HK1222958B - Method and apparatus for uplink ack/nack resource allocation - Google Patents

Description

Method and apparatus for uplink ACK/NACK resource allocation

This application is a divisional application of an original Chinese invention patent application entitled “Method and Apparatus for Uplink ACK/NACK Resource Allocation.” The original Chinese application number is 200980115212.1; the filing date of the original application is May 1, 2009, and its international application number is PCT/US2009/042632.

Cross-reference to related applications

This application claims the benefit of U.S. Provisional Patent Application No. 61/049,827, filed May 2, 2008, entitled “METHODS OF UL ACK/NACK RESOURCE ALLOCATION FOR TDD IN E-UTRAN,” which is incorporated herein by reference in its entirety.

Technical Field

The following description relates generally to wireless communication systems, and more particularly, to efficiently allocating resources via a flexible symbol mapping approach.

Background Art

Wireless communication systems are widely deployed to provide various types of communication content, such as voice and data. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, 3GPP Long Term Evolution (LTE) systems (including E-UTRA), and orthogonal frequency division multiple access (OFDMA) systems.

Orthogonal frequency division multiplexing (OFDM) communication systems effectively partition the total system bandwidth into multiple ( _NF ) subcarriers, which may also be referred to as frequency subchannels, tones, or bins. For an OFDM system, the data to be transmitted (i.e., information bits) is first encoded using a particular coding scheme to produce coded bits, and the coded bits are further grouped into multi-bit symbols that are then mapped to modulation symbols. Each modulation symbol corresponds to a point in a signal constellation defined by the particular modulation scheme used for data transmission (e.g., M-PSK or M-QAM). At each time interval, which may depend on the bandwidth of each frequency subcarrier, a modulation symbol may be transmitted on each of the _NF frequency subcarriers. Consequently, OFDM can be used to combat intersymbol interference (ISI) caused by frequency-selective fading, which is characterized by varying amounts of attenuation across the system bandwidth.

Typically, a wireless multiple-access communication system can simultaneously support communication for multiple wireless terminals, which 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 the base station to the terminal, and the reverse link (or uplink) refers to the communication link from the terminal to the base station. This communication link can be established via a single-input single-output, multiple-input single-output, or multiple-input multiple-output (MIMO) system.

A MIMO system uses multiple (NT) transmit antennas and multiple (NR) receive antennas for data transmission. The MIMO channel formed by the NT transmit antennas and the NR receive antennas can be decomposed into NS independent channels, also referred to as spatial channels, where _NS ≤ min{ _NT , _NR }. Typically, each of the NS independent channels corresponds to a dimension. If the additional dimensions created by the multiple transmit and receive antennas are utilized, the MIMO system can provide improved performance (e.g., higher throughput and/or greater reliability). The MIMO system also supports time division duplex (TDD) and frequency division duplex (FDD) systems. In a TDD system, the forward link and reverse link transmissions are on the same frequency region, so that the reciprocity principle allows the forward link channel to be estimated from the reverse link channel. This enables the access point to extract transmit beamforming gain on the forward link when multiple antennas are available at the access point.

One consideration in deploying the above-described system relates to how resources are allocated during downlink communications. Resources are typically generated within the context of resource blocks and typically consume multiple subcarriers. Therefore, conservation of resource block generation and transmission is a desirable feature of wireless communications. One area where such resources are consumed supports multiple acknowledgements (ACKs) during the uplink (UL) handshake sequence, which is a response to a downlink (DL) subframe transmission. UL transmissions can also include negative acknowledgements (NACKs), hence the common use of the term "ACK/NACK." In frequency division duplex (FDD) scenarios, the number of resources is controlled because there is an implicit one-to-one resource mapping between UL subframe transmissions and DL subframe transmissions. However, in time division duplex (TDD) scenarios, there can be an asymmetric difference between the number of DL subframes and corresponding UL subframes. However, if a one-to-one mapping is employed, these asymmetries can lead to inefficient resource allocation.

Summary of the Invention

The following presents a simplified summary to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview and is not intended to identify key/critical elements or to delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

Systems and methods are provided for flexibly and efficiently mapping uplink acknowledgement/negative acknowledgement (ACK/NACK) responses in a time division duplex network. Various symbol mapping methods are provided to account for the asymmetric difference between downlink channel communications and uplink channel communications, wherein the asymmetry occurs when the number of downlink subframes is greater than the number of uplink subframes. In one aspect, a symbol priority mapping method is provided. This includes sorting downlink control channels on a downlink subframe that have a first control channel element (CCE) located in a first symbol mapping and are associated with reserved resources for an uplink channel, wherein such resources may include resource blocks associated with ACK/NACK responses. After the first sorting, the downlink control channels with the first CCE in the second OFDM symbol are then sorted, followed by the downlink control channels with the first CCE in the third OFDM symbol, and so on, as needed. In another aspect, a mixed symbol subframe priority mapping may be applied. Similar to symbol-first mapping, subframe-first mapping includes sorting downlink control channels on a downlink subframe that have a first control channel element (CCE) located in a first symbol mapping and are associated with reserved resources for uplink channels. Subframe-first mapping then sorts the remaining downlink control channels in the first downlink subframe that are not associated with the first CCE. This can then be followed by sorting the remaining downlink control channels in the second downlink subframe that are not associated with the first CCE or the first downlink subframe, and so on.

