8APSK mapping scheme for LDPC-BICM-ID system

Abstract

The present invention relates to the field of communication modulation constellation mapping, and is particularly suitable for an LDPC coding joint iterative demodulation decoding system. An 8APSK mapping scheme of an LDPC-BICM-ID system constructs a structure consisting of an inner ring and an outer ring on a plane-rectangular coordinate system with a real part as a horizontal axis and an imaginary part as a vertical axis, wherein the outer ring is distributed with five signal points, and the inner ring is distributed with three signal points, and an amplitude of each signal point is determined by positions of the inner ring and the outer ring where the signal points are located, an angle between a line connecting each signal point and the original point and the positive half axis of thereal axis represents a phase of a modulation signal of the signal. The system can improve spectral efficiency while obtaining coding gain, reliably transmit more information without increasing bandwidth, and can meet requirements of communication quality of wireless communication technology.

Description

Technical field: [0001] The invention relates to the field of communication modulation constellation mapping, and is particularly suitable for LDPC code joint iterative demodulation and decoding systems. Background technique: [0002] The research of DVB-S2 (the second generation standard of satellite digital video broadcasting) shows that better transmission performance can be obtained by using LDPC and 8PSK coded modulation combination in Bit Interleaved Coded Modulation Iterative Decoding (BICM-ID) system. However, as spectrum bandwidth resources become more and more tight, high-order modulation methods combining amplitude and phase should be considered to improve spectrum efficiency. Amplitude Phase Shift Keying (APSK) is more suitable for satellite channel data transmission because of its constellation distribution is circular, the amplitude fluctuation of the modulated signal is small, and the spectrum efficiency is high. Therefore, the 8th-order amplitude phase shift ...

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Problems solved by technology

[0004] In 2017, Yuan Jianguo et al. proposed a (2,6)-scheme mapping scheme in "A Novel 8APSK Mapping Scheme for BICM-ID System", which shows through simulation that (2,6)-scheme is in the joint LDPC In the BICM-ID system of the code, better bit error rate performance can be obtained than the traditional 8PSK Gray (Gray), SP (set partition), SSP (semi-set partition) mapping, but this (2,6)-scheme mapping The scheme gradually increases the code length of LDPC code, and the gain effect is not obvious in the case of low code rate

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