HK1150099B - Scrambling and modulation to constrain the constellation size of ack/nak transmission - Google Patents

Abstract

Aspects describe maximizing a Euclidean distance for an ACK transmission as a function of the number of bits in a HARQ-ACK and a modulation order. Encoding includes placing escape sequences in the HARQ-ACK, wherein the number of escape sequences is based on the number of bits and the modulation order. Multiple encoded ACK blocks are combined to obtain a vector sequence that is multiplexed with the encoded data and interleaved, such as on a "time-first" manner. Scrambling is performed as a function of the size and the modulation order. For a 1-bit ACK, the scrambling is performed to achieve any two corners in any constellation for transmission for the ACK. For a 2-bit ACK, the scrambling is performed to achieve any four corners in any constellation for transmission for the ACK.

Description

Scrambling and modulation to constrain constellation size for ACK/NACK transmissions

Cross referencing

The present application claims benefit of U.S. provisional application No. 61/039,724 entitled METHOD AND APPARATUS FOR ACK TRANSMISSION in a wireless COMMUNICATION SYSTEM (a METHOD AND APPARATUS FOR ACK TRANSMISSION IN A WIRELESS COMMUNICATION SYSTEM), filed on 26.3.2008, AND assigned to the present assignee, AND which is incorporated herein by reference in its entirety.

Technical Field

The following description relates generally to wireless communications, and more particularly to maximizing Euclidean distance (Euclidean distance) for coding, scrambling, and modulation of ACKs/NAKs.

Background

Wireless communication systems are widely deployed to provide various types of communication content such as voice, data, video, music, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the 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, and Orthogonal Frequency Division Multiple Access (OFDMA) systems, among others.

Generally, a wireless multiple-access communication system can simultaneously support communication for multiple wireless terminals. Each terminal communicates with one or more base stations via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. This communication link may be established via a single-input single-output, multiple-input single-output, or multiple-input multiple-output (MIMO) system.

As terminals or devices communicate with each other and send packets back and forth, the sending device should know whether a packet has been successfully received or whether the packet should be retransmitted. Thus, the receiving device may send an Acknowledgement (ACK) indicating successful receipt of the packet. A Negative Acknowledgement (NAK) is transmitted if the packet is not successfully received. This negative acknowledgement indicates that the packet should be resent.

Hybrid automatic repeat request (HARQ) utilizes forward error correction codes to correct a subset of errors and relies on error detection to detect uncorrectable errors. The erroneously received packets are discarded and the receiving device requests retransmission of unsuccessfully received packets. HARQ protection may be used for the data, however, retransmission of ACK/NAK on the uplink does not have HARQ protection.

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 aspects. 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.

Aspects relate to improving reliability of ACK transmissions on the uplink by selecting constellation points corresponding to edges of a constellation. One aspect relates to a method for maximizing the euclidean distance for ACK/NAK transmissions. The method includes encoding an ACK transmission as a function of a size of the ACK and a modulation order to obtain a bit sequence. The ACK transmission is intended for at least one device. The method further comprises the following steps: combining two or more bit sequences according to a modulation order; and scrambling the combined bit sequence in accordance with the size of the ACK transmission and the modulation order. Scrambling constrains the constellation size of the ACK transmission embedded in the data channel. Further, the method includes sending an ACK transmission to the at least one device in reply to receipt of the packet from the at least one device.

Another aspect relates to a communication device that includes a memory and a processor. The memory retains instructions related to: encoding the ACK with an escape sequence to obtain a bit sequence; combining two or more bit sequences; scrambling the combined bit sequence according to the size of the ACK and the modulation order; and transmitting the ACK. A processor is coupled to the memory and configured to execute the instructions retained in the memory.

Yet another aspect relates to a communications apparatus that improves reliability of ACK transmissions on an uplink. The apparatus includes means for encoding an ACK transmission with an escape sequence as a function of a size of the ACK and a modulation order and means for obtaining a bit sequence by concatenation of a plurality of encoded ACK blocks. The apparatus also includes means for scrambling the interleaved bit sequence as a function of the ACK size and the modulation order to obtain the HARQ-ACK and means for conveying the HARQ-ACK.

Yet another aspect relates to a computer program product that includes a computer-readable medium. The computer-readable medium comprises a first set of codes for causing a computer to encode a 1-bit ACK that is different from a 2-bit ACK. The encoding is a function of modulation order. The computer-readable medium comprises a second set of codes for causing a computer to combine a plurality of encoded blocks obtained from the encoding. Further comprising: a third set of codes for causing a computer to scramble the combined plurality of encoded blocks; and a fourth set of codes for causing the computer to send the scrambled encoded block. The scrambling is a function of the number of ACK bits and the modulation order.

Yet another aspect relates to at least one processor configured to maximize a euclidean distance for ACK/NAK transmissions. The processor includes a first module for encoding an ACK transmission based on a size of the ACK and a modulation order to obtain a bit sequence. The size of the ACK is 1 bit or 2 bits. The processor further comprises: a second module for combining two or more bit sequences; and a third module for scrambling the combined bit sequence as a function of a size of the ACK and the modulation order. The scrambling constrains a constellation size of 1 bit of an ACK embedded in the data channel to binary phase shift keying and a constellation size of 2 bits to quadrature phase shift keying. Also included in the processor is a fourth module for transmitting the ACK.

To the accomplishment of the foregoing and related ends, the one or more aspects 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 aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed. Other advantages and novel features will become apparent from the following detailed description when considered in conjunction with the drawings and the disclosed aspects are intended to include all such aspects and their equivalents.