To accomplish the foregoing and related ends, certain illustrative aspects are described herein in connection with the following description and annexed drawings. However, these aspects are indicative of but a few of the various ways in which the principles of the claimed subject matter may be employed, and the claimed subject matter is intended to include all such aspects and their equivalents. Additional advantages and novel features will become apparent from the following detailed description when considered in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a high-level block diagram of a system that utilizes symbol mapping components to facilitate efficient allocation of resources in a wireless communication system.

2 is a block diagram illustrating symbol priority mapping for efficient allocation of resources.

3 is a block diagram illustrating hybrid symbol and subframe-first mapping for efficient allocation of resources.

4 is a block diagram illustrating subframe-first mapping for efficient allocation of resources.

5 illustrates a wireless communication methodology that utilizes symbol mapping to facilitate efficient allocation of resources in a wireless communication system.

FIG6 illustrates example logic modules for wireless symbol mapping.

7 illustrates example logic modules for an alternative wireless symbol mapping process.

8 illustrates an example communications apparatus that utilizes wireless symbol mapping.

FIG9 illustrates a multiple access wireless communication system.

10 and 11 illustrate example communication systems.

DETAILED DESCRIPTION

Systems and methods are provided for efficiently allocating resources during an uplink acknowledgement/negative acknowledgement (ACK/NACK) sequence. In one aspect, a method for allocating resources for wireless communications is provided. The method includes grouping downlink control channels from a plurality of subframes and sorting the downlink control channels on a downlink subframe that have a first control channel element in a first symbol mapping and are associated with reserved resources for an uplink channel. The method uses symbol-first mapping or a hybrid symbol/subframe-first mapping to efficiently allocate the resources.

1 , a symbol mapping component is used to facilitate efficient allocation of resources in a wireless communication system 100. System 100 includes one or more base stations 120 (also referred to as nodes, evolved NodeBs (eNBs)), which can be entities capable of communicating to one or more second devices 130 via a wireless network 110. Each device 130 can be, for example, an access terminal (also referred to as a terminal, user equipment, mobility management entity (MME), or mobile device). Base station 120 transmits data to device 130 via a downlink 140 (DL) and receives data via an uplink 150 (UL). The designations of uplink and downlink are arbitrary, as device 130 can also transmit data via a downlink and receive data via an uplink channel. Note that while two components 120 and 130 are shown, more than two components can be used on network 110, where these additional components can also be adapted for the symbol mapping described herein. In one aspect, symbol mapping component 160 is used to sort, sequence, or map symbols 170 and control the allocation of resources, such as ACK/NACK resources 180. The apparatus 130 includes a mapped symbol decoder 190 to process the mapped symbols 170 and resources 180. As described in more detail below with respect to FIG. 2 through FIG. 4 , symbol mapping component 160 may include a symbol-first mapping approach, a mixed symbol-subframe-first mapping approach, or a subframe-first mapping approach. Before we begin, note that various acronyms are used for brevity. These acronyms are defined at the end of the specification.

In general, UL resource allocation must take into account the number of UL subframes and DL subframes. In one example, for a given uplink-downlink configuration, consider uplink ACK/NACK resource allocation when n _DL ≤ n _UL , where n _DL is the number of downlink subframes and n _UL is the number of uplink subframes. When n _DL ≤ n _UL , the implicit mapping of UL ACK/NACK to the first control channel element (CCE) of the DLPDCCH in TDD can be handled similarly as in FDD. Note that n _DL includes (multiple) special subframes. For UL ACK/NACK resource allocation when n _DL > n _UL , consider the asymmetric case. In the asymmetric case (where the number of DL subframes is greater than the UL subframes), within one UL subframe, the UL ACK/NACK responds to multiple DL subframes. Note that the DL subframe includes (multiple) special subframes.

In general, system 100 flexibly and efficiently maps uplink acknowledgement/negative acknowledgement (ACK/NACK) responses in a time division duplex network (also applicable to FDD). Various symbol mapping methods are provided to account for the asymmetric difference between downlink channel communications and uplink channel communications, wherein the asymmetry occurs when the number of downlink subframes is greater than the number of uplink subframes. In one aspect, a symbol priority mapping method is provided. This includes sorting downlink control channels on a downlink subframe that have a first control channel element (CCE) located in a first symbol mapping and are associated with reserved resources for an uplink channel, wherein such resources may include resource blocks associated with ACK/NACK responses. After the first sorting, the downlink control channels having the first CCE in the second OFDM symbol are then sorted, followed by the downlink control channels having the first CCE in the third OFDM symbol, and so on, as needed. The symbol priority mapping method is described in more detail with respect to FIG.

