Effect of Carrier Phase Error on Coherent FH/CDMA System with MRC Scheme over Rayleigh Fading Channel
Rayleigh衰落信道下相位误差对相干跳频多址接入MRC分集接收系统的影响

A novel hybrid communications system, i.e., coherent Frequency-Hopping CDMA (FH/CDMA) system with Maximum Rate Combining (MRC) diversity reception and multicarrier scheme, is analyzed in Rayleigh fading channel. Due to the introduction of phase modulation, the phase precision in recovering carrier will affect on the system performance. The carrier recovery is implemented with the first-order Phase-Locked Loop (PLL) in the presence of AWGN in carrier recovery the loop, where the resulting steady-state phase error is appeared. The average Bit Error Rate (BER) of the ideal and the partial coherent FH/CDMA system are derived with means of Beaulieu series and characteristic function. Simulation results demonstrate that the BER performance of multi-user system is less susceptive to phase error and the dominating degradation is due to Multiple-Access Interference (MAI), compared to the single-user system. It is also shown that the effect of phase error and fading channel can be reduced by MRC reception more efficiently.