HK1211392B - Scrambling and modulation to constrain the constellation size of ack/nak transmission - Google Patents

Description

Scrambling and modulation to constrain the constellation size of ACK/NAK transmissions

Information about divisional applications

This application is a divisional application of the invention patent application with application number 200980110293.6, which entered the Chinese national phase and has the international application date of March 26, 2009, the international application number of PCT/US2009/038370, and the invention name of “Scrambling and modulation for constellation size constellation for constraining ACK/NAK transmission on data channel”.

Cross Reference

This application claims the benefit of U.S. Provisional Application No. 61/039,724, filed on March 26, 2008, entitled “A METHOD AND APPARATUS FOR ACK TRANSMISSION IN A WIRELESS COMMUNICATION SYSTEM,” which is assigned to the assignee of this application and is incorporated herein by reference in its entirety.

Technical Field

The following description relates generally to wireless communications, and more particularly, to maximizing the Euclidean distance of coding, scrambling, and modulation of ACK/NAKs.

Background Art

Wireless communication systems are widely deployed to provide various types of communication content, such as voice, data, video, music, etc. 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, and orthogonal frequency division multiple access (OFDMA) systems, among others.

In general, 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 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.

As terminals or devices communicate with each other and send packets back and forth, the sending device needs to know whether a packet has been successfully received or whether it should be retransmitted. Therefore, the receiving device can send an acknowledgment (ACK) indicating that the packet was successfully received. If the packet was not successfully received, a negative acknowledgement (NAK) is sent. This NAK indicates that the packet should be retransmitted.

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. Packets received in error are discarded, and the receiving device requests retransmission of unsuccessfully received packets. HARQ protection is available for data; however, retransmissions of ACK/NAKs on the uplink do not have HARQ protection.

Summary of the Invention

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of the aspects. This summary is not an extensive overview of all aspects covered and is neither intended to identify important or critical elements of all aspects nor to 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.

Several aspects relate to improving the reliability of ACK transmissions on an uplink by selecting constellation points corresponding to edges of the constellation. One aspect relates to a method for maximizing the Euclidean distance of ACK/NAK transmissions. The method includes encoding an ACK transmission to obtain a bit sequence based on the size of the ACK and a modulation order. The ACK transmission is intended for at least one device. The method also includes combining two or more bit sequences based on the modulation order; and scrambling the combined bit sequence based on the size of the ACK transmission and the modulation order. The scrambling constellation constrains the size of the ACK transmission embedded in a data channel. Furthermore, the method includes sending the ACK transmission to the at least one device in response to receipt of a packet from the at least one device.

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

Yet another aspect relates to a communications device for improving the reliability of ACK transmissions on an uplink. The device includes means for encoding the ACK transmission with an escape sequence based on the size and modulation order of the ACK, and means for obtaining a bit sequence by concatenating multiple encoded ACK blocks. The device also includes means for scrambling the interleaved bit sequence based on the ACK size and modulation order to obtain a HARQ-ACK, and means for transmitting the HARQ-ACK.

Yet another aspect relates to a computer program product comprising a computer-readable medium. The computer-readable medium comprises a first set of codes for causing a computer to encode a 1-bit ACK, as distinct from a 2-bit ACK. The encoding is a function of a 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. The computer-readable medium further comprises: 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 a computer to transmit 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 the Euclidean distance of ACK/NAK transmissions. The processor includes a first module for encoding an ACK transmission based on the size and modulation order of the ACK to obtain a bit sequence. The ACK size is 1 bit or 2 bits. The processor also includes a second module for combining two or more bit sequences; and a third module for scrambling the combined bit sequence based on the size and modulation order of the ACK. The scrambling constellation constrains a 1-bit constellation size of the ACK embedded in the data channel to binary phase shift keying and a 2-bit constellation size to quadrature phase shift keying. Also included in the processor is a fourth module for transmitting the ACK.

To achieve the foregoing and related ends, one or more aspects include features that will be fully described below and particularly pointed out in the claims. The following description and drawings set forth in detail certain illustrative features of the one or more aspects. However, these features are indicative of only a few of the various ways in which the principles of the various aspects may be employed. Additional 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.

BRIEF DESCRIPTION OF THE DRAWINGS

1 illustrates a system for maximizing the Euclidean distance for coding, scrambling, and modulation of ACK/NAKs by selecting constellation points corresponding to the edges of the constellation.

2 illustrates modulation mapping according to an aspect.

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

4 illustrates a method for encoding and scrambling a one-bit HARQ-ACK, according to an aspect.

5 illustrates a method for scrambling a 1-bit HARQ-ACK according to an aspect.

6 illustrates a method for encoding and scrambling a two-bit HARQ-ACK, according to an aspect.

7 illustrates a method for scrambling a 2-bit HARQ-ACK according to an aspect.

8 illustrates an example system that utilizes coding, scrambling, and modulation to maximize Euclidean distance for ACK/NAKs according to an aspect.

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

10 is an illustration of a system that facilitates corners in any constellation diagram enabling transmission of ACKs in accordance with various aspects presented herein.

11 illustrates a multiple access wireless communication system according to one or more aspects.

