幅度相位双差分空时码的性能分析

Performance analysis of amplitude-phase double differential space time codes

本文在介绍幅度相位双差分空时码的基础上,给出了影响其性能的主要参数——幅度系数。通过对16-APSK(2个幅度、8个相位)星座调制的幅度相位双差分空时码在慢瑞利衰落信道下进行仿真,分析了在总功率一定的情况下,2个幅度系数的选择对其性能的影响,并将采用不同幅度系数的幅度相位双差分空时码与只有相位差分的空时码的抗噪性能进行了比较。仿真结果表明当幅度系数取得合适的时候,幅度相位双差分空时码在提高了传输速率的同时,它的性能也优于只有相位差分的空时码,尤其是当信噪比较低时,幅度相位双差分空时码的性能较好。

Based on the amplitude-phase Double Differential Space Time Codes （DDSTC）, a main parameter-amplitude coefficient, which affects the performance of DDSTC is analyzed in this paper. Through simulating the amplitude-phase DDSTC with 16-APSK （2 amplitudes, 8 phases） modulation in slow Rayleigh fading channels, their performances are shown by changing the two amplitude coefficients when the total power is constant, and compared with Differential Space Time Codes （DSTC）/Phase only. Simulation results show that the amplitude-phase DDSTC can achieve better performances than DSTC/Phase in addition to higher band rate when the amplitude coefficients are chosen properly, especially when the signal to noise ratio （SNR） is low.