e.g., interference level estimation, erasure detection, multi-mode control channel, etc.), and/or other factors.

In accordance with another aspect, the apparatus 202 mayTo include a puncturer 206 associated with code word generator 204. A set of codewords can be generated and the deleter 206 facilitates deleting a subset of codewords in the set of codewords based at least in part on predefined codeword criteria. For example, the pruner 206 facilitates the removal of the cross-correlation values that produce the worst case cross-correlation values (e.g.,) And/or other undesired pairs of cross-correlation values. In one embodiment, the puncturer 206 facilitates constructing a complex orthogonal code based on deletions (and/or an extended orthogonal code based on deletions) such that by employing codeword deletion conditionsSuch that the worst-case cross-correlation value between any two deleted complex orthogonal sequences is 1/2 (rather than being) Thus, the conditions 1 and 2 related to the equations 4a and 4b described in the present application cannot be satisfied.

In yet another aspect, the puncturer 206 also facilitates deleting a desired number of codewords to discard the codewords to meet a desired spectral efficiency (e.g., a predetermined threshold number of valid codewords desired for a given number of tones). The remaining codewords in the codeword set may be selected as codewords that facilitate transmission of certain control channel information (e.g., CQICH). The discarded codewords may be used for other purposes, such as erasure decoding, interference level estimation, and/or multi-mode control channel operation (e.g., to facilitate transmission of other control channel information, such as PMICH and/or SRCH), as desired.

The apparatus 202 further includes a processor 208 that can be coupled to the data store 210, the codeword generation 204, and the deleter 206, and that can process and/or analyze data to facilitate designing and/or generating codewords, selecting codewords, deleting codewords, and/or the like to facilitate transferring information (including control channel information) between communication devices.

The apparatus 202 can also include a data store 210 that is operatively coupled to the processor 208 and that can store data to be transmitted, received data, information related to generation of codewords, deletion of codewords, transmission and reception of control channel information (e.g., information related to complex orthogonal modulation, deletion-based complex orthogonal modulation, and/or extended deletion-based complex orthogonal modulation, etc.), information related to erasure decoding and/or interference level estimation, and any other information that facilitates design and/or generation of codewords to facilitate transmission and/or reception of information (e.g., control channel information) between communication devices (e.g., mobile devices (e.g., 116) and base station 102). Data storage 210 may additionally store protocols and/or algorithms associated with designing and/or generating codewords, deleting codewords, quadrature modulation (e.g., binary quadrature modulation, complex quadrature modulation based on deletion and/or complex quadrature modulation based on extended deletion, etc.), erasure decoding, interference level estimation, etc.

It is to be appreciated that the data store 210 described herein can include volatile memory and/or nonvolatile memory. By way of illustration, and not limitation, nonvolatile memory can include Read Only Memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable PROM (EEPROM), flash memory, and/or nonvolatile random access memory (NVRAM). Volatile memory can include Random Access Memory (RAM), which acts as external cache memory. By way of illustration and not limitation, RAM may take many forms, such as Synchronous RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), Enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The data store 210 of the subject systems and methods is intended to comprise, without being limited to, these and any other suitable types of memory.

Referring to fig. 3-7, methodologies relating to utilizing composite sequences for bandwidth efficient non-coherent signaling in a wireless communication environment are illustrated. While, for purposes of simplicity of explanation, the methodologies are described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more embodiments, occur in different orders and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a methodology in accordance with one or more embodiments.

Referring to fig. 3, a methodology 300 that facilitates transmitting information (e.g., control channel information) related to a wireless communication system is illustrated. At 302, a set of codewords is generated. In an aspect, codewords can be generated to facilitate transmission of control channel information between a transmitting communication device (e.g., mobile device 116) and a receiving communication device (e.g., base station 102). In another aspect, the codewords may be designed according to BPSK or QPSK to facilitate efficient bandwidth non-coherent signaling. For example, to facilitate bandwidth efficiency, complex orthogonal modulation may be utilized and higher order modulation (e.g., QPSK) employed for non-coherent signals related to control channel transmission to facilitate reducing the number of tones used to transmit the control channel information.

At 304, the subset of codewords can be deleted based at least in part on predefined codeword criteria (e.g., as described in detail herein). For example, a set of codewords is generated, wherein some codeword pairs in the set of codewords produce worst case cross-correlation values (e.g.,) This is undesirable for the transmission of control channel information. In accordance with one aspect, subsets of codewords having poor or other undesirable correlation values can be deleted, such as to produce worst case cross-correlation valuesThe codeword pair of (1).

In yet another aspect, another subset of codewords may be deleted and discarded such that enough codewords remain in the set to meet a desired spectral efficiency (e.g., a predetermined threshold number of valid codewords desired for a given number of tones). The remaining codewords in the set may be selected and used to facilitate transmission of control channel information (e.g., CQICH). For example, the discarded codeword or a portion thereof may be used for other purposes, such as interference level estimation, erasure detection, and/or transmission of other control information (e.g., PMICH, SRCH, etc.). For example, by dividing the designed codeword into multiple subsets of codewords, complex orthogonal codes may be used for one or more control channels, such as CQICH, PMICH, and/or SRCH, to further improve bandwidth efficiency.

Referring to fig. 4, illustrated is a methodology 400 that facilitates generating codewords to facilitate transmission of information (e.g., control channel information) related to a wireless communication system. At 402, control channel information having a plurality of bits to be transmitted is determined. In an aspect, the number of bits of control channel information (e.g., CQICH) to be transmitted between a transmitting communication device (e.g., mobile device 116) and a receiving communication device (e.g., base station 102) may be determined. At 404, a type of quadrature modulation to be used to facilitate transmission is determined. For example, whether BPSK or higher order modulation (e.g., QPSK) is used to facilitate transmission of control channel information and/or other information between communication devices can be determined based at least in part on a number of bits of information to be transmitted and/or an available bandwidth.