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

DETAILED DESCRIPTION

Various aspects will now be 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. However, it will be apparent that the described aspects can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form to facilitate describing these aspects.

As used in this application, the terms "component," "module," "system," and the like are intended to refer to any computer-related entity: hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to, a process executing on a processor, 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 may 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 may be executed by various computer-readable media having various data structures stored thereon. The components may communicate via local and/or remote processes, for example, based on signals having one or more data packets (e.g., data from a component interacting with another component in a local system, a distributed system, and/or other systems across a network such as the Internet).

In addition, various aspects are described herein in conjunction with mobile devices. A mobile device may also be referred to as a system, a subscriber unit, a subscriber station, a mobile station, a mobile, a wireless terminal, a node, a device, a remote station, a remote terminal, an access terminal, a user terminal, a terminal, a wireless communication device, a wireless communication apparatus, a user agent, a user device, or a user equipment (UE), and may contain some or all of their functionality. A mobile device may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a smartphone, 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. In addition, various aspects are described herein in conjunction with a base station. A base station may be used to communicate with a wireless terminal and may also be referred to as an access point, a node, a Node B, an eNode B, an e-NB, or some other network entity, and may contain some or all of their functionality.

Various aspects or features will be presented in terms of systems that may include a number of devices, components, modules, etc. 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 this 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, the use of the word "exemplary" is intended to present concepts in a concrete manner.

Referring to FIG. 1 , a system 100 is illustrated for maximizing the Euclidean distance for decoding, scrambling, and modulation of ACK/NAKs by selecting constellation points corresponding to the edges of the constellation. System 100 is configured to help improve the reliability of ACK/NAK transmissions on the uplink by selecting constellation points corresponding to the edges of the constellation. For ACK/NAKs, regardless of the physical uplink shared channel (PUSCH) modulation scheme, the modulation symbols used for control signal transmissions carry one or two bits of decoded control information. System 100 utilizes escape sequences in the decoding of ACK/NAK information, which can be correctly interpreted. While various aspects will be described with reference to ACKs, these aspects are also applicable to NAK transmissions.

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

For the purposes of this embodiment, transmitter 102 has received a packet from receiver 104 and will send an acknowledgment (ACK) or a negative acknowledgement (NAK) to receiver 104 in response. An ACK contains an acknowledgement character indicating that the data received (from second device 104) was received correctly. A NAK indicates that the data was received in error and, therefore, the data (e.g., packet) should be retransmitted. For ACK/NAK, the encoding, scrambling, and modulation should maximize the Euclidean distance. For ACK/NAK (in the case of frequency division duplex (FDD)), the modulation symbols used for control signal transmission carry at most two bits of decoded control information, regardless of the physical uplink shared channel (PUSCH) modulation scheme.

To maximize the Euclidean distance, the encoder 106 may be configured to encode the ACK information based on the number of bits (e.g., 1 bit, 2 bits) and the modulation order _Qm . The modulation order _Qm may be an order of 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 16QAM. Higher-order modulation means that the modulation alphabet is expanded to include additional signal transmission alternatives, which allows more bits of information to be transmitted per modulation symbol. For QPSK, the modulation alphabet includes four different signal transmission alternatives. Expanding to 16QAM modulation provides sixteen different signal transmission alternatives. Further expansion to 64QAM provides the availability of sixty-four different signal transmission alternatives.

As previously described, encoder 106 is configured to encode the ACK information according to the number of bits and the modulation order Q _m . The following table (Table 1) illustrates the encoding of a 1-bit HARQ-ACK, where "x" represents an escape sequence, which is used to inform scrambler 110 that a specific 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 a coded bit sequence by concatenating multiple coded HARQ-ACK blocks, where Q _ACK is the total number of decoded bits for all coded HARQ-ACK blocks. These are derived as blocks because later in the coding chain, the blocks are input to the modulator. Therefore, QPSK modularity will use the concatenation of multiple coded HARQ-ACK blocks in sets of two. 16QAM modulation will use the concatenation of multiple coded HARQ-ACK blocks in sets of four. Furthermore, a 64QAM modulator will use the concatenation of multiple coded HARQ-ACK blocks in sets of six.

The vector sequence is outputted by representing the channel decoding for HARQ-ACK information, where Q′ _ACK =Q _ACK /Q _m . The vector sequence is obtained as follows:

Set i, k to 0

while i＜Q _ACK

i＝i+Q _m

k＝k+1

end while

The vector sequence is then multiplexed with the coded data and interleaved in a "time-first" manner by interleaver 108. The output of channel interleaver 108 is the input to the PUSCH processing. Scrambler 110 performs the following operations depending on whether the ACK is a 1-bit ACK or a 2-bit ACK and the modulation order (e.g., QPSK, 16QAM, 64QAM). Therefore, scrambling varies with the size and modulation order.

The scrambler 110 attempts to obtain two corners in any constellation for transmission of the ACK on the PUSCH (e.g., efficient binary phase shift keying (BPSK) modulation). Thus, for a 1-bit ACK with Q _M of 2 (QPSK), the decoded bit sequence [b(i)x] is scrambled as , where this scrambling may be performed according to the following pseudocode:

where x and y are tags, and where c(i) is the scrambling sequence. may be used to initialize the scrambling sequence generator 112 at the beginning of each subframe, where n _RNTI corresponds to the Radio Network Temporary Identifier (RNTI) associated with the PUSCH transmission.

