【摘要】 研究了移动卫星信道的统计特性 ,给出了非频率选择性信道条件下描述移动卫星信道的有遮蔽莱斯衰落模型 ,用实验和修正的方法给出了模型参数。在此模型基础上分析了相干PSK调制方式下窄带系统和宽带扩频系统的误码性能 ,计算了数值曲线。结果表明移动卫星信道中存在的多径和阴影现象使系统的误码性能恶化 ,而采用宽带扩频调制则可极大改善系统的性能。此外 ,推导了相干PSK方式下由于接收信号相位的抖动所引起的不可消减的误码率下限更多还原

【Abstract】 The paper deals with the statistical characterization of mobile satellite channel, and introduces a statistical channel model-the Shadowing Rician Fading model for frequency nonselective land mobile satellite channel. The parameters contained in the model are given by means of trial and error. Based on the model, the BER(Bit Error Ratio)performance is analyzed for narrow-band modulation and wide-band spread -spectrum modulation of coherent PSK (Phase Shift Keying) signals. The results show that the multipath and fading phenomenon in the channels worsens the system bit error performance, while the use of wide band spread spectrum modulation can improve it efficiently. In addition, an analytical expression is derived for the irreducible probability of bit error of coherent PSK signals due to phase variations caused by fading and shadowing. At last, the numerical results are obtained and discussed.更多还原