KR20030056550A - Apparatus and method for rate matching in data telecommunication system - Google Patents

Abstract

PURPOSE: A rate matching apparatus of a data communication system and a method thereof are provided to match channel-encoded symbols with a transmission rate appropriate for a physical layer to transmit. CONSTITUTION: According to the rate matching apparatus in a digital communication system, a channel encoder unit(220) performs a channel encoding as to input information bits. A multiplexer unit(260) performs a time division multiplexing as to symbols channel-encoded by the above channel encoder unit regularly. A parameter converter unit(1440) provides input parameter value required in the transmission rate matching. And a transmission rate matching unit(1430) reproduces symbols as much as appropriate for a physical layer by puncturing or repetition as to multiplexed channel encoded symbols and then matches them with a transmission rate appropriate for the physical layer to transmit, according to the above input parameter value.

Description

Apparatus and method for rate matching in data telecommunication system

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a rate matching device and a method of a data communication system, and more particularly, to match a rate of channel coded symbols to a physical channel in a digital mobile communication system.

In general, in wired and wireless digital communication systems, in order to improve the reception quality (indicated by bit error rate, frame error rate, etc.) of a transmission signal under the condition of using the same energy, or to reduce the transmission energy required to satisfy the same reception quality, Source data on the side is channel-coded using an error correction code and then transmitted. In this case, a convolutional code and a linear block code may be used as the channel code.

Recently, Turbo Codes, first proposed in 1993, have been used to obtain higher channel coding gains.

On the other hand, in a multi-access communication system using a multi-user and a multi-channel communication system for multi-users, in order to improve data transmission efficiency and improve system performance, channel-coded symbols are matched with a given number of transmission channel symbols. A process to make it work This process is called "rate matching".

Rate matching also refers to performing a process of matching an output symbol rate with a transmission symbol rate. Typically, there is a method of puncturing or repetition of some of the channel coded symbols as a method of matching the rate.

The rate matching device that was used before the new prior art (rate and rate matching device and method of data communication system, application number 10-2000-0038716) was proposed is configured as shown in FIG.

Referring to FIG. 1, a channel encoder 100 encodes input information bits k according to a code rate R = k / n, and encodes encoded symbols n. Outputs

In addition, the multiplexer (MUX) 110 multiplexes the symbols encoded by the channel encoder 100.

In addition, the rate matching block 12 matches the channel coded symbols multiplexed by the multiplexer 110 to a rate suitable for a physical channel by puncturing or repetition, thereby providing a channel transmitter (FIG. (Not shown).

At this time, the channel encoder 100 operates at a rising edge or a falling edge of a symbol clock having a speed of clock CLOCK, and the multiplexer 110 and the rate matching unit 120 are n. It operates at the rising edge or falling edge of a clock with a speed of CLOCK.

The rate matching device as shown in FIG. 1 is a proposed configuration for applying to a case of channel coding using a non-systematic code such as a convolutional code or a linear block code. Symbols channel-coded by unstructured codes, such as convolutional codes or linear block codes, have no weight between the symbols. This is because the error sensitivity of the coded symbols output from the channel encoder 100 is almost similar for all the symbols in one frame. Therefore, even if the symbols encoded by the channel encoder 100 are inputted to the rate matching unit 120 without being distinguished and punctured or repeated, there is no difference in performance.

However, since symbols coded by a structural code such as a turbo code have weights among the symbols, it is preferable that the channel coded symbols are input to the rate matching unit 120 and punctured or repeated in the same manner. not. This is because the weights of information symbols or systematic symbols and parity symbols are not the same.

That is, when the number of channel-coded symbols is larger than the number of symbols suitable for the physical channel and the puncturing is to be performed, the additional symbols among the turbo-coded symbols may be punctured when the rate matching unit 120 performs the puncturing process. It is desirable that they are not as perforated as possible.

In addition, when the rate matching unit 120 iteratively processes, information symbols of the turbo coded symbols should be repeated as much as possible to increase the energy of the symbol. However, it is advantageous that the additional symbols are not repeated. That is, in the case of using a structural code such as a turbo code, it is not preferable to use a rate matching device as shown in FIG.

In order to solve these problems, some schemes of rate matching the symbols encoded by the turbo code have been proposed, but only applicable to the rate matching of the turbo coded symbols. This could not be applied in case of rate matching the symbols encoded by the channel.

Proposed a method of rate matching the symbols encoded by the unstructured code and the symbols encoded by the structural code is a "rate and rate matching device and method of the data communication system (application number: 10-2000-0038716)" ( Hereinafter referred to as "prior art"). Here, in a data communication system designed to support both unstructured and structured codes, two different structures are not required to match the rate for each code, and one structure can be applied to each code. We wanted to reduce the complexity.

DETAILED DESCRIPTION Hereinafter, a detailed description of the prior art and embodiments of the present invention will be made with reference to the accompanying drawings. In the following, in adding reference numerals to components of each drawing, it should be noted that the same reference numerals are used to refer to the same components as much as possible, even if displayed on different drawings. In addition, in the following description of the prior art and the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the prior art and the present invention, the detailed description thereof will be omitted.

The conditions required for designing the rate matching device mentioned in the prior art are as follows.

First, prior to describing the prior art, the conditions to be considered in case of rate matching of symbols encoded by unstructured codes (hereinafter, typically referred to as "convolutional codes") such as convolutional codes or linear block codes are summarized. If you look like this:

Among the following conditions, (Conditions 1A to 3A) are the conditions to be considered in case of rate matching of the coded symbols by puncturing (the puncturing conditions of the symbols coded by the channel by the unstructured code), and (condition 1C to 2C are conditions to be considered in case of rate matching of coded symbols by repetition (repetition condition of symbol coded by channel code by unstructured code).

-Puncturing condition of symbol coded by unstructured code

(Condition 1A): The input symbol sequence, which is an encoded symbol, is punctured in a puncturing pattern having a certain period.

(Condition 2A): Minimize the number of puncturing bits of the input symbol.

(Condition 3A): A uniform puncturing pattern is used so that it can be punctured evenly in an input symbol sequence which is a coded symbol output from a channel encoder.

-Repetition Condition of Channel Coded Symbol by Unstructured Code

(Condition 1C): The input symbol sequence, which is a channel coded symbol, is repeated in a repetition pattern having a certain period.

(Condition 2C): A uniform repetition pattern is used so that it can be repeated evenly in an input symbol sequence which is a coded symbol output from a channel encoder.

In summary, the puncturing and repetition conditions are that both puncturing and repetition must be evenly distributed in the symbol sequences sequentially output from the channel encoder 100. These items start from the assumption that the error sensitivity of a symbol output from an encoder using convolutional code is almost the same for all symbols in one frame (signer).

In the case of rate matching the symbols encoded by the structural code (particularly, the turbo code), the following matters should be considered.

Among the following conditions, (conditions 1B to 5B) are conditions to be considered when rate matching the channel coded symbols by puncturing (the puncturing conditions of the channel coded symbols by structural codes), and (conditions 1D to 5D). Are the conditions (repetition conditions of the channel coded symbols by the structural code) to be considered when rate matching the channel coded symbols by repetition.

-Puncturing condition of symbol encoded by channel code

(Condition 1B): The part corresponding to the information symbol among the symbols encoded by the channel encoder should not be punctured. Particularly, in the case of code that performs channel decoding using an iterative decoder such as a turbo code, it is preferable not to puncture a portion corresponding to an information symbol.

(Condition 2B): Since the turbo encoder is composed of a plurality of component encoders or constituent encoders connected in parallel, the minimum free dista * Nce of the entire code is the maximum free distance of each of the two component encoders. It is preferable to set it as. Therefore, it is necessary to puncture the output symbols of the two component encoders evenly to obtain the best performance.

(Condition 3B): In most iterative decoders, since the decoding is performed from the first internal decoder, the first output symbol of the first component encoder should not be punctured. In other words, since the first symbol of the encoder indicates the starting point of the encoding, the first symbol should not be punctured regardless of whether the first symbol is a structural or additional bit.

(Condition 4B): The output additional symbol of each component encoder must be punctured using a uniform puncturing pattern so that the codeword symbols output from the encoder can be punctured evenly as in the conventional convolutional code.

(Condition 5B): Due to the adverse effect on the performance of the channel decoder, the termination bits used for the turbo encoder should not be punctured. For example, when the SOVA (Soft Output Viterbi Algorithm) decoder is used, the performance when puncturing the end bits is lower than the performance without puncturing.

-Repetition Condition of Channel Coded Symbol by Structural Code

(Condition 1D): The part corresponding to the information symbol among the symbols encoded by the channel encoder should be repeated as much as possible to increase the energy of the symbol. In particular, since the turbo code uses an iterative decoder, the part corresponding to the information symbol should be repeated frequently.

(Condition 2D): Since the turbo encoder consists of two component encoders connected in parallel, it is preferable that the minimum free dista * Nce of the entire code maximizes the minimum free distance of each of the two encoders. Do. Therefore, when additional symbols are repeated, the output additional symbols of the two constituent encoders should be repeated evenly to obtain the best performance.

(Condition 3D): In most iterative decoders, since the decoding is performed from the first internal decoder, the first output symbol of the first component encoder is preferentially repeated when additional symbols are repeated.

(Condition 4D): The output additional symbols of each constituent encoder must be repeated using a uniform repetition pattern so that the coded symbols outputted from the encoder can be repeated equally like the existing convolutional codes.

(Condition 5D): Due to the effect on the performance of the decoder, the termination bits used for the turbo encoder are repeated. For example, when using a SOVA (Soft Output ViterbiAlgorithm) decoder, there is a difference in performance due to repetition of end bits.

The prior art implements a rate matching device that satisfies the conditions given in (Conditions 1B to 5B) / (Conditions 1D to 5D) in addition to the above (Conditions 1A to 3A) / (Conditions 1C to 2C). That is, the conventional rate matching device for puncturing also performs an operation as a rate matching device for convolutional coded symbols satisfying the above conditions (conditions 1A to 3A), and among the above conditions (condition 1B An operation as a rate matching device for turbo coded symbols satisfying ˜5B) is also performed.

The repetition rate matching device according to the prior art also performs an operation as a rate matching device for convolutional coded symbols satisfying the above conditions (conditions 1C to 2C), and among the above conditions (conditions 1D to 5D). It also performs an operation as a rate matching device for turbo coded symbols that satisfy

Next, the basic configuration of the rate matching device of the prior art will be described.

The construction of a rate matching device according to the prior art is shown in FIGS. 2 and 3. 2 illustrates an example of hardware implementation of a rate matching device according to the prior art, and FIG. 3 illustrates an example of software implementation of a rate matching device according to the prior art.