For a 1-bit ACK with Q _M of 4 (16QAM), the decoded bit sequence [b(i)xxx] is scrambled as For a 1-bit ACK with Q _M of 6 (64QAM), the decoded bit sequence [b(i)xxxxx] is scrambled as

For a 2-bit ACK, the scrambler 110 attempts to obtain four corners in any constellation for transmission of the ACK on the PUSCH (e.g., valid QPSK modulation). Thus, for a 2-bit ACK with _Qm of 2 (QPSK), the decoded bit sequence [b(i)b(i+1)] is scrambled as If the ACK is 2 bits and _Qm is 4 (16QAM), the decoded bit sequence [b(i)b(i+1)xx] is scrambled as For a _Qm of 6 (64QAM) and 2 bits, the decoded bit sequence [b(i)b(i+1)xxxx] is scrambled as

As discussed above, during scrambling, " _1s " are appended. However, according to some aspects, instead of "1," another value is used, such as "2," a non-zero 1, or a non-binary 1. The remainder of the processing performed by transmitter 102 (e.g., modulation, transform precoder, etc.) is transparent to the presence or absence of control information. Signal generator 112 is configured to transmit an ACK/NAK to second device 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. The memory 114 may store information related to encoding a modulation order for an ACK transmission to obtain a coded HARQ-ACK block, concatenating two or more of the coded HARQ-ACK blocks to obtain a decoded bit sequence, scrambling the decoded bit sequence according to an ACK size and a modulation order, and transmitting the scrambled bit sequence, as well as 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 the Euclidean distance of ACK transmissions in the communication network. The processor 116 may be a processor dedicated to analyzing and/or generating information received by the first device 102, a processor that controls one or more components of the system 100, and/or a processor that both analyzes and generates information received by the first device 102 and controls one or more components of the system 100.

Memory 114 may store protocols associated with maximizing the Euclidean distance of ACK transmissions, taking actions to control communications between first device 102 and second device 104, and the like, so that system 100 can use the stored protocols and/or algorithms to implement improved communications in a wireless network, as described herein. It should be understood that the data storage (e.g., memory) components described herein may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. By way of example and not limitation, non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) acting as an external cache memory. By way of illustration and not limitation, RAM may come in 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). Memory of the disclosed aspects is intended to comprise, without being limited to, these and other suitable types of memory.

To better understand the disclosed aspects, FIG2 illustrates a modulation mapping according to one aspect. As illustrated, at 202 is a signal constellation diagram for QPSK modulation, which consists of four different signal transmission alternatives. To visualize these signal transmission alternatives, a two-dimensional plane is divided into four quadrants 204, 206, 208, and 210. Four points represent the four different alternatives, one point in each quadrant 204 through 210. QPSK allows up to two bits of information to be transmitted during each modulation symbol interval. For a single bit, the disclosed aspects implement two corners, specifically, the upper right corner (in quadrant 204) and the lower left corner (in quadrant 208), corresponding to "00" and "11."

At 212, a signal constellation diagram for 16QAM is illustrated. Extension to 16QAM modulation allows for the availability of sixteen different signal transmission alternatives. In the case of 16QAM, up to four bits of information can be transmitted during each modulation symbol interval, as illustrated by the points in each quadrant 214, 216, 218, and 220. In the case of 16QAM modulation, the quadruplet of bits b(i), b(i+1), b(i+2), b(i+3) is mapped to a complex-valued modulation symbol x=I+jQ according to the following table (Table 3):

Table 3

For 16QAM, the disclosed aspects attempt to achieve the four corners of the constellation. Thus, the modulation mapping for the upper right quadrant 214 is "0011." For the upper left quadrant 216, the modulation mapping is "1011." For the lower left quadrant 218, the modulation mapping is "1111," and for the lower right quadrant 220, the modulation mapping is "0111." The corners can be achieved by utilizing escape sequences 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 six bits of information can be conveyed in each modulation symbol interval. The constellation diagram for 64QAM is illustrated at 222. In the case of 64QAM modulation, the sextuplet 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 corners of the upper right quadrant 224 are "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 can maximize the Euclidean distance to obtain the four corners of the constellation 222.

FIG3 illustrates a system 300 for improving the reliability of ACK transmissions on the uplink by selecting constellation points corresponding to the edges of the constellation. System 300 can limit the maximum modulation order used to signal ACK/NAK on the PUSCH. Two devices, labeled transmitter 302 and receiver 304, are included in the system. Note that the terms "transmitter" and "receiver" are used for simplicity, and both devices 302 and 304 can transmit and receive communications.

Transmitter 302 includes an encoder 306 configured to encode 1-bit and 2-bit HARQ-ACKs according to the number of bits and the modulation order _Qm . Also included is an interleaver 308 configured to interleave the encoded data, for example, in a "time-first" manner. Also included in transmitter 302 is a scrambler 310 configured to scramble the ACKs, which are delivered to receiver 304 by signal generator 312.