Drawings

Fig. 1 illustrates a system for maximizing euclidean distance of coding, scrambling, and modulation of ACK/NAK by selecting constellation points corresponding to edges of a constellation.

Fig. 2 illustrates modulation mapping in accordance with an aspect.

Fig. 3 illustrates a system for improving reliability of ACK transmissions on the uplink by selecting constellation points corresponding to edges of a constellation.

Fig. 4 illustrates a methodology for encoding and scrambling one-bit HARQ-ACKs in accordance with an aspect.

Fig. 5 illustrates a methodology for scrambling 1-bit HARQ-ACKs in accordance with an aspect.

Fig. 6 illustrates a methodology for encoding and scrambling a two-bit HARQ-ACK in accordance with an aspect.

Fig. 7 illustrates a methodology for scrambling 2-bit HARQ-ACKs in accordance with an aspect.

Fig. 8 illustrates an example system that utilizes coding, scrambling, and modulation to maximize euclidean distance of ACK/NAK, according to an aspect.

Fig. 9 illustrates a system that facilitates maximizing a euclidean distance for ACK/NAKs in accordance with one or more of the disclosed aspects.

Fig. 10 is an illustration of a system that facilitates a corner in any constellation that enables transmission of an ACK in accordance with various aspects presented herein.

Fig. 11 illustrates a multiple access wireless communication system, in accordance with one or more aspects.

Fig. 12 illustrates an exemplary wireless communication system in accordance with various aspects.

Detailed Description

Various aspects are now described with reference to the drawings. 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 aspects. It may be evident, however, that such aspect(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 these aspects.

As used in this application, the terms "component," "module," "system," and the like are intended to refer to a computer-related entity: 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 executing on a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application executing on a computing device and the computing device can be a component. One or more components may reside within a process and/or thread of execution and a component may 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 such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a regional system, distributed system, and/or across a network such as the internet with other systems by way of the signal).

Further, various aspects are described herein in connection with a mobile device. A mobile device may also be called, and may contain some or all of the functionality of, a system, a subscriber unit, subscriber station, mobile, wireless terminal, node, device, remote station, remote terminal, access terminal, user terminal, wireless communication device, wireless communication apparatus, user agent, user device, or User Equipment (UE). A mobile device may be a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a smart phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a laptop computer, a handheld communication device, a handheld computing device, a satellite radio, a wireless modem card, and/or another processing device for communicating via a wireless system. Moreover, various aspects are described herein in connection with a base station. A base station may be used for communicating with wireless terminals and may also be referred to as, and may contain some or all the functionality of, an access point, a node B, e, a B, e-NB, or some other network entity.

Various aspects or features will be presented in terms of systems that may include a number of devices, components, modules, and the like. It is to be understood and appreciated that the various systems may include additional devices, components, modules, etc. and/or may not include all of the devices, components, modules etc. discussed in connection with the figures. Combinations of these methods may also be used.

Additionally, in the description, the word "exemplary" is used to mean serving as an example, instance, or illustration. Any aspect or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word exemplary is intended to present concepts in a concrete fashion.

Referring to fig. 1, a system 100 is illustrated for maximizing euclidean distance of decoding, scrambling, and modulation of ACK/NAK by selecting constellation points corresponding to edges of the constellation. The system 100 is configured to help improve the reliability of ACK/NAK transmissions on the uplink by selecting constellation points that correspond to the edges of the constellation. For ACK/NAK, regardless of the Physical Uplink Shared Channel (PUSCH) modulation scheme, the modulation symbols used for control signal transmission carry one or two bits of coded control information. System 100 utilizes an escape sequence in the coding of ACK/NAK information, which can be correctly interpreted. Although various aspects will be described with reference to ACKs, these aspects may also apply to NAK transmissions.

A first device 102 in communication with a second device 104 is included in the system 100. The first apparatus 102 and the second apparatus 104 are configured to both send and receive information. In describing the various aspects, the first apparatus 102 may also be referred to as a transmitter and the second apparatus may be referred to as a receiver. As will be appreciated, multiple transmitters 102 and receivers 104 may be included in the system 100, although a single transmitter 102 that transmits communication data signals to a single receiver 104 is illustrated for simplicity.

For purposes of this particular embodiment, transmitter 102 has received a packet from receiver 104 and will send an Acknowledgement (ACK) or a Negative Acknowledgement (NAK) in reply to receiver 104. The ACK contains an acknowledgement character indicating that the received data (from the second device 104) has been correctly received. The NAK indicates that the data was received in error and, therefore, that the data (e.g., packet) should be retransmitted. For ACK/NAK, the coding, scrambling, and modulation should maximize the euclidean distance. For ACK/NAK (in the case of Frequency Division Duplex (FDD)), regardless of the Physical Uplink Shared Channel (PUSCH) modulation scheme, the modulation symbols used for control signal transmission carry at most two bits of coded control information.

To maximize euclidean distance, encoder 106 may be configured to depend on the number of bits (e.g., 1 bit, 2 bits) and the modulation order Q_mThe ACK information is encoded. Modulation order Q_mAnd may be of order 2, 4 or 6. A modulation order of 2 corresponds to Quadrature Phase Shift Keying (QPSK). A modulation order of 4 corresponds to 16QAM (quadrature amplitude modulation), which is a higher order modulation of QPSK. A modulation order of 6 corresponds to 64QAM, which is a higher order modulation than 16 QAM. Higher order modulation means that the modulation alphabet is spreadTo include additional signaling alternatives that allow more bits of information to be transmitted per modulation symbol. For QPSK, the modulation alphabet contains four different signal transmission alternatives. The extension to 16QAM modulation provides sixteen different signal transmission alternatives. A further extension to 64QAM provides the availability of sixty-four different signal transmission alternatives.

