A modulation and demodulation method and system for three-dimensional spatial signals based on mppam modulation

Abstract

The present invention provides a three-dimensional spatial signal modulation and demodulation method and system based on MPPAM modulation, including performing analog / digital, serial-parallel conversion on the original signal, analyzing and training according to the obtained signal, and selecting the best three-dimensional constellation The dot diagram, the pulse signals with different pulse positions and pulse amplitudes constitute the training set, and the pulse signals in the training set are modulated with different MPPAM modulation signals, and then the channel transmission is simulated, based on the received signal-to-noise ratio and signal power obtained by the simulation The functional relationship between noise power and noise power, determine the best MPPAM modulation signal, use the three-dimensional constellation point diagram to correlate and demodulate the simulated received signal, construct the objective function based on machine learning algorithm for training, determine the best three-dimensional constellation point diagram, use for the demodulation of the actual received signal. It solves the problems of slow signal transmission rate, high bit error rate and low bandwidth utilization rate when sending and receiving MPPAM signals in complex environment channels, and has low modulation complexity.

Description

technical field [0001] The invention relates to the technical field of digital communication, in particular to a three-dimensional spatial signal modulation and demodulation method and system based on MPPAM modulation. Background technique [0002] With the rapid development of ultra-wideband communication systems, from the perspective of digital modulation, in order to achieve a higher transmission rate, the order of traditional quadrature amplitude modulation (QAM) is increased from 64 to 256, or even higher. However, the main problem of traditional 2D mapping schemes is that under the same transmission power constraint, the higher the mapping order, the smaller the minimum Euclidean distance (MED). This is a natural consequence of increasing the number of constellation points under the same transmit power constraint. This shortcoming significantly reduces the robustness of the transmitted signal in the radio channel, thus placing higher signal-to-noise ratio (SNR) requir...

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Problems solved by technology

[0004] After creatively designing various three-dimensional signal constellation structures, designers have not done much research on how to realize the communication system. They usually send three-dimensional signals at different times or at different center frequencies, that is, the three-dimensional signals are connected to each other. Sending through a one-dimensional signal without interference will not only reduce the signal rate to a certain extent, but also the implementation complexity of the system is relatively high

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