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

For example, Table A 314 may include the following information: For 1 bit and Q _m of 2 (QPSK), the coded HARQ-ACK is "x" representing an escape sequence or placeholder that may be used to scramble the HARQ-ACK bits (via scrambler 310) in a manner that maximizes the Euclidean distance of the modulation symbols carrying the HARQ-ACK information. For Q _m of 4 (16QAM) and 1 bit, the coded HARQ-ACK is "x" including three escape sequences (or placeholders). For Q _m of 6 (64QAM) and 1 bit, the coded HARQ-ACK is "x" including five escape sequences (placeholders).

Table B 316 may provide encoding for a 2-bit HARQ-ACK with a Q _m of 2 (QPSK), the encoded HARQ-ACK is For 2 bits and a Q _m of 4 (16QAM), the encoded HARQ-ACK includes two escape sequences (or placeholders) and is expressed as Furthermore, for 2 bits and a Q _m of 6 (64QAM), the encoded HARQ-ACK includes four placeholders or escape sequences and is expressed as Thus, 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 B 316.

A concatenation 318 of multiple coded HARQ-ACK blocks is performed to obtain a bit sequence and a vector sequence. The vector sequence is multiplexed with the coded data and interleaved (by the interleaver 108) in a "time-first" manner. The scrambler 110 performs scrambling based on the ACK bit size (1-bit ACK 320 or 2-bit ACK 322) and the modulation order 324.

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

In view of the exemplary system shown and described above, reference to the following flow chart will better understand the methods that can be implemented according to the disclosed subject matter. Although the method is shown and described as a series of blocks for the purpose of simplicity of explanation, it should be understood and appreciated that the claimed subject matter is not limited to the number or order of blocks, because some blocks may occur in an order different from the order depicted and described herein and/or occur substantially simultaneously with other blocks. In addition, it may not be necessary for all illustrated blocks to implement the methods described herein. It should be understood that the functionality associated with the blocks can be implemented by software, hardware, a combination thereof, or any other suitable means (e.g., a device, system, process, component). In addition, it should be further understood that the methods disclosed below and throughout this specification can be stored on an article of manufacture to facilitate the transport and transmission of the methods to various devices. Those skilled in the art will understand and appreciate that the methods can alternatively be represented as a series of related states or events (e.g., in the form of a state diagram).

FIG4 illustrates a method 400 for encoding and scrambling a one-bit HARQ-ACK according to an aspect. The encoding and scrambling may be determined based on the number of bits and the modulation order. The modulation order _Qm may be 2 (QPSK), 4 (16QAM), or 6 (64QAM). At 402, if _Qm is 2, a HARQ-ACK block is derived by adding one escape sequence (or placeholder), and thus, the encoded HARQ-ACK is . Additionally, if _Qm is 4, a HARQ-ACK block is derived at 404 by adding three escape sequences (or placeholders). For _Qm 4, the encoded HARQ-ACK is . If _Qm is 6, a HARQ-ACK block is derived at 406 by adding five escape sequences (or placeholders), and the encoded HARQ-ACK is .

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

At 410, the bit sequence is scrambled. This scrambling may include copying the previously scrambled bits at 412, where the first escape sequence is the copied bits. At 414, a hint of the escape sequence (if present) is appended with "1s." Additional information related to scrambling will be discussed with reference to the following figure.

FIG5 illustrates a method 500 for scrambling a 1-bit HARQ-ACK according to an aspect. The 1-bit HARQ-ACK may be encoded as discussed with reference to FIG4 . The scrambling of the HARQ-ACK varies with the size of the ACK (e.g., 1 bit) and the modulation order (e.g., QPSK, 16QAM, 64QAM). At 502, if the modulation order _Qm is 2 (QPSK), the coded bit sequence [b(i)x] is scrambled as where Additionally, at 504, if the modulation order _Qm is 4 (16QAM), the coded bit sequence [b(i)xxx] is scrambled as Additionally, at 506, if _Qm is 6 (64QAM), the coded bit sequence [b(i)xxxxx] is scrambled as

6, a method 600 for encoding and scrambling a two-bit HARQ-ACK is illustrated according to one aspect. The encoding and scrambling may be determined based on the number of bits and the modulation order. The modulation order _Qm may be 2 (QPSK), 4 (16QAM), or 6 (64QAM).

At 602, if _Qm is 2 (QPSK), two coded bits are utilized. At 604, if _Qm is 4 (16QAM), two escape sequences are added, and the encoded HARQ-ACK block is. Additionally, at 606, if _Qm is 6 (64QAM), four escape sequences are added, and the HARQ-ACK block is.

At 608, a bit sequence is obtained by concatenating the plurality of encoded HARQ-ACK blocks, as determined at 602, 604, or 606. At 610, a scrambling process is performed on the bit sequence, which will now be described with reference to FIG. 7 , which illustrates a method 700 for scrambling a 2-bit HARQ-ACK according to one aspect. The scrambling is performed based on the number of bits (2 bits) and the modulation order (e.g., QPSK, 16QAM, 64QAM). The scrambling is performed to achieve four corners in any constellation for transmission of the ACK on the PUSCH (e.g., effective QPSK modulation).