As previously described, the encoder 106 is configured to depend on the number of bits and the modulation order Q_mThe ACK information is encoded. The following table (table 1) illustrates the encoding of a 1-bit HARQ-ACK, where "x" denotes an escape sequence to inform the scrambler 110 that a particular scrambling function should be performed:

TABLE 1

The following table (table 2) illustrates the encoding of 2-bit HARQ-ACK:

TABLE 2

The encoder 106 obtains an encoded bit sequence by concatenation of multiple encoded HARQ-ACK blocksWherein Q_ACKIs the total number of coded bits of all encoded HARQ-ACK blocks. These are derived as blocks since the blocks are later input into the modulator in the coding chain. Therefore, QPSK modularization (modulation) will employ concatenation of multiple coded HARQ-ACK blocks in a set of two. 16QAM modulation will be adopted at fourA concatenation of multiple encoded HARQ-ACK blocks in the set of (a). Furthermore, a 64QAM modulator will employ a concatenation of multiple encoded HARQ-ACK blocks in a set of six.

ByRepresenting a vector sequence output for channel coding of HARQ-ACK information, where Q'_ACK＝Q_ACK/Q_m. The vector sequence is obtained as follows:

vector sequenceThen multiplexed with the encoded data and interleaved by interleaver 108 in a "time first" fashion. The output of the channel interleaver 108 is the input to the processing of the PUSCH. The scrambler 110 performs the following operations depending on whether the ACK is a 1-bit ACK or a 2-bit ACK and depending on a modulation order (e.g., QPSK, 16QAM, 64 QAM). Thus, scrambling is a function of size and modulation order.

The scrambler 110 attempts to obtain two corners in any constellation for the transmission of ACK on PUSCH (e.g., efficient Binary Phase Shift Keying (BPSK) modulation). Thus, for Q having a value of 2_M1 bit ACK for (QPSK), sequence of decoded bits [ b (i) x]Is scrambled intoWhereinThis scrambling may be performed according to the following pseudo code:

wherein x and y are tags, and wherein c (i) is a scrambling sequence. May be used at the beginning of each sub-frameTo initialize the scrambling sequence generator 112, where n_RNTICorresponding to a Radio Network Temporary Identifier (RNTI) associated with the PUSCH transmission.

For Q with a value of 4_M1-bit ACK for (16QAM), sequence of decoded bits [ b (i) x x x x x]Is scrambled intoFor Q with a value of 6_M1-bit ACK for (64QAM), sequence of decoded bits [ b (i) x x x x x x x]Is scrambled into

For a 2-bit ACK, the scrambler 110 attempts to obtain four corners in any constellation for transmission of an ACK on PUSCH (e.g., effective QPSK modulation). Thus, for Q having a value of 2_m2-bit ACK for (QPSK), sequence of decoded bits [ b (i) b (i +1)]Is scrambled intoIf ACK is 2 bits and Q_mIs 4(16QAM), the decoded bit sequence [ b (i) b (i +1) x x]Is scrambled intoFor Q of 6_m(64QAM) and a 2-bit, decoded sequence of bits [ b (i) b (i +1) x x x x x x]Is scrambled into

As discussed above, during scrambling, a "1 s" is appended. However, according to some aspects, a "1" is not used and others are used, such as a "2" or a non-zero 1, or a non-binary, etc. The remainder of the processing performed by the transmitter 102 (e.g., modulation, transform pre-decoder, etc.) is transparent to the presence or absence of control information. The signal generator 112 is configured to convey the ACK/NAK to the second apparatus 104.

The system 100 may include a memory 114 operatively coupled to the first device 102. The memory 114 may be external to the first device 102 or may reside within the first device 102. Memory 114 may store information related to encoding modulation orders for ACK transmissions to obtain encoded HARQ-ACK blocks, concatenating two or more of the encoded HARQ-ACK blocks to obtain a coded bit sequence, scrambling the coded bit sequence as a function of ACK size and modulation order, and transmitting the scrambled bit sequence, and other suitable information related to signals transmitted and received in a communication network. The processor 116 may be operatively connected to the first device 102 (and/or the memory 114) to facilitate analysis of information related to maximizing euclidean distance of ACK transmissions in the communication network. Processor 116 may be a processor dedicated to analyzing and/or generating information received by first apparatus 102, a processor that controls one or more components of system 100, and/or a processor that both analyzes and generates information received by first apparatus 102 and controls one or more components of system 100.

Memory 114 may store protocols associated with maximizing euclidean distance for ACK transmissions, taking action to control communications between first device 102 and second device 104, etc., such that system 100 may use the stored protocols and/or algorithms to enable improved communications in a wireless network, as described herein. It will be appreciated that the data store (e.g., memories) components described herein can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. By way of example, and not limitation, nonvolatile memory can include Read Only Memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), electrically erasable ROM (EEPROM), or flash memory. 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 disclosed aspects of memory are intended to comprise, without being limited to, these and other suitable types of memory.

To fully appreciate the disclosed aspects, fig. 2 illustrates modulation mapping according to an aspect. As illustrated, at 202 is a QPSK modulated signal constellation, which consists of four different signal transmission alternatives. To visualize these signaling alternatives, the two-dimensional plane is divided into four quadrants 204, 206, 208, and 210. Four points represent four different alternatives, one in each quadrant 204-210. QPSK allows up to 2 bits of information to be transmitted during each modulation symbol interval. For the 1 bit, the disclosed aspects enable two corners, specifically, an upper right corner (in quadrant 204) and a lower left corner (in quadrant 208) corresponding to "00" and "11".

