MXPA05008889A - Efficient automatic repeat request methods and apparatus - Google Patents

Abstract

Different NAK signals are used to indicate different relative levels of success in regard toan unsuccessful attempt to decode a received signal. An ACK signal is used in the case of successful decoding. The device which generated and transmitted the original encoded signal receives the NAK signal and selects a portion of redundant information, e.g., additional error correction bits, to be transmitted based on the value of the NAK signal. If the NAK signal indicates a low level of decoding success indicating a relatively large number of errors in the decoded signal, a large set of redundant information is selected and transmitted. If the NAK signal indicates a relatively successful decoding, e.g., relatively few errors, a small set of redundant information is selected and transmitted. Where a small set of redundant information is transmitted new information can be transmitted with the redundant information.

Description

METHODS AND APPARATUS FOR REQUESTING EFFICIENT AUTOMATIC REPETITION Field of the Invention The present invention is directed to improved communication methods in a wireless communication system, and more specifically, to improved automatic repeat request methods in a multiple access wireless communication system.

Antecedents of the Invention Cellular communication systems are becoming more common. In cellular systems, a communication area is divided into a plurality of cells. Each cell normally includes at least one base station. The base station in each cell communicates with a plurality of devices, for example, mobile terminals, located within the same cell as the base station. The base station normally serves as a point of attachment of the mobile terminal to a communication network that includes the base station. Since access to the communication network is obtained through a mobile terminal, through the base station to which it is coupled, for example, through a wireless link, the base stations are sometimes known as access nodes.

In cellular wireless data communication systems, data is often transported between a base station and a mobile terminal through a quantum of resources called a traffic segment. In such systems, the available resource for the communication of data in a cell, for example, a traffic channel, is often divided into multiple segments of traffic. The control information can be transmitted through other channels, for example, recognition channels. The downlink traffic segments transport data traffic from a base station to one or more wireless terminals, while the uplink traffic segments transport data traffic from one or more wireless terminals to a base station. The recognition channels include recognition segments that can be used to indicate whether or not the information found in one or more corresponding traffic segments was received successfully. An uplink recognition channel can be used through a mobile apparatus to signal the information transmitted by the base station that was received successfully, for example, which could be 'decoded by the mobile terminal. This can be achieved by sending a Recognition (Ack) on a segment of the uplink recognition channel. Failure to successfully receive information can be communicated by sending a negative acknowledgment (NAK) instead of an ACK. The ACK and the NAK can be represented using a single bit, for example, a 1 representing an ACK and a 0 representing a NAK. A downlink recognition channel can be used through a base station to indicate whether the information transmitted by the mobile in an uplink traffic channel was received successfully, for example, it could be decoded by the base station in the same way that the uplink recognition channel is used through the mobile terminals. The transmitter, for example the base station or mobile terminal, upon receiving a NAK, may choose to transmit the same data again. The retransmission of previously transmitted information represents the transmission of redundant information. Although transmission can lead to improved transmission success, it can be a relatively expensive process since the transmission resources are consumed by the need to transmit the same data several times. The selective retransmission process can also lead to delays to achieve a successful transmission result. The mechanism through which a determination is made whether redundant information, for example, information previously transmitted, needs to be transmitted or not, is sometimes called an automatic repetition request mechanism (ARQ). In order to increase the resilience of error and reduce the need for data retransmission, an error correction coding can be used. The error correction codes (ECCs) result in the addition of redundant information, for example, one or more ECCs, which are aggregated in a selective manner to the transmitted information. By using redundant information, it may be possible to retrieve the transmitted information even when some errors occur during the transmission process. In order to provide efficient utilization of the communication bandwidth, it is generally desirable to minimize the amount of redundant information, for example, error correction codes, transmitted along with the information that will be communicated. As a result, even when error correction coding techniques are used, as a result of transmission errors, the need for an ARQ mechanism still remains. By virtue of the above description, it should be appreciated that ARQ mechanisms and methods are needed and recommended to communicate redundant information and increase the existing use of limited amounts of available bandwidth for data communication.

SUMMARY OF THE INVENTION The methods and apparatus of the present invention are directed to techniques that can be used in combination with error correction codes, to minimize the amount of redundant information that needs to be retransmitted, for example, in the case of errors in the communication. The present invention is also directed to new and novel automatic repetition requisition (ARQ) mechanisms and to methods for implementing said mechanisms. Improved ARQ mechanisms which can be used with Low Density Parity Check Codes (LDPCs), which differ from, and offer various advantages over, other well-known error correction codes including Reed-Solomon codes are describe and are used in several of the modalities. The methods and apparatus of the present invention utilize NAK (negative recognition) signals that are transmitted to indicate a transmission failure, for example, non-correctable errors in a decoded signal and / or an unsatisfactory level of reliability with respect to the decoded information. . An unsatisfactory level of reliability can be determined from one or more reliability statistics maintained by a decoder, for example, a count of non-correctable error values and / or temporary information. In cases where decoding is successful, a recognition signal (ack) is transmitted to the apparatus from which the decoded signal was successfully received. In accordance with the present invention, the NAK signals can assume any of a plurality of values, for example, values in a group of previously selected values or a value in a range of continuous values. The value of a NAK signal is used to convey useful information to determine the amount of redundant information that must be transmitted to facilitate the decoding of the information signal transmitted in original form. The signal value NAK can be determined, according to the present invention, based on error statistics of the decoder, for example, a count of errors detected in a decoded signal or other information, such as temporal information values indicating the reliability of the decoded values generated from the transmitted signal, as part of a decoding process. These statistics provide a measure of the success of the decoding, for example, between fewer non-recoverable errors, the success of decoding is greater, than when there is a greater number of unrecoverable errors. Since the decoding error ranges are a function of the quality of the received coded signal, the NAK signal values generated in accordance with the present invention indicate the received coded signal quality. As part of the coding process used in various embodiments of the present invention, an encoded information signal is generated together with a group of redundant information, for example, additional error correction bits that do not need to be transmitted with the encoded information signal original. In some cases, the original encoded information signal includes some error correction bits, although this number is usually much smaller, for example, less than half, of the number of error correction bits included in the redundant information group which was not transmitted with the encoded information signal. The redundant information is stored for a period of time after the transmission of the encoded information signal, for example, in the case where a NAK is received. In the case where an ACK is received, the redundant information bits can usually and are discarded without being transmitted.

The apparatus that transmits the original encoded information signal determined from the value of a received NAK signal, the amount of redundant information that must be transmitted to facilitate the decoding of the original information signal. Different amounts of redundant information will normally be selected for different NAK signal values. This provides an efficient repetition mechanism which avoids the need to see a fixed amount of redundant information, regardless of the quality of the received signal which could not be decoded. By varying the amount of redundant information to reflect the relative level of decoding success, transmission efficiencies can be achieved without the need, in most cases, to retransmit the entire original signal. In some cases, for example, when a continuous range of NAK signal values is supported, the granularity of the transmitted NAK signals may be finer than the granularity at which different amounts of redundant information are selected for transmission. Accordingly, in such cases the multiple NAK signal values may correspond to the same size part of the redundant information, although at least some NAK signal values will correspond to different size portions of the redundant information.

The selected part of redundant information is transmitted after receiving a NAK signal. The apparatus that receives the redundant information uses it in combination with the information obtained from the original received signal in an attempt to successfully decode the previously received signal. Successful decoding of the previously received signal through the use of redundant information results in an ACK that is transmitted in response to the reception of the redundant information. However, if the device receiving the redundant information does not yet have the capacity to successfully decode received information, a NAK is transmitted in response to the reception of the redundant information. The value of the NAK is selected to indicate the current decoding success level. Therefore, the NAK transmitted in response to the reception of redundant information will normally have a different value to the NAK transmitted in response to the original received signal due to a higher level of decoding success achieved through the use of the redundant information. In various modalities, information signals are transmitted using traffic channel segments. Each traffic channel segment has a fixed data capacity. In case where the redundant information transmitted in response to a NAK does not require the full capacity of the channel segment that is being used to communicate the redundant information, the additional information projected for the apparatus to which the redundant information is directed may be included in the signal that is used to communicate the redundant information. In some embodiments, the allocation information, which indicates the allocation of a traffic channel segment to be used by a particular device, is transmitted in an assignment message. The assignment messages according to the present invention may include information indicating whether the corresponding traffic segment will be used to communicate new information or redundant information. In the case where the redundant information will be communicated, the assignment message may also include sufficient information to identify the previously transmitted signal to which the redundant information that will be transmitted will correspond. This information may, for example, be information that identifies the previous traffic channel segment in which the original encoded information to which the redundant information corresponds. The multi-level NAK and the retransmission methods of the present invention are well suited for a wide range of coding and transmission methods. The Low Density Parity Check coding methods are particularly well adapted to be used in accordance with the present invention, since said coding methods allow the generation of redundant information at the time of coding which can be used to increase the opportunities for coding. successful decoding and / or the reliability of decoded information, but, assuming no transmission errors, which need not be used to achieve successful decoding. The LDPC decoding methods also have the advantage of providing useful decoding statistics, which can and are used in various modes, to measure the level of decoding success. Although allocation messages and LDPC decoding techniques are used in various embodiments of the present invention, it should be appreciated that the multi-level NAK methods of the present invention and the selection of different amounts of redundant information to transmit in response to a NAK signal, are well suited for a wide range of applications which do not use allocation messages or LDPC codes. Numerous additional features, benefits and embodiments of the present invention will be described in the detailed description which follows.