Referring to FIG. 2, the channel encoder 200 performs channel encoding on input information bits according to a code rate R = k / n to output encoded symbols. Here, n denotes the number of coded symbols constituting one code word, and k denotes the number of input information bits constituting an input information word.

In addition, each of the n bit rate matching units 231 through 239 separately receives encoded symbols in units of frames output from the channel encoder 200 by the same number of input symbols determined according to the code rate, and punctures / receives the received symbols. Repeat it. That is, each of the n bit rate matching units 231 through 239 inputs encoded symbols output from the channel encoder 200 in the same way as the product of the number of encoded symbols in the frame and the code rate. For example, if the number of encoded symbols in one frame is 10 and the code rate is R = 1/5, two symbols are input separately to each of the five rate matching units. Each of the rate matching units 231 through 239 punctures and outputs input symbols according to a predetermined puncturing pattern, or repeatedly outputs input symbols according to a predetermined repeating pattern.

In addition, the multiplexer (MUX) 240 multiplexes the rate matched symbols from each of the rate matchers 231 through 239 and outputs the multiplexed symbols to a channel transmitter (not shown). Here, since the channel transmitter is not within the scope of the prior art and the present invention, a detailed configuration and operation description thereof will be omitted. The rate matching operation of each of the rate matching units 231 to 239 is described in more detail in the following description of the related art.

Referring to FIG. 3, the channel encoder 200 outputs encoded symbols by channel coding input information bits according to a code rate (R = k / n).

In addition, the digital signal processor (DSP) 250 has a rate matching module, and rate matching (punctuation / repetition) of the channel coded symbols by the channel encoder 200 is performed by the rate matching module. ) In this case, the symbols matched by the rate matching DSP 250 are output to a channel transmitter (not shown).

Here, the rate matching DSP 250 receives and punctures / repeats the symbols of one frame among the n separated data streams in the same manner as shown in FIG. 2. At this time, the number of symbols received from each stream is equal to the number of input symbols determined according to the code rate. In other words, the DSP 250 is one component in hardware, but its operation is performed in the same manner as the n rate matching units 231 to 239 shown in FIG. The DSP 250 may be implemented as a central processing unit (CPU), and the rate matching operation may be implemented as a subroutine. Here, when " rate matching units " is used, it refers to rate matching modules in the DSP 250.

As shown in FIG. 2 and FIG. 3, the rate matching device according to the prior art has a number corresponding to a code rate (for example, an inverse of the code rate when k = 1, and a rate matching when k = 1 is not). The number of parts may have a structure consisting of a rate matching part equal to the inverse of the code rate k multiplied by each, and each rate matching part is determined according to the code rate (the number of coded symbols in the frame and the code). Multiplied by a rate), and punctures the received symbols according to a predetermined puncturing pattern or iteratively processes the predetermined symbols. This configuration has a big difference in that the rate matching device shown in FIG. 1 processes channel coded symbols in units of frames, and separates and processes channel coded symbols. However, the rate matching device according to the prior art having such a changed structure can be used for convolutional codes and also for turbo codes. That is, the rate matching device according to the prior art has a single structure that can be applied to both the convolutional code and the turbo code even though two different conditions are required.

The rate matching device according to the prior art may also be configured as shown in FIG. The rate matching device is a combination of a rate matching device as shown in FIG. 1 and a rate matching device according to the prior art as shown in FIGS. 2 and 3. At this time, since only one rate matching unit 230 is implemented, even if the rate matching device is implemented in hardware, there is no increase in complexity.

Referring to FIG. 8, the channel encoder 200 performs channel coding on input information bits according to a code rate R = k / n and outputs encoded symbols. In this case, the encoded symbols are multiplexed by the multiplexer (MUX) 260 and the multiplexed encoded symbols are output to the rate matching unit 230. Subsequently, symbols that are punctured / repeated and matched by the rate matching unit 230 are output to a channel transmitter (not shown) and processed for channel transmission.

The random access memory (RAM) 270 receives and stores an initial value during the rate matching process by the rate matching unit 230, and then provides the random value to the rate matching unit 270.

In addition, the channel encoder 200 is operated in the period of every symbol clock having the speed of clock (CLOCK), and the multiplexer (MUX) 260 and the rate matching unit 230 have a speed of (n CLOCK). Operate at a preset period of the clock. At this time, the initial values provided to the RAM 270 include the number of input symbols Nc, the number of output symbols Ni, an error value e, and a parameter (a, b) for determining a puncturing / repeat pattern. The number of symbols to be punctured for each frame of coded symbols is determined by the number Nc of input symbols and the number Ni of output symbols.

Further, the RAM 270 may determine the number of input symbols Nc corresponding to each symbol clock in the set period, the number of output symbols Ni, an error value e, and a parameter for determining a puncturing / repeating pattern (a, b). ) Is being saved.

In addition, when the rate matching unit 230 performs rate matching by puncturing, the number of corresponding input symbols Nc, the number of output symbols Ni, and the error value e stored in the RAM 270 in every symbol clock period. And receiving the parameters (a, b) for determining the puncturing pattern to determine whether a specific symbol processed in every symbol clock period is a symbol to be punctured, and performing puncturing according to the corresponding puncturing pattern. Further, when the rate matching unit 230 performs rate matching by repetition, the number Nc of corresponding input symbols stored in the RAM 270 in each symbol clock period, the number Ni of output symbols, and the error value e And receiving the parameters (a, b) for determining a repetition pattern to determine whether a particular symbol processed in every symbol clock period is a symbol to be repeated, and performing repetitive operation according to the corresponding repetition pattern.

If a convolutional code or a linear block code is used for the channel encoder 200, a parameter (Nc, Ni, e, b, a) for one puncture / repeat is initially set to the RAM 270. ) And set it up. That is, a rate matching block (RMB) 230 may operate as shown in FIG. 1 without having to update the RAM 270.

On the other hand, when a turbo code is used for the channel encoder 200, the rate matching unit 230 must be operated sequentially from RMB1 to RMBn in every symbol clock period designated as the period n. In this case, RMBx (x is 1 to n) is associated with Nc, Ni, e, b and a values, and period n is a clock period having a CLOCK speed. In other words, in every period of the clock having a rate of n × CLOCK, the rate matching unit 230 is updated with Nc, Ni, e, b, and a values to operate as one of RMBx (x is 1 to n). Thus, at every period n, the rate matcher 230 is updated with Nc, Ni, e, b and a values to operate as each RMBx. For example, the rate matching unit 230 receives the values of Nc, Ni, e, b, and a for RMB1 during one period of 1 / (n × CLOCK), and the next period of 1 / (n × CLOCK). An operation such as receiving Nc, Ni, e, b and a values for RMB2 is performed until the values for RMBn are received. Next, in the next period "n", the same operation as described above is repeated again. Therefore, the RAM (Nc, Ni, e, b, a) for determining the state value of the processed RMBx at one point, that is, the symbols Nc, Ni, e, b, a for puncturing / repeat Save at 270. Therefore, when this RMBx is processed again next time, this value can be used to process all the operations of n RMB1 to RMBn with one RMB. At this time, since the processing speed uses n × CLOCK as shown in FIGS. 1 and 2, there is no increase in complexity.

Meanwhile, in FIG. 2, each of the rate matching units 231 to 239 separates and inputs the symbols encoded by the channel encoder 200 to be equal to the product of the number of encoded symbols in one frame and the code rate. It was. However, it should be noted that each of the rate matching units 231 to 239 may input the symbols encoded by the channel encoder 200 into different numbers. For example, one of the rate matching units 231 to 239 separates and inputs a number of symbols smaller than a product of the code rate and the number of coded symbols in one frame among the coded symbols. Alternatively, the other rate matching unit may separately input a number of symbols larger than the product of the code rate and the number of coded symbols in one frame among the coded symbols. However, for convenience of description, the following description will be limited to an example in which the rate matching units 231 to 239 are inputted by separating the symbols encoded by the channel encoder 200 by the same number.

The configuration and operation of the rate matching device will now be described. Here, for convenience of explanation, the case where the code rate R = 1/3 and thus the rate matching unit consists of three will be described as an example. However, the rate matching device according to the prior art can be equally applied to the case where the rate matching unit consists of n, that is, the code rate R = k / n. In the following, Ncs represents the total number of encoded symbols included in one frame output from the channel encoder. In addition, Nc represents the number of symbols input to each rate matching unit, and the number of input symbols is determined as Nc = R × Ncs. In the following description, Nc = R × Ncs = 1/3 × Ncs = Ncs / 3. In addition, Nis is the sum of the total number of symbols output after the rate matching process, that is, the number of symbols output from each rate matching unit. In addition, Ni represents the number of symbols output from each rate matching unit, and the number of output symbols is determined as Ni = R x Nis (hereinafter, Nis / 3). Therefore, the number of symbols (bits) to be punctured / repeated at each rate matching part depends on the relationship of y = Nc-Ni. The values of Nc and Ni can be changed.

In the prior art, parameters (a, b) are used, which is a constant value determined according to the puncturing / repeat pattern in one frame, that is, a constant value for determining the puncturing / repeat pattern. The parameter a is an offset value that determines the position of the first symbol of the puncturing / repeating pattern. That is, by a, it is determined how many symbols among the encoded symbols included in one frame are the first symbols of the puncturing / repetition pattern. When the value of parameter a increases, the symbol located in front of the frame is punctured / repeated. In addition, the parameter b is a value that controls the period of puncturing in the frame, and by changing this value, all coded symbols included in the frame can be punctured / repeated.

As described above, the rate matching device according to the prior art may perform a rate matching operation by puncturing or may perform a rate matching operation by repetition. In the following description, a transmission rate matching device according to an embodiment of the prior art is divided into a case of puncturing and a case of repetitive processing.

A. An example of a rate matching device by puncturing will be described by dividing a case of a convolutional code and an example of a turbo code.

A1. Example of rate matching device by puncturing (in case of convolutional code)

4 is a block diagram of a transmission rate matching device according to the prior art. This configuration shows an example that the rate matching device as shown in FIG. 2 and FIG. 3 is applied to a rate matching process by puncturing convolutional coded symbols.

Referring to FIG. 4, the convolutional encoder 210 inputs an input information bit Ik, encodes the data according to a code rate R = 1/3, and outputs encoded symbols C1k, C2k, and C3k. In this case, each of the encoded symbols C1k, C2k, and C3k is separated and input to each of the rate matching units 231 to 233.

Here, the first rate matching unit 231 inputs the encoded symbol C1k, punctures it, and outputs it. At this time, the puncturing process is performed according to the number of puncturing symbols y = Nc-Ni and the puncturing pattern determination parameters (a, b) determined by the number Nc of input symbols and the number Ni of output symbols. As an example, the first rate matching unit 231 may output symbols such as "... 11x10x01x ..." (where x is a punctured symbol).