At 212, a signal constellation for 16QAM is illustrated. The extension to 16QAM modulation allows the availability of sixteen different signal transmission alternatives. In the case of 16QAM, up to 4 bits of information may be transmitted during each modulation symbol interval, as illustrated by the dots in each quadrant 214, 216, 218, and 220. In the case of 16QAM modulation, quadruplets of bits b (I), b (I +1), b (I +2), b (I +3) are mapped to complex-valued modulation symbols x ═ I + jQ according to the following table (table 3):

TABLE 3

For 16QAM, the disclosed aspects attempt to achieve four corners of the constellation diagram. Thus, the modulation in the upper right quadrant 214 is mapped to "0011". For the upper left quadrant 216, the modulation maps to "1011". For the lower left quadrant 218, the modulation maps to "1111", and for the lower right quadrant 220, the modulation maps to "0111". The corner may be achieved via utilization of an escape sequence and the encoding, scrambling, and modulation disclosed herein.

The modulation scheme can be further extended to 64QAM, which provides sixty-four different signal transmission alternatives. In this case, up to 6 bits of information may be conveyed per modulation symbol interval. A constellation diagram for 64QAM is illustrated at 222. In the case of 64QAM modulation, six sets of bits b (I), b (I +1), b (I +2), b (I +3), b (I +4), b (I +5) are mapped to a complex-valued modulation symbol x ═ I + jQ according to the following table (table 4):

TABLE 4

The 64QAM constellation 222 is decomposed into four quadrants 224, 226, 228, and 230. The corner of the upper right quadrant 224 is "001111". The upper left quadrant 226 is "101111". The lower left quadrant 228 is "111111" and the lower right quadrant 230 is "011111". The disclosed encoding, scrambling, and modulation of the disclosed aspects may maximize euclidean distance in order to obtain the four corners of the constellation diagram 222.

Fig. 3 illustrates a system 300 for improving reliability of ACK transmissions on the uplink by selecting constellation points corresponding to edges of a constellation. System 300 can limit a maximum modulation order to signal ACK/NAK on PUSCH. Two devices, labeled transmitter 302 and receiver 304, are included in the system. It should be noted that the terms "transmitter" and "receiver" are utilized for simplicity, and both devices 302, 304 can transmit and receive communications.

The transmitter 302 includes an encoder 306 configured to modulate the modulation order Q according to the number of bits_mThe 1-bit and 2-bit HARQ-ACKs are encoded. Also included is an interleaver 308 configured to interleave the encoded data, e.g., in a "time-first" manner. A scrambler 310 configured to scramble ACKs is also included in the transmitter 302, which are conveyed by the signal generator 312 to the receiver 304.

To perform appropriate encoding of the 1-bit and 2-bit HARQ-ACKs, encoder 306 may be configured to reference information that may be included in table a314 and table B316. Table a314 (as discussed above) may include information related to the encoding of a 1-bit HARQ-ACK. Table B316 may include information related to the encoding of a 2-bit HARQ-ACK. Each table 314, 316 may include a modulation order Q_mCross reference to (3).

For example, table a314 may include the following information: for Q of 1 bit and 2_m(QPSK) with encoded HARQ-ACK of"x" represents an escape sequence or placeholder that may be used to scramble the HARQ-ACK bits (by scrambler 310) in a manner that maximizes the Euclidean distance of the modulation symbols carrying the HARQ-ACK information. For Q of 4_m(16QAM) and 1 bit, encoded HARQ-ACK to include threeOf escape sequences (or placeholders)For Q of 6_m(64QAM) and 1 bit, the encoded HARQ-ACK being one comprising five escape sequences (placeholders)

Table B316 may provide for Q having a value of 2_mCoding of 2-bit HARQ-ACK of (QPSK), the coded HARQ-ACK beingFor Q of 2 bits and 4_m(16QAM), the encoded HARQ-ACK includes two escape sequences (or placeholders) and is expressed asFurther, for Q with a 2-bit sum of 6_m(64QAM), the encoded HARQ-ACK includes four placeholder or escape sequences and is expressed asThus, if the HARQ-ACK includes 1 bit of information, it is encoded according to table a 314. If the HARQ-ACK includes 2 bits of information, it is encoded according to Table B316.

A concatenation 318 of multiple encoded HARQ-ACK blocks is performed to obtain a bit sequence and obtain a vector sequence. The sequence of vectors is multiplexed with the encoded data and interleaved (by interleaver 108) in a "time-first" manner. The scrambler 110 performs scrambling depending on the bit size of the ACK (1-bit ACK320 or 2-bit ACK322) and the modulation order 324.

The system 300 also includes a memory 326 and a processor 328 operatively connected to the transmitter 302. Memory 326 retains instructions related to ACK encoding and scrambling to constrain the modulation order of ACK transmissions embedded in the data channel to BPSK for 1-bit ACKs and to QPSK for 2-bit ACKs, regardless of the modulation order used for data transmissions. The processor 328 is coupled to the memory 326 and is configured to execute instructions retained in the memory 326.

In view of the exemplary systems shown and described above, methodologies that may be implemented in accordance with the disclosed subject matter will be better appreciated with reference to the following flow charts. While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of blocks, it is to be understood and appreciated that the claimed subject matter is not limited by the number or order of blocks, as some blocks may occur in different orders and/or substantially concurrently with other blocks from what is depicted and described herein. Moreover, not all illustrated blocks may be required to implement the methodologies described herein. It is to be appreciated that the functionality associated with the blocks may be implemented by software, hardware, a combination thereof, or any other suitable means (e.g., device, system, process, component). Additionally, it should be further appreciated that the methodologies disclosed hereinafter and throughout this specification are capable of being stored on an article of manufacture to facilitate transporting and transferring such methodologies to various devices. 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.