Brief Description of the Figures Figure 1 illustrates an exemplary communication system implemented in accordance with, and using the methods of the present invention. Figure 2 is an illustration of an exemplary base station implemented in accordance with the present invention. Figure 3 is an illustration of an exemplary wireless terminal implemented in accordance with the present invention. Fig. 4 is a drawing including diagrams illustrating exemplary downlink and example downlink channels and used to illustrate an example method for assigning traffic channel segments according to the present invention. Figure 5 illustrates an example for using redundant incremental codes, for example, redundant LDPC codes, according to the present invention. Figure 6 is a diagram illustrating the time and Segment Index windows within the time window, according to the present invention. Figure 7 illustrates an example assignment message structure, and provides an example for using incremental redundant codes, for example, incremental redundant LDPC codes, according to the present invention. Figures 8 and 12 illustrate examples of using incremental redundant codes and using a multi-level NAK signal, according to the present invention. Figure 9 is a drawing illustrating an example representation of the codeword phase of a recognition signal including an ACK and a NAK of three example levels, according to the present invention. Figure 10 is a drawing illustrating an exemplary representation of the codeword phase of a recognition signal that includes an ACK and a continuous range of NAK and as an example NAK is mapped to a required range of bits , according to the present invention. Figure 11, which comprises the combination of Figures 11A-11D, illustrates the steps that are carried out according to an example mode in which they are used Multiple level NAKs according to the present invention.

Detailed Description of the Invention The method and apparatus of the present invention are well suited for cellular communication systems, although they are not limited in terms of applicability to said systems. The cellular systems in which the present invention can be used normally include multiple cells, wherein each cell includes at least one base station and a plurality of wireless terminals, for example, mobile nodes. Figure 1 illustrates an exemplary wireless communication system 100 implemented in accordance with, and utilizing the methods of the present invention. The exemplary wireless communication system 100 supports the efficient automatic repetition (ARQ) requests according to the present invention. The example wireless communication system 100 is an OFDM multiple access system of dispersion spectrum (orthogonal frequency division multiplexing). Although the exemplary OFDM wireless communication system is used in this application for purposes of explaining the present invention, the present invention is not broader in scope than said example, and the present invention can be applied to many other communication systems, for example , a CDMA wireless communication system. The system 100 includes a plurality of cells: cell 1 102, cell M 104. Each cell (cell 1 102, cell M 104) includes a base station (BS), (BS 1 106, BS M 108), respectively and represents the wireless coverage area of the base station. BS 1 106 is coupled to a plurality of end nodes, (EN (1) 110, EN (X) 112) via wireless links (114, 116), respectively. The BS M 108 is coupled to a plurality of end nodes (EN (lf) 118, EN (X ') 120) via wireless links (122, 124), respectively. The end nodes 110, 112, 118, 120 can be mobile and / or stationary wireless communication devices and are referred to as wireless terminals (WTs). Mobile WTs are sometimes referred to as mobile nodes (MNs). The MNs can be moved through the system 100. The BS 1 106 and BS M 108 are coupled to network node 126 through network links 128, 130, respectively. The network node 126 is coupled to other network nodes and to the Internet via the network link 132. The network links 128, 130, 132 may be, for example, fiber optic cables. Figure 2 is an illustration of an exemplary base station 200 implemented in accordance with the present invention. The example base station 200 may be a more detailed representation of any of the base stations 106, 108 of FIG. 1. The base station 200 includes a receiver 202, a transmitter 204, a processor 206, an interface and / or 208 and a memory 210 coupled together via the bus 212 through which the various elements can exchange data and information. The receiver 202 includes a decoder 214 and a generation module NAK 218. The decoder 214 includes a demodulator 216 and a quality determination module 217. The receiver 202 is coupled to an antenna 220 through which the BS 200 can receive signals, for example, uplink signals of the WTs 300 (see Figure 3), including the signals of the recognition channel and the signals of the uplink traffic channels that include data. The decoder 214, for example an LDPC decoder performs decoding operations of the received signals, according to the present invention. The demodulator 216 carries out demodulation operations on signals received in accordance with the present invention. The quality determination module 217 generates and maintains decoding statistical information indicating the quality of the decoded signal, for example, a count measurement, number and / or level of detected errors and / or statistics on the reliability of the decoded signal. , such as temporary information values. The generation module NAK 218 generates a NAK, according to the present invention, when a received signal, for example, received data, can not be decoded successfully. The receiver 202 is coupled to the transmitter 204 through the link 222, through which a NAK generated for subsequent transmission through the transmitter 204 can be communicated to a WT 300. The transmitter 204 includes an encoder 224. The encoder 224, for For example, an LDPC encoder includes a modulator 226, a recognition signal processing module 228 and a transmission control module 230. The operations of the encoder 224 include information bit coding blocks in coded bit blocks. The modulator 226 modulates information in signals, for example, downlink information signals, downlink traffic signals and recognition signals. The transmitter 204 is coupled to the antenna 232, through which downlink signals can be transmitted to the WTs 300. The recognition signal processing module 228 processes recognition signal information, for example, a NAK signal. received from a WT 300 corresponding to a previous downlink traffic channel transmission which was not decoded successfully by the WT 300. Such processing may include obtaining a received NAK level, in accordance with the present invention. The retransmission control module 230 controls the transmission of redundant information, eg, redundant bit blocks, to the WT 300, according to the present invention. The retransmission control module 230 can carry out the control in response to the information from the recognition signal processing module 228. The retransmission control can include controlling the number and / or size of the redundant block that will be transmitted, controlling if it transmits the block of information bits and / or control if it aborts the additional transmissions related to a coded block. The memory 210 includes routines 234 and data / information 236. The processor 206, for example, a CPU, executes the routines 234 and uses the data / information 236 in the memory 210, to control the operation of the base station 200 and increase the methods of the present invention. The I / O interface 208 couples the BS 200 to other network nodes, for example, routers, other base stations, triple AAA server nodes, etc., and the Internet. The I / O interface 208 allows the WTs 300 to operate within the cell of the BS 200 to communicate with similar nodes outside the cell coverage area of the BS 200. The routines 234 include communication routines 238 and the control routines of the base station 240. The control routines of the base station 240 include a programmer module 242, an automatic repeat request control module 224, and signaling routines 246.

The communication routines 238 are used to control that the base station 200 performs various communication operations and implement various communication protocols. The control routines of the base station 240 are used to control the operations of the base station 200, for example, controlling the I / O interface 208, controlling the receiver 202, controlling the transmitter 204, controlling the power, programming, controlling ARQ , signaling, etc., to implement the steps of the method of the present invention. The programmer module 242 is used to control the allocation of programming resources and / or transmission communication. The programmer module 242 can serve as a programmer. The programming module 242 can program users, for example, the WTs 300 for channel segments, for example, uplink traffic channel segments and downlink traffic channel segments. The automatic repeat request control module 244 uses the information / data 236 in the memory 210 and works in conjunction with the receiver 202, and the transmitter 204 to control the operation of ARQ, in accordance with the present invention. The signaling routines 246 perform the operation to control the signal generation, signal transmission and signal reception through the wireless interface, for example, through the antenna 220, 232, and through the interface I / OR 208. The data / information 236 includes data 248, data / information 250 of the wireless terminal (WT), system information 252, downlink assignment messages 254, downlink traffic messages 256, acknowledgment messages received 258 , uplink assignment messages 260, uplink traffic channel messages 262 and uplink traffic recognition messages 264. The data 248 includes user data, eg, data received from the WTs 300 through links wireless, data received from other network nodes, data that will be transmitted to the WTs 300, and data that will be transmitted to other network nodes. The data / information of the wireless terminal 266 includes a plurality of WT data / information, WT information 1 266, WT information N 268, WT information 1 266 including data 270, terminal ID information 272, bit blocks of information 274, encoded bit blocks 276 and determined quality of decoded information 282. Data 270 includes user data received by WT 1 BS 200 projected for a similar node of WT 1, e.g. WT N, and data from the WT 1. user projected to be transmitted from BS 200 to WT 1.

