Multiplication-free quasi-cyclic matrix serial multiplier in deep space communication

Abstract

The invention provides a quasi-cyclic matrix serial multiplier, free of multiplication, in deep space communication. The quasi-cyclic matrix serial multiplier free of the multiplication is used for realizing multiplication of a vector m and a quasi cyclic matrix F in CCSDS space communication standard multiple code class QC-LDPC approximate lower triangular codes. The multiplier comprises four cyclic matrix generator polynomials pre-stored in all the code class matrix F, a generator polynomial lookup table of a 2048-position null vector, four 2048-position binary adders outputting the generator polynomial lookup table and conducting analog 2 adding on contents of a shifting register, and four 2048-position shifting registers for storing results of cyclic shift left one position. The quasi-cyclic matrix serial multiplier is compatible with all the code classes, removes the multiplication, and has the advantages of being few in logic resource, simple in structure, low in consumption, low in cost and the like.

Description

technical field [0001] The invention relates to the field of channel coding, in particular to a quasi-circular matrix serial multiplier in CCSDS deep space communication standard multi-code QC-LDPC approximate lower triangular coding. Background technique [0002] Low-Density Parity-Check (LDPC) code is one of the efficient channel coding techniques, and QC-LDPC (Quasic-LDPC, QC-LDPC) code is a special LDPC code. Both the generation matrix G and the check matrix H of the QC-LDPC code are arrays composed of circulant matrices, which have the characteristics of a segmented cycle, so they are called QC-LDPC codes. The first row of the circulant matrix is ​​the result of the cyclic right shift of the last row by 1 bit, and the remaining rows are the result of the cyclic right shift of the previous row by 1 bit. Therefore, the circulant matrix is ​​completely characterized by its first row. Usually, the first row of a circulant matrix is ​​called its generator polynomial. [00...

AI Technical Summary

Problems solved by technology

The disadvantage of this solution is that the number of registers is large, and a large number of AND gates are required to complete the multiplication operation. Such a large number of logic resources will inevitably result in high power consumption and high cost of the circuit.

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