时间反演UWB通信系统的窄带干扰抑制

超宽带(ultra wide band, UWB)通信系统工作在3.1~10.6 GHz的频谱范围内,与现存的一些通信系统共用频谱资源。为了防止UWB通信系统对其他通信系统造成干扰,美国联邦通信委员会将UWB的室内辐射功率谱密度限制在-41.3 dBm/MHz以下,但UWB通信系统会受到其共存的窄带系统的严重干扰。针对此问题,本文在接收端设计了一种自适应无限脉冲响应陷波器,推导了-3 dB处的自适应带宽,同时结合最速下降算法,找到陷波器的最优带宽,从而抑制UWB中的窄带干扰(narrow band interference, NBI)。最后使用蒙特卡罗仿真验证出自适应陷波器有效抑制了时间反演(time reversal, TR)UWB通信系统中的NBI,提升系统误比特率(bit error rate, BER)。

Narrow band interference suppression of time reversal UWB communication system

Ultra wide band (UWB) communication systems work in the scope of 3.1~10.6 GHz spectrum with other pre-existing wireless systems. In order to prevent the interference of UWB communication systems to other systems, the federal communications commission regulations have set conditions that the indoor radiation power is under 41.3 dBm/MHz, but the UWB communication system will be seriously interfered by the narrowband systems. Aiming at this problem, an adaptive notch at the receiver is designd and derives the adaptive bandwidth equation at -3 dB. At the same time, the fastest descent algorithm is combined to find the optimal band width of the notch filter. Finally, simulation results show that the adaptive notch reduces the narrow band interference (NBI) in time reversal (TR) UWB communication system and improves the bit error rate (BER).