The identification information (ID) of the terminal 272 includes an assigned ID of the base station to identify the WT 1 in communications and operations with the BS 200. The information bit blocks 274 include information blocks, e.g. user data bits, which will be encoded by the encoder 224 of the transmitter 204. The encoded bit blocks 276 include blocks of information bits 278 and redundant bit blocks 280. For each encoded block of information bits there is usually a block of corresponding redundant bits. The block of coded bits is normally transmitted even if one or more parts of the redundant bits are transmitted in the case of a NAK. The encoded information bit blocks 276 may include some redundant information, for example, ECC bits, generated as part of the coding process. The encoded bit blocks 276 are produced from a coding operation, for example, an LDPC coding operation, carried out by the encoder 224 in blocks of information bits 274. The information bit blocks 276, can usually be include the information, for example, text, voice, and other data, included in the input bits blocks of information 274. They may also include some redundant information generated as part of the coding process. Redundant bit blocks 280 include additional redundant information, for example, additional bits of error correction coding. The redundant bit blocks 280 include a plurality of redundant bit groups, redundant bits part 1 284 to redundant bits part N 286 for each bit block of coded information 278. For transmission purposes, an encoded block 278 of information bits can be grouped with a corresponding first part 284 and transmitted as a coded information group. The remaining parts of redundant bits corresponding to the transmitted block of coded bits 278 can be stored as a group of redundant information which is accessed and used in the case of a NAK, although it can be discarded at the time of receiving an ACK indication of successful reception and decoding of the corresponding transmitted block of encoded information bits 278. The determined quality of decoded information 282, is an output of the decoder 214 which indicates the quality level of the decoded information, and hence the level of decoding success . The NAK generation module 218 compares the determined quality of the decoded information 282 with the information included in the NAK level information 296, to determine whether the decoding was successful or not. Therefore, the module 218 determines whether a NAK should be generated and if so, the appropriate NAK level to generate as a function of the decoding success level, when the decoding was not completely successful. The system information 252 includes tone information 288, modulation information 290, timing information 292, code information 294 and level information NAK 296. The tone information 288 includes information identifying pitches used in jump sequences, channels and / or segments. The modulation information 290 includes information used by the BS 200 to implement various modulation schemes used by the modulator 216 and the demodulator 226. The timing information 292 may include timing information used for jump sequences, super-slots, residences, duration of channel segments, and timing relationships between different channel segments, for example, a timing relationship between an allocation segment, a traffic channel segment and a recognition channel segment. The timing information 292 may also include timing information used in ARQ methods of the present invention. The code information 294 includes information identifying code ranges, the type of code used, for example, information related to LDPC, ECC used in the generation of encoded information, and information related to ECC used in retrieving encoded information. The NAK level information 296 includes independent level information 298 and continuous level information 299. The level information NAK 296 includes information that can be used through the generation module NAK 218 to generate NAKs, according to the present invention, for subsequent transmission to a WT 300. The NAK level information 296 also includes information that can be used by an ACK 228 signal processing module to interpret and process the NAK signals received from the WTs 300. The independent level information 298 includes information that defines and relates to independent levels of NAK, used in some embodiments of the present invention. The independent level information 298 may include a plurality of NAK signal values, each of the possible NAK signal values corresponding to a different encoded signal quality level, a phase value corresponding to the ACK, and different phase values. which correspond to each of the different NAK levels. The continuous level information 299 includes information that defines and relates to continuous levels of NAK signal values, used in some embodiments of the present invention. The continuous level information 299 includes a continuous range of NAK signal values that correspond to a continuous phase interval NAK, a phase value that corresponds to an ACK, a range of required bits corresponding to, and that are mapped to the range continuous signal phase NAK. The downlink assignment messages 254 include allocation messages used to identify a WT that has been assigned a downlink traffic channel segment. The downlink assignment messages 254 may include a new / old bit indicator used to carry if the corresponding downlink traffic segment is a first time traffic segment or not. The downlink assignment messages 254 may also include information indicating the projected WT ID, for a first time traffic segment, or information used to obtain the Index, of the first time segment, for a first segment no time. The downlink assignment messages 254 are transmitted by the BS 200 to the WTs 300 in the downlink assignment segments. Messages from the downlink traffic channel 256 include data and information, for example, blocks of information bits 274, encoded and subsequently transmitted from the BS 200 to the WT 300 in the downlink traffic channel segments. The acknowledgment messages received 258 include recognition signals from the WTs 300 to the BS 200 indicating whether the WT 300 has successfully decoded the transmitted information, for example, a recognition signal carrying information in the phase that identifies positive recognition (ACK) or a negative recognition level (NAK), wherein the level of negative recognition can be used to determine the retransmission, for example, number of redundant bits that will be sent subsequently, according to the present invention. The uplink assignment messages 260 include allocation messages used to notify a WT 300 assigned to it an uplink traffic channel segment. The uplink assignment messages 260 may include a new / old bit indicator which is used to carry if the corresponding uplink traffic segments are a first time traffic segment or not. The uplink assignment messages 260 can also include information indicating the projected WT ID, for first time traffic segment, or information that is used to obtain the index of the first time segment, of a non-first segment time.

The uplink assignment messages 262 are transmitted by the BS 200 to the WTs 300 in the uplink allocation segments. The uplink traffic channel messages 262 include data and received information that has been successfully decoded from the coded signals transmitted in the uplink traffic channel segments through the WT 300 to the BS 200. The uplink traffic recognition messages 264, include recognition messages generated by the generation module NAK 218 based on the quality of the decoded information, for example, an ACK message of a successful information retrieval and messages corresponding to several levels of NAKs for an unsuccessful decoding attempt, in accordance with the present invention. Figure 3 is an illustration of an exemplary wireless terminal 300 implemented in accordance with the present invention. The exemplary wireless terminal 300 may be a more detailed representation of any of the end nodes 110, 112, 118, 120 of Figure 1. The terminal 300 includes a receiver 302, a transmitter 304, a processor 306 and a memory 310 coupled together through bus 312, through which different elements can exchange data and information.

The receiver 302 includes a decoder 314 and a generating module NAK 318. The decoder 314 includes a demodulator 316 and a quality determination module 317. The receiver 302 is coupled to an antenna 320 through which the WT 300 can receive signals, for example, downlink signals of the BS 200, including allocation channel signals, recognition channel signals and downlink traffic channel signals including data. The decoder 314, for example, an LDPC decoder performs decoding operations of received signals, in accordance with the present invention. The demodulator 316 performs demodulation operations on signals received in accordance with the present invention. The quality determination module 317 generates and maintains statistical decoding information indicating the quality of the decoded signal, for example, a control measure, number, and / or level of detected errors and / or statistics on the reliability of the signal decoded, such as temporary information values. The NAK generation module 318 generates a NAK, according to the present invention, when a received signal, for example, received data, can not be decoded successfully. The receiver 302 is coupled to the transmitter 304 through the link 322, through which a generated NAK can be communicated for subsequent transmission through the transmitter 304 to the BS 200. The transmitter 304 includes an encoder 324. The encoder 324, for example, an LDPC encoder includes a modulator 326, a recognition signal processing module 328 and a retransmission control module 330. The operations of the encoder 324 include blocks of information bit coding in coded bit blocks. The modulator 326 modulates information in signals, for example, uplink traffic signals and recognition signals. The transmitter 304 is coupled to the antenna 332 through which the uplink signals can be transmitted to the BS 200. The recognition signal processing module 328 processes the recognition signal information, for example, a NAK signal. received from the BS 200 corresponding to a previous transmission of the uplink traffic channel which was not successfully decoded by the BS 200. Said processing may include obtaining a level of the received NAK, in accordance with the present invention. The retransmission control module 330 controls the transmission of redundant information, for example, redundant bit blocks, to BS 200 according to the present invention. The retransmission control module 330 may carry out the control in response to the information from the recognition signal processing module 328. The retransmission control may include controlling the number and / or size of the redundant block that will be transmitted, controlling if it retransmits the bit information block and / or controls if it aborts additional transmissions related to a coded block. The memory 310 includes routines 334 and data / information 336. The processor 306, for example, a CPU, executes the routines 334 and uses the data / information 336 in the memory 310, to control the operation of the wireless terminal 300 and implement the methods of the present invention. The routines 334 include communication routine 338 and control routines of the wireless terminal 340. The control routines of the wireless terminal 340 include an automatic repeat request control module 342 and signaling routines 344. The communication routine 338 used to control that the wireless terminal 300 performs various communication operations and implements various communication protocols. The control routines of the wireless terminal 340 are used to control the operations of the wireless terminal 300, for example, control of the receiver 302, control of the transmitter 304, power control, ARQ control, signaling, etc., and to implement the steps of the method of the present invention. The automatic repeat request control module 342 uses the data / information 336 in the memory 310 and works together with the receiver 302, and transmitter 304 to control the operation of ARQ, in accordance with the present invention. Signaling routines 344 perform the operation to control signal generation, signal transmission and signal reception through the wireless interface, for example, through antennas 320 and 332. Data / information 336 includes data 346, terminal ID information 348, tone information 350, modulation information 352, code information 354, timing information 356, information bit blocks 358, encoded bit blocks 360, determined quality of decoded information 362, information NAK level 364, received downlink assignment messages 368, received downlink traffic messages 370, downlink traffic recognition messages 372, received uplink assignment messages 374, uplink traffic channel messages 376, and acknowledgment messages received from uplink traffic 378. Data 346 inc. They display user data received by the WT 300 of the BS 200, for example, data from a similar communication node of the WT 300, and user data projected to be transmitted to the BS 200 from the WT 300. The identification information (ID) terminal 348 includes an ID assigned to the base station which is used to identify the WT 300 in communications and operations with the BS 200. The information bit blocks 358 include blocks of information, for example, bit blocks of user data, which will be encoded by the encoder 324 of the transmitter 304. The encoded bit blocks 360 include information bit blocks 380 and redundant bit blocks 382. The encoded bit blocks 360 may be the output of the encoding operation , for example, an LDPC coding operation carried out by the encoder 324 in the information bit blocks 358. The information bits blocks 380 include the information included in the input blocks of the information bits 358. The redundant bit blocks 382 include additional redundant information, for example, additional bits of error coding. Redundant bit blocks 382 include a plurality of redundant bit blocks, redundant bits part 1 384, redundant bits part N 386.

