移动卫星通信的信道模型和传输特性分析  

A Statistical Model for Mobile Satellite Channel and Digital Transmission Analysis

作　　者：邱晶[1] 余平[1] 杨士中[1] 

机构地区：[1]重庆大学通信工程学院,重庆400044

出　　处：《重庆大学学报（自然科学版）》2003年第7期37-41,共5页Journal of Chongqing University

基　　金：教育部重点项目资助 (2 0 0 0 -6187)

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 。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.

关 键 词：移动卫星通信 信道模型 衰落模型 扩频 传输特性 

分 类 号：TN927.23[电子电信—通信与信息系统]