At 406, the number of codewords to be used is determined. In one aspect, determining facilitates certain controlsThe transmission of channel information (e.g., CQICH) and/or the number of codewords desired for other purposes (e.g., transmission of other control channel information, interference level estimation, erasure decoding, etc.). For example, the determination may be made based at least in part on a number of bits of information to be transmitted between the communication devices. In another aspect, a first subset of codewords, where each pair of codewords produces a desired (e.g., good) cross-correlation property, may be used to facilitate transmission of certain control channel information (e.g., CQICH). Deleting another subset of codewords that includes a codeword that produces an undesirable cross-correlation property (e.g., a worst case cross-correlation value)) The codeword pair of (1). In accordance with one embodiment, the designed set of codewords can be a complex erasure-based orthogonal code (and/or an extended erasure-based orthogonal code), which can be constructed such that by employing a codeword erasure condition,the worst-case cross-correlation value between any two complex orthogonal sequences based on deletion is 1/2 (instead of) And thus conditions 1 and 2 related to formulas 4a and 4b described in the present application are not satisfied. Thus, no codeword pair will produce a worst case cross-correlation value

In another aspect, one or more other subsets of codewords may also be deleted and discarded such that the number of codewords in the first set of codewords is a desired number (e.g., a predetermined threshold number) of codewords that meet a desired spectral efficiency (e.g., a desired number of valid codewords for a given number of tones). The discarded subset of codewords may be used for other purposes such as erasure decoding, interference level estimation, and/or multi-mode control channel operation, as desired.

At 408, the number of tones is determined. In an aspect, the number of tones (e.g., QPSK tones) may be determined based at least in part on the number of bits of information transmitted between communication devices and/or the type of code used for codeword design (e.g., Hadamard codes).

Referring to fig. 5, illustrated is a methodology 500 that employs scrambling to facilitate transmitting information (e.g., control channel information) related to a wireless communication system. At 502, a set of complex orthogonal codewords is generated. In an aspect, a set of complex orthogonal codewords can be generated based at least in part on predefined codeword criteria (e.g., as described in detail herein). The complex orthogonal codewords can be designed, generated, and employed to facilitate transmission of information, such as certain control channel information (e.g., CQICH) and/or other information (e.g., information regarding erasure decoding, interference level estimation, other control channel information), from a transmitting communication device (e.g., mobile device 116) to a receiving communication device (e.g., base station 102). In another aspect, each complex orthogonal codeword includes an I-phase and a Q-phase. At 504, the I-phase and Q-phase of each codeword in the complex orthogonal codeword set can be individually scrambled, e.g., where a first scrambling code can be used for the I-phase and another scrambling code for the Q-phase. In one aspect, to help reduce peak cross-correlation of complex quadrature modulation in a non-coherent receiver, independent real scrambling codes may be applied to the I-phase and Q-phase of each codeword in a set of codewords, as described in detail above. In accordance with another aspect, the codeword can be further scrambled with a complex PN sequence of a predetermined length (e.g., a length determined at least in part by the number of tones) specific to the transmitting communication device (e.g., mobile device 116) to provide better autocorrelation over multiple channels.

Referring to fig. 6, illustrated is a methodology 600 that facilitates erasure-type decoding to facilitate transmission of information (e.g., control channel information) related to a wireless communication system. At 602, a codeword is determined. In an aspect, codewords are determined to facilitate erasure decoding with respect to non-coherent signaling to facilitate transmission of information between a transmitting communication device (e.g., mobile device 116) and a receiving communication device (e.g., base station 102). In another aspect, the codeword may be determined by ML decoding, as described in detail herein, for example, with respect to equations (2) - (3) described with reference to system 100. At 604, a codeword is selected that is completely orthogonal (e.g., has a cross-correlation of 0) to the determined codeword. At 606, an average of the decoder output energy values corresponding to the selected codeword is calculated. At 608, the difference (or alternatively, the ratio of the two) between the determined energy value of the codeword and the calculated average output energy value corresponding to the selected codeword is determined. At 610, the metric (e.g., the determined difference or ratio between the determined energy value of the codeword and the calculated average output energy value corresponding to the selected codeword) is compared to a predetermined threshold level of validity for the decoding result. At 612, a determination is made whether the determined codeword is a valid decoding result based at least in part on a predetermined threshold level. For example, if the metric is equal to or greater than a predetermined threshold level, the determined codeword is determined to be a valid decoding result, and if the metric is less than the predetermined threshold level, an erasure is declared with respect to the determined codeword.

Referring to fig. 7, illustrated is a methodology 700 that facilitates erasure-type decoding to facilitate transmission of information (e.g., control channel information) related to a wireless communication system. In an aspect, erasure-type decoding can be applied to non-coherent signaling to facilitate transmission of information between a transmitting communication device (e.g., mobile device 116) and a receiving communication device (e.g., base station 102). At 702, the determined codeword can be used as a known sequence. At 704, propagation channel coefficients are estimated based at least in part on the determined codeword (e.g., assuming decoding is correct). At 706, a signal component corresponding to the determined codeword is removed from the received signal. In an aspect, a signal can be transmitted from one communication device (e.g., mobile device 116) to another communication device (e.g., base station 102). The signal component of the received signal is removed (e.g., subtracted) from the received signal. At 708, the average power of the remaining signal (e.g., the signal remaining after removal of the signal component from the received signal) is calculated. At 710, a background noise level is estimated based at least in part on the average power value of the residual signal. It should be noted that if the decoding is not correct, the background noise level may be high. At 712, an SNR is computed based at least in part on the propagation channel estimate and the background noise level estimate. For example, the propagation channel estimate and the background noise level estimate may be used to calculate the SNR. At 714, the SNR value is compared to a predetermined threshold level for the validity of the decoding result. At 716, a determination is made as to whether the determined codeword is a valid decoding result based at least in part on the predetermined threshold level. For example, if the SNR value is determined to be equal to or greater than the predetermined threshold level, the determined codeword is determined to be a valid decoding result, and if the SNR value is less than the predetermined threshold level, the declaration is erased, and thus the determined codeword is determined not to be a valid decoding result.