The determined quality of the decoded information 362 is an output of the decoder 314 which indicates the quality level of the decoded information. The generation module 318 can compare the determined quality of the decoded information 362 with information included in the NAK level information 364 to determine whether a NAK should be generated and / or determine the appropriate level NAK to be generated. The tone information 350 includes information identifying pitches that are used in the jump sequences, channels and / or segments. The modulation information 352 includes information used by the WT 300 to implement various modulation schemes used by the demodulator 316 and the modulator 326. The timing information 356 may include timing information that is used for jump sequences, super-slots, residences, duration of channel segments and timing relationships between different channel segments, for example, a timing relationship between an allocation segment, a traffic channel segment and a recognition channel segment. The timing information 356 may also include timing information that is used in ARQ methods of the present invention. The code information 354 includes information that identifies coding ranges, the type of code used, for example, information related to LDPC, ECC used in the generation of encoded information, and information related to ECC used in the retrieval of encoded information. The NAK level information 364 includes independent level information 388 and continuous level information 390. The NAK level information 364 includes information that may be used by the NAK generation module 318 to generate NAKs, in accordance with the present invention, for the subsequent transmission to the BS 200. The NAK level information 364 also includes information that can be used by the signal processing module ACK 328 to interpret and process the received NAK signals of the BS 200. The independent level information 388 includes information that defines and relates to independent levels of NAKs, which is used in some embodiments of the present invention. The independent level information 388 may include a plurality of NAK signal values, each of the possible NAK signal values corresponding to a different encoded signal quality level, a phase value corresponding to an ACK and different phase values which correspond to each of the different NAK levels. The continuous level information 390 includes information that defines and relates to continuous levels of NAK signal values, used in some embodiments of the present invention. The continuous level information 390 includes a continuous range of NAK signal values that correspond to a continuous phase interval NAK, a phase value corresponding to an ACK, a range of required bits corresponding to, and which are mapped from of the continuous phase range of the NAK signals. The downlink assignment messages received 368 include allocation messages used to notify the WT 300 that a downlink traffic channel segment has been assigned to it. The received downlink assignment messages 368 may include a new / old bit indicator used to carry if the corresponding downlink traffic segment is a first time traffic segment or not. The downlink assignment messages 368 may also include information indicating the projected WT ID, for a first time traffic segment, or information that is used to obtain the index of the first time segment, of a non-segment of first time. The downlink assignment messages are transmitted through the BS 200 to the WTs 300 in the downlink assignment segments. Messages from downlink traffic channel received 370 include data and information, for example, blocks of information bits 358 that have been decoded successfully by the decoder 314. The downlink traffic messages are transmitted from the BS 200 to the WT 300 in segments of the downlink traffic channel. The downlink traffic recognition messages 372, include messages transmitted in the recognition signals from the WT 300 to the BS 200, indicating whether the WT 300 has successfully decoded the received information, for example, a signal of recognition that transports the information in its phase that identifies a positive recognition (ACK) or information in the phase that identifies a level of negative recognition (NAK), where the level of negative recognition can be used to determine the retransmission for example, number of redundant bits that are being requested to be sent subsequently, according to the present invention. The uplink assignment messages received 374 include allocation messages used to notify a WT 300 assigned to it an uplink traffic channel segment. The uplink assignment messages received 374 may include a new / old bit indicator which is used to carry if the corresponding uplink traffic segment is a first time traffic segment or not. The uplink assignment messages 374 may also include information indicating the projected WT ID, for a first time traffic segment, or information that is used to obtain the first time segment index, for a non-segment of first time. The uplink assignment messages are transmitted through the BS 200 to the WTs 300 in uplink allocation segments. The uplink traffic channel messages 376 include data and information, for example, blocks of information bits 358 that are encoded in coded bit blocks, and transmitted in uplink signals in segments of the uplink traffic channel through the WT 300 to the BS 200. The acknowledgment messages received for the uplink traffic 378, include recognition signals from the BS 200 to the WT 300 that indicate whether the BS 200 has successfully decoded or not. transmitted information, for example, a recognition signal that carries information in the phase that identifies positive recognition (ACK) or a negative recognition level (NAK), where the level of negative recognition can be used to determine the retransmission, by example, number of redundant bits required to be sent subsequently, in accordance with the present invention. In an example system, with one cell, the traffic segments are dynamically shared between the wireless signals 300 that are in communication with a base station 200 in the cell, for example, cell 1 102. The programming function in the base station 200, assigns each uplink and downlink segment to one of the wireless terminals, for example, mobile terminals 300 in the cell based on a number of criteria. Assignments are communicated through control resources called allocation segments. In corresponding form to each traffic segment there is a unique allocation segment that includes the identifier of the wireless terminal 300 to which the traffic segment is assigned. The data transmitted by the base station 200 in a downlink traffic segment is decoded by the receiver of the projected terminal. The data transmitted by the assigned wireless terminal 300 in the uplink segment is decoded by the base station 200. Normally, the transmitted segment includes redundant bits, for example, an error correction code, which aids the receiving apparatus, for example, the base station 200 or the wireless terminal, for example, mobile 300 to determine if the data is decoded correctly. This is done because a wireless channel used to transmit the data between the base station 200 and the wireless terminal, for example, mobile 300 may not be reliable and the data traffic usually has a high integrity requirement to be useful. Subsequently the receiving apparatus provides feedback to the transmitter. The feedback indicates the successful or unsuccessful decoding of the received traffic segment. Successful decoding of a received segment is indicated by sending a positive acknowledgment, for example, an ACK. Unsuccessful decoding of a segment is indicated by sending a negative acknowledgment, for example, a NAK. The recognition is sent using a control resource, for example, a control channel comprising a plurality of recognition segments. Each ACK or NAK may be transmitted in a different recognition segment corresponding in a predetermined manner to one or more traffic channel segments. In a particular mode, a unique recognition segment is associated with each traffic segment. The transmitter, upon receipt of a NAK may choose to retransmit the same data, or in accordance with the present invention, transmit redundant information representing information of the supplementary error correction code. Therefore, the example system of the present invention supports an automatic repetition request mechanism wherein the redundant information, for example, incremental LDPC information corresponding to the previously transmitted data, can be transmitted in response to a received NAK. . Figure 4 is used to illustrate an example method which can be used to assign data that will be transmitted to segments of the traffic channel and use the recognition segments to carry recognition information (ACKs or NAKs) corresponding to the data transmitted in the segments of the traffic channel. Figure 4 illustrates a downlink channel diagram 400 in which the horizontal axis 400 represents time and the vertical axis 404 represents the frequency, for example, frequency tones. Figure 4 also includes a diagram 450 of uplink channels in which the horizontal axis 452 represents the time and the vertical axis 454 represents the frequency, for example, frequency tones. In Figure 4, a traffic segment is represented logically as a rectangular block. The diagram 400 includes the following downlink channel segments: a corresponding downlink traffic segment assignment segment 406, a corresponding uplink traffic segment assignment segment 408, a downlink traffic segment 410 and a knowledge segment corresponding to an uplink traffic segment 412. The diagram 450 includes the following uplink channel segments: an uplink traffic channel segment 456 and an uplink recognition segment 458. In a real system, the physical frequencies, for example, tones, that are occupied by the traffic segment may not be contiguous, for example, due to a jump or other reasons, and may vary over time. Each segment of traffic channel may correspond to one or more tones. In addition, each segment of the traffic channel may last one or more periods of time, for example, symbol periods. Figure 4 shows that there is an allocation channel in the downlink. The allocation channel includes an allocation segment sequence 406. Each allocation segment 406, represented as a rectangular block, is used to transmit the allocation information of a particular downlink traffic segment. The assignment information includes the identifier of the wireless Terminal (s) 300, which is to receive the data in the associated downlink traffic segment 410. In order to facilitate the reception operation, the reception information may also include information such as channel coding and modulation ranges that will be used for process the data in the corresponding downlink traffic segment. A downlink traffic segment 410 is associated with a corresponding allocation segment 406 'in a prescribed, for example, predetermined, known manner. Each uplink traffic segment 456, like each downlink traffic segment 410, is assigned by the programmer of the base station 200 which will be used by one or more wireless terminals, eg mobile 300. The allocation information communicates using allocation segments 408 in the downlink having a predetermined relationship with the assigned uplink traffic segments 456. Since the relationship between the allocation segments 406, 408 and the traffic segments 410, 456 is predetermined and known, there is no need in the exemplary embodiment to include information in an allocation segment 406, 408 that indicates the segment (s) of the traffic channel 410, 456 to which the allocation information in a particular allocation segment corresponds; .

