KR20090063004A - Method and apparatus for derate matching - Google Patents

Abstract

A derate matching method and an apparatus therefor are provided to simultaneously derate-match a plurality of large sized data, thereby shortening a derate matching time. A derate matching apparatus successively stores received data(S300). The derate matching apparatus calculates the number of bits to be derate-matched initially among the received data and performs derate matching(S310). The derate matching apparatus repeats a derate matching process until variables, I and K, become the same(S320). The derate matching apparatus combines accumulated bits to be derate-matched while the variable I becomes from 1 to K in order to generate output data(S330).

Description

Derate matching method and apparatus {METHOD AND APPARATUS FOR DERATE MATCHING}

The present invention relates to a derate matching method and apparatus, and more particularly, to a derate matching method and apparatus of a mobile communication system.

The present invention is derived from the research conducted as part of the IT growth engine technology development project of the Ministry of Information and Communication and the Ministry of Information and Communication Research and Development. [Task Management Number: 2005-S-404-13, Project Name: 3G Evolution Wireless Transmission Technology] .

The third generation (3G) Long Term Evolution (LTE) mobile communication system, which is a strong candidate for the fourth generation (4G) mobile communication technology standard, aims to support various services based on packet data transmission. The LTE mobile communication system supports maximum transmission speeds of 100 Mbps and 50 Mbps in downlink and uplink, respectively, based on a maximum 20 MHz transmission bandwidth. It provides data transmission efficiency, efficient use of frequency resources, mobility, low latency, and optimized technology and quality of service for packet data transmission.

In addition, the mobile communication terminal of the 3G LTE mobile communication system also supports data transmission rates of downlink 30Mbps and uplink 15Mbps at a moving speed of 120Km / h based on the 20MHz bandwidth. In addition, high-quality and high-speed multimedia services can be provided, and mobile video services can be provided in earnest.

The transmitting end (base station, etc.) of the 3G LTE mobile communication system performs rate matching, and the receiving end (mobile communication terminal) of the mobile communication system performs derate matching.

Rate matching refers to a process of repetition or puncturing according to a rate matching pattern to adjust the coded bit number to the number of bits required for network transmission before sending the coded bit number to the network. Conversely, the matching means a process of solving the rate matched state before decoding the repeated or punctured received data at the receiving end of the mobile communication system.

The derate matching apparatus of the receiving end performing such a derate matching applies a derate matching algorithm for solving a rate matched state from the first to last bits of data received from the network. This requires as many clocks as the number of received data.

However, when the transmission rate is increased and the number of input data increases in one transmission time interval (hereinafter, referred to as "TTI"), the size of the input data may be larger than the clock number corresponding to the TTI. In this case, there is a problem in that the derate matching algorithm cannot be applied to the input data as one processing.

An object of the present invention is to provide a derate matching method and apparatus that enables high-speed data processing by increasing the number of data processing per clock during derate matching.

In order to achieve the above-described problem, a derate matching method of a mobile communication terminal according to an aspect of the present invention includes a method for derate matching an input bit number to a target output bit number using at least one bit among received data. Calculating the number of derate matching times, calculating the number of processing bits to be derate matched for each derate matching, and applying the number of processing bits per time to each derate matching to derate matching the received data. It includes a step.

In addition, the derate matching device of a mobile communication terminal according to another aspect of the present invention performs derate matching of the number of bits per processing bit using at least one bit of the received data to generate a plurality of output bits per time. And a combiner configured to combine the derate matching unit and the plurality of output bits per time to generate data including as many bits as a target output bit.

According to the exemplary embodiment of the present invention, in case of large received data, derate matching time can be shortened by derate matching a plurality of data at the same time.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, the terms “… unit”, “… unit”, “module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. have.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Now, a derate matching method and apparatus in a mobile communication system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Although the embodiment of the present invention has been described taking the 3G LTE mobile communication system as an example, the embodiment of the present invention may be applied to other mobile communication systems.

1 is a diagram schematically illustrating a rate matching device at a transmitting end of a mobile communication system according to an exemplary embodiment of the present invention.

As shown in FIG. 1, the rate matching device 100 includes a bit separator 110, a first rate matcher 120, a virtual buffer 130, a second rate matcher 140, and a bit collector 150. ).

