基于智能天线的认知无线电网络频谱访问协议

摘要

Smart antenna with the characteristics of spatial separation is introduced into cognitive radio which greatly improve the spectrum efficiency in space domain. In order to further improve the spectrum utilization efficiency,a spectrum access protocol which can be used in space and enables cognitive users to coexist with primary user and optimizes the allocation of spectrum and spatial resource and the using efficiency is improved. In addition,the successful communication probability and network throughput of the cognitive users are simulated and analyzed theoretically. The results show that compared with the Omni antenna, the cognitive radio systems based on smart antenna can get more opportunities for transmission, and throughput is significantly improved.%认知无线电技术可以择机地使用注册信道,从而提高频谱的利用率.但是这种提高只是局限于时域上的.将具有空间分隔特性的智能天线引入次无线电系统,设计了一种在空间上可以复用的频谱访问协议.该协议使次用户(SU)和主用户(PU)可以同时共存,优化了频谱和空间资源的分配,进一步提高了频谱的使用效率.此外,还对SU的传输成功概率和网络吞吐量进行了理论分析和仿真.结果表明:与使用传统全向天线的认知无线电相比,基于智能天线的认知无线电系统能获得更多的传输机会,吞吐量显著提升.