It is to be appreciated that, in accordance with one or more aspects described herein, inferences can be made regarding designing, generating, selecting, deleting, and/or utilizing codewords to facilitate information transmission (e.g., control channel, erasure coding, interference level estimation, etc.). As used herein, the terms to "infer" and "inference" refer generally to the process of reasoning about or inferring states of the system, environment, and/or user from a set of observations as captured via events and/or data. Inference can be employed to identify a specific context or action, or can generate a probability distribution over states, for example. The inference can be probabilistic-that is, the computation of a probability distribution over states of interest based on a consideration of data and events. Inference can also refer to techniques employed for composing higher-level events from a set of events and/or data. The inference results in the construction of new events from a set of observed events and/or stored event data, regardless of whether the events are correlated in close temporal proximity, and whether the events and data come from one or more event and data sources.

According to one example, one or more of the methods described above include making inferences pertaining to: codewords related to orthogonal modulation (e.g., binary orthogonal modulation, complex orthogonal modulation, erasure-based complex orthogonal modulation, extended erasure-based complex orthogonal modulation, etc.) are designed and/or generated to facilitate transmission of information (e.g., control channel information, information regarding erasure decoding, information regarding interference level estimation, etc.) between communication devices (e.g., mobile device 116, base station 102). By way of further explanation, inferences can be made regarding: determining whether an orthogonal modulation type has the highest bandwidth efficiency for a given amount of information transmitted between communication devices, and/or determining whether and/or which codewords are deleted from a set of codewords. It will be appreciated that the above-described examples are exemplary in nature and are not intended to limit the number of inferences that can be made or in what manner these inferences are made in conjunction with the various embodiments and/or methods described herein.

Fig. 8 illustrates a mobile device 800 that facilitates transmitting or receiving information (e.g., control channel information) related to a wireless communication system. Mobile device 800 may comprise a receiver 802 that receives a signal from, for instance, a receive antenna (not shown), performs conventional actions on (e.g., filters, amplifies, downconverts, etc.) the received signal, and digitizes the conditioned signal to obtain samples. Receiver 802 can be, for example, an MMSE receiver, and can comprise a demodulator 804 that can demodulate received symbols and provide them to a processor 806 for channel estimation. In an aspect, demodulator 804 may be used to demodulate BPSK or QPSK modulated received symbols, as described in detail previously. Processor 806 can be a processor dedicated to analyzing information received by receiver 802 and/or generating information for transmission by a transmitter 808, a processor that controls one or more components of mobile device 800, and/or a processor that both analyzes information received by receiver 802, generates information for transmission by transmitter 808, and controls one or more components of mobile device 800. Mobile device 800 further comprises a modulator 810 that can operate in conjunction with transmitter 808 to transmit signals (e.g., data) to, for instance, base station 102, another mobile device, etc. In an aspect, modulator 810 can be employed to modulate a signal, e.g., with BPSK or QPSK modulation, to transmit control channel information and/or other information to another communication device (e.g., base station 102, another mobile device, etc.). The mobile device 800 includes the same or similar functionality as the communication device described in detail herein (e.g., with respect to the system 100).

Mobile device 800 additionally can comprise data storage 812 that is operatively coupled to processor 806 and that can store data to be transmitted, received data, information regarding transmission or reception of control channel information (e.g., information regarding complex orthogonal modulation, erasure-based complex orthogonal modulation, and/or extended erasure-based complex orthogonal modulation, etc.), information related to erasure decoding and/or interference level estimation, and any other suitable information that facilitates transmission and/or reception of information (e.g., control channel information) between communication devices (e.g., mobile device 800 and base station 102). The data memory 812 may additionally store protocols and/or algorithms and/or codewords associated with quadrature modulation (e.g., binary quadrature modulation, complex quadrature modulation, erasure-based complex quadrature modulation and/or extended erasure-based complex quadrature modulation, etc.).

It is to be appreciated that the data store 812 can include volatile memory and/or nonvolatile memory as described herein. By way of illustration, and not limitation, nonvolatile memory can include Read Only Memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable PROM (EEPROM), flash memory, and/or nonvolatile random access memory (NVRAM). Volatile memory can include Random Access Memory (RAM), which acts as external cache memory. By way of illustration and not limitation, RAM may take many forms, such as Synchronous RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), Enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The data store 812 of the present invention is intended to comprise, without being limited to, these and any other suitable types of memory.

Fig. 9 illustrates a system 900 that facilitates transmitting or receiving information (e.g., control channel information) related to a wireless communication system. System 900 includes a base station 902 (e.g., an access point, etc.) that can have a receiver 904 that can receive signals from one or more mobile devices 906 (e.g., having the same or similar functionality as mobile device 116 and/or mobile device 800) via a plurality of receive antennas 908 and a transmitter 910 that can transmit signals (e.g., data) to the one or more mobile devices 906 via a transmit antenna 912. Receiver 904 can receive information from receive antennas 908 and is operatively coupled to a demodulator 914, which demodulator 914 demodulates received information. In an aspect, modulator 914 may be used to demodulate received BPSK or QPSK modulated symbols, as described in detail previously. Demodulated symbols can be analyzed by a processor 916, which processor 916 can be a processor dedicated to analyzing information received by receiver 904 and/or generating information for transmission by transmitter 910, a processor that controls one or more components of base station 902, and/or a processor that both analyzes information received by receiver 904, generates information for transmission by transmitter 910, and controls one or more components of base station 902.

Base station 902 can additionally comprise a modulator 916 that can operate in conjunction with transmitter 910 to transmit signals (e.g., data) to, for instance, mobile device 906, another device, etc. In an aspect, modulator 916 can be configured to modulate a signal, e.g., with BPSK or QPSK modulation, to transmit control channel information and/or other information to another communication device (e.g., mobile device 906, another mobile device, etc.). Base station 902 and mobile device 906 each include the same or similar functionality as the communication devices described in detail herein (e.g., with respect to system 100).