Fig. 4 illustrates a methodology 400 for encoding and scrambling one-bit HARQ-ACKs in accordance with an aspect. The encoding and scrambling may be determined in terms of the number of bits and the modulation order. Modulation order Q_mMay be 2(QPSK), 4(16QAM) or 6(64 QAM). At 402, if Q_mIs 2, the HARQ-ACK block is derived by adding an escape sequence (or placeholder), and thus the encoded HARQ-ACK isIn addition, if Q_m4, then at 404, a HARQ-ACK block is derived by adding three escape sequences (or placeholders). For Q_m4 coded HARQ-ACK ofIf Q is_mAt 6, a HARQ-ACK block is derived by adding five escape sequences (or placeholders) at 406, and the encoded HARQ-ACK is

At 408, a bit sequence is generated by concatenating the plurality of encoded HARQ-ACKs, as obtained at 402, 404, or 406. The encoded HARQ-ACKs are treated as blocks so that the blocks are utilized in an appropriate manner when performing further processing. For example, a QPSK modulator would employ concatenation of multiple encoded HARQ-ACK blocks in a set of two; 16QAM modulation will employ concatenation of multiple encoded HARQ-ACK blocks in a set of four; and a 64QAM modulator will employ a concatenation of multiple encoded HARQ-ACK blocks in a set of six.

At 410, the bit sequence is scrambled. This scrambling may include replicating the previously scrambled bits at 412, where the first escape sequence is replicated bits. At 414, the hint for the escape sequence (if present) is appended with "1 s". Further information related to scrambling will be discussed with reference to the following figures.

Fig. 5 illustrates a methodology 500 for scrambling 1-bit HARQ-ACKs in accordance with an aspect. The 1-bit HARQ-ACK may be encoded as discussed with reference to fig. 4. The scrambling of the HARQ-ACK is a function of the size of the ACK (e.g., 1 bit) and the modulation order (e.g., QPSK, 16QAM, 64 QAM). At 502, if modulation order Q_mFor 2(QPSK), the decoded bit sequence [ b (i) x]Scrambling is asWhereinAdditionally, at 504, if order Q is modulated_mIs 4(16QAM), the decoded bit sequence [ b (i) x x x x x]Scrambling is asIn addition, at 506,if Q is_mIs 6(64QAM), the decoded bit sequence [ b (i) x x x x x x x]Scrambling is as

Referring now to fig. 6, a methodology 600 for encoding and scrambling a two-bit HARQ-ACK is illustrated in accordance with an aspect. The encoding and scrambling may be determined in terms of the number of bits and the modulation order. Modulation order Q_mMay be 2(QPSK), 4(16QAM) or 6(64 QAM).

At 602, if Q_mFor 2(QPSK), two decoded bits are utilizedAt 604, if Q_mIs 4(16QAM), then two escape sequences are added and the encoded HARQ-ACK block isAdditionally, at 606, if Q_mIs 6(64QAM), then four escape sequences are added, and the HARQ-ACK block is

At 608, a bit sequence is obtained by concatenating multiple encoded HARQ-ACK blocksAs determined at 602, 604, or 606. A scrambling process is performed on a bit sequence at 610, which will now be described with reference to fig. 7, which illustrates a methodology 700 for scrambling a 2-bit HARQ-ACK in accordance with an aspect. Scrambling is performed depending on the number of bits (2 bits) and the modulation order (e.g., QPSK, 16QAM, 64 QAM). Scrambling is performed to achieve four corners in any constellation for the transmission of ACK on PUSCH (e.g., effective QPSK modulation).

At 702, if Q_mFor 2(QPSK), the decoded bit sequence [ b (i) b (i +1)]Scrambling is asAdditionally, at 704, if Q_mIs 4(64QAM), the decoded bit sequence [ b (i) b (i +1) x x]Scrambling is asIn addition, if Q_mIs 6(64QAM), the decoded bit sequence [ b (i) b (i +1) x x x x x x x]Scrambling is as

Referring to fig. 8, an example system 800 is illustrated that utilizes coding, scrambling, and modulation to maximize the euclidean distance of the ACK/NAK, according to an aspect. System 800 may reside at least partially within a mobile device. It is to be appreciated that system 800 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 800 includes a logical grouping 802 of electrical components that can act separately or in conjunction. Logical grouping 802 can include an electrical component for encoding an ACK transmission with an escape sequence as a function of a size and a modulation order of the HARQ-ACK 804. The size may be 1 bit or 2 bits, and the modulation order may be 2(QPSK), 4(16QAM), or 6(64 QAM).

Also included in logical grouping 802 is an electrical component 806 for obtaining a bit sequence by concatenating the plurality of encoded ACK blocks, and an electrical component 808 for scrambling the interleaved bit sequence as a function of ACK size and modulation order. Scrambling constrains the constellation size of the ACK transmission embedded in the data channel. Electrical component 808 constrains the constellation size to binary phase shift keying for 1-bit transmissions and to quadrature phase shift keying for 2-bit ACK transmissions. Further, logical grouping 802 includes an electrical component for transmitting an ACK 810.