In another aspect, a mixed symbol-subframe priority mapping may be applied. Similar to symbol-first mapping, subframe priority mapping includes sorting downlink control channels on a downlink subframe that have a first control channel element (CCE) located in a first symbol mapping and are associated with reserved resources for uplink channels. Subframe priority mapping then sorts the remaining downlink control channels in the first downlink subframe that are not associated with the first CCE. This may then sort the remaining downlink control channels in the second downlink subframe that are not associated with the first CCE or the first downlink subframe, and so on. Mixed symbol-subframe priority mapping is described in more detail with respect to FIG. 3 . Subframe priority mapping is described with respect to FIG. 4 .

Note that system 100 can be used with an access terminal or mobile device and can be, for example, a module such as an SD card, a network card, a wireless network card, a computer (including a laptop, desktop computer, personal digital assistant (PDA)), a mobile phone, a smartphone, or any other suitable terminal that can be used to access a network. A terminal accesses the network via an access component (not shown). In one example, the connection between the terminal and the access component can be wireless in nature, where the access component can be a base station and the mobile device a wireless terminal. For example, the terminal and the base station can communicate via any suitable wireless protocol, including, but not limited to, time division multiple access (TDMA), code division multiple access (CDMA), frequency division multiple access (FDMA), orthogonal frequency division multiplexing (OFDM), FLASH OFDM, orthogonal frequency division multiple access (OFDMA), or any other suitable protocol.

An access component may be an access node associated with a wired or wireless network. To this end, an access component may be, for example, a router, a switch, or the like. An access component may include one or more interfaces, such as a communication module, for communicating with other network nodes. Additionally, an access component may be a base station (or wireless access point) in a cellular network, where a base station (or wireless access point) is used to provide wireless coverage to multiple subscribers. Such base stations (or wireless access points) may be arranged to provide a continuous coverage area to one or more cellular phones and/or other wireless terminals.

2 , system 200 provides a symbol priority mapping component 210 for efficient resource allocation. Generally, PDCCHs having a first control channel element (CCE) located in a first OFDM symbol are sorted at 220. This is followed by PDCCHs sorted by the first control channel element (CCE) located in a second OFDM symbol at 230, and PDCCHs sorted by the first control channel element (CCE) located in a third OFDM symbol at 240, and so on.

The subframe-first approach (see FIG4 ) may end up with unused PUCCH resources or impose strict constraints at the scheduler at the expense of inefficiently utilizing DL PDCCH resources. To overcome these constraints, a flexible alternative is provided and is referred to as OFDM symbol-first mapping and is described as follows:

DL PDCCHs in multiple subframes are grouped together. As shown in Figure 2, the PDCCHs are reordered so that the PDCCHs whose first CCE is in the first OFDM symbol on the DL subframe are mapped to the edge of the frequency band reserved for UL dynamic ACK/NACK. This ordering is followed by the PDCCH whose first CCE is in the second OFDM symbol, and the PDCCH whose first CCE is in the third OFDM symbol is mapped, and so on. If some DL subframes do not use up N ACK/NACK resources (N is a positive integer), then with OFDM symbol-first mapping, the eNB can schedule some of the unused resources in the reserved frequency band for ACK transmission for PUSCH transmission.

As an example, consider the M DL:1 UL asymmetry pattern (M is a positive integer). Assume that in the first DL subframe, the PDCCH region spans three OFDM symbols, while the other M-1 subframes use two OFDM symbols for PDCCH transmission. Assume that N ACK/NACK resources are required to support a PDCCH span of three OFDM symbols, with approximately N/3 resources used for PDCCH in each OFDM symbol. ACK resources are reserved in each DL subframe, which would be transmitted using three OFDM symbols. Because DL subframes are semi-statically configured, DL subframes must cover the maximum possible PDCCH time span in each configuration period.

In the case of subframe-first mapping, the first DL subframe will occupy the first N ACK/NACK resources; the second DL subframe cannot use up all N resources because the PDCCH spans 2 OFDM symbols instead of 3. However, the corresponding ACK resources cannot be released because the implicit mapping of the third DL subframe assumes that each DL subframe uses up all N ACK resources. For the last DL subframe, the corresponding unused ACK resources can be used by PUSCH transmission because no other implicit mapping is involved. In the case of OFDM symbol-first mapping, M DL subframes will occupy the first N+2(M-1)N/3 ACK/NACK resources, and the remaining (M-1)N/3 resources remain unused and can be used for PUSCH transmission. However, in the case of OFDM symbol priority mapping, if the first DL subframe utilizes 3 OFDM symbols to transmit PDCCH, while for other DL subframes, the PDCCH spans 1 OFDM symbol, some of the ACK resources may be wasted because in order to have the desired implicit mapping, the ACK resources corresponding to the PDCCH whose first CCE is located in the second OFDM symbol cannot be released.

3 , system 300 provides a hybrid symbol and subframe priority mapping component 310 for efficient resource allocation. Similar to the first sorting described in FIG2 , a PDCCH having a first control channel element (CCE) located in a first OFDM symbol is sorted at 320, followed by the remaining PDCCHs in the first DL subframe. At 330 and 340, the remaining PDCCHs in the second and third DL subframes are sorted, as appropriate.

As mentioned above, OFDM symbol-first mapping may lead to some possible ACK resource inefficiency, and in this aspect, a hybrid approach is provided and denoted as "hybrid OFDM symbol and subframe-first mapping."