Processor 916 is coupled to memory 918 that can store information related to data to be transmitted, received data, information related to transmission or reception of control channel information (e.g., information related to complex orthogonal modulation, erasure-based complex orthogonal modulation, and/or extended erasure-based complex orthogonal modulation, etc.), information related to erasure-type decoding and/or interference level estimation, and any other suitable information that facilitates determining a transmission of information (e.g., control channel information) between communication devices. Memory 918 can additionally store protocols and/or algorithms and/or codewords associated with quadrature modulation (e.g., binary quadrature modulation, complex quadrature modulation, erasure-based complex quadrature modulation, and/or extended erasure-based complex quadrature modulation, etc.).

It is to be appreciated that the memory 918 described herein can include volatile and/or nonvolatile memory. By way of illustration, and not limitation, nonvolatile memory can include Read Only Memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable PROM (EEPROM), flash memory, and/or nonvolatile random access memory (NVRAM). Volatile memory can include Random Access Memory (RAM), which acts as external cache memory. By way of illustration and not limitation, RAM may take many forms, such as Synchronous RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), Enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The memory 918 of the present invention is intended to comprise, without being limited to, these and any other suitable types of memory.

Fig. 10 shows an example of a wireless communication system 1000. For simplicity of illustration, the wireless communication system 1000 depicts one base station 1010 and one mobile device 1050. However, it is to be appreciated that system 1000 can include more than one base station and/or more than one mobile device, wherein additional base stations and/or mobile devices can be substantially similar or different from example base station 1010 and mobile device 1050 described below. In addition, it is to be appreciated that base station 1010 and/or mobile device 1050 can employ the systems (fig. 1-2, 8-9, and 11-12) and/or methods (fig. 3-7) described herein to facilitate wireless communication there between. It is to be appreciated that base station 1010 and mobile device 1050 can each be the same as or similar to a respective component described in detail herein (e.g., with respect to system 100, system 200, system 800, and/or system 900), and/or include the same or similar functional blocks, respectively.

At base station 1010, traffic data for a number of data streams is provided from a data source 1012 to a Transmit (TX) data processor 1014. In accordance with one example, each data stream is transmitted over a respective antenna. TX data processor 1014 formats, codes, and interleaves the traffic data stream based on a particular coding scheme selected for that data stream to provide coded data.

The coded data for each data stream may be multiplexed with pilot data using Orthogonal Frequency Division Multiplexing (OFDM) techniques. Additionally or alternatively, the pilot symbols may be Frequency Division Multiplexed (FDM), Time Division Multiplexed (TDM), or Code Division Multiplexed (CDM). The pilot data is typically a known data pattern that is processed in a known manner and can be used at mobile device 1050 to estimate channel response. The multiplexed pilot and coded data for each data stream is modulated (e.g., symbol mapped) based on a particular modulation scheme (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM), etc.) selected for that data stream to provide modulation symbols. The data rate, coding, and modulation for each data stream can be determined by instructions performed or provided by processor 1030.

The modulation symbols for the data streams are provided to a TX MIMO processor 1020, which may further process the modulation symbols (e.g., for OFDM). TX MIMO processor 1020 then forwards N_TN are provided by a plurality of transmitters (TMTR)1022a through 1022t_TA stream of modulation symbols. In various embodiments, TX MIMO processor 1020 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.

Each receiver 1022 receives and processes a respective symbol stream to provide one or more analog signals, and further conditions (e.g., amplifies, filters, and upconverts) the analog signals to provide a modulated signal suitable for transmission over the MIMO channel. In addition, N from transmitters 1022a through 1022t_TEach modulated signal being from N_TThe antennas 1024a to 1024t transmit.

At mobile device 1050, the transmitted modulated signal consists of N_RAntennas 1052a through 1052r receive and provide received signals from each antenna 1052 to a respective receiver (RCVR)1054a through 1054 r. Each receiver 1054 conditions (e.g., filters, amplifies, and downconverts) a respective signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding "received" symbol stream.

RX data processor 1060 from N_RA receiver 1054 receives N_RA stream of symbols, and processes the received stream of symbols in accordance with a particular receiver processing technique to provide N_TA "detected" symbol stream. RX data processor 1060 demodulates, deinterleaves, and decodes each detected symbol stream to recover the traffic data for the data stream. The processing by RX data processor 1060 is complementary to that performed by TX MIMO processor 1020 and TX data processor 1014 at base station 1010.

A processor 1070 periodically determines a precoding matrix to employ (as discussed below). Processor 1070 can also generate a reverse link message comprising a matrix index portion and a rank value portion.

The reverse link message may comprise various types of information regarding the communication link and/or the received data stream. The reverse link message is processed by a TX data processor 1038, which also receives traffic data for a number of data streams from a data source 1036, modulated by a modulator 1080, conditioned by transmitters 1054a through 1054r, and transmitted back to base station 1010.

At base station 1010, the modulated signals from mobile device 1050 are received by antennas 1024, conditioned by receivers 1022, demodulated by a demodulator 1040, and processed by a RX data processor 1042 to extract the reverse link message transmitted by mobile device 1050. Processor 1030 can also process the extracted message to determine which precoding matrix to use for determining the beamforming weights.

Processors 1030 and 1070 can direct (e.g., control, adjust, manage, etc.) operation at base station 1010 and mobile device 1050, respectively. Processors 1030 and 1070 can be coupled to memory 1032 and 1072 that store program codes and data, respectively. Processors 1030 and 1070 can also perform computations to derive frequency and impulse response estimates for the uplink and downlink, respectively.

It is to be understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For a hardware implementation, the processing units may be implemented within one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.

When the embodiments are implemented in software, firmware, middleware, microcode, program code or code segments, they may be stored in a machine-readable medium, such as a storage component. A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, any set of instructions, a data structure, or a program statement. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted using any suitable means including memory sharing, message passing, token passing, network transmission, etc.

