【摘要】 研究了深空通信系统的性能计算。系统采用Feher正交相移键控(FQPSK)调制和双波散射功率(TWDP)衰落信道,因为TWDP信道模型的散射传输波中含有两个镜面反射多径分量,可依据不同参数表达不同的衰落,因此适合描述复杂的电磁深空通信环境;FQPSK调制与标准QPSK相比具有频谱主瓣窄和滚降快的优势,因此更适合应用于深空通信系统中。为简化系统性能计算,推导了FQPSK调制在TWDP衰落下的误码率闭式解,并验证了推导的正确性。基于深空通信系统仿真平台,分析了不同种类QPSK调制及各种TWDP衰落参数下的误码率性能。结果表明,FQPSK与QPSK相比,结合卷积编码后可实现性能提升。更多还原

【Abstract】 The performance computation for deep space communication systems was studied. The systems adopt the Feher quadrature phase shift keying( FQPSK) modulation and the TWDP( two-wave with diffuse power) fading channel because the TWDP fading channel model can express different fadings according to different parameters so it is suitable for complex electromagnetic deep-space communication,and the FQPSK modulation is widely used in deepspace communication systems due to its constant envelope and high spectrum efficiency characteristics. To simplify the computation of system performance,the closed-form BER of the FQPSK modulation in a TWDP fading was derived and the correctness of the derivation was verified by simulation. Based on the software platform of deep-space communication systems,the performances of the FQPSK modulation under different TWDP fading parameters were simulated,and the results show that the FQPSK modulation can suitably be applied to deep space communication systems for its better features in comparison with other QPSK modulations,which is important to actual system design.更多还原