认知无线电中的干扰抑制合并算法

认知无线电中,认知用户允许接入授权频谱会对主用户造成严重干扰。为解决这一问题,结合多天线技术,提出一种干扰抑制算法。该方法不需要干扰信号的先验信息,可有效降低主用户与认知用户之间的干扰。从理论上推导了采用新算法后系统的SINR(信干噪比)表达式,给出了误码率下限。仿真结果表明,SIR(信干比)为0 dB、接收天线数目为2、BER为10-3时,干扰抑制合并算法性能优于传统的最大比合并算法6 dB。

Algorithm of interference rejection combining in cognitive radio systems

The cognitive users could cause harmful interference to the primary users when they access the licensed spectrum in cognitive radios. To solve this problem, this paper presented an interference rejection combining(IRC)employing multiple antennas. It didn't require any priori information about the interference, effectively reducing the interference between primary users and cognitive users. Furthermore, it derived the theoretical expression of SINR (signal-to-interference-plus-noise power ratio)and gave the lower bound of BER(bit error rate). It carried out the computer simulation under the condition of one transmit antenna and two receive antennas. The results show that when SIR (signal-to-interference ratio) is 0 dB, at BER of 10-3, IRC gives about 6 dB better performance than MRC (maximum ratio combining).