For a software implementation, the techniques described herein may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in memory units and executed by processors. The memory unit may be implemented within the processor or external to the processor, in which case it can be communicatively coupled to the processor via various means as is known in the art.

Referring to fig. 11, illustrated is a system 1100 that facilitates communicating information (e.g., control channel information) between communication devices associated with a wireless communication environment. For example, system 1100 can reside in part in a communication device, such as a mobile device (e.g., 116). It is to be appreciated that system 1100 is represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor, software, or combination thereof (e.g., firmware). System 1100 includes a logical grouping 1102 of electrical components that can act in conjunction.

For instance, logical grouping 1102 can include an electrical component for generating a set of codewords 1104. In an aspect, generating the set of codewords facilitates communicating information (such as control channel information) between communication devices (such as mobile device 116 and base station 102). In another aspect, the codeword structure relates to quadrature modulation of non-coherent signaling (e.g., binary quadrature modulation, complex quadrature modulation, erasure-based complex quadrature modulation, extended erasure-based complex quadrature modulation). Moreover, logical grouping 1102 can include an electrical component for removing a subset of codewords from the set of codewords based at least in part on predefined codeword criteria 1106. For example, the subset of codewords includes a set of words that produce worst-case cross-correlation values (e.g., such as) Such codeword pairs may be deleted so that the worst case cross-correlation between the remaining pairs of codewords may be improved. According to one embodiment, the code may be encodedThe word set is designed as an erasure-based complex orthogonal code (and/or an extended erasure-based orthogonal code), which is constructed such that by employing a codeword erasure condition,the worst-case cross-correlation between any two complex orthogonal sequences based on deletion is 1/2 (instead of) And thus conditions 1 and 2 related to formulas 4a and 4b described in the present application are not satisfied. Thus, no codeword pair produces a worst case cross-correlation value

As another example, another subset of codewords may be deleted and discarded codewords, the number of codewords remaining in the set to facilitate transmission of certain control information (e.g., CQICH) being a desired number of codewords (e.g., a predetermined threshold number) that can meet a desired spectral efficiency (e.g., a desired number of valid codewords for a given number of tones). The discarded codeword or a portion thereof may be used for other purposes such as desired interference level estimation, erasure-type detection, etc. Thus, in a bandwidth efficient manner, higher order modulation (e.g., QPSK) is employed for non-coherent signaling to enable information transmission, such as control channel information transmission. Logical grouping 1102 also includes an electrical component for transmitting a signal associated with at least a portion of the set of codewords 1108. In an aspect, a signal can be transmitted using non-coherent signaling using a set of complex orthogonal codewords (e.g., complex orthogonal codewords based on erasures extended) where the signal can be transmitted from one communication device (e.g., mobile device 116) to another communication device (e.g., base station 102). In another aspect, a portion of a set of codewords may include codewords selected in the set of codewords that contain a desired (e.g., good) cross-correlation property (e.g., codewords that correlate with a cross-correlation value of 1/2 or less), wherein the selected codewords may be used to facilitate transmission of control channel information (e.g., CQICH). In yet another aspect, a portion of the set of codewords comprises discarded codewords, and the discarded codewords or a portion thereof can be used to facilitate erasure decoding, interference level estimation, multi-mode control channel operation, to facilitate transmission of other control information (e.g., PMICH, SRCH, etc.), and/or for other desired purposes. Additionally, system 1100 includes a memory 1110 that retains instructions for executing functions associated with electrical components 1104, 1106, and 1108. While shown as being external to memory 1110, it is to be understood that one or more of electrical components 1104, 1106, and 1108 can exist within memory 1110.

Referring to fig. 12, illustrated is a system 1200 that facilitates communicating information (e.g., control channel information) between communication devices associated with a wireless communication system. System 1200 can reside, at least partially, within a communication device such as base station 102. As depicted, system 1200 includes functional blocks that can represent functions implemented by a processor, software, or combination thereof (e.g., firmware). System 1200 includes a logical grouping 1202 of electrical components that can act in conjunction. Logical grouping 1202 includes an electrical component for receiving a signal related to a portion of a set of codewords 1204. In an aspect, the received signal can be non-coherent signaling of control channel information transmitted from one communication device (e.g., mobile device 116) to another communication device (e.g., base station 102). In another aspect, the codeword structure relates to quadrature modulation of non-coherent signaling (e.g., binary quadrature modulation, complex quadrature modulation, erasure-based complex quadrature modulation, extended erasure-based complex quadrature modulation). In yet another aspect, a portion of the set of codewords includes a selected codeword, where the selected codeword is a codeword that has a desired cross-correlation property and that can be used to facilitate the transmission and reception of certain control information (e.g., CQICH) and/or other information. In one aspect, a portion of the set of codewords can be designed such that pairs of codewords that produce worst-case cross-correlations are deleted from the portion of the set of codewords such that the worst-case codewords are not part of the received set of codewords. In yet another aspect, a portion of the set of codewords also includes discarded codewords, where the discarded codewords can be used for other purposes, such as to facilitate erasure detection, interference level estimation, multi-mode control channel operation, and/or other desired purposes.

Moreover, logical grouping 1202 can include an electrical component for decoding 1206 the received signal. Moreover, logical grouping 1202 can include an electrical component for performing erasure-type decoding on the non-coherent signaling 1208. The erasure decoding can be performed in virtually any of a variety of ways, such as described in detail above, for example. Additionally, system 1200 includes a memory 1210 that retains instructions for executing functions associated with electrical components 1204, 1206, and 1208. While shown as being external to memory 1210, it is to be understood that one or more of electrical components 1204, 1206, and 1208 can exist within memory 1210.

The above description includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the embodiments described in this application are intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term "includes" is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term "comprising" as "comprising" is interpreted when employed as a transitional word in a claim.