Initially, the DL PDCCHs in multiple subframes are grouped together. Similar to the above, these PDCCHs are reordered so that the PDCCHs whose first CCE is located in the first OFDM symbol across all DL subframes are mapped to the band edge of the reserved resources for UL dynamic ACK/NACK. This sequence may be followed by the remaining PDCCHs in the first DL subframe, the remaining PDCCHs in the second subframe, and so on, and are shown at 330 and 340, respectively.

Consider the same M DL:1 UL asymmetry pattern as described above with respect to FIG. Assume that in the first DL subframe, the PDCCH region spans 3 OFDM symbols, while the other M-1 subframes use 1 OFDM symbol for PDCCH transmission. Assume that N ACK/NACK resources are required to support a PDCCH span of 3 OFDM symbols, with approximately N/3 resources used for PDCCH in each OFDM symbol. ACK resources are reserved for transmission using 3 OFDM symbols in each DL subframe. Because DL subframes are semi-statically configured, DL subframes must cover the maximum possible PDCCH time span in each configuration period.

In the case of subframe-first mapping, the first DL subframe will occupy the first N ACK/NACK resources; the second DL subframe cannot use up all N resources because the PDCCH spans 1 OFDM symbol instead of 3. However, the corresponding ACK resources cannot be released because the implicit mapping of the third DL subframe assumes that each DL subframe uses up all N ACK resources. For the last DL subframe, the corresponding unused ACK resources can be used by PUSCH transmission because no other implicit mapping is involved. In the case of OFDM symbol-first mapping, M DL subframes will utilize the first N+2(M-1)N/3 ACK/NACK resources, and the remaining (M-1)N/3 resources remain unused and can be used for PUSCH transmission. Note that exactly M-1 subframes use 1 instead of 2 OFDM for PDCCH transmission, so the same number of ACK resources are used. In case of the hybrid approach, M DL subframes will occupy the first N+(M-1)N/3 ACK/NACK resources, and the remaining 2(M-1)N/3 resources remain unused and can be used for PUSCH transmission.

4 , system 400 illustrates a subframe-first mapping component 410 for resource allocation. In the case of an asymmetric configuration, each UL subframe will transmit ACK/NACKs corresponding to multiple subframes. The subframe-first mapping method maps the DL PDCCH on a subframe-by-subframe basis, as shown at 420 through 440 , respectively. That is, the first DL subframe will occupy the first N ACK/NACK resources, followed by the second DL subframe, and so on. Depending on the asymmetric configuration, the UL ACK resources will be M times larger than the resources required in an FDD system, where M is the number of asymmetries (M DL vs. 1 UL).

To reduce overhead, the total number of ACK resources can be configured to be less than the total number of DL PDCCHs across multiple DL subframes. However, this implies that some PDCCHs in one DL subframe will collide with certain other PDCCHs in another subframe, so scheduling should take this constraint into account. This also implies that PDCCHs on different subframes may not coexist, thus imposing certain waste on PDCCH resources. On the other hand, since the number of PDCCHs in each DL subframe is dynamic and depends on the PCFICH, the number of active users/buffer size in the subframe when UL ACK resources are reserved is semi-static. Therefore, if some of the DL subframes do not use up all N ACK/NACK resources, the reserved bandwidth is not utilized.

5 , a wireless communication method 500 is illustrated. Although the method (and other methods described herein) is shown and described as a series of acts for purposes of explanation simplicity, it should be understood and appreciated that the method is not limited by the order of the acts, as some acts may occur in an order different from that shown and described herein and/or concurrently with other acts, according to one or more embodiments. For example, one skilled in the art will understand and appreciate that a method may alternatively be represented as a series of related states or events (e.g., in the form of a state diagram). Furthermore, depending on the claimed subject matter, not all illustrated acts may be utilized to implement a method.

Proceed to 510 and group downlink control channels (e.g., PDCCH) from multiple subframes. At 520, the control channels are reordered so that the control channel having the first control channel element (CCE) located in the first OFDM symbol on the subframe is mapped to the edge of the frequency band of the reserved resources for uplink ACK/NACK. After 520, at least three alternative processing methods can be applied individually and/or in different combinations. At 530, as previously described with respect to FIG. 2, the first processing method uses OFDM symbol priority mapping. At 540, as described with respect to FIG. 3, the alternative processing method utilizes mixed OFDM symbol and subframe priority mapping. At 550, a third method is a subframe priority mapping process that can be applied alternatively.

The techniques described herein may be implemented by various means. For example, these techniques may be implemented in hardware, software, or a combination thereof. For hardware implementations, the processing unit 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, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof. In the case of software, implementation may be via modules (e.g., procedures, functions, etc.) that perform the functions described herein. The software code may be stored in a memory unit and executed by a processor.

6 and 7, systems related to wireless signal processing are provided. The systems are represented as a series of interrelated functional blocks, which can represent functions implemented by a processor, software, hardware, firmware, or any suitable combination thereof.