In addition, the second rate matching unit 232 inputs the encoded symbol C2k, punctures it, and outputs the result. At this time, the puncturing process is performed according to the number of puncturing symbols y = Nc-Ni and the puncturing pattern determination parameters (a, b) determined by the number Nc of input symbols and the number Ni of output symbols. As an example, the second rate matching unit 232 may output symbols such as "11 x 11 x 10 x ..." (where x is a punctured symbol).

In addition, the third rate matching unit 233 inputs the encoded symbol C3k, punctures it, and outputs the result. At this time, the puncturing process is performed according to the number of puncturing symbols y = Nc-Ni and the puncturing pattern determination parameters (a, b) determined by the number Nc of input symbols and the number Ni of output symbols. As an example, the third rate matching unit 233 may output symbols such as "... 01x11x11x ..." (where x is a punctured symbol).

Coded symbols whose rate matched by the rate matching units 231 to 233 are multiplexed by the multiplexer (MUX) 240 and then output to a channel transmitter (not shown).

In Fig. 4, the number Nc of input symbols and the number Ni of output symbols are set to Nc = R × Ncs and Ni = R × Nis in the same manner for all the rate matching units 231 to 233. The rate matching units 231 to 233 which separate and puncture channel coded symbols are punctured by the same number of symbols, indicating that the error sensitivity of the coded symbols is almost the same for all symbols in one frame. By home. That is, a puncturing pattern having a substantially uniform shape is provided in one frame irrespective of the number of various puncturing bits arbitrarily determined by the type of service. This is because, in the case of convolutional code, the entire symbol in one frame may be punctured uniformly.

Therefore, according to the related art, the symbols encoded by the convolutional encoder 210 are divided into the same number and input to the rate matching units 231 to 233. Each of the rate matching units 231 to 233 punctures and outputs the same number of input symbols. In this case, the puncturing pattern parameters may be determined identically or differently. That is, the puncturing patterns may be determined in the same rate matching units 231 to 233 or may be determined differently.

A2. Another example of rate matching device by perforation (for turbo code)

5 is another configuration diagram of a rate matching device by perforation according to the prior art. This configuration shows an example that the rate matching device as shown in FIG. 2 and FIG. 3 is applied to a rate matching process by puncturing a turbo coded symbol.

Referring to FIG. 5, the turbo encoder 220 inputs an input information bit Ik and encodes the data according to a code rate R = 1/3, and then outputs encoded symbols C1k, C2k, and C3k. In this case, the information symbols C1k among the encoded symbols are separated and input to the first rate matching unit 231, and additional symbols C2k and C3k are separated to form the second and the second symbols. 3 are input to the rate matching units 232 and 233, respectively.

Here, the turbo encoder 220 includes a first component coder 222, a second component coder 224, and an interleaver 226, as shown in FIG. 6. Since the configuration of the turbo encoder 220 is well known to those skilled in the art, a detailed description of the operation will be omitted.

The input X (t) of the turbo encoder 220 corresponds to the input information bit Ik shown in FIG. The outputs X (t), Y (t) and Y '(t) of the turbo encoder 220 correspond to the encoded symbols C1k, C2k and C3k shown in FIG. Since the input information bit Ik is output as it is to the first output X (t) of the turbo encoder 220, the input information bit Ik is output as it is to C1k.

In addition, the first rate matching unit 231 inputs the encoded symbol C1k, punctures it, and outputs the punctured signal. At this time, the standard of the puncture treatment is as follows.

Since the number of input symbols Nc is code rate R = 1/3, it is determined that Nc = R × Ncs = Ncs / 3 which is one third of the total number of coded symbols. The number Ni of output symbols is determined to be Ni = R × Ncs because no puncture is found in the portion corresponding to the information symbols according to (Condition 1B). Since the puncturing pattern determination parameters (a, b) do not have puncturing according to (Condition 1B), they may be set to any constant. For example, the first rate matching unit 231 may output a symbol such as "..111101011...".

In addition, the second rate matching unit 232 inputs the encoded symbol C2k, punctures it, and outputs the result. At this time, the standard of the puncture treatment is as follows.

Since the number of input symbols Nc is code rate R = 1/3, it is determined as R × Ncs = Ncs / 3 which is one third of the total number of coded symbols. According to (Condition 2B) and (Condition 4B), the output additional symbols of the two component decoders 222 and 224 must be punctured evenly and output after being punctured for the entire input symbol Ncs for one frame. Since the total number of symbols is Nis, the number Ni of symbols output after being punctured by the second rate matching unit 232 becomes [Nis- (R × Ncs)] / 2. At this time, if Ni = [Nis- (R × Ncs)] / 2 is odd, the number of output symbols Ni is [Nis- (R × Ncs) +1] / 2 or [Nis- (R × Ncs)- 1] / 2. The selection of the two is determined according to the relationship between the second rate matching unit 232 and the third rate matching unit 233. That is, when the number of output symbols of the second rate matching unit 232 is determined to be [Nis- (R × Ncs) +1] / 2, the number of output symbols of the third rate matching unit 233 is [Nis- ( R x Ncs) -1] / 2. In contrast, when the number of output symbols of the second rate matching unit 232 is determined to be [Nis- (R × Ncs) -1] / 2, the number of output symbols of the third rate matching unit 233 is equal to [Nis- ( R x N cs) +1] / 2.

The puncturing pattern determination parameters (a, b) may be selected as any integer value according to the desired puncturing pattern. The determination of this integer value depends entirely on the perforation pattern, and constants of b = 1 and a = 2 can be used. Integer value determination of the puncture pattern determination parameter will be described in detail with reference to the table described below. As an example, the second rate matching unit 232 may output symbols such as "... 11x11x10x ..." (where x is a punctured symbol).

The third rate matching unit 233 inputs the encoded symbol C3k, punctures it, and outputs the puncturing process. At this time, the standard of the puncture treatment is as follows.

Since the number of input symbols Nc is code rate R = 1/3, it is determined that Nc = R × Ncs = Ncs / 3 which is one third of the total number of input symbols (coded symbols). According to (Condition 2B) and (Condition 4B), the total additional symbols of the outputs of the two component decoders must be punctured evenly, and the total number of symbols output after puncturing the entire input symbol for one frame is Nis. Thus, the number Ni of symbols output after being punctured by the second rate matching unit 232 becomes [Nis- (R × Ncs)] / 2. At this time, if Ni = (Nis-R × Ncs) is odd, the number of output symbols is N = [Nis- (R × Ncs) -1] / 2 or [Nis- (R × Ncs) +1] / Becomes two. The selection of the two is determined according to the relationship between the second rate matching unit 232 and the third rate matching unit 233. That is, when the number of output symbols of the second rate matching unit 232 is determined to be [Nis- (R × Ncs) +1] / 2, the number of output symbols of the third rate matching unit 233 is [Nis- ( R x Ncs) -1] / 2. On the contrary, when the number of output symbols of the second rate matching unit 232 is determined to be [Nis- (R × Ncs) -1] / 2, the number of output symbols of the third rate matching unit 233 is [Nis- ( R x N cs) +1] / 2.

The puncturing pattern determination parameters (a, b) may be selected as any integer value according to the desired puncturing pattern. The determination of this integer value depends entirely on the perforation pattern, and constants of b = 1 and a = 2 can be used. Integer value determination of the puncture pattern determination parameter will be described in detail with reference to the table described below. As an example, the third rate matching unit 233 may output symbols such as "... 01x11x11x ..." (where x is a punctured symbol).

In FIG. 5, the symbols encoded by the turbo encoder 220 are separated and input to the rate matching units 231 to 233 with the same number. In this case, the first rate matching unit 231 outputs an input symbol as an output symbol as it is. In addition, the second rate matching unit 232 and the third rate matching unit 233 puncture and output the same number of input symbols. In this case, the puncturing pattern parameters may be determined identically or differently. That is, the puncturing pattern may be determined in the rate matching units 232 and 233 or may be determined differently.

A3. Determination of various parameters for drilling operation

In the above-described prior art, each rate matching unit punctures the same number of symbols (except for the rate matching unit 231 of FIG. 5). However, the number of symbols punctured at each rate matching unit may be determined differently. If the number of symbols Ni to be outputted in each rate matching unit is given differently, the number of symbols punctured in each rate matching unit will be determined differently. In addition, the pattern of symbols punctured at each rate matching unit may also be determined identically or differently by changing the constant values (a, b) of the puncturing pattern determination parameter. That is, although the rate matching device according to the related art has a single unified structure, various parameters such as the number of input symbols, the number of output symbols, the number of symbols to be punctured, and the puncturing pattern determination parameter can be determined differently. Examples of changing various parameters are shown in Table 1 below. In this case, it is assumed that the code rate is R = 1/3. Accordingly, three rate matching units are provided corresponding to the inverse of the code rate, and Nc = Ncs / 3 symbols are equally input to each rate matching unit. Here, it is described that the same number of symbols (the number obtained by multiplying the number of encoded symbols in one frame by the code rate) is input to each rate matching unit. However, as described above, the prior art can be equally applied to each data rate matching unit even when different numbers, that is, smaller or larger numbers of symbols than the product of the coded symbols and the code rate in one frame are input separately. It should be noted that there is. In the following, RMB1, RMB2, and RMB3 represent a rate matching part.

In Table 1, RMB1, RMB2, and RMB3 indicate a rate matching block. Mathematical symbols Represents the largest integer not greater than x, Denotes the smallest integer not less than x. In addition, p, q, r, s, t, w, x, y, z are arbitrary constants. Also, in Case 9 and Case 10, 1 / p + 1 / q + 1 / r = 1. This is because Ncs (1 / p + 1 / q + 1 / r) = Ncs. In addition, NA (Not Available) is a case in which the input symbol is output as it is without puncturing, and indicates that regardless of whether (a, b) is set. In addition, a and b are positive numbers. In the case where the input symbols are punctured for rate matching, the relationship of Ncs > = Nis, that is, the number of input symbols is larger than the number of output symbols. A detailed description of each case is as follows.

-(Case 1, Case 2): (Case 1), (Case 2) is a case of puncturing all symbols in a frame in a uniform pattern. In this case, (Case 1) matches each transmission rate since the puncturing determination parameters are a (1) = a (2) = a (3) = p and b (1) = b (2) = b (3) = q. Negative puncturing patterns are the same, and (Case 2) is not a (1) = a (2) = a (3) and b (1) = b (2) = b (3), so that each bit rate matching part is punctured. The pattern is different.

-(Case 3): In case of puncturing, puncturing only the additional symbols without puncturing the information symbols. At this time, since the puncturing pattern determination parameters were set to a (2) = 2 = a (3) and b (2) = 1 = b (3), both rate matching units RMB2 and RMB3 had the same puncturing pattern, It is a structure that perforates half and a half.