The bit separator 110 separates an input signal N _TTI consisting of encoded bits into information bits and first and second redundant bits Parity 1 bits and Parity 2 bits to match the first rate. Output to the unit 120.

The first rate matching unit 120 performs rate matching on the received information bits and the first and second surplus bits and outputs them to the virtual buffer 130 (N _sys , N _p1 , N _p2 ). In this case, the first rate matching unit 120 performs puncturing or repetition for rate matching using a rate matching algorithm according to a rate matching pattern determined for the first and second surplus bits except for the information bits.

The virtual buffer 130 stores the first and second surplus bits N _p1 and N _p2 that are rate matched with the information bits N _sys output from the first matching unit 120.

The second rate matcher 140 stores the virtual buffer 130 such that the data size of the information bits N _sys and the first and second surplus bits N _p1 and N _p2 is the number of bits that can be transmitted in the physical channel of the network. Rate matching is performed on the information bits N _sys and the first and second redundancy bits N _p1 and N _{p2 output} using the rate matching algorithm, respectively, according to a rate matching pattern. The data is output to the bit collector 150 (N _t , _sys , N _t , _{p 1} , N _t , _{p 2} ).

The bit collector 150 sums the rate matched bits output from the second rate matcher 140, and then interleaves the outputs. At this time, the interleaved data is modulated and output to the network.

Meanwhile, the receiving end receives the modulated data from the network, deinterleaves the received data and outputs the derate matching device. At this time, the derate matching device of the receiving end derates the received data and restores the data before rate matching.

In detail, the derate matching apparatus may be included as a derate matching unit in a channel decoding apparatus (not shown) of the receiving end. The derate matching unit de-interleaves the received data deinterleaved at the front end and converts the data into a data before rate matching to decode the data at the rear end and the cyclic redundancy check (CRC) unit (not shown). Channel-decode the received data. In this case, the derate matching unit receives the derate matching parameter calculated by the derate matching parameter calculator (not shown) and applies the derate matching parameter to the derate matching pattern.

In this case, the derate matching parameter calculator (not shown) calculates a derate matching parameter applied to a pattern for derate matching the received data. The derate matching parameter includes an initial error value e _ini , an increase value e _{plus of} error e value and a decrease value e _minus of error e value.

Hereinafter, a derate matching device and method according to an embodiment of the present invention will be described in detail with reference to FIGS. 2, 3, 4A, and 4B.

2 is a diagram schematically illustrating a derate matching device at a receiving end of a mobile communication system according to an exemplary embodiment of the present invention.

As shown in FIG. 2, the derate matching device 200 according to the embodiment of the present invention includes an input unit 210, a derate matching unit 220, and a coupling unit 230.

The input unit 210 receives the deinterleaved received data Din and sequentially stores the temporary data sequentially and sequentially provides the deinterleaved matching unit 220. At this time, the received data temporarily stored in the input unit 210 is composed of a plurality of bits. The input unit 210 sequentially transfers the number of bits requested by the derate matching unit 220 from among the plurality of bits of the received data.

The derate matching unit 220 derates the received data into data before rate matching. In this case, the derate matching unit 220 according to an embodiment of the present invention can perform high-speed data processing by simultaneously derate matching a plurality of bits of one received data. The derate matching processing unit 220 sequentially receives at least one bit to be derate matching at a time through the input unit 210.

In detail, the derate matching unit 220 obtains the number of bits to be derate matched simultaneously using Equations 1 and 2 below.

<Equation 1>

In Equation 1, N [i] denotes the number of bits to be subjected to the i-th derate matching process, and e _ini [i] denotes an initial error value to be applied to the i-th derate matching process. At this time, the value of i may be set as a natural number increasing from 2 to K. That is, the derate matching unit 220 divides one frame of the received data into K times to perform derate matching. K is a natural number of 2 or more at this time.

However, the derate matching unit 220 may use e _ini [0] to obtain the number of bits (ie, N [1]) to be derate matched during the first derate matching using Equation 1. In this case, e _ini [0] is an initial error value of the received data and is a value transmitted from the derate matching parameter calculator (not shown).

The derate matching unit 220 may set N [i] using the total number of input bits of the received data, the target number of output bits after the derate matching process, and Equation 2 below. In this case, the value of N [i] may be changed at every derate matching process according to the total number of input bits, the number of target output bits, and the initial error value instead of the fixed value.

