差分空间调制中的非恒模调制方法

摘要

Differential spatial modulation ( DSM) is concerned because it does not rely on any channel state information ( CSI ) . The traditional DSM uses equal energy constellations, such as phase shift keying ( PSK) . However,in high-speed transmission,PSK has a lower noise immunity than non-constant modulus constellations,and with the improvement of the modulation order,the disadvantage is particularly evident. For this problem,a non-constant modulus modulation method in DSM system is proposed. The amplitude iteration problem of non-constant modulus modulation in DSM system is eliminated by a precoding process-ing at the transmitter. In addition,in order to obtain the diversity gain,a method that reduces the transmis-sion rate to achieve full diversity gain is adopted and a power balance is added to make the system be able to use non-constant mode modulation. The simulation results show that the performance of the proposed al-gorithm is better than that of PSK with the improvement of signal-to-noise ratio( SNR) .%差分空间调制(DSM)由于不依靠信道状态信息(CSI)而备受关注.传统的DSM采用了恒模调制的方法,例如相移键控(PSK),但是在高速传输时PSK对星座图的空间自由度利用很低.针对该问题提出了一种DSM系统中的非恒模调制方法,通过对发射信号做相关预编码处理,使之消除非恒模调制在DSM系统中存在的幅度迭代问题.除此之外,为了使之可以体现分集增益,通过减小传输速率来达到满分集增益,并且加入一个功率均衡项来使该系统可以利用非恒模调制.仿真结果表明所提算法随着信噪比的提高,性能会逐渐优于PSK.