(Case 4): In the case of structural puncturing, only the additional symbols are punctured without puncturing the information symbols. At this time, since the perforation pattern determination parameters are set to a (2) = 2 (5 = a (3), b (2) = 1 = b (3), the rate matching units RMB2 and RMB3 have different perforation patterns. It is a structure that perforates both sides evenly.

-(Case 5): In the general case for the above (Case 3), by setting the puncturing pattern determination parameter to a (2) = p = a (3), it is a structure that allows the setting of various puncturing patterns.

-(Case 6): In the general case for (Case 4) above, by setting the puncturing pattern determination parameters a (2) = p, a (3) = q, the structure to enable the setting of various puncturing patterns to be.

-(Case 7): In the more general case for (Case 5) above, by setting the puncturing pattern determination parameter to a (2) = p = a (3), b (2) = q = b (3) It is a structure that allows setting of various perforation patterns.

-(Case 8): In the more general case for (Case 6) above, the puncturing pattern determination parameters are a (2) = p, a (3) = r, b (2) = q, b (3) = By setting it to s, it is a structure which enables setting of various puncturing patterns.

(Case 9, Case 10): This is the case when all possible parameters are changed. That is, the number of output symbols can be set to any integer, and the variables a and b of the puncturing pattern determination parameter can also be set to any integer.

In Table 1, Case 1 and Case 2 may be applied to rate matching convolutional coded symbols, and Case 3 to Case 8 may be applied to rate matching turbo coded symbols. .

As the variable a of the puncturing pattern determination parameter is changed, the puncturing pattern may be changed. Table 2 below shows that the perforation pattern is changed as the variable a is changed. In Table 2 below, it is assumed that Nc = 10, Ni = 8, y = Nc-Ni = 10-8 = 2, and b = 1, and symbols punctured according to the puncturing pattern are represented by x. .

As can be seen from the above [Table 2], even if b is fixed to 1 and only a is set differently, different perforation patterns can be obtained. As the value of a increases, it can be seen that the first symbol of the perforation pattern is located in front. Of course, if b is changed, more perforation patterns will be obtained. In addition, by using b = 1 and using a as a value satisfying Equation 1 below, the first symbol may not always be punctured. Therefore, in the case of (condition 3B) mentioned above, what is necessary is just to set a to have a value of the range of the following [Equation 1].

In Equation 1, when Nc = 10 and y = 2, Nc / y = 10/2 = 5, so if a has a value of 1,2,3,4, the first symbol will not be punctured. will be.

To satisfy (Condition 5B), end bits should not be punched. To do this, set Nc to the value obtained by subtracting the number of end bits. That is, when the number of terminal bits is NT, and the number of input symbols Nc is set to Nc-NT, the terminal bits are not always punctured. Therefore, (condition 5B) may be satisfied. In other words, the termination bit is not input to the rate matcher. Accordingly, the rate matching pattern only considers the frame size of Nc-NT. After puncturing or repetition by the rate matcher, the terminating bit is appended to the end of the output symbols of the rate matcher.

A4. Rate matching algorithm by puncturing

7 is a flowchart illustrating a rate matching method by puncturing according to the prior art, and is based on a rate matching algorithm as shown in Table 3 below.

In Table 3 below, So = {d1, d2,... , dNc} represents symbols input to one rate matching unit, that is, input symbols in frame units with one rate matching unit, and is composed of a total of Nc symbols. In addition, the shift parameter S (f) is an initial value used in an algorithm, and when a rate matching device according to the prior art is used in the downlink of a digital communication system (coded to be transmitted from a base station to a terminal) In case of rate matching for a symbol), it is always used as '0'. Here, f is an argument indicating the order of frames when channel encoding is performed over several frames. In addition, m is a subscript indicating the order of symbols inputted for rate matching, and 1, 2, 3,... , In order of Nc.

As can be seen in Table 3 below, various parameters, that is, the number of input symbols Nc, the number of output symbols Ni, and the puncturing pattern determination parameters (a, b) may be changed. For example, various parameters may be changed as shown in Table 1 above. In this case, the number Nc of the input symbols may be determined by a number other than Ncs / 3 according to the code rate R. FIG. 7 illustrates a case where an algorithm as shown in Table 3 below is applied to the downlink of a digital communication system, that is, S (f) = 0.

Advantages of using the algorithm shown in Table 3 above are as follows.

First, each coded symbol in a frame unit can be variably punctured.

Second, various types of perforation patterns can be generated by adjusting the parameters Nc, Ni, (a, b).

Third, the complexity and calculation time of each rate matching unit can be reduced by 1 / R. This is because, when using a plurality of rate matching units, the number of symbols to be punctured by each rate matching unit is reduced by that number compared to using one rate matching unit.

Referring to FIG. 7, in the operation of rate matching, initialization of various parameters such as the number of input symbols Nc, the number of output symbols Ni and the puncturing pattern determination parameters (a, b) is performed (701).

If the values of Nc and Ni are determined by initialization of various parameters (701), the number of symbols to be punctured y = Nc-Ni is calculated (702).

Then, an initial error value e between the current puncture rate and the required puncture rate is obtained (703). Here, the initial error value is obtained according to e = b * Nc mod a * Nc.

Next, after setting m = 1 indicating the order of input symbols (704), an operation of determining whether a symbol to be punctured from an initial symbol is performed (705 to 709).

If it is determined that the obtained error value e is less than or equal to 0 (707), the error value is updated according to e = e + a * Nc after puncturing the corresponding symbol (708). In contrast, when it is determined that the obtained error value e is equal to or greater than 0 (707), the puncturing operation is not performed. The operation of determining whether to puncture the encoded symbols by inputting them in order and puncturing accordingly is repeatedly performed 705 until all symbols of one frame are determined to be input. During this repetitive operation, the error value is updated according to e = e-a * y (706).

As shown in the above algorithm, the position of the first symbol to be punctured or repeated is controlled by the parameter (a, b). Assume that the position of the first symbol to be punctured is INITIAL_OFFSET_m. In the above algorithm, INITIAL_OFFSET_m = 'm', initially when e ≦ 0. Table 4 below shows an example of the INITIAL_OFFSET_m determination. In Table 4 below, it is assumed that b * Nc is smaller than a * Nc.

"INITIAL_OFFSET_m = k = 4"

In the following [Table 5], Ppnc means the period of puncture or iteration in the above algorithm.

As shown in Table 5, by controlling the (a, b) parameters, the position of the first symbol to be punctured or repeated can be controlled.

For example, when b is constant, the value of INITIAL_OFFSET_m decreases as a increases. Thus, as a increases, the position of the first symbol to be punctured / repeats will be determined to be close to the first position. If a is selected to be larger than by / Nc, then INITIAL_OFFSET_m = 1. This means that the first symbol will be punctured or repeated. As a result, the position of the first symbol to be punctured / repeated can be adjusted by selecting a value between 1 and Ppnc as the value of a. For example, if b = 1 and a = 2, the position of the first symbol to be punctured / repeat will always be equal to Ppnc / 2.

In the case of the parameter b, the INITIAL_OFFSET_m can be controlled according to the parameter a, and when the value of a is determined as shown in Table 6 below, the value of b can be expressed as 1 ≦ b ≦ a. . If a is constant, INITIAL_OFFSET_m will increase as b increases, and INITIAL_OFFSET_m will decrease as b decreases. Thus, the puncture / repeat position can be controlled by adjusting the value of the (a, b) parameters. Although the value of b can be arbitrarily determined, it is meaningless to select a value of b larger than a, as shown in Table 6 below, because the initial value of e is when the value of b is greater than a. Because it will be cycled to. In other words, the value of e repeats itself.

As shown in the above example, the initial value of e changes as the value of b changes. However, when the value of b becomes larger than the value of a, the initial value of e repeats itself circularly. Therefore, assigning a value greater than a to b is meaningless. In conclusion, the perforation or repeating pattern can be controlled by adjusting the (a, b) parameters.

B. An example of a rate matching device by repetition will be described by dividing a case of convolutional code and an example of turbo code.

B1. An example of rate matching device by repetition (in case of convolutional code)

9 is a configuration diagram of a rate matching device by repetition according to the related art. This configuration shows an example applied to the case where the rate matching device as shown in FIGS. 2 and 3 performs rate matching processing by repeating convolutional coded symbols.

Referring to FIG. 9, the convolutional encoder 210 receives an input information bit Ik and encodes the code according to a code rate R = 1/3, and then outputs coded symbols C1k, C2k, and C3k. In this case, each of the encoded symbols C1k, C2k, and C3k is separated and input to each rate matching block 231 to 233.

Here, the first rate matching unit 231 inputs the encoded symbol C1k, repeats it, and outputs the same. At this time, the criterion of the repetition process is based on the number of repeating symbols y = Ni-Nc and the repeating pattern determination parameters (a, b) determined by the number of input symbols Nc and the number of output symbols Ni. For example, the first rate matching unit 231 may output symbols such as "11 (11) 101 (00) 010 ...". Here, (11) and (00) are repeated symbols.

In addition, the second rate matching unit 232 inputs the encoded symbol C2k, selectively iterates and outputs the encoded symbol C2k. At this time, the criterion of the repetition process is based on the number of repetition symbols y = Ni-Nc determined by the number Nc of input symbols, the number Ni of output symbols, and the repetition pattern determination parameters (a, b). As an example, the second rate matching unit 232 may output symbols such as "... (11) 01 (00) 1100 ...". Here, (11) and (00) are repeated symbols.

In addition, the third rate matching unit 233 inputs the encoded symbol C3k, repeats the output, and outputs the same. At this time, the basis of the repetition process is based on the number of repetition symbols y = Ni-Nc determined by the number Nc of input symbols, the number Ni of output symbols, and the repetition pattern determination parameters (a, b). As an example, the third rate matching unit 233 may output symbols such as "... 0 (11) 1101 (11) ...". Where (11) is a repeated symbol.

The encoded symbols whose rate matched by the rate matching units 231 to 233 are multiplexed by the multiplexer (MUX) 240 and then output to a channel transmitter (not shown).

In Fig. 9, the number Nc of input symbols and the number Ni of output symbols are set to Nc = R × Ncs and Ni = R × Nis in the same manner for all the rate matching units 231 to 233. As described above, the rate matching units 231 to 233, which separate and repeat the channel coded symbols and repeat the same number of symbols, determine that the error sensitivity of the coded symbols is applied to all symbols in one frame. By the assumption that they are about the same. That is, a repetitive pattern of a substantially uniform form is provided in one frame regardless of various number of repetition bits (y = Ni-Nc) arbitrarily determined by the type of service. This is because in the case of convolutional code, the entire symbols in one frame may be repeated uniformly.

