Unequal probability high-order constellation point design method and demapping method

Abstract

The invention belongs to the technical field of high-speed satellite communication coding modulation, and provides an unequal probability high-order constellation point design method and a demapping method. According to the method, good error performance can be obtained under the condition of nonlinear distortion caused by a high-power amplifier. The technical scheme adopted by the invention is asfollows: the unequal approximate high-order constellation point design method and the demapping method comprise the following steps: designing the occurrence probability of a two-dimensional signal constellation represented by S and each signal point on the basis of a 64-order quadrature amplitude modulation QAM square constellation diagram; completing mapping from the inequivalence symbols to the inequivalence constellation points, forming and filtering, and performing up-conversion to complete signal transmission; the receiving end firstly performing matched filtering and downsampling on the received signals, and after nonlinear demapping, directly obtaining the probability of 4-bit symbols according to a one-to-one mapping principle; and finally, sending the probability information into a multi-system code or binary code decoder for decoding. The method is mainly applied to a high-speed satellite communication coding modulation occasion.

Description

technical field [0001] The invention belongs to the technical field of high-speed satellite communication coding and modulation, and in particular relates to a method for designing non-isoproteus constellation points and a demapping method for realizing high-order modulated signal constellations under a nonlinear channel. Background technique [0002] In space applications, the amount of data generated by image remote sensing, lidar, etc. continues to increase, and the data bandwidth required for data transmission is also required to continue to increase. In response to this problem, the use of high-order modulation to improve spectrum utilization has gradually become an inevitable requirement for the development of satellite data transmission in the future. However, the envelope of the high-order modulation signal fluctuates greatly, and is sensitive to the nonlinearity of the on-board power amplifier. In order to fully improve the utilization efficiency of satellite power...

AI Technical Summary

Problems solved by technology

However, the envelope fluctuation of the high-order modulation signal is relatively large, and it is sensitive to the nonlinearity of the on-board power amplifier

In order to fully improve the utilization efficiency of satellite power, the high-power amplifier in the satellite channel generally works near the saturation point, which will cause large nonlinear distortion, especially the signal point distortion with large amplitude is more serious

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