CPM-PSWFs Signal Demodulation Method Based on Waveform Coherence

Abstract

In order to further improve the frequency bandwidth efficiency and power efficiency of existing Continuous Phase Modulation (CPM) and demodulation systems, a continuous phase modulation and demodulation method based on Prolate Spheroidal Wave Functions (PSWFs) signal is proposed, which is called CPM Based on PSWFs (CPM-PSWFs). In this method, the signal space has PSWFs signal with high energy aggregation in the time-frequency domain and a flexible and controllable time-bandwidth product as the baseband pulse signal of the CPM signal to generate the modulation signal. At the receiving end, the coherent detection method of the PSWFs signal waveform is used to demodulate the signal. First, the principle of CPM signal generation based on PSWFs signal is given. Secondly, a demodulation method of CPM-PSWFs signal using coherent detection of PSWFs signal waveform is introduced. Finally, the modulation and demodulation performance of CPM-PSWFs signal is simulated and analyzed. Experimental results show that: under the same parameter conditions, compared with the existing CPM signals based on rectangular pulses, raised cosine pulses and other signals, CPM-PSWFs modulated signals can have higher energy concentration and higher frequency bandwidth efficiency. The demodulation method based on PSWFs waveform coherence can be superior to the demodulation performance of the existing CPM signal differential coherent detection.