According to some aspects, the ACK transmission is 1 bit in size and the modulation order is 2, a sequence of coded bits [ b (i) x]Is scrambled intoWhereinAccording to another aspect, the ACK transmission is 1 bit in size and the modulation order is 4, a sequence of coded bits [ b (i) x x x x x x]Is scrambled intoAccording to another aspect, the ACK transmission is 1 bit in size and the modulation order is 6, a sequence of bits coded [ b (i) x x x x x x x]Is scrambled intoAccording to another aspect, the ACK transmission is 2 bits in size and the modulation order is 2, a sequence of bits coded [ b (i) b (i +1) ]]Is scrambled intoIn yet another aspect, the size of the ACK transmission is 2 bits and the modulation order is 4, a coded bit sequence [ b (i) b (i +1) x x]Is scrambled intoAccording to another aspect, the ACK transmission is 2 bits in size and the modulation order is 6, a sequence of coded bits [ b (i) b (i +1) x x x x x x]Is scrambled into

System 800 can include a memory 812 that retains instructions for executing functions associated with electrical components 804, 806, 808, and 810, or other components. While shown as being external to memory 812, it is to be understood that one or more of electrical components 804, 806, 808, and 810 can exist within memory 812.

Referring now to fig. 9, a system 900 is illustrated in accordance with one or more of the disclosed aspects, the system 900 facilitates maximizing a euclidean distance for ACK/NAK. System 900 may reside in a user device. System 900 includes a receiver 902 that can receive a signal from, for instance, a receiver antenna. Receiver 902 may perform typical actions thereon such as filtering, amplifying, downconverting, etc. the received signal. Receiver 902 may also digitize the conditioned signal to obtain samples. A demodulator 904 can obtain received symbols in each symbol period and provide received symbols to a processor 906.

Processor 906 can be a processor dedicated to analyzing information received by receiver component 902 and/or generating information for transmission by a transmitter 908. Additionally or alternatively, processor 906 may control one or more components of user device 900, analyze information received by receiver 902, generate information for transmission by transmitter 908, and/or control one or more components of user device 900. Processor 906 may include a controller component capable of coordinating communication with additional user devices.

User device 900 can additionally include memory 908, memory 908 operatively coupled to processor 906 and can store information related to coordinating communications and any other suitable information. Memory 910 may additionally store protocols associated with maximizing euclidean distance. User device 900 can further comprise a symbol modulator 912 and a transmitter 908 that transmits the modulated signal.

Fig. 10 is an illustration of a system 1000 that the system 1000 facilitates enabling corners in any constellation for transmission of ACKs, in accordance with various aspects presented herein. System 1000 includes a base station or access point 1002. As illustrated, base station 1002 receives signal(s) from one or more communication devices 1004 (e.g., user devices) through a receive antenna 1006 and transmits to the one or more communication devices 1004 via a transmit antenna 1008.

Base station 1002 includes a receiver 1010 that receives information from receive antennas 1006 and is operatively associated with a demodulator 1012 that demodulates received information. The demodulated symbols are analyzed by a processor 1014 that is coupled to a memory 1016, and the memory 1016 stores information related to maximizing euclidean distance. A modulator 1018 can multiplex the signal for transmission by a transmitter 1020 through transmit antenna 1008 to communication devices 1004.

Referring now to fig. 11, a multiple access wireless communication system 1100 in accordance with one or more aspects is illustrated. The wireless communication system 1100 can include one or more base stations in contact with one or more user devices. Each base station provides coverage for multiple sectors. A three sector base station 1102 is illustrated that includes multiple antenna groups, one including antennas 1104 and 1106, another including antennas 1108 and 1110, and a third including antennas 1112 and 1114. According to the figure, only two antennas are shown for each antenna group, however, more or fewer antennas may be used for each antenna group. Mobile device 1116 is in communication with antennas 1112 and 1114, where antennas 1112 and 1114 transmit information to mobile device 1116 over a forward link 1118 and receive information from mobile device 1116 over a reverse link 1120. 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. Mobile device 1122 is in communication with antennas 1104 and 1106, where antennas 1104 and 1106 transmit information to mobile device 1122 over a forward link 1124 and receive information from mobile device 1122 over a reverse link 1126. In a FDD system, communication links 1118, 1120, 1124 and 1126 may utilize different frequency for communication, for example. For example, forward link 1118 may use a different frequency than that utilized by reverse link 1120.

Each group of antennas or the area in which they are designated to communicate can be referred to as a sector of base station 1102. In one or more aspects, antenna groups each are designed to communicate to mobile devices in a sector or the areas covered by base station 1102. A base station may be a fixed station used for communicating with the terminals.

In communication over forward links 1118 and 1124, the transmitting antennas of base station 1102 can utilize beamforming in order to improve signal-to-noise ratio of the forward links for the different mobile devices 1116 and 1122. Also, a base station utilizing beamforming to transmit to mobile devices scattered randomly through its coverage may cause less interference to mobile devices in neighboring cells than a base station transmitting through a single antenna to all mobile devices in its coverage area.

Fig. 12 illustrates an exemplary wireless communication system 1200 in accordance with various aspects. The wireless communication system 1200 depicts one base station and one terminal for sake of brevity. It is to be appreciated, however, that system 1200 can include more than one base station or access point and/or more than one terminal or user device, wherein additional base stations and/or terminals can be substantially similar or different for the exemplary base station and terminal described below. In addition, it is to be appreciated that the base station and/or the terminal can employ the systems and/or methods described herein to facilitate wireless communication there between.

