基于特征扩频的卫星转发器频谱资源聚合研究

Spectrum aggregation for satellite transponders based on eigen-based spread spectrum

针对CDMA卫星通信系统受到严重外部干扰,且可连续使用的频谱受限问题,提出3种基于特征扩频的卫星转发器频谱聚合方案,实现多个转发器频谱高效聚合的同时对抗系统受到的外部干扰。通过仿真表明,所提方案能够克服基于现有认知多载波CDMA方法进行卫星转发器频谱聚合的设计复杂度较高、频谱聚合效率低的缺点,并且所提整体特征扩频方案在性能和支持用户数方面均优于另外2种多载波特征扩频方案,提高了系统对多个转发器的非连续频谱利用率,进而提升系统容量。

The existing CDMA satellite systems are faced with serious extemal interference and limited by the continuousavailable spectrum. In order to realize the spectrum aggregation of multiple satellite transponders and combat the externalinterference simultaneously, three spectrum aggregation schemes based on the eigen-based spread spectrum are proposed.Numerical results show that all the three proposed schemes can overcome the high system design complexity and lowspectrum aggregation efficiency of the scheme based on the existing cognitive multicarrier CDMA, and the proposedoverall eigen-based CDMA （O-ECDMA） scheme outperforms the other two proposed schemes based on multicarrier ei-gen-based CDMA. Moreover, the discontinuous spectrum efficiency of multiple satellite transponders and the system ca-pacity are both improved.