Figure 4 shows that there is a recognition channel in the uplink as in the downlink. The uplink recognition channel includes a sequence of recognition segments 458. An uplink recognition segment 458 indicates whether the information in the associated downlink traffic segment 410 was correctly received or not, for example, if it was possible to correctly decode the information received in the corresponding traffic segment 410. The wireless terminal 300 to which the associated downlink traffic segment 410 is assigned, transmits the acknowledgment in the corresponding uplink acknowledgment segment 458, although all other wireless terminals normally do not transmit using said particular recognition segment 458. The recognition information may include as little as one bit, either an ACK, for example, a "1", indicating success of reception, or a NAK, for example, "0" indicating the reception failure. A downlink traffic segment 410 is associated with a corresponding uplink acknowledgment segment 458 in a prescribed, eg predetermined, manner. Similarly, there is a downlink recognition channel in which the recognition segments 412 include the recognition information of the corresponding uplink traffic segments 456. The cascading codes, for example, cascaded LDPC codes, can be used. according to the present invention, to provide redundant information transmitted in response to the reception of a NAK. A segment of uplink or downlink traffic is used to carry a block of information bits. In one embodiment of the present invention, the information bit block is encoded in a block of encoded bits using channel coding methods, such as Low Density Parity Check (LDPC) coding which is described for example in the Publication of T. Richardson and R. Urban e, "Efficient encoding of low-density parity-check codes", IEEE Trans. Inform. Theory, vol. 47, no. 2, pages 638-656, February 2001, which is expressly incorporated by reference to the present invention. The subsequently encoded bit block is mapped to a group of constellation symbols, for example, as part of a symbol mapping operation that can also be described as a modulation operation. The symbols generated are transmitted through a wireless channel. The receiving apparatus performs a symbol recovery operation and subsequently processes the recovered symbols to obtain the transmitted bits. The recovered block of encoded bits is subject to a channel decoding operation, for example, an LDPC decoding operation, in an attempt to recover the information bit block subject to the encoding operation in LDPC before transmission. Channel coding adds redundancy to the transmitted signal in order to combat the corruption likely to occur during transmission through the wireless channel. Due to a fixed modulation scheme, the greater the number of redundant bits added, the greater the amount of corruption that the transmission can support even if it is still decoding correctly (retrieving information bits). When a block of information bits will be transmitted for the first time in a traffic segment, the information bit block is encoded in a code word having some specific redundancy. In a particular embodiment of the present invention, the encoded bits transmitted in a first traffic segment represent a code word of an LDPC code. The LDPC codes are well suited for hybrid ARQ, wherein the additional redundant information in the form of correction code information is transmitted instead of retransmitting the information originally transmitted when a NAK is received. Due to an LDPC code, as represented by using a Tanner graph, an extension of the code can be defined by entering additional variable nodes and restricting nodes in the graph. In effect, the code extension includes bit parity revisions in the original codeword. In the particular mode in the Tanner chart, the additional parity check bits are represented as variable nodes of an additional degree, each connected to a single additional restriction node. The LDPC decoding proceeds by carrying out decoding that passes messages in the extended graph. Additional parity revisions, for example, the extension of the graph can be previously defined in the form of an explicit structure or implicitly defined in the form of a random process which generates the extent manipulated to a certain degree, which is available both for the transmitter and for the receiver. According to the present invention, the incremental redundant bits, transmitted in response to a NAK, extend the codeword of the first transmitted codeword (transmitted in a first traffic segment) to form a codeword larger than the which one has hope that can be successfully decoded due to the increased redundancy compared to the initial code word. In one embodiment, the additional parity check bits, formed by carrying out parity checks of the original information bits or the original LDPC code word, comprise the incremental redundant bits. In another embodiment of the present invention, the incremental bits include part or all of the information and / or part or all of the parity check bits transmitted in the first traffic segment, for example, the first transmission of information bits to which correspond the increment bits. According to one feature of the present invention, when the two traffic segments, eg, first and second traffic segments, associated with the same information bits are NAKed, the transmitter can transmit redundant bits in increment in a third segment of traffic. traffic, so that the receiver can combine the three traffic segments received to achieve a better decoding performance. Redundant redundant bits are constructed similarly to those found in the second traffic segment. The above procedure can be repeated a number of times, for example, times N, where N is a positive integer, until some termination criterion is met, for example, the success of the decoding is achieved. In some embodiments, N is greater than 3, for example, 4 or 5. Figure 5 illustrates an example for using redundant incremental codes, for example, redundant LDPC codes, in accordance with the present invention. Figure 5 includes a transmitter 502 that includes an encoder 504, implemented in accordance with the present invention. Figure 5 also includes a receiver 522 that includes a decoder 524, implemented in accordance with the present invention. The transmitter 502 can be used as the transmitter 204 of the BS 200 of FIG. 2 or the transmitter 304 of the WT 300 shown in FIG. 3. The receiver 522 can be used as the receiver 202 of the BS 200 or the receiver 302 of the WT 300. When a block of information bits 506 will be transmitted, the transmitter 502 with its encoder 504, uses a large parity revision matrix to generate code bits 508 that include a large block of revision bits of parity. The encoded bits 508 include a block of information bits 510 and a block of redundant bits 512. The block of redundant bits 512 includes a first part 514, a second part 516, a third part 518 and a fourth 519. In a first traffic segment 520, the information bits 510 are transmitted and the first part of the parity check bits 514 are transmitted. The combination of the encoded information bits 510 and the first part 514 of the parity check bits form a first group of encoded information that will be transmitted. The remaining parity check bits, from the second to the fourth parity check bits, form a redundant information group that is stored and used in the case of a NAK. If the receiver 522 with its decoder 524 can not decode the information bits 510 and sends a NAK 526, the transmitter 502 sends the second part of the parity check bits 516 and in a second traffic segment 528. The receiver 522 uses both of the received segments 520, 528 in the decoding process in an attempt to decode the information bits 510. It is now assumed that the receiver 522 still can not decode the information bits 510, as can be evidenced through the apparatus receiver 522 sending another NAK 530 in a recognition segment corresponding to the second traffic segment 528. Subsequently, the transmitter 502 transmits the third part of the parity check bits 518 in a third traffic segment 532. The receiver 522 must use part or all of the segments received, for example, the segments 520, 528, 532 for decoding information bits 510. If the receiver 522 decodes If the information bits 510 are successful at some point, then the transmitter can discard the unused parity check bits. In the example of Figure 5, the receiving apparatus 522 does not have the ability to decode the first and second traffic segments 520, 528 and respond to each of these segments with a NAK 526, 530, respectively. By combining the information ((510 and 514), (516)) received in the first and second traffic segments (520, 528) with the information in increment, for example, LDPC information in increment, 518 received in the third segment of traffic 532, the receiving apparatus 522 finally has the ability to successfully decode the received information 510. This results in the receiving apparatus 522 transmitting an ACK 534 in the recognition segment corresponding to the third traffic segment 532. In response to ACK 534, the transmission apparatus 502 is informed that it is not necessary to transmit additional redundant information, for example, additional redundant bits, for example, additional LDPC bits, 519. In the previous example, when multiple segments of traffic 520, 528, 532 associated with the same information bits 510 are transmitted, the retransmission traffic segments 528, 532 include additional redundant bits, for example, of parity check 516, 518 without the original information 510 transmitted in the first traffic segment 520. In another embodiment of the present invention, in addition to the additional redundant bits, a retransmission traffic segment may also include new bits of information, for example, bits that do not correspond to the code word transmitted in a previous traffic segment. Therefore, if the receiver has the ability to correctly decode the first-time transmission segment and the retransmission segment, the receiver effectively receives not only the information bits included in the first-time transmission segment, for example. , the first traffic segment, but also the new information bits added in the transmission segment, for example, second or third traffic segment. The incremental allocation according to the present invention will now be described in an exemplary embodiment. A feature of the present invention is directed to a traffic segment allocation method that allows the use of incremental redundant coding, for example, incremental redundant LDPC coding. The downlink traffic segments must be considered first. In several exemplary embodiments used to explain the present invention, for each downlink traffic segment, there is a corresponding assignment segment, which indicates the allocation information of the downlink traffic segment. The association between a downlink traffic segment and the corresponding allocation segment is previously determined and fixed. According to the present invention, in some embodiments the assignment segment explicitly indicates whether the corresponding traffic segment is the first time transmission or not. If it is the first time transmission, the allocation segment must include information such as the identifier of the wireless terminal (s). If it is not the first time transmission, according to the present invention, the allocation segment must include, for example, in place of the identifier of the wireless terminal, information that can link the previously transmitted traffic segments that are associated with the same block of information bits. Said information is called "incremental allocation" in the present description. Due to the incremental allocation, the receiver of the traffic segments may subsequently combine said segments together and effectively decode the block of the information bits. According to the present invention, each of the traffic segments are uniquely indexed through a certain time interval, for example, a periodic time interval. For example, Figure 6 illustrates segments of traffic N, indexed as 1, 2, ..., N in a time interval T 616, where for purposes of illustration in the example, N = 3. In general, the value of N is a number greater than 3. Figure 6 is a frequency diagram 600, for example, frequency tone, on vertical axis 602 versus time on horizontal axis 604. The example of the figure 6, shows each traffic segment occupying the same frequencies, but in different time slots. Figure 6 shows a traffic segment N 606, followed by a traffic segment 1 608, followed by a traffic segment 2 610, followed by a traffic segment N 612, followed by a traffic segment 1 614. The additional segments , in a time interval T 616, could be included in cases where N is equal to a number greater than 3. Any segment of traffic passed within the time window of T 616, can be uniquely identified through the segment index. The time interval T 616 is therefore referred to as the valid time window. According to a feature of the present invention, the wireless terminal 300 stores the allocated traffic segments within the valid time window that could not be decoded. The wireless terminal 300 also stores the assignment information passed within the valid time window. This information is stored in the memory included in the wireless terminal 300. It is considered a traffic segment representing the nth transmission associated with a block of information bits, where n >; l. The following describes some modalities of the incremental assignment. In one embodiment, the incremental assignment includes the index of the first time traffic segment of the same information bit block. In another embodiment, the incremental assignment includes the index of the transmission of the segment (n-l) th of the same block of information bits. Even in another modality, the incremental allocation includes an index difference? (?