Therefore, according to the related art, the symbols encoded by the convolutional encoder 210 are divided into the same number and input to the rate matching units 231 to 233. In this case, each of the rate matching units 231 to 233 repeatedly outputs the same number of input symbols. In this case, the repetition pattern parameters in the rate matching units 231 to 233 may be determined identically or differently. That is, the repetition pattern may be determined in the same rate matching units 231 to 233 or may be determined differently.

B2. Another example of rate matching device by repetition (for turbo code)

10 is another configuration diagram of a rate matching device by repetition according to the related art. This configuration shows an example applied to the case where the rate matching device as shown in FIGS. 2 and 3 applies the rate matching process by repetition of the turbo coded symbols.

Referring to FIG. 10, the turbo encoder 220 inputs an input information bit Ik and encodes it according to a code rate R = 1/3, and then outputs encoded symbols C1k, C2k, and C3k. In this case, the information symbols C1k among the encoded symbols are separated and input to the first rate matching unit 231, and the additional symbols C2k and C3k are separated to form the second and the second symbols. It is input to each of the three rate matching units 232 and 233.

Here, the turbo encoder 220 includes a first component coder 222, a second component coder 224, and an interleaver 226 as shown in FIG. 6.

The first and second component encoders 222 and 223 may use recursive systematic codes (RSC). Since the configuration of the turbo encoder 220 is well known to those skilled in the art, a detailed description of the operation will be omitted. The input X (t) of the turbo encoder 220 corresponds to the input information bit Ik shown in FIG. The outputs X (t), Y (t), and Y '(t) of the turbo encoder 220 correspond to the coded symbols C1k, C2k, and C3k shown in FIG. In addition, since the input information bit Ik is output as it is to the first output X (t) of the turbo encoder 220, the input information bit Ik is outputted as C1k as it is shown in FIG.

In addition, the first rate matching unit 231 inputs the encoded symbol C1k, performs a repetitive process, and then outputs the encoded symbol C1k. At this time, the standard of the repeat process is as follows.

Since the number of input symbols Nc is code rate R = 1/3, it is determined as R × Ncs = Ncs / 3, which is the product of the total number of input symbols and the code rate. In addition, since the number Ni of output symbols must be repeated according to (condition 1D), it is determined as Ni = Nis-(2R x Ncs). In addition, the repeating pattern determination parameter (a, b) may be selected to any integer value according to the desired repeating pattern. The determination of this integer value is entirely determined by the repeating pattern, and representatively, constants of b = 1 and a = 2 may be used. At this time, the integer value determination of the repeating pattern determination parameter is described in detail with reference to the table described below. As an example, the first rate matching unit 231 may output symbols, such as " 1 (11) 101 (00) 11... Here, (11) and (00) represent repeated symbols.

In addition, the second rate matching unit 232 inputs the encoded symbol C2k and outputs the same without repetition. However, the second rate matching unit 232 may repeat when severe repetition is required for the encoded symbol C2k. In addition, since the number of input symbols Nc is code rate R = 1/3, it is determined as R × Ncs = Ncs / 3 which is the product of the total number of input symbols (coded symbols) and the code rate. Further, the number Ni of output symbols is determined to be RxNcs equal to the number of input symbols since there should be no repetition in two additional symbols according to (Condition 2D) and (Condition 4D). For example, the second rate matching unit 232 may output symbols, such as "... 110111101 ...", which is not repeated.

In addition, the third rate matching unit 233 receives the encoded symbol C3k and outputs the same without repetition. However, the third rate matching unit 233 may repeat when severe repetition is required for the encoded symbol C2k. In addition, since the number of input symbols Nc is code rate R = 1/3, it is determined as R × Ncs = Ncs / 3 which is a product of the total number of input symbols (coded symbols) and the code rate. In addition, the number Ni of output symbols is determined to be RxNcs equal to the number of input symbols since there should be no repetition in two additional symbols according to (Condition 2D) and (Condition 4D). In addition, the repeating pattern determination parameter (a, b) may be selected to any integer value according to the desired repeating pattern. However, if the rate matching units 232 and 233 do not repeat, then the (a, b) parameters are meaningless for the above rate matching units 232 and 233. The determination of this integer value is entirely determined by the repeating pattern, and representatively, constants of b = 1 and a = 2 may be used. Here, the integer value determination of the repeating pattern determination parameter will be described in detail with reference to the table described below. For example, the third rate matching unit 233 may output symbols, such as "... 01011010 ...", which is not repeated.

In FIG. 10, the symbols encoded by the turbo encoder 220 are divided into equal numbers and input to the rate matching units 231 to 233. That is, the first rate matching unit 231 inputs an information symbol among encoded symbols and repeatedly outputs the information symbol according to a predetermined repetition parameter. Also, the second rate matching unit 232 and the third rate matching unit 233 input additional symbols among the encoded symbols and output the same without repetitive processing.

B3. Determination of various parameters for repeat operation

As described above, the repetition patterns processed by the rate matching units may be identical to or different from each other. That is, the pattern of repeated symbols processed in each rate matching unit and the number of repeated symbols may be variably determined. If the number of symbols Ni to be output from each rate matching unit is differently assigned, the number of symbols repeated in each rate matching unit will be determined differently. In addition, the pattern of the symbol repeated in each rate matching unit may be determined in the same manner by changing the constant values (a, b) of the repeating pattern determination parameter, or may be determined differently. That is, although the rate matching device according to the related art has a single unified structure, various parameters such as the number of input symbols, the number of output symbols, the number of symbols to be repeated, and the repeating pattern determination parameter can be determined differently. Examples of changing various parameters are shown in Table 7 below. In this case, it is assumed that the code rate is R = 1/3. Accordingly, three Rate Matching Blocks (RMBs) are provided corresponding to reciprocal of code rates, and Nc = Ncs / 3 symbols are input to each rate matcher. Here, it is described that the same number of symbols (the number obtained by multiplying the number of encoded symbols in one frame by the code rate) is input to each rate matching unit. However, as described above, the prior art can be equally applied to each data rate matching unit even when different numbers, that is, smaller or larger numbers of symbols than the product of the coded symbols and the code rate in one frame are input separately. It should be noted that there is. In the following, RMB1, RMB2, and RMB3 represent a rate matching part.

In the above [Table 7], RMB1, RMB2, and RMB3 represent a rate matching block. In addition, p, q, r, s, t, w, x are arbitrary constants. In addition, NA (Not Available) is a case in which an input symbol is output without being repeated, indicating that (a, b) may be set regardless. Where a and b are positive numbers. In addition, when Ncs≤Nis, that is, the number of input symbols is smaller than the number of output symbols, it is necessary to repeat the input symbols for rate matching. Each case is described as follows.

(Case 1): In systematic repetition, only information symbols are repeated, and additional symbols are not repeated. At this time, a (1) = 2 and b (1) = 1 were used as constants for determining the repeating pattern.

(Case 2): In the system repetition, only information symbols are repeated, and additional symbols are not repeated. At this time, a repeating pattern determined by a (1) = p and b (1) = q is used.

The above (Case 1) and (Case 2) can be applied to the case of repeatedly processing only turbo-coded information symbols as shown in FIG.

-(Case 3): Repeated processing of both the information symbol and the additional symbol, in which case the repetition pattern corresponds to the case in which all of the RMB1, RMB2, and RMB3 are identically determined. The number of repeated symbols is different for RMB1, RMB2, and RMB3.

-(Case 4): Repeated processing of both the information symbol and the additional symbol, in which case the repetition pattern corresponds to a case where all of the rate matching units RMB1, RMB2, and RMB3 are partially or differently determined. In the case of the rate matching units RMB2 and RMB3, the number of repeated symbols is the same.

Table 8 below shows that the repetition pattern may be changed as the variable a of the repetition pattern determination parameter is changed. In Table 8 below, it is assumed that Nc = 8, Ni = 10, y = Ni-Nc = 10-8 = 2, and b = 1, and the symbols repeated according to the repetition pattern are represented by (). have.

As can be seen from Table 8 above, b can be fixed to 1 and only a can be set differently to obtain various repetitive patterns. Of course, changing b will yield more diverse repeating patterns. Further, by using b = 1 and using a as a value satisfying Equation 2 below, the first symbol can always be repeated. Therefore, in the case of (condition 3D) mentioned above, what is necessary is just to set a to have a value of the range of the following [Equation 2].

In [Equation 2], Is the largest integer (less than or equal to) not greater than Nc / y. In Equation 2, when Nc = 8 and y = 2, Nc / y = 8/2 = 4, so if a has a value greater than 4, the first symbol will be repeated.

In order to satisfy (Condition 5D), the end bit must be repeated. To do this, Nc can be set to the number of end bits. In other words, when the number of end bits is NT, when the number of input symbols Nc is set to Nc + NT, the end bits of the information symbols are always repeated. Therefore, (condition 5D) may be satisfied. In other words, an end bit is applied to the rate matcher and is considered for repetition.

B4. Rate matching algorithm by iteration

11 is a flowchart illustrating a rate matching method by repetition according to the prior art, and is based on a rate matching algorithm as shown in Table 9 below.

In Table 9 below, So = {d1, d2,... , dNc} represents symbols input for rate matching, that is, symbols input for rate matching in one frame unit, and is composed of a total of Nc symbols. In addition, the shift parameter S (f) is an initial value used in an algorithm, and when a rate matching device according to the prior art is used in the downlink of a digital communication system (coded to be transmitted from a base station to a terminal) In case of rate matching for a symbol), it is always used as '0'. In addition, m is a subscript indicating the order of symbols inputted for rate matching, and 1, 2, 3,... , In order of Nc.

As can be seen in Table 9 below, various parameters, that is, the number of input symbols Nc, the number of output symbols Ni, and the repeating pattern determination parameters (a, b) may be changed. For example, various parameters may be changed as shown in Table 7 above. In this case, the number Nc of the input symbols may be determined by a number other than Ncs / 3 according to the code rate R. FIG. 11 illustrates a case where an algorithm as shown in Table 9 below is applied to the downlink of a digital communication system, that is, S (f) = 0.

Advantages of the algorithm shown in [Table 9] are as follows.

First, each coded symbol (each codeword symbol) in frame units may be variably repeated.

Second, various types of repeating patterns can be generated by adjusting the parameters Nc, Ni, (a, b).

Third, the complexity and calculation time of each rate matching unit can be reduced by 1 / R. This is because, when using a plurality of rate matching units, the number of symbols to be repeatedly processed by each rate matching unit is reduced by that number compared to using one rate matching unit. For example, the number of symbols to be repeated in each rate matching unit can be reduced by the code rate R as compared with the case of using one rate matching unit.

Referring to FIG. 11, in the operation of rate matching, initialization of various parameters such as the number of input symbols Nc, the number of output symbols Ni, and the repeating pattern determination parameters (a, b) is performed (1101).