At 702, if _Qm is 2 (QPSK), the decoded bit sequence [b(i)b(i+1)] is scrambled as . Additionally, at 704, if _Qm is 4 (64QAM), the decoded bit sequence [b(i)b(i+1)xx] is scrambled as . Additionally, if _Qm is 6 (64QAM), the decoded bit sequence [b(i)b(i+1)xx xx] is scrambled as

8 , an example system 800 is illustrated according to one aspect that utilizes coding, scrambling, and modulation to maximize the Euclidean distance of ACK/NAKs. System 800 can reside at least partially within a mobile device. It should 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 a combination thereof (e.g., firmware).

System 800 includes a logical grouping 802 of electrical components that can function independently or in conjunction. Logical grouping 802 can include an electrical component 804 for encoding an ACK transmission with an escape sequence depending on the size and modulation order of the HARQ-ACK. The size can be 1 or 2 bits, and the modulation order can be 2 (QPSK), 4 (16QAM), or 6 (64QAM).

Also included in logical grouping 802 is an electrical component 806 for obtaining a bit sequence by concatenating multiple encoded ACK blocks, and an electrical component 808 for scrambling the interleaved bit sequence based on the ACK size and the modulation order. The scrambling constellation ...

According to some aspects, the ACK transmission has a size of 1 bit and a modulation order of 2, and the decoded bit sequence [b(i)x] is scrambled as wherein According to another aspect, the ACK transmission has a size of 1 bit and a modulation order of 4, and the decoded bit sequence [b(i)x x x] is scrambled as According to another aspect, the ACK transmission has a size of 1 bit and a modulation order of 6, and the decoded bit sequence [b(i)x x x x x] is scrambled as According to another aspect, the ACK transmission has a size of 2 bits and a modulation order of 2, and the decoded bit sequence [b(i)b(i+1)] is scrambled as In yet another aspect, the ACK transmission has a size of 2 bits and a modulation order of 4, and the decoded bit sequence [b(i)b(i+1)x x] is scrambled as According to another aspect, the ACK transmission has a size of 2 bits and a modulation order of 6, and the decoded bit sequence [b(i)b(i+1)x x x x] is scrambled as

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. Although electrical components 804, 806, 808, and 810 are shown as being external to memory 812, it is understood that one or more of electrical components 804, 806, 808, and 810 can reside within memory 812.

9 , a system 900 is illustrated that facilitates maximizing the Euclidean distance of ACK/NAKs according to one or more of the disclosed aspects. System 900 may reside in a user device. System 900 includes a receiver 902 that may receive a signal from, for example, a receiver antenna. Receiver 902 may perform typical actions on the received signal, such as filtering, amplifying, and downconverting the received signal. Receiver 902 may also digitize the conditioned signal to obtain samples. A demodulator 904 may obtain received symbols in each symbol period and provide the 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 transmitter 908. Additionally or alternatively, processor 906 can 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 can include a controller component capable of coordinating communications with additional user devices.

The user device 900 may further include a memory 908 operatively coupled to the processor 906 and capable of storing information related to coordinated communications and any other suitable information. The memory 910 may further store a protocol associated with maximizing the Euclidean distance. The user device 900 may further include a symbol modulator 912 and a transmitter 908 that transmits the modulated signal.

FIG10 is an illustration of a system 1000 that facilitates achieving corners in any constellation diagram for transmission of ACKs in accordance with various aspects presented herein. The system 1000 includes a base station or access point 1002. As illustrated, the base station 1002 receives signals from one or more communication devices 1004 (e.g., user devices) via receive antennas 1006 and transmits to the one or more communication devices 1004 via transmit antennas 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 the received information. The demodulated symbols are analyzed by a processor 1014 that is coupled to a memory 1016 that stores information related to maximizing the Euclidean distance. A modulator 1018 may multiplex the signals for transmission by a transmitter 1020 to the communication device 1004 via the transmit antennas 1008.

Referring now to FIG. 11 , a multiple-access wireless communication system 1100 is illustrated in accordance with one or more aspects. Wireless communication system 1100 may include one or more base stations in communication with one or more user devices. Each base station provides coverage for multiple sectors. A three-sector base station 1102 is illustrated, comprising multiple antenna groups, one antenna group comprising antennas 1104 and 1106, another antenna group comprising antennas 1108 and 1110, and a third antenna group comprising antennas 1112 and 1114. The figure shows only two antennas for each antenna group, however, more or fewer antennas may be used for each antenna group. A mobile device 1116 communicates with antennas 1112 and 1114, where antennas 1112 and 1114 transmit information to mobile device 1116 via a forward link 1118 and receive information from mobile device 1116 via a reverse link 1120. The forward link (or downlink) refers to the communication link from the base station to the mobile device, and the reverse link (or uplink) refers to the communication link from the mobile device to the base station. Mobile device 1122 communicates with antennas 1104 and 1106, where antennas 1104 and 1106 transmit information to mobile device 1122 via forward link 1124 and receive information from mobile device 1122 via reverse link 1126. In an FDD system, for example, communication links 1118, 1120, 1124, and 1126 can utilize different frequencies for communication. For example, forward link 1118 can use a different frequency than that used 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, each antenna group is designed to communicate to mobile devices in the sector or area covered by base station 1102. A base station can be a fixed station used for communicating with terminals.