> 0) The index of the current traffic segment must be observed as I. For example, the incremental assignment may indicate that the first time traffic segment of the same information bit block is determined as (1-?) Mod N. In another example , the incremental assignment indicates that the transmission of the segment (nl) th of the same block of information bits is determined as (I-?) mod N. Figure 7 expands to the example of figure 5, and displays the information of assignment, for example, allocation segments of the three traffic segments of the block of information bits reported in the example of Figure 5, according to the present invention. Fig. 7 includes an example assignment segment message 700 that includes a new / old indicator bit 702 and segment index bits / ID 704. The new / old flag bit 702 is a bit indicator 1 that can be used for communicate whether the corresponding traffic segment is a segment of first-time traffic or not a segment of first-time traffic. If the new / old bit indicator is, for example, 0, the assignment message may communicate that this assignment is for a first time traffic segment and that the information in the segment index / WT ID bits indicates that an identifier of the WT is assigned the corresponding traffic segment. If the new / old bit indicator is, for example, 1, the assignment message may communicate that this assignment is not a first-time traffic segment, since the information in the bits of the segment index / ID 704 indicates a Index of the first time segment. Figure 7 further includes a diagram 720 of the downstream channels plotting frequency, for example, frequency tone on vertical axis 722 versus time on horizontal axis 724. Diagram 720 includes three downlink assignment segments 724, 726, 728 and three traffic channel segments 730, 732, 734, respectively. Figure 7 also includes a diagram 750 of uplink channels that plot the frequency, e.g., frequency tones, on the vertical axis 752 versus time on the horizontal axis 754. The diagram 750 includes three uplink recognition segments 756 , 758, 760 corresponding to the downlink traffic segments 730, 732, 734, respectively. Three example transmission intervals are shown, the first transmission interval 762, the second transmission interval 764 and the third transmission interval 766. In the first transmission interval 762, the assignment segment 724 carries the new / old flag bit = 0 736 indicating that the corresponding traffic segment 730 is a first time traffic segment. The allocation segment 724 also carries the segment index / WT ID bits 738 which indicate an identifier of the wireless terminal assigned to the traffic segment 730. The base station transmits the segment information of the traffic segment 730 which includes bits of information and a first part of the redundant bits. The projected WT does not have the ability to decode the information bits successfully and transmits an uplink NAK signal in the corresponding uplink recognition channel segment 756. In the second transmission time slot 764, the transmission segment assignment 726 carries the new / old indicator bit = 1 740 which indicates that the corresponding traffic segment 732 is not a first time traffic segment. The assignment segment 726 also carries information from the segment index / ID WT 742 indicating the index of the first time segment, for example, information indicating the index of the traffic segment 732. The base station transmits the information of the traffic segment 732 that includes a second part of the redundant bits. The projected WT does not yet have the ability to decode the information bits in a successful manner, and transmits an uplink NAK signal in the corresponding uplink recognition channel segment 758. In the third transmission time slot 766, the allocation segment 728 carries the new / old indicator bit = 1746 which indicates that the corresponding traffic segment 734 is not a first time traffic segment. The assignment segment 728 also carries the segment index information / WT ID 748 indicating the index of the first time segment, for example, information indicating the index of the traffic segment 734. The base station transmits the information of the segment of traffic 734 that includes a third of the redundant bits. The projected WT has the ability to decode the information bits in a successful manner and transmits an uplink ACK signal in the corresponding uplink recognition channel segment 760. The same incremental allocation method can be used to allow the use of Increasing redundant codes in the uplink traffic segment. In the case of uplink, the base station must, and in various modes, indicate that an assignment is of a first time traffic segment when the base station is ready to receive a new block of information bits. Upon receiving the allocation segment of a first-time segment, the transmitter of the wireless terminal must start a new block of information bits and generate a large block of parity check bits for a new block of information bits. The wireless terminal must, and in fact transmits the information bit block and the first part of the parity check bits. If the receiver of the base station can not decode the information bit block, the base station must, and in fact assigns another segment of uplink traffic. The assignment includes information that indicates that the traffic segment does not mean that a segment will be transmitted for the first time. In addition, the assignment includes the incremental allocation. Upon receiving the allocation segment of a non-first-time segment, the transmitter of the wireless terminal again scans, through the information stored in its memory, to retrieve the corresponding block of information bits using the incremental allocation information, and subsequently transmits the subsequent part of the parity check bits according to the present invention. The multi-level negative recognition and the allocation of adaptation resources should be described in accordance with the present invention. The present invention is further directed to a method for sending a recognition segment corresponding to a traffic segment in order to improve the performance of the hybrid ARQ scheme using incremental redundant coding, for example, incremental redundant LDPC coding. In the above method, the receiver sends an ACK if the information bit receiver has been decoded correctly and a NAK if more redundant bits are needed to decode the information bit block. Upon receiving a NAK, the transmitter sends incremental redundant bits to increase the probability that the receiver can correctly decode the information bit block. However, when the transmitter has only a NAK feedback from the receiver, the transmitter may not know that so much incremental information is necessary. The effective amount of incremental information supplied depends on how many redundant bits are transmitted and how much energy is spent per bit. In some cases, the receiver may need a large number of increasing information, although the transmitter only sends a small amount, resulting in excessive latency due to a large number of ARQ circuits that are required to achieve successful transmission. In other cases, the receiver may need a small amount of increasing information, for example, a few bits, while the transmitter sends a large amount of redundant information, wasting system resources. According to a characteristic of the present invention, when the receiver needs information in increment, it first estimates the amount of information in effective increment, for example in bits, which it requires in order to correctly decode the block of information bits, and subsequently sends a multi-level NAK, where each level of NAK represents a different amount of effective increment information required. Therefore, in said embodiment, the receiver transmits, in addition to a NAK, an indicator of the amount of redundant information that will be supplied, for example, as determined through its estimate of required bits. In this mode, when the receiver does not need any redundant bits in increment, it sends an ACK. The above method for indicating the amount of redundant information required or desired applies to both downlink and uplink traffic segments. The effective information included in the incrementing bits is a measure of the "real" information content, which may be different from the number of redundant incremental bits transmitted.The amount of air link resources (number of symbols transmitted, their power and modulation) assigned to a traffic segment determines the number of effective incremental bits included in the segment, for example, the transmission power of the traffic segment, and in some systems, the amount of bandwidth and frequency time increases with the number of effective incremental redundant bits required in the segment.Therefore, based on the multi-level NAK feedback information, the transmitter can adaptively determine the number of effective incremental redundant bits that will be included in the the traffic segment and therefore adjusts the amount of air link resource allocated to the traffic segment In order to facilitate the operation of the receiver, the incremental allocation can, and in several modalities, in fact also include the information indicating the number of effective incremental bits included in the traffic segment. According to the present invention, the number of bits included in the kth-time segment transmission may not be, and in several cases, it is not the same for all k, where k >; 0. Figure 8 continues with the example of Figure 5 and shows how the third level NAK recognition, according to the present invention, can improve ARQ performance. Figure 8 includes a diagram 800 of downlink channels that plot the frequency, for example, frequency tones on vertical axis 802 versus time on horizontal axis 804. Diagram 800 includes two assignment segments 806, 808 and two corresponding downlink traffic channel segments 810, 812, respectively. Figure 8 also includes a diagram 850 of the uplink channels that trace the frequency, for example, frequency tones on the vertical axis 852 versus time on the horizontal axis 854. The diagram 850 includes two uplink recognition segments 856 , 858 corresponding to the downlink traffic segments 810, 812, respectively. Specifically, when a block of information bits will be transmitted, the transmitter generates a large low density parity check code word. In the first transmission time 860, the base station transmits an assignment message in the allocation segment 806 which includes a new / old bit indicator 816 = 0 indicating that the traffic segment 810 is a segment of first time traffic. . The assignment message in the allocation segment 806 also includes bits of the segment index / ID WT 818 which includes an identifier of the WT assigned to the downlink traffic segment 810. In the first traffic segment 810, the bits of information and the first part of the code word are transmitted. It is now assumed that the receiver does not decode the information bits and therefore sends a level 2 NAK in the recognition segment 856. Upon receiving the level-2 NAK, the transmitter sends an assignment message in the allocation segment 808. The assignment message includes a new / old bit indicator 864 = 1 which indicates that the corresponding traffic segment 812 is not a first time traffic segment, and a segment indicating bit / WT 866 ID which includes information that indicates the index of the segment for the first time. Subsequently, the transmitter sends both the second and third parts of the parity check bits in the second traffic segment 812 at a power level which is directed to the supply of a certain number of effective information bits. Using both of the received segments 810, 812 to decode the information bits, the receiver now probably decodes the information bits successfully this time and sends an ACK on the recognition segment 858. In this example, the level NAK mechanism multiple helps to reduce the ARQ circuits required, as compared to the example shown in Figure 7. Figure 9 is a drawing 900 which is used to illustrate the phase of the multi-level ACK code word / ACK in a mode of example of the present invention. Figure 9 includes a phase representation of an ACK 902, for a NAK of level 1 904, for a NAK of level 2 906 and for a NAK of level 3 908. As illustrated in figure 9, the word of code used in the recognition segment is such that the distance Euclidean between ACK 902 and any of the multi-level NAKs 904, 906, 908, is much greater than between any of the two multi-level NAKs 904, 906, 908.