Claims (57)

1. A method that facilitates information transfer, comprising:

generating a set of codewords to facilitate transmission of information including control channel information, wherein each codeword in the set of codewords is a complex orthogonal codeword;

deleting a subset of the set of codewords based at least in part on predefined codeword criteria, wherein deleting the subset of the set of codewords comprises: removing codeword pairs having worst case cross-correlation values from the set of codewords to create a set of bandwidth efficient non-coherent signaling codewords having predefined cross-correlation properties.

2. The method of claim 1, further comprising:

a signal associated with at least a portion of the generated set of codewords is transmitted.

3. The method of claim 2, wherein at least a portion of the generated set of codewords is a subset of codewords remaining after other codewords are deleted.

4. The method of claim 1, wherein the predefined codeword criteria relates to at least one of: available bandwidth, a number of codewords in the set of codewords, a number of bits of control channel information to be transmitted at a given time, cross-correlation values for respective pairs of codewords, a type of orthogonal modulation transmission desired to be used, a worst case cross-correlation value defined between codewords, a number of tones employed to facilitate transmission of control channel information, a number of erased codewords for other operations, or a combination thereof, wherein the other operations include at least one of: interference level estimation, erasure detection, multi-mode control channel operation, or a combination thereof.

5. The method of claim 1, further comprising:

scrambling in-phase and quadrature phase of each codeword in the generated set of codewords, wherein the scrambling in-phase is performed with a first sequence and the scrambling in quadrature phase is performed with a different sequence.

6. The method of claim 1, further comprising:

each code word in the generated set of code words is scrambled with a complex pseudo random noise sequence of a predetermined length specific to the communication device.

7. As in claimThe method of claim 1, wherein the worst case cross-correlation value is。

8. The method of claim 1, further comprising:

the generated set of codewords is constructed at least in part according to a complex orthogonal modulation.

9. The method of claim 1, further comprising:

determining a number of bits of control channel information to be transmitted;

determining an available bandwidth;

determining a quadrature modulation type;

determining a number of codewords to be used to facilitate at least one other operation;

the number of tones is determined.

10. The method of claim 1, further comprising: by applying a vector to the generated set s of code words_kAdding another set of codewordsTo spread the generated set of code words, where s_kAndorthogonal, the other set of code wordsIs obtained by the following steps: exchanging complex code words s_kExcept for a potential composite scrambled portion that applies in common to all of the codewords.

11. The method of claim 1, further comprising:

transmitting control channel information using a subset of codewords that do not produce worst case cross-correlation values;

using the portion of the deleted codeword for at least one other operation, the at least one other operation comprising at least one of: interference level estimation, erasure detection, multi-mode control channel transmission, or a combination thereof, wherein a portion of the codewords deleted are discarded codewords selected such that the maximum cross-correlation values of the subsets of codewords are not increased when the subsets of codewords operate together.

12. The method of claim 1, the predefined cross-correlation property relating to a correlation value 1/2.

13. The method of claim 1, the complex orthogonal code is a erasure-based complex orthogonal code or a spread erasure-based complex orthogonal code.

14. The method of claim 1, further comprising:

dividing the set of codewords into a plurality of subsets of codewords;

utilizing the first subset of codewords to facilitate transmission of a first type of control channel information;

utilizing at least one other codeword subset comprising a discarded codeword to facilitate at least one of: erasure decoding, estimating an interference level, transmitting at least one other type of control channel information, or a combination thereof, to facilitate improving bandwidth efficiency.

15. The method of claim 14, the first type of control channel information comprising a Channel Quality Indication Channel (CQICH), the at least one other type of control channel information comprising at least one of: the Precoding Matrix Indicator Channel (PMICH), the Scheduling Request Channel (SRCH), or a combination thereof.

16. An apparatus that facilitates information transfer, comprising:

a codeword generator to generate a set of codewords to facilitate transmission of information including control channel information based at least in part on a predefined codeword criteria, wherein each codeword in the set of codewords is a complex orthogonal codeword;

a deleter to delete a subset of the set of codewords based at least in part on a predefined codeword criterion, wherein deleting the subset of the set of codewords comprises: removing codeword pairs having worst case cross-correlation values from the set of codewords to create a set of bandwidth efficient non-coherent signaling codewords having predefined cross-correlation properties.

17. The apparatus of claim 16, wherein the codeword is a complex orthogonal codeword.

18. The apparatus of claim 17, the complex orthogonal code is a erasure-based complex orthogonal code or a spread erasure-based complex orthogonal code.

19. The apparatus of claim 18, the deleter facilitates construction of at least one of the erasure-based complex orthogonal code or the extended erasure-based complex orthogonal code to facilitate de-scrambling by employing a codeword erasure conditionSuch that the cross-correlation between any two deleted complex orthogonal sequences is 1/2 or less, where c_m(k)And c_n(k)Are mutually orthogonal binary sequences for the in-phase and quadrature phase of the kth complex quadrature codeword.

20. The apparatus of claim 18, the codeword generator and the deleter cooperating to facilitate de-scrambling a set s of codewords generated by the de-scrambler_kAdding another set of codewordsTo spread the generated set of code words, where s_kAndorthogonal, the other set of code wordsIs obtained by the following steps: exchanging complex code words s_kExcept for a potential complex scrambled portion that applies in common to all of the codewords.

21. The apparatus of claim 16, wherein the predefined codeword criteria relates to at least one of: available bandwidth, a number of codewords in the set of codewords, a number of bits of control channel information to be transmitted at a given time, cross-correlation values for respective pairs of codewords, a type of orthogonal modulation transmission desired to be used, a worst case cross-correlation value defined between codewords, a number of tones employed to facilitate transmission of control channel information, a number of erased codewords for other operations, or a combination thereof, wherein the other operations include at least one of: interference level estimation, erasure detection, multi-mode control channel operation, or a combination thereof.