6 , a wireless communication system 600 is provided. The system 600 includes a logic module 602 for processing multiple control channels from one or more subframes and a logic module 604 for sequencing the control channels on a downlink subframe having a first control channel element in a first symbol map and associated with reserved resources for an uplink channel. The system 600 also includes a logic module 606 for generating a symbol-first map or a mixed symbol/subframe-first map to process the resources.

7 , a wireless communication system 700 is provided. The system 700 includes a logic module 702 for processing multiple control channels from one or more subframes and a logic module 704 for receiving, from a downlink subframe, the control channel having a first control channel element in a first symbol mapping and associated with reserved resources for an uplink channel. The system 700 also includes a logic module 706 for processing the resources using a symbol-first mapping or a mixed symbol/subframe-first mapping.

FIG8 illustrates a communication device 800, which may be a wireless communication device, such as a wireless terminal. Additionally or alternatively, the communication device 800 may reside within a wired network. The communication device 800 may include a memory 802 that may retain instructions for performing signal analysis within the wireless communication terminal. Furthermore, the communication device 800 may include a processor 804 that may execute instructions within the memory 802 and/or instructions received from another network device, wherein the instructions may relate to configuring or operating the communication device 800 or a related communication device.

9 , a multiple-access wireless communication system 900 is illustrated. Multiple-access wireless communication system 900 includes multiple cells, including cells 902, 904, and 906. In aspects of system 900, cells 902, 904, and 906 may include Node Bs that include multiple sectors. The multiple sectors may be formed by antenna groups, with each antenna responsible for communicating with UEs in a portion of the cell. For example, in cell 902, antenna groups 912, 914, and 916 may each correspond to a different sector. In cell 904, antenna groups 918, 920, and 922 may each correspond to a different sector. In cell 906, antenna groups 924, 926, and 928 may each correspond to a different sector. Cells 902, 904, and 906 may include multiple wireless communication devices (e.g., user equipment or UEs) that may communicate with one or more sectors of each cell 902, 904, or 906. For example, UEs 930 and 932 may communicate with Node B 942 , UEs 934 and 936 may communicate with Node B 944 , and UEs 938 and 940 may communicate with Node B 946 .

10 , a multiple access wireless communication system is illustrated according to one aspect. An access point 1000 (AP) includes multiple antenna groups, one group including 1004 and 1006, another group including 1008 and 1010, and an additional group including 1012 and 1014. In FIG10 , only two antennas are shown for each antenna group, however, more or fewer antennas may be used for each antenna group. An access terminal 1016 (AT) communicates with antennas 1012 and 1014, where antennas 1012 and 1014 transmit information to the access terminal 1016 via a forward link 1020 and receive information from the access terminal 1016 via a reverse link 1018. An access terminal 1022 communicates with antennas 1006 and 1008, where antennas 1006 and 1008 transmit information to the access terminal 1022 via a forward link 1026 and receive information from the access terminal 1022 via a reverse link 1024. In an FDD system, communication links 1018, 1020, 1024, and 1026 may utilize different frequencies for communication. For example, forward link 1020 may utilize a different frequency than that used by reverse link 1018.

Each antenna group and/or the area in which it is designed to communicate is often referred to as a sector of the access point. Each antenna group is designed to communicate to access terminals in a sector of the area covered by access point 1000. In communications via forward links 1020 and 1026, the transmit antennas of access point 1000 utilize beamforming to improve the signal-to-noise ratio of the forward links for different access terminals 1016 and 1022. Furthermore, an access point that uses beamforming to transmit to access terminals randomly distributed throughout its coverage area causes less interference to access terminals in neighboring cells than an access point that transmits to all access terminals via a single antenna. An access point may be a fixed station used to communicate with terminals and may also be referred to as an access point, a Node B, or some other terminology. An access terminal may also be referred to as an access terminal, user equipment (UE), a wireless communication device, a terminal, an access terminal, or some other terminology.

11 , system 1100 illustrates a transmitter system 1110 (also referred to as an access point) and a receiver system 1150 (also referred to as an access terminal) in MIMO system 1100. At transmitter system 1110, traffic data for several data streams is provided from a data source 1112 to a transmit (TX) data processor 1114. Each data stream is transmitted via a respective transmit antenna. TX data processor 1114 formats, codes, and interleaves the traffic data for each data stream based on a particular coding scheme selected to provide coded data for that data stream.

The coded data for each data stream may be multiplexed with pilot data using OFDM techniques. The pilot data is typically a known data pattern that is processed in a known manner and can be used at the receiver system to estimate the channel response. The multiplexed pilot and coded data for the data stream are then modulated (i.e., symbol mapped) based on a particular modulation scheme (e.g., BPSK, QPSK, M-PSK, or M-QAM) selected to provide modulation symbols for each data stream. The data rate, coding, and modulation used for each data stream may be determined by instructions executed by processor 1130.

The modulation symbols for all data streams are then provided to a TX MIMO processor 1120, which may further process the modulation symbols (e.g., for OFDM). TX MIMO processor 1120 then provides NT modulation symbol streams to NT transmitters (TMTR) 1122a through 1122t. In a particular embodiment, TX MIMO processor 1120 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.