In another embodiment of the present invention, the number of NAK levels is infinite. Figure 10 is a drawing 1000 that is used to illustrate the NAK phase of ACK / infinity level. Figure 10 includes a phase representation of an ACK 1002, a phase representation of an example NAK 1004 and a continuous phase range NAK 1006. Figure 10 also includes a continuous integer range of required bits 1050 corresponding to the range continuous of the NAK phase 1006, a minimum value of required bits 1052 and a maximum value of required bits 1054. Figure 10 shows that the phase of the received symbol or code word, which is a continuous variable of x 1008 a and 1010, can be mapped to a continuous integer range of the number of additional information bits needed. Figure 10 shows an exemplary NAK 1004 mapped to, as illustrated by arrow 1060, a specific number of required bits 1056. Figure 11, which comprises the combination of figures from HA to 11D, is a flow chart 1110 of an example method of automatic repeat request (ARQ) according to the present invention. From start node 1102 the operation proceeds to step 1104. In step 1104, a first device, for example, a mobile node, and a second device, for example, a base station (BS) are started. The operation proceeds from step 1104 to step 1108. The information that will be transmitted, e.g., text, voice or other digital data 1106 is processed through the base station in step 1108. In step 1108, the encoder in the station base encodes the information 1106, the coding generating a first group of encoded information and a first group of redundant information. The first group of encoded information may include, for example, a block of encoded information bits 510 and a first part 514 of the error correction bits generated as part of the encoding process. The first redundant information group may include the remaining redundant bits 516, 518, 519 generated as part of the encoding carried out in the information 1106. In step 1110, the base station stores the first group of redundant information. The operation proceeds from step 1110 to step 1112. In step 1112, the BS selects a traffic channel slot, and therefore a traffic channel segment corresponding to the selected slot, for the transmission of the first information group. encoded In step 1114, the BS generates a traffic channel assignment message indicating the allocation of the selected traffic channel slot, the assignment message including an MN identifier and an indicator indicating that the coded information will be transmitted to the MN in the slot of the traffic channel does not correspond to a previously transmitted signal. Subsequently, in step 1116, the BS transits the generated allocation message in an allocation channel slot, for example, the traffic channel slot corresponding to the allocation slot that is used to transmit the allocation message. Subsequently, in step 1118, the MN receives the assignment message. Subsequently in step 1120, the BS transmits the first group of encoded information in a signal transmitted in the allocated traffic channel slot. The operation proceeds from step 1120 to step 1122. In step 1122, the MN receives the signal including the first coded information group. The operation proceeds from step 1122 through connection node A 1124 to step 1126. In step 1126, the MN performs a decoding operation on the received signal that includes the first group of encoded information. As part of the decoding operation of step 1120, sub-step 1128 is carried out. In a sub-step 1128, the MN maintains decoding statistics, for example, counting of non-correctable errors detected, reliability information of decoding results and / or time values. The operation proceeds from step 1126 to step 1130. In step 1130, the MN determines if the decoded information was decoded successfully. This can be done by comparing one or more decoding statistics with a threshold value level that indicates successful decoding. The level of threshold value may be, for example, a source of zero non-correctable errors in the results of the decoding process. If in step 1130 it is determined that the encoded information was decoded successfully, then the operation proceeds to step 1132. In step 1132, the MN transmits an ACK signal to the BS. The operation proceeds from step 1132 through connection node B 1134 to step 1108 where the BS processes additional information that will be transmitted. If in step 1130 it is determined that the encoded information was not decoded successfully, the operation proceeds to step 1136. In step 1136, the MN determines the decoding success level, for example, from the decoding statistics which indicate the quality of the decoded information, such as error statistics (for example, counting errors not corrected and detected) and / or reliability statistics). The operation proceeds step 1136 to step 1138. In step 1138, the MN generates a NAK signal, wherein the generation includes selecting a signal value NAK from a plurality of possible NAK signal values based on the determined level of success of decoding. Subsequently in step 1140, the MN transmits the generated NAK signal. Subsequently, in step 1142, the BS receives the signal NAK. The operation proceeds from step 1142 to step 1144. In step 1144, the BS determines from the value of the received NAK signal, the amount of redundant information, from the first group of stored redundant information, to transmit to the MN. More information is selected to be transmitted when the NAK value indicates a low level of decoding success, for example, a large number of errors in the decoding result, than that which is selected to be transmitted when the NAK value indicates a higher level of decoding success. of decoding success, for example, fewer errors. The operation proceeds from step 1144 through connection node C 1146 to step 1148. In step 1148, the BS determines whether the determined amount of redundant information is less than the capacity of a traffic segment. If the BS determines that the determined amount of redundant information is less than the capacity of a traffic segment, the operation proceeds to step 1150, otherwise the operation proceeds to connection node D 1152. In step 1150, the BS determines if there is enough storage capacity in the traffic segment to carry a part of a second group of encoded information. In step 1150, the BS determines that there is sufficient capacity in the traffic segment to carry a part of a second group of encoded information, and the information proceeds to step 1156, otherwise the operation proceeds to the connecting node D 1152. In step 1156, the BS processes additional information that will be transmitted, for example, text, voice or other digital data 1154. In step 1156, the BS encodes additional information 1154, wherein the encoding generates a second group of encoded information and a second group of redundant information. From step 1156, the operation proceeds to step 1158. In step 1158, the BS stores the second group of redundant information. The operation proceeds from step 1158 to step 1160. In step 1160, the BS selects a part of the second group of encoded information to be transmitted with the selected redundant information obtained from the first group of stored redundant information. Subsequently, the operation proceeds to connection node D 1152. From connection node D 1152, the operation proceeds to step 1162. In step 1162, the BS selects a traffic channel slot for transmission of the selected group of information redundant. Later, the step 1164 the BS generates a traffic channel assignment message indicating the allocation of the selected traffic channel slot, the assignment message including an indicator indicating that the redundant information will be transmitted in the traffic channel slot which is being assigned, the information that identifies the previous signal which corresponds to the redundant information, and if new information coded with the redundant information will be transmitted, a new indicator of coded information. The information identifying the previous signal may be, for example, a traffic slot or an allocation slot identifier associated with the previous signal and / or mobile node identifier associated with the previous signal. Subsequently, in step 1166, the BS transmits the generated traffic allocation message in an allocation channel slot. Subsequently, in step 1168, the MN receives the assignment message that was transmitted in step 1166. The operation proceeds from step 1168 to step 1170. In step 1170, the BS transmits the selected group of redundant information corresponding to the first group of coded information, and new coded information corresponding to the second group of information that assumes the space that is available in the assigned slot. Subsequently, in step 1172, the MN receives the signal that includes the redundant information. The operation proceeds from step 1172 to step 1174. In step 1174, the MN determines from the received assignment message the previously received signal to which the redundant information corresponds. The operation proceeds from step 1174 to step 1176. In step 1176, the MN performs an additional decoding operation using the received redundant information and the information obtained from the previously received signal (s) to which the redundant information corresponds. The operation proceeds from step 1176 through connection node E 1178 to step 1130, where the MN determines whether the encoded information was decoded successfully. The operation proceeds from step 1176 as previously described, for example, with repeated NAKs and transmission of additional redundant information until successful decoding of the first coded information group is achieved. Figure 12 is another example of using a multi-level NAK, according to the present invention within the context of transmission of the uplink information. In the example of Figure 12, the base station is responsible for assigning uplink traffic channel segments in addition to downlink traffic channel segments, as explained with respect to the example of Figure 8. Figure 12 it includes a diagram 1200 of uplink channels that plot the frequency, for example, frequency tones, on vertical axis 1202 versus time on horizontal axis 1204. Diagram 1200 includes two uplink assignment segments 1206, 1208 and two recognition segments 1210, 1212 that are used to communicate information with respect to the signals sent in the uplink. Figure 8 also includes a diagram 1250 of the uplink channels that plot the frequency, for example, frequency tones, on the vertical axis 1252 versus time on the horizontal axis 1254. The diagram 1250 includes two traffic channel segments uplink 1256, 1258. The allocation segment 1206 corresponds to the uplink traffic segment 1256; the uplink traffic segment 1256 corresponds to the recognition segment 1210. The allocation segment 1208 corresponds to the uplink traffic segment 1258; the uplink traffic segment 1258 corresponds to the recognition segment 1212. Specifically, when a block of information bits will be transmitted, the transmitter in the WT generates a large low density parity check codeword. In the first transmission time 1260, the base station transmits an allocation message in the allocation segment 1206 which includes a new / old bit indicator 1216 = 0 indicating that the uplink traffic segment 1256 is a traffic segment first time The assignment message in the allocation segment 1206 also includes segment index bits / WT ID 1218 which include an identifier of the WT allocated for the uplink traffic segment 1256. In the first uplink traffic segment 1256, the information bits and the first part in the code word comprising a group of coded information are transmitted through the WT to the BS. It is now assumed that the receiver in the BS does not decode the information bits and therefore sends a level 2 NAK in the recognition segment 1210. The transmitter in the BS sends an uplink assignment message in the WT to the WT. allocation segment 1208. The assignment message includes a new / old bit indicator 1264 = 1 indicating that the corresponding traffic segment 1258 is not a segment of first-time traffic and segment indicator bits and / or WT 1266 that includes information that indicates the index of the first time segment. The WT receives the level 2 NAK in the recognition channel segment 1210 and the assignment in the allocation segment 1208. Subsequently the WT transmitter sends selected redundant information in response to the NAK, for example, both the second and the third parts of a group of stored parity check bits, in the second uplink traffic segment 1258 at a power level that directs the provision of a number of effective information bits. The BS receives the uplink traffic channel segment 1258. By using the information of both of the received segments 1256, 1258, the BS decodes the information bits. In response to the determination that the decoding operation was successful, the receiver of the BS sends an ACK in the recognition segment 1212. In this example, the multi-level NAK mechanism helps to reduce the ARQ circuits required, compared to the example shown in figure 7. It should be noted that the traffic channel segment that corresponds to an allocation segment with frequency, in terms of time, follows the allocation segment. However, it is possible that the allocation and the corresponding traffic channel segments overlap partially or totally resulting in simultaneous transmission in an allocation segment and the corresponding traffic segment, where different frequencies are used for the different segments. Although described within the context of an OFDM system, the ARQ methods and apparatuses of the present invention, as well as the novel recognition methods described herein, are applicable to a wide range of communication systems that include many of the non-cellular systems and / or not OFDM. Furthermore, although it is described within the context of an exemplary wireless communication system, it will be understood that the methods and apparatus of the present invention can be used in other applications which do not comprise wireless communication links, but where it is desirable to reduce or minimize the need for transmission data loss during communication between a transmitting and receiving device. For example, the method of the present invention can be used with fiber optic communications, cable based networks and other communication systems where the transmission of information occurs. In various embodiments, the nodes described herein are implemented using one or more modules to carry out the steps corresponding to one or more methods of the present invention, for example, signal processing steps, message generation and / or transmission. Therefore, in some embodiments several features of the present invention are implemented using modules. These modules can be implemented using software, hardware or a combination of software and hardware. Many of the methods or steps of methods described above can be implemented using machine executable instructions, such as software, included in a machine-readable medium such as a memory device, e.g., RAM, floppy disk, etc., for controlling a machine, for example a general-purpose computer with or without additional hardware, to implement all or part of the methods described above, for example, in one or more nodes. Accordingly, among other things, the present invention is directed to a machine-readable medium that includes machine executable instructions for causing a machine, e.g., an associated processor or hardware, to perform one or more of the steps of the method (s) described above. Those skilled in the art will appreciate numerous additional variations in the methods and apparatus of the present invention described above, by virtue of the detailed description of the previous invention. Said variations will be considered within the scope of the present invention. The methods and apparatuses of the present invention can, and in various embodiments, are in fact used with CDMA, orthogonal frequency division multiplexing (OFDM) communication techniques, or other various types of communication techniques that can be used to provide Wireless communication links between access nodes and mobile nodes. In some modalities, the access nodes are implemented as base stations, which establishes communication links with mobile nodes using OFDM and / or CDMA. In various modalities the mobile nodes are implemented as note computers, personal data assistants (PDAs) or other portable devices including reception / transmission circuits and logic and / or routines, to implement the methods of the present invention.

