【摘要】 该文提出两种基于主动干扰消除(AIC)的OFDM机会频谱接入信号频谱成型方法,扩展AIC(EAIC)和EAIC-混合模式(EAIC-H)。在这两种方法中,除了OFDM信号外,系统还主动发送一些抵消信号(EAIC子载波)用来抵消OFDM信号的频谱泄漏在目标频带上形成的干扰。在时域上,这些抵消信号的持续时间比OFDM符号长,从而在干扰抵消方面可以得到比现有方法更好的效果。仿真结果表明EAIC方法可以形成很深的频谱凹槽(大约80dB),大幅度超过AIC方法。和EAIC方法相比,EAIC-H方法在调制阶数较高的情况下,如64QAM,能够在干扰抵消能力和信噪比损失两个方面取得更好的平衡和折中。更多还原

【Abstract】 In this paper, two novel methods called EAIC (Extended Active Interference Cancellation) and EAIC-H (EAIC-Hybrid) for spectral sculpting of OFDM signal are proposed. In EAIC and EAIC-H, cancellation signals are added to OFDM signal to cancel interference in target spectrum band caused by data tones, so that interference perceived by primary user can be limited. The cancellation signal (EAIC tones) has longer time duration than that of OFDM symbol, which enables a better notching capability than that of most existing methods. Simulation results show that the proposed methods can obtain very deep spectral notches of about 80 dB. Compared with EAIC, EAIC-H provides a better tradeoff between notching performance and SNR degradation for high order modulation.更多还原