M-APSK (amplitude phase shift keying) signal to noise estimation method based on iterative decoding and decision feedback

Abstract

The invention discloses an M-APSK (amplitude phase shift keying) signal to noise ration estimation method based on iterative decoding and decision feedback. The method includes subjecting a transport signal to utilize a variable bit rate decoder to obtain feedback result, modulating to obtain a receiving signal without noise, finding out relative position of the receiving signal on a constellation map, dividing into a plurality of circular rings, obtaining each circular ring receiving signal through solving rotation, calculating amplitude mean value of each circular ring receiving signal, calculating useful signal total power and transport signal total power according to the amplitude mean value, and calculating estimated value of signal to noise ratio. The concept of iterative estimation is adopted, iterative decoding output information bit is used for inverse modulation and constellation map division, and the data-aided algorithm is adopted to finish estimation of the signal to noise ratio, so that the problem of major errors in the constellation map division is solved, signal to noise estimation accuracy is improved, the problem of realizability and complexity brought by the maximum likelihood estimation method is avoided, and the M-APSK signal to noise ration estimation method based on iterative decoding and decision feedback has better application prospect.

Description

technical field [0001] The invention relates to the technical field of satellite communication, in particular to an M-APSK signal-to-noise ratio estimation method based on iterative decoding and decision feedback for improving the transmission rate and spectrum utilization rate of satellite communication. Background technique [0002] With the increase of demand for high-speed data services, the development trend of satellite communication will also adopt adaptive coding and modulation technology. Adaptive coding and modulation technology (ACM) is to improve the power of the system when the power is constant by changing the code rate and modulation order. transmission rate, but the adaptive modulation technology requires a high-precision signal-to-noise ratio estimation algorithm, and the estimation accuracy has a major impact on the selection of modulation and coding methods, such as figure 1 In the overall block diagram of the adaptive coding and modulation technology show...

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Problems solved by technology

[0007] The purpose of the present invention is in order to overcome the solution method for APSK modulated signal signal-to-noise ratio estimation in the prior art in the prior art, system overhead is large, transmission efficiency is low or, practicability is poor, the estimation accuracy of signal-to-noise is relatively poor etc.

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