In communications via forward links 1118 and 1124, the transmit antennas of base station 1102 may utilize beamforming in order to improve the signal-to-noise ratio of the forward links for the different mobile devices 1116 and 1122. Furthermore, a base station that utilizes beamforming to transmit to mobile devices randomly dispersed throughout its coverage area may cause less interference to mobile devices in neighboring cells than a base station that transmits to all mobile devices in its coverage area via a single antenna.

FIG12 illustrates an exemplary wireless communication system 1200 according to various aspects. For simplicity, wireless communication system 1200 depicts one base station and one terminal. However, it should be appreciated that system 1200 may include more than one base station or access point and/or more than one terminal or user device, wherein the additional base stations and/or terminals may be substantially similar to or different from the exemplary base stations and terminals described below. Furthermore, it should be appreciated that the base stations and/or terminals may employ the systems and/or methods described herein to facilitate wireless communication therebetween.

12 , on the downlink, at access point 1205, a transmit (TX) data processor 1210 receives, formats, decodes, 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. The symbol modulator 1215 multiplexes the 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. 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 the symbol stream and converts it 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 via a wireless channel. The downlink signal is then transmitted to the terminal via antenna 1225. At terminal 1230, antenna 1235 receives the downlink signal and provides the 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. The symbol demodulator 1245 further receives the frequency response estimate for the downlink from the 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 the RX data processor 1255, which demodulates (i.e., symbol demaps), deinterleaves, and decodes the data symbol estimates to recover the transmitted traffic data. The processing performed by the symbol demodulator 1245 and the RX data processor 1255 are complementary to the processing performed by the symbol modulator 1215 and the TX data processor 1210, respectively, at the 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 with pilot symbols, performs modulation, and provides a symbol stream. A transmitter unit 1270 then receives and processes the symbol stream to generate an uplink signal, which is transmitted by antenna 1235 to access point 1205.

At access point 1205, an uplink signal from terminal 1230 is received by antenna 1225 and processed by 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, ...) 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 multiple access systems (e.g., FDMA, OFDMA, CDMA, TDMA, etc.), multiple terminals can transmit simultaneously on the uplink. For such systems, pilot subbands can be shared among different terminals. Channel estimation techniques can be used in situations where the pilot subband for each terminal spans the entire operating band (possibly except for the band edges). The pilot subband structure will be required to obtain frequency diversity for each terminal. The techniques described herein can be implemented by various means. For example, these techniques can be implemented in hardware, software, or a combination thereof. For hardware implementations, the processing unit for channel estimation can be implemented in 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 can be by modules (e.g., procedures, functions, etc.) that perform the functions described herein. The software code can be stored in a memory unit and executed by processors 1290 and 1250.

It should be understood that the aspects described herein can be implemented by hardware, software, firmware, or any combination thereof. When implemented in software, the functions can be stored on a computer-readable medium or transmitted via a computer-readable medium as one or more instructions or codes. Computer-readable media include both computer storage media and communication media (including any media that facilitates the transfer of a computer program from one location to another). Storage media can be any available media that can be accessed by a general-purpose or special-purpose computer. In a non-limiting example, the computer-readable medium can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage devices, magnetic disk storage devices or other magnetic storage devices, or any other media that can be used to carry or store desired program code devices in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer. Moreover, any connection can be appropriately referred to as 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 within the definition of medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc. Disks typically 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 logic, logic blocks, modules, and circuits described in conjunction with the aspects disclosed herein may be implemented or performed using 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. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a combination of multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration. In addition, at least one processor may include one or more modules operable to perform one or more of the steps and/or actions described above.

For software implementation, the techniques described herein can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described herein. The software code can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or external to the processor, in which case the memory unit can be communicatively coupled to the processor via various means as known in the art. In addition, at least one processor can include one or more modules operable to perform the functions described herein.

The techniques described herein may be used in 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 radio technologies such as Universal Terrestrial Radio Access (UTRA) and CDMA2000. UTRA includes Wideband CDMA (W-CDMA) and other CDMA variants. In addition, CDMA2000 covers the IS-2000, IS-95, and IS-856 standards. A TDMA system may implement radio technologies such as Global System for Mobile Communications (GSM). An OFDMA system may implement radio technologies such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-Telecom, and others. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) is a release of UMTS that uses E-UTRA, which employs OFDMA on the downlink and SC-FDMA on the uplink. UTRA, E-UTRA, UMTS, LTE, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). Additionally, CDMA2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). Furthermore, the wireless communication systems may additionally include peer-to-peer (e.g., mobile-to-mobile) ad hoc network systems, which often use unpaired unlicensed spectrum, 802.xx wireless LAN, Bluetooth, and any other short-range or long-range wireless communication technology.

In addition, the various aspects or features described herein can be implemented as methods, devices, or articles of manufacture using standard programming and/or engineering techniques. As used herein, the term "article of manufacture" is intended to encompass a computer program that can be accessed from any computer-readable device, carrier, or medium. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic tapes, etc.), optical disks (e.g., compact disks (CDs), digital versatile disks (DVDs), etc.), smart cards, and flash memory devices (e.g., EPROMs, cards, sticks, key drives, etc.). In addition, the various storage media described herein may represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and/or carrying instructions and/or data. In addition, a computer program product may include a computer-readable medium having one or more instructions or codes operable to cause a computer to perform the functions described herein.

