天线相关性对空时频移键控(ST-FSK)系统性能的影响

Effect of Antenna Correlation on ST-FSK System Performance

给出了在已知天线相关因子条件下接收端的非相干ML判决度量,讨论了天线存在相关性时进制数、天线相关因子、信噪比和可靠性指标的关系.理论分析和仿真结果都表明:发射天线相关性的存在相当于破坏了发射信号的酉特性,迫使系统付出额外的“功率”代价.相应的“功率”代价随着相关因子的增加而非线性增加,而与进制数的关系很小.

Space-time frequency keying （ST-FSK） can be merged naturally into frequency-hopping communication systems. Based on a previous study, this paper presents an incoherent ML decision metric in the receiver with knowledge of transmitter antenna correlation, and discusses the relationship between correlation factor, SNR, and reliability index for binary ST-FSK and quaternary ST-FSK in the presence of antenna correlation. The theoretical analysis employs random variable decomposition. Simulation results show that the presence of transmitting antenna correlation, which is equivalent to destruction of unitary characteristics, imposes extra power cost on the performance of ST-FSK systems. The corresponding power cost increases nonlinearly with correlation factor, but makes little difference for binary ST-FSK and quaternary ST-FSK