Then, when the values of Nc and Ni are determined by initializing various parameters (1101), the number of symbols to be repeated y = Nc-Ni is calculated (1102).

Next, an initial error value e between the current repetition rate and the required repetition rate is obtained (1103). Here, the initial error value is obtained according to e = b * Nc mod a * Nc.

Subsequently, after setting m = 1 indicating the order of input symbols (1104), an operation of determining whether a symbol to be repeated from the initial symbol is repeated (1105 to 1109) is performed.

If it is determined that the obtained error value e is less than or equal to 0 (1107), the corresponding symbol is repeated and the error value is updated according to e = e + a * Nc (1108). In contrast, when it is determined that the obtained error value e is equal to or greater than 0 (1107), the iterative processing operation is not performed. The operation of determining whether to repeat the encoded symbols in order and repeating them is repeatedly performed until it is determined that all symbols of one frame are input (1105). During this repetitive operation, the error value is updated according to e = e-a * y (1106).

The prior art described above provides an apparatus and a method for performing rate matching on channels coded by unstructured codes and symbols coded by structural codes by a single structure in a data communication system. Another object of the present invention is to provide an apparatus and method for performing rate matching on symbols selectively encoded by each code in a data communication system supporting both an unstructured code and a structured code. The prior art for achieving these objectives is to propose a rate matching device and method that can be applied to both when using some or all of the unstructured code (convolutional code or linear block code) and structural code (turbo code) . The rate matching device is composed of a rate matching unit corresponding to the reciprocal of the coded symbols of the channel coded symbols, and initially includes variables (number of input symbols, number of output symbols, punctuation / repetition pattern) under a single rate matching structure. By only changing the value of the decision parameter), it is possible to match the rate coded between the symbols encoded by the unstructured code or the symbols encoded by the structural code. That is, the difference between the conventional technique and the conventional technique before the conventional technique illustrated in FIG. 1 is that the channel coded symbols are separated into a bit rate matching part corresponding to the inverse of the code rate and are formed in parallel. Accordingly, the above-described prior art, which proposes a rate matching device and method which can be applied to both the case of using some or all of unstructured code (convolutional code or linear block code) and structural code (turbo code), consequently It can be said to be a hybrid structure.

12 and 13 illustrate how the prior art shown in FIGS. 2 to 11 operate. The newly defined e_ini, e_minus, and e_plus are calculated by the following equation.

e_ini = {2 * S (f) * | Nc-Ni | + b * Nc-1 (mod a * Nc)} + 1

e_minus = a * | Nc-Ni |

e_plus = a * Nc

The above e_ini, e_minus, and e_plus are the TS (Technical Specification) 25 of the wireless transmission technology proposed by 3GPP (3rd Generation Partnership Project, http://www.3gpp.org), one of the standardization bodies of 3G mobile communication systems. This parameter is used in TR25.212 in the series. The technique used in TS 25.212 was based on the prior art described above. In TS 25.212, when rate matching is performed by repetition, the channel rate matching unit performs time division multiplexing on the non-structural code (convolutional code or linear block code) and the structural code (turbo code) as shown in FIG. In B, rate matching is performed by the algorithm described in B1. In other words, the algorithm described in B2 is not used. When the rate matching is performed by puncturing, the contents of the prior art and TS25.212 are the same.

12 is an explanatory diagram showing a rate matching process for an unstructured code according to the prior art, where iterations (Ncs = 24, Nis = 29) and puncturing (Ncs = 24) for an unstructured code (convolutional code or linear block code) are shown. , Nis = 19).

When calculated by the above Equation 3, Equation 4 and Equation 5, e_ini = 24, e_minus = 10, and e_plus = 48. However, S (f) = 0. The symbols 4, 9, 13, 18, and 23 are repeated or punctured by the algorithm of FIGS. 7 and 11. The same symbol is repeated or punctured because Nis-Ncs = 29-24 = 5 when repeated and Ncs-Nis = 24-19 = 5 when punctured are the same. If the number Nis of output symbols is different, other symbols may be repeated or punctured.

13A to 13C illustrate a rate matching process by repetition (Ncs = 75, Nis = 85) and puncturing (Ncs = 75, Nis = 65) for a structural code (turbo code).

Since it is an example of the channel code rate R = 1/3, it is implemented by three rate matching units. It consists of one rate matching section for information bits (squares surrounded by double lines) and two rate matching sections for additional bits (squares surrounded by single lines). Circles enclosed by double lines indicate the end bits of the turbo code. In the case of rate matching by repetition, Nc and Ni are set as follows for each rate matching unit.

First rate matching part: Nc (1) = 27, Ni (1) = 37, a (1) = 2, b (1) = 1

Second rate matching part: Nc (2) = 24, Ni (2) = 24, a (2) = 2, b (2) = 1

Third rate matching part: Nc (3) = 24, Ni (3) = 24, a (3) = 2, b (3) = 1

Ncs = Nc (1) + Nc (2) + Nc (3) = 75

Nis = Ni (1) + Ni (2) + Ni (3) = 85

e_ini (1) = 27

e_minus (1) = 20

e_plus (1) = 54

In the case of rate matching by puncturing, Nc and Ni are set as follows for each rate matching unit.

First rate matching part: Nc (1) = 27, Ni (1) = 27, a (1) = 2, b (1) = 1

Second rate matching part: Nc (2) = 24, Ni (2) = 19, a (2) = 2, b (2) = 1

Third rate matching part: Nc (3) = 24, Ni (3) = 19, a (3) = 2, b (3) = 1

Ncs = Nc (1) + Nc (2) + Nc (3) = 75

Nis = Ni (1) + Ni (2) + Ni (3) = 65

e_ini (2) = e_ini (3) = 24

e_minus (2) = e_minus (3) = 10

e_plus (2) = e_plus (3) = 48

The differences between FIGS. 13A, 13B, and 13C do not occur in case of rate matching by puncturing, but in case of rate matching by repetition. It is not clear how the output of a plurality of rate matching units existing in parallel is time-division multiplexed in the prior art (rate and rate matching apparatus and method of data communication system, application number 10-2000-0038716). That is, FIGS. 13A and 13B. It is not clear which method of FIG. 13C is time division multiplexing. After rate matching, after channel division multiplexing, channel interleaving is generally performed to prevent a concatenation error from occurring in a fading environment. The characteristics of the channel interleaver are preferably implemented differently in order to maximize the effect according to the method of time division multiplexing. Do. This problem occurs because a plurality of rate matching units are used instead of one rate matching unit.

Therefore, in order to improve the above-mentioned problem, when channel coded symbols are time division multiplexed as shown in FIG. 1, rate matching is achieved using only one rate matching unit using regularity where the symbols are located. In addition, by only changing the parameter setting, a method applicable to all combinations of unstructured code and structure code, rate matching by repetition and puncturing is required.

The present invention is proposed to meet the above requirements, and supports both unstructured code (convolutional code or linear block code) and structural code (turbo code) as one rate matching unit, and inputs to the rate matching unit. A rate matching device for matching channel coded symbols to a data rate suitable for a physical channel to be transmitted by adjusting only values of variables (type of channel code, number of input symbols, number of output symbols, punctuation / repetition pattern determination parameter), and a The purpose is to provide a method.

1 is a block diagram of a general rate matching device.

2 and 3 is a block diagram of a rate matching device according to the prior art.

4 is a block diagram of a transmission rate matching device according to the prior art.

5 is another configuration diagram of a rate matching device by perforation according to the prior art.

6 is a detailed block diagram of the turbo encoder of FIG. 5 according to the prior art.

7 is a flowchart illustrating a rate matching method by puncturing according to the prior art.

8 is another configuration diagram of a rate matching device according to the prior art.

9 is a configuration diagram of a rate matching device by repetition according to the related art.

10 is another configuration diagram of a rate matching device by repetition according to the related art.

11 is a flowchart of a rate matching method by repetition according to the prior art.

12 is an explanatory diagram showing a rate matching process for an unstructured code according to the prior art;

13A is an explanatory diagram illustrating a rate matching process for a structural code according to the related art (time division multiplexing method 1 after rate matching).

FIG. 13B is another explanatory diagram showing a rate matching process for structural codes according to the prior art (time division multiplexing method 2 after rate matching). FIG.

13C is another explanatory diagram illustrating a rate matching process for a structural code according to the related art (time division multiplexing method 3 after rate matching).

14 is a block diagram of an embodiment of a rate matching device according to the present invention;

15A and 15B are flowcharts of one embodiment of a rate matching method according to the present invention;

16A is a block diagram of an embodiment of a rate matching device in case of an unstructured code according to the present invention;

16B is an explanatory diagram illustrating a rate matching method by repetition in the case of an unstructured code according to the present invention.

16c is an explanatory diagram illustrating a rate matching method by puncturing in case of an unstructured code according to the present invention;

17A is a block diagram of an embodiment of a rate matching device in case of a structural code according to the present invention;

17B is an explanatory diagram illustrating a rate matching method by repetition in case of a structural code according to the present invention;

17c is a diagram illustrating an example of a rate matching method by puncturing in case of a structural code according to the present invention;

* Explanation of symbols for the main parts of the drawings

200: channel encoder 210: convolutional encoder

220: turbo encoder 260: multiplexer

1430: rate matching unit 1440: parameter conversion unit

According to an aspect of the present invention, there is provided a rate matching device in a digital communication system, comprising: channel encoding means for channel encoding input information bits; Multiplexing means for regularly time division multiplexing the symbols encoded by the channel encoding means; Parameter converting means for providing an input parameter value required for rate matching; And one rate matching means for matching the multiplexed channel coded symbols to a suitable data rate for the physical channel to be reproduced by reproducing the number of symbols suitable for the physical channel by puncturing or repetition. It is characterized by.

In addition, the present invention provides a rate matching method in a digital communication system, comprising: a first step of a channel encoder channel encoding input information bits; A second step in which a multiplexer regularly time division multiplexes the channel coded symbols; And reconstructing the multiplexed channel coded symbols by a puncturing or repetition by repetition or repetition of the number of symbols suitable for a physical channel according to an input parameter value required for rate matching to match a rate suitable for a physical channel to be transmitted. It is characterized by comprising a third step.

According to the present invention, in order to match the bit rate of channel coded symbols to a physical channel in a digital mobile communication system, only one bit rate matching part is used for the symbols encoded by unstructured codes and structural codes in a digital communication system. Match

In this case, rate matching is achieved using only one rate matching unit using regularity of symbol positions when channel coded symbols are time division multiplexed. We also propose a rate matching algorithm that is applicable to all combinations of unstructured and structural codes, rate matching by repetition and puncturing, by varying only the parameter settings.