Furthermore, the steps and/or actions of the methods or algorithms described in conjunction 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. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a 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 so that the processor can read information from and write information to the storage medium. In an alternative, the storage medium may be integral to the processor. Furthermore, in some aspects, the processor and storage medium may reside in an ASIC. Alternatively, the ASIC may reside in a user terminal. In an alternative, the processor and storage medium may reside in a user terminal as discrete components. Furthermore, in some aspects, the steps and/or actions of the methods or algorithms may reside as one or any combination or set of code and/or instructions on a machine-readable medium and/or computer-readable medium, which may be incorporated into a computer program product.

Although the foregoing disclosure discusses illustrative aspects and/or aspects, it should be noted that various changes and modifications may be made herein without departing from the scope of the described aspects and/or aspects as defined by the appended claims. Therefore, the described aspects are intended to encompass all such changes, modifications, and variations that are within the scope of the appended claims. Furthermore, although the elements of the described aspects and/or aspects may be described or claimed in the singular, the plural is also encompassed unless expressly specified to be limited to the singular. Additionally, unless otherwise specified, all or a portion of any aspect and/or aspect may be utilized together with all or a portion of any other aspect and/or aspect.

To the extent the term "comprising" is used in the detailed description or the claims, the term is intended to be inclusive in a manner similar to the way the term "including" is interpreted when "comprising" is used as a transitional word in the claims. Furthermore, the term "or," as used in the detailed description or the claims, is intended to mean an inclusive "or" rather than an exclusive "or." That is, unless specified otherwise or clear from the context, the phrase "X employs A or B" is intended to refer to any of the natural inclusive permutations. That is, the phrase "X employs A or B" is satisfied by any of the following examples: X employs A; X employs B; or X employs both A and B. Additionally, 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 the context to be directed to the singular.

Claims (22)

