基于DBF的星—地异构共存认知MIMO系统的干扰减缓

Interference mitigation for satellite-terrestrial heterogeneous coexistence cognitive MIMO system based on DBF

针对星—地网络和地面无线网络共存现象逐渐增多和共存干扰日益严重的问题,分析了一种地球同步轨道(GEO,geosynchronous earth orbit)星—地网络和地面4G移动通信网络异构共存的典型场景,提出了一种地面次用户卫星地面站对地面主用户多入多出(MIMO,multiple input multiple output)4G基站干扰的异构多用户认知系统模型,并推导了其通用信号处理过程。同时,在4G基站系统内采用数字波束形成(DBF,digital beam forming)技术最小化多天线多用户的认知干扰,设计了一种基于固定方位干扰的最优波束权重(OBW-FAI,optimal beam weight based on fixed azimuth interference)抗干扰算法,权重向量只与干扰源方位有关,不需要实时和重复计算,计算量小。最后,数值仿真结果验证了所提系统和算法可以一定程度地改善星—地网络和地面无线网络异构共存的干扰。

For the coexistence and increasing interference of satellite-terrestrial network and terrestrial wireless network,a typical scenario where the geostationary earth orbit （GEO） satellite-terrestrial network and the 4G mobile communica-tion network coexist heterogeneously was analyzed. Besides, a multi-user cognitive system model that secondary satelliteterminals interfere the primary multiple input multiple output （MIMO） 4G based stations was also proposed, with whosegeneral signal processing was deduced. Meanwhile, digital beam forming （DBF） technology in 4G based station systemwas adopted to minimize the cognitive interference caused by multi-antennas and multi-users. And an optimal beamweight based on fixed azimuth interference （OBW-FAI） was proposed. Weight vector was only related to the azimuth ofthe interferences, thus the proposed algorithm does not need real-time and repeat calculations, and had small complexity.Finally, the numerical simulation results verify that the proposed system and algorithm can effectively reduce interferencebetween satellite-terrestrial network and terrestrial wireless network to a certain extent.