The present invention provides a rate matching device and method that satisfies the conditions set forth in (Conditions 1B to 5B) / (Conditions 1D to 5D) together with (Conditions 1A to 3A) / (Conditions 1C to 2C) as described above. Is an implementation of That is, since the rate matching apparatus and method are implemented with the same purpose as the prior art, the same conditions must be satisfied. Therefore, the present invention excludes the mixed structure of the unstructured code (one bit rate matching part) and the structural code (multiple bit rate matching part) adopted by the prior art, uses only one bit rate matching part, and uses the unstructured code and structural part. Combination of rate matching by code, puncturing and repetition is implemented by setting input parameters such as type of channel code, number of input symbols, number of output symbols, puncturing / repeating pattern determination parameter, and the like.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the following, in adding reference numerals to the components of each drawing, the same components as those of the prior art example described above have the same reference numerals as much as possible even though they are shown in different drawings. In addition, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The configuration of the rate matching device according to the present invention is shown in Figs. 14, 16A and 17A.

The rate matching device of FIG. 1 used in the hardware implementation of the rate matching device according to the present invention before the prior art (the rate matching device and method of the data communication system, application number 10-2000-0038716) is proposed. It is similar to the hardware implementation of. That is, the present invention implements the rate matching unit for the various combinations using the conventional rate matching unit as shown in FIG. 1 using the algorithm shown in FIG.

Referring to FIG. 14, the channel encoder 200 encodes input information bits k according to a code rate R = k / n and outputs coded symbols. do. Here, although illustrated for the case of k = 1 for convenience of explanation, it is obvious that the case where k = 1 is not implemented by the same method.

In addition, the multiplexer (MUX) 260 time-division multiplexes the symbols encoded by the channel encoder 200.

In addition, the rate matching block 1430 matches the channel coded symbols multiplexed by the multiplexer 260 at a rate suitable for a physical channel by puncturing or repetition to provide a channel interleaver. Output to the included channel transmitter (not shown).

The rate matching device as shown in FIG. 14 is configured to be used for both non-systematic codes such as convolutional codes or linear block codes and systematic codes such as turbo codes.

Symbols channel-coded by non-systematic code such as convolutional code or linear block code have no weight between the symbols. This is because the error sensitivity of the coded symbols output from the channel encoder 200 is almost similar for all the symbols in one frame. Accordingly, as shown in FIG. 14, even if the symbols encoded by the channel encoder 200 are time-division multiplexed without being distinguished and input to the rate matching unit 260 and punctured or repeated, there is no difference in performance.

However, since symbols coded by a structural code such as a turbo code have weights among the symbols, channel coded symbols are input to the rate matching unit 260 to be punctured or repeated in the same manner. Not good. This is because the weights of information symbols or systematic symbols and parity symbols are not the same. Therefore, if the number of channel-coded symbols is larger than the number of symbols suitable for the physical channel, and the puncturing process is performed by the rate matching unit 260, additional symbols among the turbo-coded symbols may be punctured. The symbols are preferably not as punctured as possible. In addition, when the rate matching unit 260 iteratively processes information symbols among the turbo coded symbols, the information symbols should be repeated as much as possible to increase the energy of the symbol. However, it is advantageous that additional symbols should not be repeated as much as possible. In 212, rate matching by repetition is processed in the same way as convolutional coded symbols. That is, after time division multiplexing, only one rate matching unit 1430 is processed.

In summary, the rate matching unit 1430 that is actually used has the same algorithm, but a structure capable of parallel processing, and a time division multiplexing after parallel processing.

In order to solve the above problem, in the prior art (appliance rate matching device and method of the data communication system, Application No. 10-2000-0038716) proposed a structure that separates the information symbols and the additional symbols in parallel, but in FIG. By looking at the time division multiplexing of the information symbols and the additional symbols, we can find regularity in the multiplexed symbols. In the regularity, the multiplexing is performed in the order of C1k, C2k, ..., Cnk when the symbols multiplexed in the kth multiplexing interval, among which C1k is usually an information symbol, and the remaining C2k, ..., Cnk becomes an additional symbol. In other words, it can be seen that the information symbols appear with a period of n. That is, the information symbol exists at the time points t = 1, n + 1, 2n + 1, 3n + 1, ..., and the additional symbol exists at the remaining time points. Unlike the convolutional code, in the case of a turbo code, an end bit must be generated such that all turbo code components have the same initial value (usually, "000 ... 0" in binary) at the end of the frame. It is preferable to the rate matching method proposed in the present invention to add the latter part as shown in FIG. In the case of rate matching by puncturing, only the intervals C1,1, C2,1, ..., Cn, Nc except for the terminal bits are processed by the rate matching unit. Details are shown in FIG. 17.

Next, an apparatus and method for rate matching of channel coded symbols by unstructured codes and structural codes by using only one rate matching unit in a digital communication system will be described in more detail.

Here, for convenience of explanation, the case of code rate R = 1/3 will be described as an example. However, the rate matching device according to the present invention can be equally applied to the case where the rate matching unit consists of n, that is, the code rate R = k / n. In the following description, Ncs represents the total number of encoded symbols included in one frame output from the channel encoder 200. In addition, Nis is the total number of symbols output after the rate matching process. Therefore, the number of symbols (bits) to be punctured / repeated in each rate matching unit 1430 is y = | Nc-Ni |.

In the present invention, parameters (a, b) are used, which is a constant value determined according to the puncturing / repeat pattern in one frame, that is, a constant value for determining the puncturing / repeat pattern.

Here, the parameter a is an offset value that determines the position of the first symbol of the puncturing / repeating pattern. That is, by a, it is determined how many symbols among the encoded symbols included in one frame are the first symbols of the puncturing / repetition pattern. If the value of the parameter a is increased, the symbol located in front of the frame is punctured / repeated. In addition, the parameter b is a value that controls the period of puncturing in the frame, and by changing this value, it is possible to puncture / repeat all coded symbols included in the frame.

The primary parameters Ncs, Nis, a, and b for the rate matching are actually the secondary parameters Ncs, Nis, e_ini, e_minus, and e_plus to be used by the rate matching unit 1430 by the parameter converter 1440 of FIG. Equation 3 is converted by Equation 3, Equation 4, and Equation 5, respectively.

When an unstructured code such as a convolutional code is used for channel coding, the secondary parameters Ncs 'and Nis' input to the rate matching unit 1430 as shown in FIG. 16A are represented by Equations 6 and 7 below. The same as the primary parameters Ncs, Nis.

NCS '= NCS

NIS '= NIS

When a structural code such as a turbo code is used for channel coding, the secondary parameters Ncs 'and Nis' input to the rate matching unit 1430 as shown in FIG. 17A are represented by Equations 8 and 9 below. It is equivalent to subtracting the number of termination bits from the primary parameters Ncs, Nis.

NCS '= NCS-N _T

NIS '= NIS-N _T

Since the determination of the primary parameters a and b is the same as the above-described prior art (rate and rate matching device and method of data communication system, application number 10-2000-0038716), the description is omitted here. A method of rate matching using the secondary parameters determined from these primary parameters will be described with reference to FIGS. 15A and 15B.

15A and 15B are flowcharts of an embodiment of a rate matching method according to the present invention, based on a rate matching algorithm as shown below.

In the following [rate matching algorithm], So = {d1, d2,... , dNcs} represents symbols input for rate matching, that is, symbols input for rate matching in one frame unit, and is composed of a total of Ncs symbols. In addition, the shift parameter S (f) is an initial value used for the algorithm, and when the rate matching device is used in the downlink of the digital communication system (the transmission rate for the coded symbol to be transmitted from the base station to the terminal) In case of matching), it is always used as '0'. In addition, m is a subscript indicating the order of symbols inputted for rate matching, and 1, 2, 3,... , In order of Ncs. In addition, as can be seen from the following [rate matching algorithm], the number of input symbols Ncs, the number of output symbols Nis, and matching pattern determination parameters (a, b) are included as input parameters.

[Rate matching algorithm]

[r (i) is the number of symbols punctured at the output terminal i for generating additional symbols in the channel encoder 200 of FIG. 14, i = 2,3, ..., n]

e = e_ini → initializaiton

m = 1 → index of current bit

do while m <= Ncs

e = e-e_minus → update error

if e <= 0 → check if the m-th bit

should be punctured

if m = 1 (mod n) → check if systematic symbol

puncture the (m + (k-1))-th bit from set So

else

puncture the m-th bit from set So

end if

e = e + e_plus → update error

enddo

m = m + 1 → next bit

endif

end if

else

skip

endif

In the processing operation of the rate matching, initialization of various parameters such as the number of input symbols Ncs, the number of output symbols Nis, the repeating pattern determination parameters (a, b), and the replacement parameter S (f) is performed (1510).

Subsequently, when the values of Ncs and Nis are determined by initializing various primary parameters (1510), the secondary parameters e_ini, e_minus, and e_plus are calculated using the primary parameters (1520).

Next, it is determined whether rate matching is to be performed by repetition or puncturing, or whether separate matching is unnecessary (1530).

If the rate matching is performed by repetition, it initializes with e = e_ini and sets the position of the current symbol to m = 1 (pointing to the first symbol) (1510). Then, it is determined whether the position of the current symbol is over (1552), and if it reaches the end, it ends, otherwise it decreases e by e_minus (1553). Subsequently, it is determined whether the reduced e is less than or equal to zero (1554), if e is less than or equal to zero, the mth symbol is repeated (1555), e is increased by e_plus (1556), and the position of the current symbol is changed to the next symbol. After changing to the position of (1557), the process transitions to step 1552 to determine whether the position of the current symbol has passed the end. If e is greater than 0, the determination result 1554 immediately changes the position of the current symbol to the position of the next symbol (1557).

On the other hand, if rate matching is performed by puncturing, it is determined whether the channel is coded by an unstructured code (convolutional code) or a structural code (turbo code) (1540).

As a result of determination 1540, if the channel encoding is performed using an unstructured code (convolutional code), e = e_ini is initialized and the position of the current symbol is set to m = 1 (pointing to the first symbol) (1561). Then, it is determined whether the position of the current symbol is over (1562). If it reaches the end, it is terminated. . In this case, if e is less than or equal to 0, the m th symbol is punctured (1565), e is increased by e_plus (1566), the position of the current symbol is changed to the position of the next symbol (1567), and the position of the current symbol ends. The process proceeds to step 1562 to determine whether it has passed. As a result of the determination (1564), if e is greater than 0, the position of the current symbol is immediately changed to the position of the next symbol (1567).

On the other hand, if the channel coding is performed by the structural code (turbo code), the number of puncturing symbols of each of the output stages at which the additional symbols are generated at the output of the channel encoder 200 r (2), r (3), ... r (n) is initialized to 0 (1571).

Then, e = e_ini is initialized and the position of the current symbol is set to m = 1 (pointing to the first symbol) (1572). Subsequently, it is determined whether the position of the current symbol is over (1573), and if it reaches the end, it is terminated, otherwise it is reduced by e_minus (1574), and it is determined whether the reduced e is less than or equal to (1575). ).

