Method of adding cyclic redundancy code of transmission block

Abstract

A method is provided for adding a cyclic redundancy check code to a transmission block. The method, based on the two-stage CRC coding scheme, comprises the following steps: step A1. judging whether the sum of the length of a transmission block and the length of Y-site CRC code is larger than the Turbo or the maximal code length of LDPC coder, if it is, going to the step A2, otherwise, that is the sum is smaller than or equal to the Turbo or the maximal coding length of LDPC coder, going to the step A3; step A2. performing Y-site CRC coding of the transmission block, and adding the coded Y bit CRC1 check code at the back of the transmission block; step A3. further dividing the transmission block into C code blocks to allow the sum of each code block and X-site CRC code length smaller than or equal to the Turbo or the maximal code length of LDPC coder, and the C value is set minimum; step A4. performing the X-site CRC coding of each code block, and adding the coded X bit CRC2 check code at the back of the code block; and step A5. performing the Turbo or LDPC channel encoding of the code blocks resulting from segmentation. The method can reduce the retransmission times of the upper layer, increaser the retransmission speed of the system and reduce the decoding complexity.

Description

technical field [0001] The invention relates to the field of digital communication, in particular to an attachment method of a cyclic redundancy check code (CRC-Cyclic Redundancy Check) of an enhanced LTE system channel coding scheme. Background technique [0002] The Cyclic Redundancy Check Code (CRC) is a systematic shortened cyclic code widely used in frame checking. [0003] The structure of the CRC code is shown in Figure 1. In the figure, k coefficients of m(x) correspond to k as information, and n-k coefficients of r(x) correspond to n-k check digits. It is customary to mark the (n-k) check digit as CRC, but actually CRC refers to the entire frame. [0004] Figure 2 shows a CRC scheme defined by the 3GPP system, which includes: [0005] Step 1: Perform 24-bit CRC encoding on a transport block, and add the encoded 24-bit CRC check to the end of the transport block; [0006] Step 2: perform code block segmentation on the transmission block with 24 CRC checks added; ...

AI Technical Summary

Problems solved by technology

[0008] However, this CRC encoding method has the following defects: when the transmission block is much larger than the current system, each transmission block uses a 24-bit CRC for error detection, which cannot meet the system's requirements for the omission rate

If according to the traditional method shown in Figure 2, each transmission block uses a 24-bit CRC for error detection, the missed detection rate cannot meet the system requirements, and it is not conducive to fast and high-throughput HARQ hybrid retransmission and reduce terminal implementation complexity

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