As shown in Equation 1, the number N of bits to be processed for the i th derate matching may be obtained by sealing a value obtained by dividing e _ini [i] by e _minus . Then, the derate matching unit 220 calculates each initial error value while i value increases from "2" to "K" value using Equation 2 below. In this case, the value "K" is the number of derate matchings in which the cumulative number of bits according to the result of the derate matching process of one received data is equal to the target number of output bits.

<Equation 2>

As shown in Equation 2, e _ini [i] is obtained by multiplying an initial error value applied to the i-1 th derate matching process by a reduction value of a predetermined error e value and the number of bits subjected to the i-1 th derate matching process. It can be found by subtracting the increase value of the error e value. The derate matching unit 220 repeats Equation 1 and Equation 2 to perform derate matching K times to satisfy the target number of input bits of the received data.

In this case, the derate matching unit 220 outputs the data by averaging the N bits previously calculated through Equation 1 when the received data is data that has been rate-matched repeatedly at the transmitting end.

When the received data is data rate-matched by the puncturing at the transmitting end, the derate matching unit 220 has N [i] − having a value of “0” among N [i] bits calculated through Equation 1 above. One bit is output, and the original data of the received data is inserted into the other bit to output N bits. At this time, the value "0" of the added bit means a dummy bit.

The combiner 230 sequentially stores the derate matched bits output from the derate matcher 220, and combines the data into one data when the number of target output bits is accumulated. That is, when the number of bits of the target output bit of the received data is output from the derate matching unit 220, the combiner 230 combines the stored bits to output the next stage of the channel decoding apparatus (not shown) of the receiver. For example, to a Viterbi decoder and a turbo decoder).

 3 is a flowchart illustrating a derate matching process according to an exemplary embodiment of the present invention.

As shown in FIG. 3, the derate matching apparatus 200 according to an embodiment of the present invention sequentially stores the received data (S300). In this case, the received data input to the derate matching device 200 is data received from the transmitter and has completed deinterleaving processing.

Then, the derate matching apparatus 200 calculates the number of bits N [1] to be derate matched first among the received data and performs derate matching (S310). In this case, N [1], which is the number of bits to be derate matched, is calculated by using an initial error value e _ini and a reduction value e _minus of the error e value according to the received data. Can be calculated.

At this time, the derate matching apparatus 200 may temporarily store data output by derate matching the first N [1] bits.

Then, the derate matching device 200 repeats the loop of step S320 until the variable i becomes equal to the K value (S320). That is, the derate matching process is performed until the cumulative bit number subjected to the derate matching process is equal to the target output bit number.

In this case, if the variable i is equal to or greater than 2 and less than or equal to K, in step S320, the derate matching apparatus 200 increases the variable i to a natural number and performs derate matching of N [i] bits. In this case, the derate matching apparatus 200 may temporarily store data that is derate matched and output sequentially in the order of output.

The derate matching device 200 ends the loop when the variable i becomes equal to K in step S320.

Then, the derate matching device 200 generates output data by combining the accumulated bits that are the result of the derate matching process while the variable i becomes a value from 1 to K (S330).

Hereinafter, reception data processed by derate matching through each step of FIG. 3 will be described below with reference to FIGS. 4A and 4B.

4A and 4B illustrate structures of derate matched received data according to an embodiment of the present invention.

The derate matching apparatus 200 performs a derate matching process corresponding to a processing method in which received data is rate matched at the transmitting end.

Specifically, when the received data is rate matched data through repetition at the transmitting end, the derate matching apparatus 200 obtains an average of N [i] bits and performs derate matching.

For example, FIG. 4A illustrates a case where the number of input bits of the received data is 50 and the number of target output bits is 20. That is, the result of the derate matching process when the 20-bit original data is 50-bit repetition rate matching from the transmitting end is shown. In this case, the initial error value transmitted through the derate matching parameter calculator (not shown) is 50, the decrease value of the error e value is 20, and the increase value of the error e value is 50.

 Then, the derate matching apparatus 200 determines the result of the calculation of "N [1] = ceil (50/20) = 3" when i value is 1 (first derate matching) in Equation 1 described in FIG. Therefore, the average of three bits is output.