Each transmitter 1122 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. NT modulated signals from transmitters 1122a through 1122t are then transmitted from NT antennas 1124a through 1124t, respectively.

At receiver system 1150, the transmitted modulated signals are received by NR antennas 1152a through 1152r and the received signal from each antenna 1152 is provided to a respective receiver (RCVR) 1154a through 1154r. Each receiver 1154 conditions (e.g., filters, amplifies, and downconverts) a respective received signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding “received” symbol stream.

An RX data processor 1160 then receives and processes the NR received symbol streams from NR receivers 1154 based on a particular receiver processing technique to provide NT "detected" symbol streams. RX data processor 1160 then demodulates, deinterleaves, and decodes each detected symbol stream to recover the traffic data for the data stream. The processing by RX data processor 1160 is complementary to that performed by TX MIMO processor 1120 and TX data processor 1114 at transmitter system 1110.

Processor 1170 periodically determines which precoding matrix to use (discussed below). Processor 1170 formulates a reverse link message comprising a matrix index portion and a rank value portion. The reverse link message may include various types of information regarding the communication link and/or the received data stream. The reverse link message is then processed by TX data processor 1138 (which also receives traffic data for several data streams from data source 1136), modulated by modulator 1180, conditioned by transmitters 1154a through 1154r, and transmitted back to transmitter system 1110.

At transmitter system 1110, the modulated signals from receiver system 1150 are received by antenna 1124, conditioned by receiver 1122, demodulated by demodulator 1140, and processed by RX data processor 1142 to extract the reverse link message transmitted by receiver system 1150. Processor 1130 then determines which precoding matrix to use to determine the beamforming weights and then processes the extracted message.

In one aspect, logical channels are classified into control channels and traffic channels. Logical Control Channels include: Broadcast Control Channel (BCCH), which is a DL channel for broadcasting system control information; Paging Control Channel (PCCH), which is a DL channel for transmitting paging information; Multicast Control Channel (MCCH), which is a point-to-multipoint DL channel for transmitting Multimedia Broadcast and Multicast Service (MBMS) scheduling and control information for one or several MTCHs. Typically, after establishing an RRC connection, this channel is only used by UEs receiving MBMS (note: old MCCH+MSCH). Dedicated Control Channel (DCCH) is a point-to-point bidirectional channel that transmits dedicated control information and is used by UEs with an RRC connection. Logical Traffic Channels include Dedicated Traffic Channel (DTCH), which is a point-to-point bidirectional channel dedicated to one UE for transmitting user information. Furthermore, Logical Traffic Channels include Multicast Traffic Channel (MTCH), a point-to-multipoint DL channel for transmitting traffic data.

Transport channels are categorized into DL and UL. DL transport channels include the broadcast channel (BCH), the downlink shared data channel (DL-SDCH), and the paging channel (PCH). The PCH is used to support UE power conservation (the network indicates the DRX cycle to the UE), is broadcast throughout the cell, and is mapped to PHY resources that can be used for other control/traffic channels. UL transport channels include the random access channel (RACH), the request channel (REQCH), the uplink shared data channel (UL-SDCH), and multiple PHY channels. The PHY channels comprise a collection of DL channels and UL channels.

For example, DL PHY channels include: Common Pilot Channel (CPICH), Synchronization Channel (SCH), Common Control Channel (CCCH), Shared DL Control Channel (SDCCH), Multicast Control Channel (MCCH), Shared UL Assignment Channel (SUACH), Acknowledgement Channel (ACKCH), DL Physical Shared Data Channel (DL-PSDCH), UL Power Control Channel (UPCCH), Paging Indicator Channel (PICH) and Load Indicator Channel (LICH).

For example, the UL PHY channels include: Physical Random Access Channel (PRACH), Channel Quality Indicator Channel (CQICH), Acknowledgement Channel (ACKCH), Antenna Subset Indicator Channel (ASICH), Shared Request Channel (SREQCH), UL Physical Shared Data Channel (UL-PSDCH) and Broadband Pilot Channel (BPICH).

Other terms/components include: 3G (3rd Generation), 3GPP (3rd Generation Partnership Project), ACLR (Adjacent channel leakage ratio), ACPR (Adjacent channel power ratio), ACS (Adjacent channel selectivity), ADS (Advanced Design System), AMC (Adaptive modulation and coding), A-MPR (Additional maximum power reduction), ARQ (Automatic repeat request), BCCH (Broadcast control channel), BTS (Base transceiver station), CDD (Cyclic delay diversity), CCDF (Complementary cumulative distribution function), CDMA (Code division multiple access), CFI (Control format indicator), Co-MIMO (Cooperative MIMO), CP (Cyclic prefix, cyclic prefix), CPICH (Common pilot channel), CPRI (Common public radio interface), CQI (Channel quality indicator), CRC (Cyclic redundancy check), DCI (Downlink control indicator), DFT (Discrete Fourier transform), DFT-SOFDM (Discrete Fourier transform spread OFDM), DL (Downlink) (base station to subscriber transmission), DL-SCH (Downlink shared channel), D-PHY (500Mbps physical layer), DSP (Digital signal processing), DT (Development toolset), DVSA (Digital vector signal analysis), EDA (Electronic design automation), E-DCH (Enhanced dedicated channel, Evolved UMTS terrestrial radio access network, eMBMS (Evolved multimedia broadcast multicast service), eNB (Evolved Node B), EPC (Evolved packet core), EPRE (Energy per resource element), ETSI (European Telecommunications Standards Institute), E-UTRA (Evolved UTRA), E-UTRAN (Evolved UTRAN), EVM (Error vector magnitude), and FDD (Frequency division duplex).

