A coding modulation and decoding method and device for grid coding and modulation code

Abstract

The invention discloses a trellis code modulated (TCM) code modulation method, and is to solve the problem of poor entirety of the prior TCM codes. The invention comprises the following steps. Firstly, a square QAM planisphere with the modulation order number larger than 4 is used as a constellation mapping scheme so that after the codes on a way I and a way Q of the constellation mapping scheme are mapped, and bit blocks are arranged repeatedly on a periodic basis on the ways I and Q, and corresponding uncoded bit blocks are different after each repeated arrangement on a periodic basis. Constellation indices including coded bit blocks and uncoded bit blocks are acquired according to original bit message block. Signaling points in the constellation mapping scheme according to the constellation indices are determined as the final emissive TCM signals. As the coded bit blocks are repeatedly arranged on a periodic basis, and corresponding uncoded bit blocks are different from each other, mappings of symbols for parallel paths on the way Q of the constellation mapping scheme are uniform, and the entirety of TCM codes can be improved.

Description

technical field [0001] The invention belongs to the technical field of data encoding, and in particular relates to an encoding modulation and decoding method and device of trellis encoding modulation codes. Background technique [0002] TCM (trellis coded modulation) coding, that is, trellis coded modulation technology, is a kind of "signal set space coding", which can combine coding and modulation without reducing frequency band utilization and power utilization. In combination, the redundancy of the signal set is used to obtain the error correction capability. [0003] TCM codes have two basic characteristics: [0004] 1. The number of signal points used in the constellation diagram is greater than the number of points required for the same modulation without coding, and these additional signal points provide redundancy for error correction coding. [0005] 2. Convolutional codes are used to introduce a certain dependency between successive signal points, so only certain...

AI Technical Summary

Problems solved by technology

The decoding process is based on the existing constellation diagram. For the case where the Euclidean distance of the TCM coded output signal points on the parallel path is short, the possibility of decoding errors is high.

Moreover, this does not conform to the TCM optimal code construction principle described above. The modulated signal should have as many regularities and symmetry as possible.

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