Referring now to fig. 12, on a downlink, at access point 1205, a Transmit (TX) data processor 1210 receives, formats, codes, interleaves, and modulates (or symbol maps) traffic data and provides modulation symbols ("data symbols"). A symbol modulator 1215 receives and processes the data symbols and pilot symbols and provides a stream of symbols. A symbol modulator 1215 multiplexes data and pilot symbols and obtains a set of N transmit symbols. Each transmit symbol may be a data symbol, a pilot symbol, or a signal value of zero. The pilot symbols may be sent continuously in each symbol period. The pilot symbols may be Frequency Division Multiplexed (FDM), Orthogonal Frequency Division Multiplexed (OFDM), Time Division Multiplexed (TDM), Frequency Division Multiplexed (FDM), or Code Division Multiplexed (CDM).

A transmitter unit (TMTR)1220 receives and converts the stream of symbols into one or more analog signals and further conditions (e.g., amplifies, filters, and frequency upconverts) the analog signals to generate a downlink signal suitable for transmission over the wireless channel. The downlink signal is then transmitted through an antenna 1225 to the terminals. At terminal 1230, an antenna 1235 receives the downlink signal and provides a received signal to a receiver unit (RCVR) 1240. Receiver unit 1240 conditions (e.g., filters, amplifies, and frequency downconverts) the received signal and digitizes the conditioned signal to obtain samples. A symbol demodulator 1245 obtains N received symbols and provides received pilot symbols to a processor 1250 for channel estimation. Symbol demodulator 1245 further receives a frequency response estimate for the downlink from processor 1250, performs data demodulation on the received data symbols to obtain data symbol estimates (which are estimates of the transmitted data symbols), and provides the data symbol estimates to an RX data processor 1255, which RX data processor 1255 demodulates (i.e., symbol demaps), deinterleaves, and decodes the data symbol estimates to recover the transmitted traffic data. The processing by symbol demodulator 1245 and RX data processor 1255 is complementary to the processing by symbol modulator 1215 and TX data processor 1210, respectively, at access point 1205.

On the uplink, a TX data processor 1260 processes traffic data and provides data symbols. A symbol modulator 1265 receives and multiplexes the data symbols and pilot symbols, performs modulation, and provides a stream of symbols. A transmitter unit 1270 then receives and processes the stream of symbols to generate an uplink signal, which is transmitted by the antenna 1235 to the access point 1205.

At access point 1205, the uplink signal from terminal 1230 is received by the antenna 1225 and processed by a receiver unit 1275 to obtain samples. A symbol demodulator 1280 then processes the samples and provides received pilot symbols and data symbol estimates for the uplink. An RX data processor 1285 processes the data symbol estimates to recover the traffic data transmitted by terminal 1230. A processor 1290 performs channel estimation for each active terminal transmitting on the uplink.

Processors 1290 and 1250 direct (e.g., control, coordinate, manage, etc.) operation at access point 1205 and terminal 1230, respectively. Respective processors 1290 and 1250 can be associated with memory units (not shown) that store program codes and data. Processors 1290 and 1250 can also perform computations to derive frequency and impulse response estimates for the uplink and downlink, respectively.

For a multiple-access system (e.g., FDMA, OFDMA, CDMA, TDMA, etc.), multiple terminals may transmit simultaneously on the uplink. For such systems, the pilot subbands may be shared among different terminals. The channel estimation techniques may be used in cases where the pilot subbands for each terminal span the entire operating band (possibly except for the band edges). The pilot subband structure would be needed to obtain frequency diversity for each terminal. 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 a hardware implementation, the processing units used for channel estimation 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. In the case of software, implementation can be through modules (e.g., procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in memory unit and executed by the processors 1290 and 1250.

It should be understood that the aspects described herein may be implemented by hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general purpose or special purpose computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

The various illustrative logics, logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Additionally, at least one processor may comprise one or more modules operable to perform one or more of the steps and/or actions described above.

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. Further, at least one processor may comprise one or more modules operable to perform the functions described herein.

The techniques described herein may be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and other systems. The terms "system" and "network" are often used interchangeably. A CDMA system may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRA includes wideband CDMA (W-CDMA) and other CDMA variants. In addition, CDMA2000 coverageIS-2000, IS-95 and IS-856 standards. A TDMA system may implement a radio technology such as global system for mobile communications (GSM). OFDMA systems may be implemented, for example, evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE802.11(Wi-Fi), IEEE802.16(WiMAX), IEEE802.20, and,And so on. UTRA and E-UTRA are parts of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) is a release of UMTS that uses E-UTRA, which uses OFDMA on the downlink and SC-FDMA on the uplink. UTRA, E-UTRA, UMTS, LTE and GSM are described in the literature from an organization named "third Generation partnership project" (3 GPP). In addition, CDMA2000 and UMB are described in literature from an organization named "third generation partnership project 2" (3GPP 2). Further, the wireless communication systems may additionally include peer-to-peer (e.g., mobile to mobile) ad hoc network systems, often using unpaired unlicensed spectrum, 802.xx wireless LANs, bluetooth, and any other short-range or long-range wireless communication technologies.

Moreover, various aspects or features described herein 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 for storing information. The term "machine-readable medium" can include, without being limited to, wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data. Additionally, a computer program product may comprise a computer-readable medium having one or more instructions or code operable to cause a computer to perform the functions described herein.

Further, the steps and/or actions of a method or algorithm described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium may be coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. Further, in some aspects, the processor and the storage medium may reside in an ASIC. Additionally, the ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal. Additionally, in some aspects, the steps and/or actions of a method or algorithm may reside as one or any combination or set of codes and/or instructions on a machine readable medium and/or computer readable medium, which may be incorporated into a computer program product.