Claims (38)

1. Novelty of the Invention Having described the present invention, it is considered as a novelty and, therefore, the content of the following is claimed as property: R E I V I N D I C A C I O N S 1. A communication method, wherein the method comprises: operating a first communication apparatus for: i) carrying out a decoding operation on a first signal including encoded signal information; ii) determine if the encoded signal information included in the first signal was decoded successfully; and iii) when it is determined that the encoded information was not successfully decoded, generate a first NAK signal having a plurality of possible NAK signal values, each corresponding to the plurality of possible NAK signal values at a different level of decoding success. The method according to claim 1, characterized in that the decoding operation produces decoded information, wherein the step of generating a first NAK signal includes: selecting the first signal value NAK as a function of the decoded information quality. The method according to claim 2, characterized in that it further comprises: when it is determined that the encoded information was not decoded successfully, generate an ACK signal having an ACK signal value; wherein each signal value NAK, at the plurality of signal values NAK, differs from any other signal values NAK in the plurality through a quantity which is the smallest amount, wherein any of the NAK signal values differs from said ACK signal value. 4. The method according to claim 3, characterized in that the NAK and ACK signals are complex signals wherein the NAK signal values and the ACK signal values are phase values. The method according to claim 1, characterized in that the operation of the first apparatus for carrying out a decoding operation includes: determining the quality of decoded information generated by the decoding of the encoded information; wherein the operation the first apparatus for generating a first NAK signal, includes operating the first apparatus for selecting the first signal value NAK as a function of the determined quality of the decoded information; and wherein the operation of the first apparatus further includes operating the first apparatus for transmitting the first NAK signal generated. 6. The method according to claim 5, characterized in that the determination of the quality of the decoded information includes: maintaining decoding statistics that indicate the reliability of the decoded information, the decoding statistics indicating the quality of the decoded information. The method according to claim 6, characterized in that the decoding statistics maintained include a count of the number of errors detected in the decoded information. The method according to claim 5, characterized in that it further comprises: operating the first apparatus for transmitting the first NAK signal; operate one second to: i) receive the first NAK signal; ii) determining, from the first signal value NAK, a redundant amount of information to transmit to the first apparatus, different amounts of redundant information that is being determined for at least two different signal values NAK. The method according to claim 5, characterized in that it further comprises: operating the first apparatus for: transmitting the first NAK signal generated; receiving a second signal including redundant information corresponding to the first received encoded signal; carry out an additional decoding operation using redundant information and information obtained from the first received signal; and determining whether the additional decoding operation successfully decoded the encoded signal information included in the first signal. The method according to claim 9, characterized in that the step of operating the first apparatus for carrying out a further decoding operation includes: receiving a channel assignment message of a second device; identify the information included in the traffic channel assignment message, the first signal to which the second signal corresponds. 11. The method according to claim 10, characterized in that the first apparatus is a mobile node and the second apparatus is a base station; wherein the information included in the traffic channel allocation message used to identify the first signal is an index of a traffic segment that is used to transmit the first signal. The method according to claim 10, characterized in that the first apparatus is a mobile node and the second apparatus is a base; and wherein the information included in the traffic channel assignment message used to identify the first signal is a difference of the traffic channel index indicating a difference between the index of a traffic channel segment associated with the message of allocation, and a segment of traffic channel used to transmit the first signal. The method according to claim 9, characterized in that the first apparatus is a base station and the second apparatus is a mobile node, wherein the method further comprises: operating the first apparatus for transmitting a link channel assignment message ascending to the second apparatus; operating the second apparatus for identifying the information included in the uplink channel allocation message, the first signal of the redundant information that will be transmitted in an uplink channel segment allocated by the channel assignment message; and operating the second apparatus for transmitting the second signal including redundant information. The method according to claim 13, characterized in that the information included in the uplink channel allocation message that is used to identify the first signal is an index of an uplink traffic segment that is used for transmit the first signal. The method according to claim 13, characterized in that the information included in the assignment message of the traffic channel that is used to identify the first signal, is a difference of the uplink traffic channel index indicating a difference between an index of an uplink traffic channel segment with the allocation message and an uplink traffic channel segment that is used to transmit the first signal. The method according to claim 9, characterized in that the second signal includes, in addition to the redundant information, new coded information, and wherein the method further comprises: operating the first apparatus for decoding the new coded information. The method according to claim 9, characterized in that it further comprises: operating the first apparatus to determine if the encoded signal information included in the first signal was decoded successfully through the additional decoding operation; and when it is determined that the encoded information was not properly decoded through the additional decoding operation, the first apparatus is operated to generate a second signal NAK having one of a plurality of possible signal values NAK, each plurality corresponding of possible NAK signal values at a different level of decoding success, the first apparatus operating to generate a second NAK signal including selecting a second NAK signal value as a function of the decoded information quality generated by the additional decoding operation . The method according to claim 1, characterized in that it further comprises: operating a second communication apparatus for: i) carrying out a coding operation on the information that will be transmitted, to produce a first group of encoded information and a redundant information group; ii) transmit the first group of information encoded in the first signal. 19. The method according to claim 18, characterized in that the second communication apparatus further includes operating the second communication apparatus for: transmitting in a traffic channel assignment message that is used to assign a traffic channel segment used to transmit the first signal, an indicator indicating that the first signal does not correspond to a previously transmitted signal. The method according to claim 18, characterized in that the operation of the second communication device further includes: operating the second communication device for: receiving a NAK signal from the first device, the NAK signal corresponding to the first signal; and determining from the value of the received NAK signal which part of the redundant information group transmits to the first apparatus. The method according to claim 20, characterized in that the operation of the second communication device to determine which part of the redundant information group to transmit to the first apparatus includes: selecting the size of the redundant information group part, as a function of the value of the received NAK signal, a greater part being selected, when the value of the signal NAK indicates a first level of success of decoding, than when the value of the signal NAK indicates a second level of success of decoding, which indicates more decoding success than the first level. The method according to claim 20, characterized in that it further comprises: operating the second communication device for transmitting the determined part of the group of redundant information to the first apparatus in a second information signal. The method according to claim 22, characterized in that it further comprises: operating the second communication apparatus for transmitting an allocation message that is used to assign a channel segment that is used to transmit the second information signal, including the assignment message information including indicating the first signal previously transmitted to which the redundant information included in the second information signal corresponds, the assignment message being transmitted before the second information signal. The method according to claim 22, characterized in that it further comprises: operating the second communication apparatus for: carrying out a second encoding operation on the additional information that will be transmitted, for producing a second group of encoded information and a second group of redundant information; and wherein the operation of the second communication apparatus for transmitting a second information signal includes operating the second communication apparatus so that the second information signal includes a portion of the second group of encoded information. 25. The method according to claim 18, characterized in that the coding operation is a low density parity revision coding operation. 26. A communication apparatus comprising: means for performing a decoding operation on a first signal including the encoded signal information; means for determining if the encoded signal information included in the first signal was decoded successfully; and means for generating a first NAK signal having one of a plurality of possible signal values NAK, when it is determined that the encoded information was not decoded successfully, each plurality of possible NAK signal values corresponding to a different level of success of decoding of signal. 27. The apparatus according to claim 26, characterized in that the means for carrying out a decoding operation produce decoded information; and wherein the means for generating the first NAK signal, selects the first signal value NAK as a function of the quality of the decoded information. The communication apparatus according to claim 27, characterized in that it further comprises: a transmitter, coupled to the means for generating a first NAK signal, for transmitting the first NAK signal generated; a receiver for receiving a second signal including redundant information corresponding to the first received encoded signal; wherein the means for carrying out the decoding operation includes means for carrying out an additional decoding operation using the redundant information and the information obtained from the first received signal. The communication apparatus according to claim 28, characterized in that it further comprises: means for determining whether the additional decoding operation successfully decoded the encoded signal information included in the first signal; and means for generating a second NAK signal by selecting a second signal value NAK as a function of the decoded information quality generated by the additional decoding operation, when it is determined that the encoded information was not properly decoded through the operation of further decoding, the second NAK signal having one of a plurality of possible signal values NAK. 30. A method for operating a communication apparatus, comprising: encoding, using an encoder, information that will be transmitted to produce a first group of encoded information and a group of redundant information; transmit the first group of information encoded in a first signal; receiving a NAK signal from an apparatus to which the first signal was transmitted; and selecting a part of the redundant information group to transmit to the first apparatus as a function of the value of the received NAK signal, the function originating different amounts of redundant information that will be selected for at least two different possible NAK signal values. The method according to claim 30, characterized in that it further comprises: including in a first allocation signal that is used to assign a segment of communication channel that is used to transmit the first signal, an indicator indicating that the first signal does not correspond to a previously transmitted signal; transmit the first assignment signal before or in parallel with the transmission of the first signal. 32. The method according to claim 30, characterized in that the selection of a part of the redundant information group that will be transmitted includes selecting a greater part of redundant information when the value of the NAK signal indicates a first level of signal quality. encoded received, that when the value of the signal NAK indicates a second level of encoded signal quality received, which is better than the first level of encoded signal quality received. 33. The method in accordance with the claim 32, characterized in that it further comprises: transmitting a second allocation signal indicating an allocation of a channel segment that will be used to transmit the selected part of the redundant information group, including the second allocation signal identifying information a channel segment that it is used to transmit the first signal; and transmitting the selected part of the redundant information group to the first apparatus in a second information signal. 34. The method of compliance with the claim 33, characterized in that it further comprises: carrying out a second encoding operation on additional information that will be transmitted to produce a second group of encoded information and a second group of redundant information; and wherein the transmission of a second information signal includes: including in the second information signal a part of the second group of encoded information. 35. The method according to claim 30, characterized in that the coding operation is a low density parity revision coding operation. 36. A communication apparatus comprising: an encoder for encoding information that will be transmitted to produce a first group of encoded information and a redundant information group; a transmitter for transmitting the first group of information encoded in a first signal; a receiver for receiving a NAK signal from an apparatus to which the first signal was transmitted; and means for selecting a part of the group of redundant information to transmit to the first apparatus, as a function of the value of the received signal NAK, the function originating different amounts of redundant information that will be selected for at least two different possible NAK signal values. 37. The apparatus according to claim 36, characterized in that it further comprises: means for generating an allocation signal that is used to assign a communication channel segment that is used to transmit the first signal of the allocation signal, which includes an indicator indicating that the first signal does not correspond to a first signal previously transmitted; and means for controlling the transmission of the first assignment signal before transmitting the first signal. 38. The method according to claim 36, characterized in that the selection means selects a part of the group of redundant information that will be transmitted, selects a first part when the value of the signal NAK indicates a first level of encoded signal quality received, the first part being a greater part of redundant information than a second part which is selected through the selection means, when the value of the signal NAK indicates a second level of encoded signal quality received which is better at the first encoded signal quality level received. RE S UME N Different NAK signals are used to indicate different relative levels of success with respect to an unsuccessful attempt to decode a received signal. An ACK signal is used in the case of successful decoding. The apparatus that generated and transmitted the original encoded signal receives the NAK signal and selects a portion of redundant information, i.e., additional error correction bits, to be transmitted based on the value of the NAK signal. If the NAK signal indicates a low level of success in decoding by indicating a relatively large number of errors in the decoded signal, a large set of redundant information is selected and transmitted. If the NAK signal indicates a relatively successful decoding, that is, relatively few errors, a small set of redundant information is selected and transmitted. Where a small set of redundant information is transmitted, new information can be transmitted with the redundant information.