Method for designing constant envelope PSK modulator-demodulator

Abstract

A method for designing a constant envelope PSK modulator-demodulator comprises the steps of S1 signal processing of a constant envelope PSK modulator and S2 signal processing of a constant envelope PSK demodulator. According to the step S1, at a transmitting terminal, binary bit streams output by a channel encoder are grouped according to a modulation parameter M; a differential phase sequence is obtained; a minimum additive group is generated by the differential phase; digital signals are subjected to digital-to-analogue conversion, and the modulation process is completed. According to the step S2, at a receiving terminal, first, received FSK signals are sampled, frequency modulation signals are subjected to phase integration; correlation operation is conducted on the signals of a synchronization sequence and all sampling points to obtain the best sampling point; the phase of the PSK signal at the best sampling point is used for extracting soft information, making hard decisions and achieving digital demodulation. According to the method, the NPSK modulation signals are subjected to constant envelope conversion to be used as modulation output, so that the power efficiency of power amplification of the transmitting terminal of a communication system is improved; the receiving terminal enables the signals to be sampled, and the PSK modulation signals can be restored and acquired through a phase integrator and a matched filter.

Description

technical field [0001] The present invention relates to the technical field of signal transmission, in particular to a design method of a constant-envelope PSK modem, which transmits PSK modulation information in the form of constant-envelope and continuous phase signals, and can accurately restore the original PSK modulation signal at the receiving end , demodulate according to the PSK modulation signal. Background technique [0002] PSK (Phase-Shift Keying, phase-shift keying) is a widely used digital modulation method, which uses phase changes to represent binary bit information. Usually each N-PSK (N∈{2 k |k=1,2,3,...}) modulation symbols can carry bit information. Although it has been widely used in wireless communication, because it is not a constant envelope modulation, PSK modulated signals generally have the problem of peak-to-average ratio, that is, the peak power is strictly greater than the average power of the signal. This phenomenon will affect the power amp...

AI Technical Summary

Problems solved by technology

This phenomenon will affect the power amplifier efficiency of the communication base station. Once the transmitter works in the nonlinear amplification range, the distortion of the transmitted signal will increase greatly with the increase of the transmission power, which will affect the normal demodulation of the signal.

Due to the limitation of the linear working range of the transmitter, the average power of the signal is often chosen to be reduced during communication, thereby reducing the power utilization of the power amplifier

Images