Parameters Estimation Of Self-interference Signals In Overlapping Carrier Techniques Based On Constant Envelope Modulation

Different from ground communication, satellite communication system has two importantlimitations: limited communication band and limited communication power. In order to furtherimprove the system capacity and channel utilization, on the one hand, people have studied theoverlapping carrier multiple access technology. In overlapping carrier multiple access technology, twoground station in the satellite network communication using the same or nearly the same frequency,two signal sharing a bandwidth for duplex communication mode. In the same bandwidth, informationtransmission rate can achieve two times than the original one. On the other hand, people introduce theconstant envelope signal. The constant envelope signals have high spectral efficiency and constantenvelope which can avoid AM-FM effect. Satellite can use nonlinear power amplifier to increase theutilization rate of power based on the constant envelope signals.In this paper, we research the PCMA technology, including the capturing and tracking. Firstly, weresearch the capturing performance based on the training sequence. Then we study the effectiveparameters estimation methods based on relevant parameter estimation methods and get goodperformance. Also we apply it to BPSK and QPSK signals, then extend to the MSK signals.Different from the existing research, we research the whole parameters estimation in PCMAtechnology including amplitude, frequency, initial phase, delay. When tracking the frequency andinitial phase, all of the existing algorithms consider them separately, and track the frequency first, thentrack initial phase. However the tracking accuracies of initial phase and frequency are affected byeach other. In this paper frequency and initial phase are seen as phase which is accurately tracked byPLL. MATLAB simulation shows when the symbol rate is10KHz and sample rate is100KHz, theperformance of PCMA has0.38dB worse than the MSK BER performance at104.Finally, by using the Xilinx ISE Design Suite14.1development platform, the hardware functionalsimulation of each loop of the tracking module based on FPGA is successfully achieved in the paper.The paper gives the system design as well as the input and output interfaces of each module. Theprogramming language is Verilog, a hardware description language. The Isim is used as the functionalsimulation software. Through simulation, the results in Isim are consistent with that in MATLAB.