Other terms include FFT (Fast Fourier transform), FRC (Fixed reference channel), FS1 (Frame structure type 1), FS2 (Frame structure type 2), GSM (Global system for mobile communication), HARQ (Hybrid automatic repeat request), HDL (Hardware description language), HI (HARQ indicator), HSDPA (High speed downlink packet access), HSPA (High speed packet access), HSUPA (High speed uplink packet access), IFFT (Inverse FFT), IOT (Interoperability test), IP (Internet protocol), LO (Local oscillator), LTE (Long term evolution), MAC (Medium access control), MBMS (Multimedia broadcast multicast) service, Multimedia Broadcast Multicast Service, MBSFN (Multicast/broadcast over single-frequency network), MCH (Multicast channel), MIMO (Multiple input multiple output), MISO (Multiple input single output), MME (Mobility management entity), MOP (Maximum output power), MPR (Maximum power reduction), MU-MIMO (Multiple user MIMO), NAS (Non-access stratum), OBSAI (Open base station architecture interface), OFDM (Orthogonal frequency division multiplexing), OFDMA (Orthogonal frequency division multiple access), PAPR (Peak-to-average power ratio), PAR (Peak-to-average ratio), PBCH (Physical broadcast channel, physical broadcast channel), P-CCPCH (Primary common control physical channel), PCFICH (Physical control format indicator channel), PCH (Paging channel), PDCCH (Physical downlink control channel), PDCP (Packet data convergence protocol), PDSCH (Physical downlink shared channel), PHICH (Physical hybrid ARQ indicator channel), PHY (Physical layer), PRACH (Physical random access channel), PMCH (Physical multicast channel), PMI (Pre-coding matrix indicator), P-SCH (Primary synchronization signal), PUCCH (Physical uplink control channel) and PUSCH (Physical uplink shared channel, physical uplink shared channel).

Other terms include QAM (Quadrature Amplitude Modulation), QPSK (Quadrature Phase Shift Keying), RACH (Random Access Channel), RAT (Radio Access Technology), RB (Resource Block), RF (Radio Frequency), RFDE (RF Design Environment), RLC (Radio Link Control), RMC (Reference Measurement Channel), RNC (Radio Network Controller), RRC (Radio Resource Control), RRM (Radio Resource Management), RS (Reference Signal), RSCP (Received Signal Code Power), RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), RSSI (Received Signal Strength Indicator), SAE (System Architecture Evolution), SAP (Service Access Controller) point, serving access point), SC-FDMA (Single carrier frequency division multiple access), SFBC (Space-frequency block coding), S-GW (Serving gateway), SIMO (Single input multiple output), SISO (Single input single output), SNR (Signal-to-noise ratio), SRS (Sounding reference signal), S-SCH (Secondary synchronization signal), SU-MIMO (Single user MIMO), TDD (Time division duplex), TDMA (Time division multiple access), TR (Technical report), TrCH (Transport channel), TS (Technical specification), TTA (Telecommunications Technology Association), TTI (Transmission time interval), UCI (Uplink Information Interval) control indicator, uplink control indicator), UE (User equipment), UL (Uplink) (subscriber to base station transmission), UL-SCH (Uplink shared channel), UMB (Ultra-mobile broadband), UMTS (Universal mobile telecommunications system), UTRA (Universal terrestrial radio access), UTRAN (Universal terrestrial radio access network), VSA (Vector signal analyzer), W-CDMA (Wideband code division multiple access).

Note that various aspects are described herein in conjunction with a terminal. A terminal may also be referred to as a system, user device, subscriber unit, subscriber station, mobile station, mobile device, remote station, remote terminal, access terminal, user terminal, user agent, or user equipment. A user device may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL) station, a PDA, a handheld device with wireless connectivity, a module within a terminal, a card attachable to or integrated within a host device (e.g., a PCMCIA card), or other processing device connected to a wireless modem.

In addition, aspects of the claimed subject matter may be implemented as methods, apparatuses, or articles of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof to control a computer or computing component to implement various aspects of the claimed subject matter. As used herein, the term "article of manufacture" is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic tapes, ...), optical disks (e.g., compact discs (CDs), digital versatile discs (DVDs), ...), smart cards, and flash memory devices (e.g., cards, sticks, key drives, ...). In addition, it should be understood that a carrier wave may be used to carry computer-readable electronic data, such as computer-readable electronic data used when transmitting and receiving voice emails or when accessing a network such as a cellular network. Of course, those skilled in the art will recognize that many modifications may be made to this configuration without departing from the scope or spirit of what is described herein.