22. The apparatus of claim 16, the codeword generator to: generating a codeword based at least in part on at least one of: a number of bits of control channel information to be transmitted, a number of codewords for at least one other operation, a number of tones for transmission, an orthogonal modulation type, an available bandwidth, or a combination thereof.

23. The apparatus of claim 16, the codeword generator to: scrambling the generated set of codewords, wherein scrambling the generated set of codewords comprises at least one of: scrambling each of the generated set of codewords using a different scrambling code for its in-phase and quadrature phase; scrambling each code word in the generated set of code words with a complex pseudo random noise sequence of a predetermined length specific to the communication device; or a combination thereof.

24. An apparatus that facilitates information transfer, comprising:

means for generating a set of codewords to facilitate transmission of information including control channel information, wherein each codeword in the set of codewords is a complex orthogonal codeword;

means for deleting a subset of the set of codewords based at least in part on predefined codeword criteria, wherein means for deleting a subset of the set of codewords comprises: means for deleting the codeword pair having the worst case cross-correlation value from the set of codewords to create a set of bandwidth efficient non-coherent signaling codewords having predefined cross-correlation properties.

25. The apparatus of claim 24, further comprising:

means for transmitting a signal associated with at least a portion of the generated set of codewords.

26. The apparatus of claim 25, wherein at least a portion of the generated set of codewords is a subset of codewords remaining after other codewords are deleted.

27. The apparatus of claim 24, wherein the predefined codeword criteria relates to at least one of: available bandwidth, a number of codewords in the set of codewords, a number of bits of control channel information to be transmitted at a given time, cross-correlation values for respective pairs of codewords, a type of orthogonal modulation transmission desired to be used, a worst case cross-correlation value defined between codewords, a number of tones employed to facilitate transmission of control channel information, a number of erased codewords for other operations, or a combination thereof, wherein the other operations include at least one of: interference level estimation, erasure detection, multi-mode control channel operation, or a combination thereof.

28. The apparatus of claim 24, further comprising:

means for scrambling an in-phase and a quadrature phase of each codeword in the generated set of codewords, wherein the in-phase scrambling is performed with a first sequence and the quadrature-phase scrambling is performed with a different sequence.

29. The apparatus of claim 24, further comprising:

means for scrambling each codeword in the generated set of codewords with a complex pseudo-random noise sequence having a predetermined length that is specific to the communication device.

30. The apparatus of claim 24, wherein the worst case cross-correlation value is。

31. The apparatus of claim 24, further comprising:

means for constructing the generated set of codewords based at least in part on complex orthogonal modulation.

32. The apparatus of claim 24, further comprising:

means for determining a number of bits of control channel information to transmit;

means for determining available bandwidth;

means for determining a quadrature modulation type;

means for determining a number of codewords to be used to facilitate at least one other operation; and

means for determining a number of tones.

33. The apparatus of claim 24, further comprising: for passing to the generated codeword set s_kAdding another set of codewordsA module for expanding the generated set of code words, wherein s_kAndorthogonal, the other set of code wordsIs obtained by the following steps: exchanging complex code words s_kExcept for a potential composite scrambled portion that applies in common to all of the codewords.

34. The apparatus of claim 24, further comprising:

means for transmitting control channel information using a subset of codewords that do not produce a worst case cross-correlation value;

means for using a portion of the deleted codeword for at least one other operation, the at least one other operation comprising at least one of: interference level estimation, erasure detection, multi-mode control channel transmission, or a combination thereof, wherein a portion of the codewords deleted are discarded codewords selected such that the maximum cross-correlation values of the subsets of codewords are not increased when the subsets of codewords operate together.

35. The apparatus of claim 24, the predefined cross-correlation property relating to a correlation value 1/2.

36. The apparatus of claim 24, the complex orthogonal code is a erasure-based complex orthogonal code or a spread erasure-based complex orthogonal code.

37. The apparatus of claim 24, further comprising:

means for dividing the set of codewords into a plurality of subsets of codewords;

means for utilizing the first subset of codewords to facilitate transmission of a first type of control channel information;

means for utilizing at least one other subset of codewords including discarded codewords to facilitate at least one of: erasure decoding, estimating an interference level, transmitting at least one other type of control channel information, or a combination thereof, to facilitate improving bandwidth efficiency.

38. The apparatus of claim 37, the first type of control channel information comprising a Channel Quality Indication Channel (CQICH), the at least one other type of control channel information comprising at least one of: the Precoding Matrix Indicator Channel (PMICH), the Scheduling Request Channel (SRCH), or a combination thereof.

39. A method that facilitates communicating information related to a communication environment, comprising:

receiving a signal related to a generated set of codewords that facilitate transmitting information including control channel information based at least in part on a predefined codeword criteria, wherein each codeword in the generated set of codewords is a complex orthogonal codeword;

decoding the received signal, wherein a subset of the generated set of codewords is deleted at least in part according to a predefined codeword criteria, the deleting comprising: removing codeword pairs having worst case cross-correlation values from the generated codeword set to create a bandwidth efficient non-coherent signaling codeword set having predefined cross-correlation properties.

40. The method of claim 39, wherein the predefined codeword criteria is based at least in part on at least one of: available bandwidth, a number of codewords in the set of codewords, a number of bits of control channel information to be transmitted at a given time, cross-correlation values for respective pairs of codewords, a type of orthogonal modulation transmission desired to be used, a worst case cross-correlation value defined between codewords, a number of tones employed to facilitate transmission of control channel information, a number of codewords for deletion for other operations, or a combination thereof, wherein the other operations include at least one of: interference level estimation, erasure detection, multi-mode control channel operation, or a combination thereof.

41. The method of claim 39, decoding the received signal further comprising: selecting a codeword associated with the received signal based at least in part on an energy level of cross-correlation between the received signal and a candidate codeword.

42. The method of claim 39, decoding the received signal further comprising: multi-peak non-coherent decoding is employed to facilitate decoding of the received signal.

