一种无线认知网络中的自适应波束成型模式选择算法

为了能够在避免对主用户干扰的同时,进一步提高频谱的利用效率,提出了一种自适应的波束成型模式选择算法。针对当前的认知网络很少考虑在空间上将主从用户进行分离,将多天线技术引入无线认知网络,利用其提供的空间自由度,从用户基站在主用户信道的零空间内设计发射波束,这样可以使得2个网络共存时,主用户能够无干扰地进行数据传输。同时,随着发射信噪比的变化,从用户基站自适应地在机会式波束成型和正交空分多址2种模式间进行选择,从而最大化网络的容量。分析和仿真结果都表明,这是一种解决网络共存、提高频谱效率的有效方法。

Adaptive beamforming mode selection algorithm in wireless cognitive networks

To further impr ove spect rum ef f iciency w hile avoiding interference to the primary user, an adaptiv e beamforming mode select ion alg orithm w as pro posed. Mult i-antenna technique could separ ate the primary and cognit iv e users by making use of it s inherent spat ial degr ee o f fr eedom. Therefor e, interfer ence fr om co gnit ive netwo rk could be cancelled ef fect ively since the data of cognit iv e users w ere t ransmit ted in the null space o f the channel of the primar y user. Meanw hile, cog nit ive netw ork adapt ively selected the oppor tunist ic beamforming o r orthogo nal space div ision multiplexing access mode w ith the v ariety o f t ransmit SNR, which resulted in max imizing the capacity. Analy sis and simulation result s show that it is an effect ive method to solv e the problem of the netw ork coexistence and impro ve spect rum ef ficiency .