What has been described above includes examples of one or more embodiments. Of course, it is not possible to describe every conceivable combination of components or methods for purposes of describing the aforementioned embodiments, but those skilled in the art will recognize that many other combinations and permutations of the various embodiments are possible. Therefore, the described embodiments are intended to embrace all such alterations, modifications, and variations that come within the spirit and scope of the appended claims. Furthermore, to the extent the term "comprising" is used in the detailed description or claims, this term is intended to be inclusive in a manner similar to how the term "comprising" is interpreted when used as a transitional word in a claim.

Claims (5)

1. A method for allocating resources for wireless communication, comprising: Group downlink control channels from multiple subframes together; The downlink control channels are mapped based on Control Channel Elements (CCEs), wherein the mapping involves sorting the downlink control channels in the packetized downlink control channels to locate the first CCEs of the plurality of downlink control channels to positions implicitly mapped to a first set of resources reserved for uplink UL dynamic acknowledgment/denial (ACK/NACK), such that the physical uplink shared channel (PUSCH) transmission can utilize a second set of unused resources from the resources reserved for uplink UL dynamic ACK/NACK. The mapping described therein includes: First, sort one or more downlink control channels from the grouped downlink control channels of the plurality of subframes that have a first CCE located in the first symbol mapping and are associated with the resources reserved for uplink UL dynamic ACK/NACK; The remaining downlink control channels in the first downlink subframe that are not associated with the first CCE are sorted and mapped to a first set of resources; The remaining downlink control channels in the second downlink subframe that are not associated with the first CCE or the first downlink subframe are sorted and mapped to a first set of resources; and The downlink control channel is transmitted according to the mapping. 2. The method according to claim 1, wherein the downlink control channel is associated with the physical downlink control channel (PDCCH). 3. A communication device comprising: Memory that holds instructions for the following operations: Group downlink control channels from multiple subframes together; The downlink control channels are mapped based on Control Channel Elements (CCEs), wherein the mapping involves sorting the downlink control channels in the packetized downlink control channels to locate the first CCEs of the plurality of downlink control channels to positions implicitly mapped to a first set of resources reserved for uplink UL dynamic acknowledgment/denial (ACK/NACK), such that the physical uplink shared channel (PUSCH) transmission can utilize a second set of unused resources from the resources reserved for uplink UL dynamic ACK/NACK. The instructions for mapping include: First, sort one or more downlink control channels from the grouped downlink control channels of the plurality of subframes that have a first CCE located in the first symbol mapping and are associated with the resources reserved for uplink UL dynamic ACK/NACK; The remaining downlink control channels in the first downlink subframe that are not associated with the first CCE are sorted and mapped to a first set of resources; The remaining downlink control channels in the second downlink subframe that are not associated with the first CCE or the first downlink subframe are sorted and mapped to a first set of resources; and The downlink control channel is transmitted according to the mapping; and The processor executes the above instructions. 4. A communication device comprising: A means for grouping downlink control channels from multiple subframes together; A means for mapping the downlink control channels based on first control channel elements (CCEs), wherein the mapping includes sorting the downlink control channels in a grouped downlink control channel to locate the first CCEs of a plurality of downlink control channels to positions implicitly mapped to a first set of resources reserved for uplink UL dynamic acknowledgment/denial (ACK/NACK), such that physical uplink shared channel (PUSCH) transmissions can utilize a second set of unused resources from the resources reserved for uplink UL dynamic acknowledgment/denial (ACK/NACK). The means for mapping said therein includes: A means for firstly sorting one or more downlink control channels from the grouped downlink control channels of the plurality of subframes, having a first CCE located in a first symbol map and associated with the resources reserved for uplink UL dynamic ACK/NACK; A means for sorting the remaining downlink control channels in a first downlink subframe that are not associated with the first CCE, and mapping them to a first set of resources; A means for sorting the remaining downlink control channels in a second downlink subframe that are not associated with the first CCE or the first downlink subframe, to map them to a first set of resources; and A means for transmitting the downlink control channel according to the mapping. 5. A non-transitory computer-readable medium having instructions stored thereon, the instructions comprising code for causing at least one computer to perform the following operations: Group downlink control channels from multiple subframes together; The downlink control channels are mapped based on Control Channel Elements (CCEs), wherein the mapping involves sorting the downlink control channels in the packetized downlink control channels to locate the first CCEs of the plurality of downlink control channels to positions implicitly mapped to a first set of resources reserved for uplink UL dynamic acknowledgment/denial (ACK/NACK), such that the physical uplink shared channel (PUSCH) transmission can utilize a second set of unused resources from the resources reserved for uplink UL dynamic ACK/NACK. The mapping described therein includes: First, sort one or more downlink control channels from the grouped downlink control channels of the plurality of subframes that have a first CCE located in the first symbol mapping and are associated with the resources reserved for uplink UL dynamic ACK/NACK; The remaining downlink control channels in the first downlink subframe that are not associated with the first CCE are sorted and mapped to a first set of resources; The remaining downlink control channels in the second downlink subframe that are not associated with the first CCE or the first downlink subframe are sorted and mapped to a first set of resources; and The downlink control channel is transmitted according to the mapping.