If the value of i is 2 according to Equation 2 for the second _derate matching (second _derate matching), according to the operation result of "e _ini [2] = 50- (20 * 3) + 50 = 40" The value of e _ini [2] is set to 40. Then, as the number of bits N [2] to be matched with the second derate, an average of two bits is output according to the calculation result of “N [2] = ceil (40/20) = 2” by applying Equation 1.

In this way, by repeating the equations (1) and (2) while the value of i increases from 1 to K, 20 bits of data, which is the target number of output bits, are output.

4B illustrates a case where the number of input bits of the received data is 20 and the number of target output bits is 50. That is, the result of the derate matching process when the 50-bit original data is punctured by 20 bits from the transmitting end is shown. In this case, the initial error value transmitted through the derate matching parameter calculator (not shown) is 50, the decrease value of the error e value is 20, and the increase value of the error e value is 50.

Then, the derate matching apparatus 200 determines the result of the calculation of "N [1] = ceil (50/20) = 3" when i value is 1 (first derate matching) in Equation 1 described in FIG. Therefore, three bits are derate matched at the same time. At this time, the derate matching apparatus 200 inserts and outputs a value of "0" in two bits of the three bits to be derate matched, and outputs the first bit P1 of the received data in the remaining one bit as it is. Outputs a total of three bits.

If the value of i is 2 according to Equation 2 for the second _derate matching (second _derate matching), according to the operation result of "e _ini [2] = 50- (20 * 3) + 50 = 40" The value of e _ini [2] is set to 40. Then, the number of bits N [2] to be matched with the second derate is applied by Equation 1 to derate match two bits simultaneously according to the operation result of "N [2] = ceil (40/20) = 2". . At this time, the derate matching apparatus 200 inserts and outputs a value of "0" in one bit of two bits to be derate matched, and outputs the second bit P2 of the received data in the remaining one bit as it is. Output two bits in total. In FIG. 4B, although the original data of the received data is output to the most significant bit of the N [i] bits, the order of the bits output when the raw data is derate matched may be changed.

In this way, by repeating the equations (1) and (2) while the variable i value increases from 1 to the K value, 50 bits of data, which is the target number of output bits, are output.

The embodiments of the present invention described above are not implemented only through an apparatus and a method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. From the description of the above-described embodiment can be easily implemented by those skilled in the art.

In addition, the scope of the present invention is not limited to the above-described embodiments, but various modifications and variations of those skilled in the art using the basic concept of the present invention as defined in the following claims also belong to the scope of the present invention.

1 is a diagram schematically illustrating a rate matching device at a transmitting end of a mobile communication system according to an exemplary embodiment of the present invention.

2 is a diagram schematically illustrating a derate matching device at a receiving end of a mobile communication system according to an exemplary embodiment of the present invention.

3 is a flowchart illustrating a derate matching process according to an exemplary embodiment of the present invention.

4A and 4B illustrate structures of derate matched received data according to an embodiment of the present invention.

Claims (7)

In the derate matching method of the mobile communication terminal, Calculating a number of derate matching times for derate matching an input bit number to a target output bit number using at least one bit of the received data; Calculating the number of processing bits to derate match each time derate matching; And Derate matching the received data by applying the number of processing bits per time for each derate matching; Derate matching method comprising a. The method of claim 1, The number of derate matching and the number of processing bits per time are It is calculated using the initial error value and the derate matching parameter applied to the received data. Derate matching method. The method of claim 2, Matching the derate, calculating i initial error values using i (i is a natural number of 2 or more) -1 initial error value and the i-1 number of processed bits; and Calculating the number of bits of said processing per i times using said i initial error value; Derate matching method. The method of claim 2, Matching the derate, When the received data is repetition rate matched data, an average of the number of bits corresponding to the number of processed bits per time among the received data is used as an output bit. Derate matching method. The method of claim 2, Matching the derate, When the received data is puncturing rate matched data, as many bits as the processing bits per time are used as output bits. Some of the output bits are at least one bit of the received data and the remaining bits are dummy bits. Derate matching method, characterized in that. The method according to claim 4 or 5, After the derate matching, Combining the output bits by the target number of output bits The derate matching method further comprising. In a derate matching device of a mobile communication terminal, A derate matching unit generating a plurality of output bits per time by performing derate matching of the number of bits per processing time using at least one bit of the received data; And A combiner that combines the plurality of output bits per time to generate data including bits as many as a target output bit Derate matching device comprising a.

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