As a result of the determination (1575), if e is 0 or less, it is determined whether the m th symbol is an information symbol or an additional symbol (1576). If the m th symbol is an additional symbol, the m th symbol is punctured (1599), and the position of the current symbol is determined. After changing to the position of the next symbol (1581), the process proceeds to step 1573 to determine whether the position of the current symbol is beyond the end.

As a result of the determination 1575, if e is greater than 0, it immediately changes the position of the current symbol to the position of the next symbol (1581), and then proceeds to determining whether the position of the current symbol exceeds the end (1573).

As a result of the determination (1576), if the m th symbol is an information symbol, an output terminal having a minimum value among r (2), r (3), ..., r (n) is found (1577). In this case, when there are several output stages having the minimum value, the front output stage is selected. Assume that the output terminal is the k-th output terminal. Then, r (k) corresponding to the kth output terminal is increased by 1 (1578), and the m + (k-1) th symbol corresponding to the additional symbol from the kth output terminal of the channel encoder 200 is punctured. (1579). Then, e is increased by e_plus (1580), the position of the current symbol is changed to the position of the next symbol (1581), and the process proceeds to step 1573 to determine whether the position of the current symbol is over.

FIG. 16A is a block diagram of a rate matching device when a convolutional code, which is an unstructured code, is used for channel encoding. FIG. 16B illustrates an example of performing rate matching by repetition using the structure of FIG. 16A. 16c shows an example of performing rate matching by puncturing using the structure of FIG. 16A.

FIG. 17A is a block diagram of a rate matching device when a turbo code, which is a structural code, is used for channel encoding. FIG. 17B illustrates an example of performing rate matching by repetition using the structure of FIG. 17A. FIG. 17C Shows an example of performing rate matching by puncturing using the structure of FIG. 17A.

If the secondary parameter generated from the primary parameter is punctured or repeated only for a specific output stage among the output stages output from the channel encoder, the e_ini value is adjusted so that the puncture or repeat is performed on the information symbol. The perforation or repetition may be evenly performed on all additional symbol output stages of the channel encoder 200 by the algorithm of. This case occurs when the denominator of e_minus / e_plus is not small with n. In this case, e_ini may be adjusted to puncture or repeat the information symbol.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

As described above, the present invention has the effect of matching the rate by using only one rate matching unit for the symbols encoded by the unstructured code and the structural code in the digital communication system.

In addition, in the present invention, rate matching is achieved using only one rate matching unit using regularity of symbol positions when channel-coded symbols are time division multiplexed, and by only setting parameters, unstructured code, structural code, repetition and There is an effect applicable to all combinations of rate matching by puncturing. That is, the present invention supports both unstructured code (convolutional code or linear block code) and structural code (turbo code) with one rate matching unit, and input variables (type of channel code, number of input symbols, By adjusting only the number of output symbols and punctuation / repetition pattern determination parameters), channel-coded symbols can be matched at a data rate suitable for a physical channel to be transmitted.

In particular, the present invention has the effect of having a simplified hardware structure while achieving the object pursued by the prior art.

Claims (21)

A rate matching device in a digital communication system, Channel encoding means for channel encoding the input information bits; Multiplexing means for regularly time division multiplexing the symbols encoded by the channel encoding means; Parameter converting means for providing an input parameter value required for rate matching; And One rate matching means for matching the multiplexed channel coded symbols with a suitable data rate for the physical channel to be reproduced by reproducing the number of symbols suitable for the physical channel by puncturing or repetition according to the input parameter value Rate matching device in a digital communication system comprising a. The method of claim 1, The input parameter value is, Substantially, it is a secondary parameter value generated from a raw parameter, and includes parameter information for determining the type of channel encoding means, the number of output symbols of the channel encoding means, the number of output symbols of the rate matching means, and the puncturing / repetition rate. And a rate matching device in a digital communication system. The method of claim 1, The channel encoding means, A rate matching device for a digital communication system, which is substantially a convolutional encoder. The method of claim 1, The channel encoding means, Substantially a linear block coder. The method of claim 1, The channel encoding means, A rate matching device for a digital communication system, which is substantially a turbo encoder. The method of claim 1, The rate matching means, And a rate matching device according to the type of the channel encoding means. The method according to claim 1 or 5 or 6, The rate matching means, And a rate matching device for recognizing the number of symbols perforated for each output terminal of the channel encoding means for outputting additional symbols. The method according to claim 1 or 5 or 6, The rate matching means, A rate matching device of the digital communication system, characterized in that the first end of the output terminal of the channel encoding means for outputting the additional symbols are punctured first. The method of claim 8, The rate matching means, A transmission rate matching device of a digital communication system, characterized in that if the plurality of output stages with minimum puncturing among the output stages of the channel encoding means for outputting additional symbols exist, the output symbols of the output stages determined in a predetermined order are preferentially punctured. . The method of claim 9, The predetermined order is A rate matching device for a digital communication system, characterized in that the order is given in order of low output terminal number. The method of claim 9, The predetermined order is A rate matching device for a digital communication system, characterized in that the order is set to have a high output terminal number. The method of claim 1, An input parameter value of the rate matching means, And a parameter value for limiting a rate matching processing interval in a time division multiplexed symbol sequence. The method of claim 12, The parameter value for limiting the rate matching processing interval is When the rate matching means is made only between the N1-th symbol and the N2 (> N1) -th symbol of the time division multiplexed symbol sequence, N1 and N2 are input to the rate matching unit as a rate matching processing interval restriction parameter value. Rate matching device in digital communication system. The method of claim 1, By using the one rate matching means, both unstructured code (convolutional code or linear block code) and structural code (turbo code) are supported, and input variables (type of channel code and input) to the one rate matching means And matching only the values of the number of symbols, the number of output symbols, and the punctuation / repetition pattern determination parameter to match the channel-coded symbols to a data rate suitable for the physical channel to be transmitted. In the rate matching method in a digital communication system, A first step of the channel encoder channel coding the input information bits; A second step in which a multiplexer regularly time division multiplexes the channel coded symbols; And According to an input parameter value required for rate matching, a rate matching unit reproduces the multiplexed channel coded symbols by puncturing or repetition to match a number of symbols suitable for a physical channel at a rate suitable for a physical channel to be transmitted. 3 steps Rate matching device in a digital communication system comprising a. The method of claim 15, The input parameter value is, Substantially, it is a secondary parameter value generated from a raw parameter, and includes parameter information for determining the type of the channel encoder, the number of output symbols of the channel encoder, the number of output symbols of the rate matching unit, and the puncturing / repetition rate. Rate matching method in digital communication system. The method according to claim 15 or 16, The third step, A fourth step of initializing an input parameter value required for rate matching; A fifth step of calculating a secondary parameter using the initialized primary parameter; A sixth step of determining a rate matching pattern; And A seventh step in which one rate matching unit reproduces a number of symbols suitable for a physical channel using the secondary parameter to match a rate suitable for a physical channel to be transmitted according to the rate matching pattern; Rate matching method in a digital communication system comprising a. The method of claim 17, In the fourth step, Initialize various parameters such as the number of input symbols (Ncs), the number of output symbols (Nis), the repeating pattern determination parameters (a, b), and the replacement parameter (S (f)), In the fifth step, when the values of Ncs and Nis are determined by the initialization of various primary parameters, the rate matching in the digital communication system is calculated using the primary parameters, e_ini, e_minus, and e_plus. Way. The method of claim 18, The seventh step, An eighth step of initializing e = e_ini and setting the position of the current symbol to m = 1 (pointing to the first symbol) upon rate matching by repetition; A ninth step of determining whether the position of the current symbol is over, ending if it has reached the end, otherwise reducing e by e_minus and comparing whether the reduced e is less than or equal to zero; As a result of the comparison of the ninth step, if e is less than or equal to zero, the m-th symbol is repeated, e is increased by e_plus, the position of the current symbol is changed to the position of the next symbol, and the tenth step is passed to the ninth step. ; And As a result of the comparison of the ninth step, if e is greater than 0, the eleventh step of changing the position of the current symbol to the position of the next symbol and then skipping to the ninth step Rate matching method in a digital communication system comprising a. The method of claim 18, The seventh step, An eighth step of determining whether the channel is coded by unstructured code (convolutional code) or structural code (turbo code) during rate matching by puncturing; As a result of the determination of the eighth step, if the channel encoding is performed using an unstructured code (convolutional code), the ninth of initializing e = e_ini and setting the position of the current symbol to m = 1 (pointing to the first symbol) step; After performing the ninth step, determining whether the current symbol has reached the end, and ending if it reaches the end, otherwise reducing e by e_minus to compare whether the reduced e is less than or equal to zero; As a result of the comparison in the tenth step, when e is less than or equal to zero, the eleventh step is punctured, the e is increased by e_plus, the position of the current symbol is changed to the position of the next symbol, and the eleventh step is passed to the tenth step. ; And As a result of the comparison of the tenth step, when e is greater than 0, the twelfth step of changing the position of the current symbol to the position of the next symbol and then skipping to the tenth step Rate matching method in a digital communication system comprising a. The method of claim 18, The seventh step, If the channel coding is performed by a structural code (turbo code), the number of puncturing symbols of each of the output terminals (r (2), r (3), ..., r ( an eighth step of initializing n)) to zero; After performing the eighth step, the ninth step of initializing e = e_ini and setting the position of the current symbol to m = 1 (indicating the first symbol); A tenth step of determining whether a position of a current symbol is over after performing the ninth step; An eleventh step of comparing the result of the determination of the tenth step to the end if it has reached the end, otherwise reducing e by e_minus and comparing the reduced e with less than zero; A twelveth step of analyzing whether the m th symbol is an information symbol or an additional symbol when e is less than or equal to the eleventh comparison result; If the m-th symbol is an additional symbol, puncturing the m-th symbol, changing the position of the current symbol to the position of the next symbol, and then skipping to the tenth step; As a result of the comparison of the eleventh step, when e is greater than 0, a fourteenth step of immediately changing the position of the current symbol to the position of the next symbol and then skipping to the tenth step; As a result of the analysis of the twelfth step, if the m th symbol is an information symbol, the output terminal having the minimum value among r (2), r (3), ..., r (n) is found and the output terminal is assumed to be the k th output terminal. A fifteenth step of increasing the r (k) corresponding to the k th output terminal by 1 and puncturing the m + (k-1) th symbols corresponding to the additional symbols from the k th output terminal of the channel encoder; And After performing the fifteenth step, e is increased by e_plus (1580), and the sixteenth step of changing the position of the current symbol to the position of the next symbol, and then proceeding to the tenth step. Rate matching method in a digital communication system comprising a.