43. The method of claim 39, wherein at least a portion of the generated set of codewords related to the received signal comprises: a subset of the generated set of codewords of the deletion, wherein the codewords are discarded codewords.

44. The method of claim 43, further comprising:

utilizing a subset of the discarded codewords to facilitate erasure decoding in non-coherent signaling.

45. The method of claim 44, the erasure decoding further comprising:

determining a codeword by maximum likelihood decoding;

selecting at least one codeword from a subset that is completely orthogonal to the determined codeword;

calculating an average of decoder output energy values corresponding to the at least one codeword;

determining at least one of a difference or a ratio between a decoder output energy value of the determined codeword and an average of decoder output energy values corresponding to the at least one codeword;

comparing at least one of the difference or the ratio to a predetermined threshold level related to valid decoding results;

determining whether at least one of the difference or the ratio is greater than or equal to a predetermined threshold level;

at least one of:

if at least one of the difference or the ratio is greater than or equal to the predetermined threshold level, determining that the determined codeword is a valid decoding result, or

Determining that the determined codeword is not a valid decoding result if at least one of the difference or the ratio is less than the predetermined threshold level.

46. The method of claim 44, the erasure decoding further comprising:

using the determined codeword as a known sequence;

estimating propagation channel coefficients based at least in part on the determined codewords;

removing a signal component corresponding to the determined codeword from the received signal;

calculating an average power of a remaining signal after removing the signal component of the received signal;

estimating a background noise level based at least in part on an average power of the residual signal;

calculating a signal-to-noise ratio based at least in part on the estimated propagation channel coefficients and the estimated background noise level;

comparing the signal-to-noise ratio to a predetermined threshold level related to valid decoding results;

judging whether the signal-to-noise ratio is greater than or equal to the preset threshold level;

at least one of:

if the signal-to-noise ratio is greater than or equal to the predetermined threshold level, determining that the determined codeword is a valid decoding result, or

If the signal-to-noise ratio is less than the predetermined threshold level, it is determined that the determined codeword is not a valid decoding result.

47. A wireless communications apparatus, comprising:

an electronic component for receiving a signal related to a generated set of codewords that facilitate transmitting information including control channel information in accordance, at least in part, with a predefined codeword criteria, wherein each codeword in the generated set of codewords is a complex orthogonal codeword; and

an electronic component for decoding the received signal, wherein a subset of the generated set of codewords is deleted at least in part according to a predefined codeword criterion, the deletion comprising: removing codeword pairs having worst case cross-correlation values from the generated codeword set to create a bandwidth efficient non-coherent signaling codeword set having predefined cross-correlation properties.

48. The wireless communications apparatus of claim 47, wherein the received signal is decoded to determine a codeword based at least in part on an energy level of cross-correlation between the received signal and a candidate codeword.

49. The wireless communications apparatus of claim 47, wherein the received signal is decoded using multi-peak non-coherent decoding.

50. The wireless communications apparatus of claim 47, wherein the predefined codeword criteria relates to at least one of: available bandwidth, a number of codewords in the set of codewords, a number of bits of control channel information to be transmitted at a given time, cross-correlation values for respective pairs of codewords, a type of orthogonal modulation transmission desired to be used, a worst case cross-correlation value defined between codewords, a number of tones employed to facilitate transmission of control channel information, a number of codewords for deletion for other operations, or a combination thereof, wherein the other operations include at least one of: interference level estimation, erasure detection, multi-mode control channel operation, or a combination thereof.

51. The wireless communications apparatus of claim 47, wherein the generated set of codewords comprises:

a first subset of codewords to facilitate control channel information transmission,

another subset of codewords, including discarded codewords;

wherein at least a portion of the another subset of codewords is utilized to facilitate information transmission involving at least one of: erasure decoding, interference level estimation, multi-mode control channel operation, or a combination thereof, wherein the multi-mode control channel operation includes additional control channel information transmission.

52. A wireless communications apparatus that facilitates information transfer in a wireless communication environment, comprising:

means for receiving a signal related to a generated set of codewords, wherein the generated set of codewords facilitates transmitting information including control channel information at least in part according to a predefined codeword criteria, wherein each codeword in the generated set of codewords is a complex orthogonal codeword;

means for decoding the received signal, wherein a subset of the generated set of codewords is deleted at least in part according to a predefined codeword criteria, the deleting comprising: removing codeword pairs having worst case cross-correlation values from the generated codeword set to create a bandwidth efficient non-coherent signaling codeword set having predefined cross-correlation properties.

53. The wireless communications apparatus of claim 52, further comprising:

means for performing erasure decoding on a received signal using a subset of the generated codewords, wherein the generated codewords are discarded codewords.

54. The wireless communications apparatus of claim 52, wherein the generated set of codewords comprises:

a first subset of codewords to facilitate control channel information transmission,

another subset of codewords, including the discarded codewords,

wherein at least a portion of the another subset of codewords is utilized to facilitate information transmission involving at least one of: erasure decoding, interference level estimation, multi-mode control channel operation, or a combination thereof, wherein the multi-mode control channel operation includes additional control channel information transmission.

55. The wireless communications apparatus of claim 52, wherein the predefined codeword criteria is based at least in part on at least one of: available bandwidth, a number of codewords in the set of codewords, a number of bits of control channel information to be transmitted at a given time, cross-correlation values for respective pairs of codewords, a type of orthogonal modulation transmission desired to be used, a worst case cross-correlation value defined between codewords, a number of tones employed to facilitate transmission of control channel information, a number of codewords for deletion for other operations, or a combination thereof, wherein the other operations include at least one of: interference level estimation, erasure detection, multi-mode control channel operation, or a combination thereof.

56. The wireless communications apparatus of claim 52, the means for decoding the received signal further comprises: means for decoding the received signal to determine a codeword based at least in part on an energy level of cross-correlation between the received signal and a candidate codeword.

57. The wireless communications apparatus of claim 52, the means for decoding the received signal further comprises: means for decoding the received signal using multi-peak non-coherent decoding.