Precoding with interference suppression sequence scheme for OFDM-based cognitive radio systems  

作　　者：ZHAO Cheng-lin ZHANG Kun SUN Xue-bin JIANG Ting 

机构地区：[1]Key Laboratory of Universal Wireless Communication, Ministry of Education, Beijing University of Posts and Telecommunications, Beijing 100876, China

出　　处：《The Journal of China Universities of Posts and Telecommunications》2011年第4期59-64,共6页中国邮电高校学报（英文版）

基　　金：supported by the National Science and Technology Specific Major Projects (2009ZX03006-006, 2009ZX03006-009);the National Natural Science Foundation of China (60432040,60972079)

摘　　要：Orthogonal frequency division multiplexing （OFDM） is considered to be one of the promising schemes for cognitive radios （CR） systems, due to its flexibility in spectrum shaping. However, the traditional way of spectrum-notching failed to suppress out-of-band leakage enough, resulting in interference with licensed users （LUs）. A novel spectrum shaping scheme is proposed in this article, where a precoder with interference suppression sequence （ISS） is for the first time introduced for shaping the spectrum of OFDM signals in OFDM-based CR systems. The precoder matrix together with ISS matrix is obtained by minimizing the power of out-of-band interference, which results in the sufficient interference suppression of OFDM signal to LUs Analysis and simulation results show that the proposed scheme can significantly suppress the interference power to LUs at a little cost of precoding efficiency. Meanwhile, the peak-to-average-power-ratio （PAPR） is invariable and the bit-error-rate （BER） performance over Rayleigh fading channel is improved.Orthogonal frequency division multiplexing （OFDM） is considered to be one of the promising schemes for cognitive radios （CR） systems, due to its flexibility in spectrum shaping. However, the traditional way of spectrum-notching failed to suppress out-of-band leakage enough, resulting in interference with licensed users （LUs）. A novel spectrum shaping scheme is proposed in this article, where a precoder with interference suppression sequence （ISS） is for the first time introduced for shaping the spectrum of OFDM signals in OFDM-based CR systems. The precoder matrix together with ISS matrix is obtained by minimizing the power of out-of-band interference, which results in the sufficient interference suppression of OFDM signal to LUs Analysis and simulation results show that the proposed scheme can significantly suppress the interference power to LUs at a little cost of precoding efficiency. Meanwhile, the peak-to-average-power-ratio （PAPR） is invariable and the bit-error-rate （BER） performance over Rayleigh fading channel is improved.

关 键 词：OFDM cognitive radio PRECODING spectrum shaping 

分 类 号：TN911.3[电子电信—通信与信息系统] TN914.42[电子电信—信息与通信工程]