While the foregoing disclosure discusses illustrative aspects and/or aspects, it should be noted that various changes and modifications could be made herein without departing from the scope of the described aspects and/or aspects as defined by the appended claims. Accordingly, the described aspects are intended to embrace all such alterations, modifications and variations that fall within the scope of the appended claims. Furthermore, although aspects and/or elements of aspects may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Additionally, all or a portion of any aspect and/or aspect may be utilized with all or a portion of any other aspect and/or aspect, unless stated otherwise.

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. Furthermore, the term "or" as used in the detailed description or claims is intended to be inclusive or rather than exclusive or. That is, unless specified otherwise, or clear from context, the phrase "X employs a or B" is intended to mean any of the natural inclusive permutations. That is, any of the following examples satisfies the phrase "X employs a or B": x is A; b is used as X; or X employs both A and B. In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form.

Claims (18)

1. A method for maximizing euclidean distance for an acknowledgement, ACK, transmission by selecting constellation points corresponding to edges of a constellation, comprising:

encoding the ACK transmission according to a size and a modulation order of the ACK transmission in a plurality of bits to obtain a bit sequence;

scrambling the bit sequence as a function of the size of the ACK transmission and the modulation order, wherein the scrambling constrains a constellation size of the ACK transmission embedded in a data channel based on the size of the ACK transmission, and the size of the ACK transmission is less than the modulation order; and

sending the ACK transmission to at least one device in response to receiving a packet.

2. The method of claim 1, wherein the scrambling constrains the constellation size to Binary Phase Shift Keying (BPSK) for 1-bit ACK transmissions.

3. The method of claim 1, wherein the scrambling constrains the constellation size to Quadrature Phase Shift Keying (QPSK) for 2-bit ACK transmissions.

4. The method of claim 1, wherein the size of the ACK transmission is 1 bit and modulation order is 2, sequence of bits coded [ b (i) x £ b @]Scrambling is asWhereinWherein b (i) is a bit value, x is a placeholder, and c (i) is a scrambling sequence.

5. The method of claim 1, wherein the size of the ACK transmission is 1 bit and modulation order is 4, a sequence of bits to be coded [ b (i) x x x x x x x]Scrambling is asWhere b (i) is a bit value and x is a placeholder.

6. The method of claim 1, wherein the size of the ACK transmission is 1 bit and modulation order is 6, a sequence of bits to be coded [ b (i) x x x x x x x x]Scrambling is asWhere b (i) is a bit value and x is a placeholder.

7. The method of claim 1, wherein the size of the ACK transmission is 2 bits and modulation order is 2, sequence of bits to be coded [ b (i) b (i +1) ]]Scrambling is asWhere b (i) and b (i +1) are bit values.

8. The method of claim 1, wherein the size of the ACK transmission is 2 bits and modulation order is 4, a sequence of coded bits [ b (i) b (i +1) x x]Scrambling is asWhere b (i) and b (i +1) are bit values and x is a placeholder.

9. The method of claim 1, wherein the size of the ACK transmission is 2 bits and modulation order is 6, a sequence of bits to be coded [ b (i) b (i +1) x x x x x x x x]Scrambling is asWhere b (i) and b (i +1) are bit values and x is a placeholder.

10. An apparatus for maximizing euclidean distance for an acknowledgement, ACK, transmission by selecting a constellation point corresponding to an edge of a constellation, comprising:

means for encoding the ACK transmission in accordance with a size and a modulation order of the ACK transmission in a plurality of bits to obtain a bit sequence;

means for scrambling the bit sequence as a function of the size of the ACK transmission and the modulation order, wherein the means for scrambling constrains a constellation size of the ACK transmission embedded in a data channel based on the size of the ACK transmission, and the size of the ACK transmission is less than the modulation order; and

means for sending the ACK transmission to at least one device in response to receiving a packet.

11. The apparatus of claim 10, wherein the scrambling constrains the constellation size to Binary Phase Shift Keying (BPSK) for 1-bit ACK transmissions.

12. The apparatus of claim 10, wherein the scrambling constrains the constellation size to Quadrature Phase Shift Keying (QPSK) for 2-bit ACK transmissions.

13. The apparatus of claim 10, wherein the size of the ACK transmission is 1 bit and modulation order is 2, a sequence of bits coded [ b (i) x]Scrambling is asWhereinWherein b (i) is a bit value, x is a placeholder, and c (i) is a scrambling sequence.

14. The apparatus of claim 10, wherein the size of the ACK transmission is 1 bit and modulation order is 4, a sequence of bits to be codedScrambling is asWhere b (i) is a bit value and x is a placeholder.

15. Apparatus according to claim 10Wherein the size of the ACK transmission is 1 bit and the modulation order is 6, encoding a sequence of bits [ b (i) x x x x x x x x]Scrambling is asWhere b (i) is a bit value and x is a placeholder.

16. The apparatus of claim 10, wherein the size of the ACK transmission is 2 bits and a modulation order of 2, a sequence of bits to be coded [ b (i) b (i +1) ]]Scrambling is asWhere b (i) and b (i +1) are bit values.

17. The apparatus of claim 10, wherein the size of the ACK transmission is 2 bits and modulation order is 4, a sequence of coded bits [ b (i) b (i +1) x x]Scrambling is asWhere b (i) and b (i +1) are bit values and x is a placeholder.

18. The apparatus of claim 10, wherein the size of the ACK transmission is 1 bit or 2 bits, and the modulation order is 2 for Quadrature Phase Shift Keying (QPSK), 4 for 16 Quadrature Amplitude Modulation (QAM), and 6 for 64 QAM.