1. A method for facilitating the maximization of Euclidean distance for ACK/NAK transmissions on an uplink by selecting constellation point corresponding to the edge of the constellation diagram, comprising: The packets will be transmitted to at least one device; Responding to the packet, an ACK/NAK transmission is received from the at least one device, wherein the ACK/NAK transmission is encoded according to the size of the ACK/NAK transmission (in bits) and the modulation order to obtain a bit sequence, the bit sequence being scrambled based on the size of the ACK/NAK transmission and the modulation order to constrain the constellation size of the ACK/NAK transmission embedded in the data channel according to the size of the ACK/NAK transmission, and the size of the ACK/NAK transmission is smaller than the modulation order; and The received ACK/NAK transmission is decoded to determine whether the packet should be retransmitted to the at least one device. 2. The method of claim 1, wherein the bit sequence is scrambled to constrain the constellation size to binary phase shift keying (BPSK) for a 1-bit ACK/NAK transmission. 3. The method of claim 1, wherein the bit sequence is scrambled to constrain the constellation size to quadrature phase shift keying (QPSK) for 2-bit ACK/NAK transmissions. 4. The method according to claim 1, wherein the ACK/NAK transmission is of size 1 bit and the modulation order is 2, and the decoded bit sequence [b(i) x] is scrambled to a sequence where b(i) is a bit value, x is a placeholder, and c(i) is a scrambling sequence. 5. The method according to claim 1, wherein the ACK/NAK transmission is of size 1 bit and the modulation order is 4, and the decoded bit sequence [b(i) x x x] is scrambled to a sequence where b(i) is a bit value, x is a placeholder, and c(i) is a scrambling sequence. 6. The method according to claim 1, wherein the ACK/NAK transmission is of size 1 bit and the modulation order is 6, and the decoded bit sequence [b(i) x x x x x] is scrambled to a sequence where b(i) is a bit value, x is a placeholder, and c(i) is a scrambling sequence. 7. The method according to claim 1, wherein the ACK/NAK transmission is 2 bits in size and the modulation order is 2, and the decoded bit sequence [b(i) b(i+1)] is scrambled to a scrambled sequence [b(i) b(i+1)] where b(i) and b(i+1) are bit values and c(i) and c(i+1) are scrambled sequences. 8. The method according to claim 1, wherein the ACK/NAK transmission is 2 bits in size and the modulation order is 4, and the decoded bit sequence [b(i) b(i+1) x x] is scrambled to a sequence where b(i) and b(i+1) are bit values, x is a placeholder, and c(i) and c(i+1) are scrambling sequences. 9. The method according to claim 1, wherein the ACK/NAK transmission is 2 bits in size and the modulation order is 6, and the decoded bit sequence [b(i) b(i+1) x x x x] is scrambled to a sequence where b(i) and b(i+1) are bit values, x is a placeholder, and c(i) and c(i+1) are scrambling sequences. 10. A communication device for facilitating the maximization of Euclidean distance for ACK/NAK transmissions on an uplink by selecting constellation point corresponding to the edge of the constellation diagram, comprising: Memory that holds instructions related to the following operations: The packets will be transmitted to at least one device; Responding to the packet, an ACK/NAK transmission is received from the at least one device, wherein the ACK/NAK transmission is encoded according to the size of the ACK/NAK transmission (in bits) and the modulation order to obtain a bit sequence, the bit sequence being scrambled based on the size of the ACK/NAK transmission and the modulation order to constrain the constellation size of the ACK/NAK transmission embedded in the data channel according to the size of the ACK/NAK transmission, and the size of the ACK/NAK transmission is smaller than the modulation order; and The received ACK/NAK transmission is decoded to determine whether the packet should be retransmitted to the at least one device; A processor coupled to the memory, the processor being configured to execute the instructions stored in the memory. 11. The communication device of claim 10, wherein the bit sequence is scrambled to constrain the constellation diagram size to binary phase shift keying (BPSK) for a 1-bit ACK/NAK transmission, and to obtain any two corners of the constellation diagram for a 1-bit ACK/NAK transmission. 12. The communication device of claim 10, wherein the bit sequence is scrambled to constrain the constellation diagram size to orthogonal phase shift keying (QPSK) for 2-bit ACK/NAK transmissions, and any four corners of the constellation diagram are obtained for 2-bit ACK/NAK transmissions. 13. The communication device of claim 10, wherein the modulation order is 2 for quadrature phase shift keying (QPSK), 4 for quadrature amplitude modulation (QAM), and 6 for 64QAM. 14. A communication device for facilitating the maximization of Euclidean distance for ACK/NAK transmissions on an uplink by selecting constellation point corresponding to the edge of the constellation diagram, comprising: A means for transmitting packets to at least one device; Means for receiving ACK/NAK transmissions from the at least one device in response to the packet, wherein the ACK/NAK transmissions are encoded according to a size and modulation order of the ACK/NAK transmissions, expressed in bits, to obtain a bit sequence, the bit sequence being scrambled based on the size and modulation order of the ACK/NAK transmissions to constrain the constellation size of the ACK/NAK transmissions embedded in the data channel according to the size of the ACK/NAK transmissions, and the size of the ACK/NAK transmissions is less than the modulation order; and A means for decoding received ACK/NAK transmissions to determine whether to retransmit the packet to the at least one device. 15. The communication device of claim 14, wherein the modulation order is 2 for quadrature phase shift keying (QPSK), 4 for quadrature amplitude modulation (QAM), and 6 for 64QAM. 16. The communication device of claim 14, wherein the bit sequence is scrambled to constrain the constellation diagram size to binary phase shift keying (BPSK) for a 1-bit ACK/NAK transmission, and to obtain any two corners of the constellation diagram for a 1-bit ACK/NAK transmission. 17. The communication device of claim 14, wherein the bit sequence is scrambled to constrain the constellation diagram size to orthogonal phase shift keying (QPSK) for 2-bit ACK/NAK transmissions, and to obtain any four corners of the constellation diagram for 2-bit ACK/NAK transmissions. 18. An apparatus for facilitating the maximization of Euclidean distance for ACK/NAK transmissions on an uplink by selecting constellation point corresponding to the edge of the constellation diagram, comprising: At least one processor configured to: The packets will be transmitted to at least one device; Responding to the packet, an ACK/NAK transmission is received from the at least one device, wherein the ACK/NAK transmission is encoded according to the size of the ACK/NAK transmission (in bits) and the modulation order to obtain a bit sequence, the bit sequence being scrambled based on the size of the ACK/NAK transmission and the modulation order to constrain the constellation size of the ACK/NAK transmission embedded in the data channel according to the size of the ACK/NAK transmission, and the size of the ACK/NAK transmission is smaller than the modulation order; and The received ACK/NAK transmission is decoded to determine whether the packet should be retransmitted to the at least one device. 19. The apparatus of claim 18, wherein the modulation order is 2 for quadrature phase shift keying (QPSK), 4 for quadrature amplitude modulation (QAM), and 6 for 64QAM. 20. The device of claim 18, wherein the bit sequence is scrambled to constrain the constellation size to binary phase shift keying (BPSK) for a 1-bit ACK/NAK transmission, and to obtain any two corners of the constellation for a 1-bit ACK/NAK transmission. 21. The device of claim 18, wherein the bit sequence is scrambled to constrain the constellation diagram size to quadrature phase shift keying (QPSK) for 2-bit ACK/NAK transmissions, and to obtain any four corners of the constellation diagram for 2-bit ACK/NAK transmissions. 22. A non-volatile computer-readable medium for maximizing the Euclidean distance of ACK/NAK transmissions on an uplink by selecting constellation point corresponding to the edge of the constellation diagram, comprising a plurality of codes for causing a computer to perform the following operations: The packets will be transmitted to at least one device; Responding to the packet, an ACK/NAK transmission is received from the at least one device, wherein the ACK/NAK transmission is encoded according to the size of the ACK/NAK transmission (in bits) and the modulation order to obtain a bit sequence, the bit sequence being scrambled based on the size of the ACK/NAK transmission and the modulation order to constrain the constellation size of the ACK/NAK transmission embedded in the data channel according to the size of the ACK/NAK transmission, and the size of the ACK/NAK transmission is smaller than the modulation order; and The received ACK/NAK transmission is decoded to determine whether the packet should be retransmitted to the at least one device.