基于欠采样的脉冲UWB通信窄带干扰消除技术

Sub-Nyquist sampling based narrowband interference mitigation for impulse radio UWB communications

针对窄带干扰(narrowband interference,NBI)的存在会对脉冲超宽带(ultra-wideband,UWB)通信系统性能带来严重的影响。提出了一种基于欠采样的低复杂度NBI检测与消除方案,以消除NBI为目标,论证了欠采样下NBI检测与消除的可行性。通过傅里叶分析,指出NBI在欠采样信号的快速傅里叶变换域中具有稀疏性和易辨别的特点,并根据这些特征实现了对NBI子空间的估计。依据NBI子空间,设计了NBI信号的正交投影矩阵,在时域实现了对NBI的消除。仿真结果表明,在可接受的UWB信号功率损失范围内,方案大大提高了欠采样信号的信号干扰噪声比。

The presence of narrowband interference （NBI） can cause severe effects in impulse radio ultra- wideband （UWB） communications. A low-complexity sub-Nyquist sampling rate based NBI detection and miti- gation scheme is proposed. With the goal of suppressing NBI, the feasibility to carry out NBI detection and sup- pression appropriately under the sub-Nyquist sampling rate is demonstrated. Fourier analysis indicates that the NBI signals have the characteristics of sparsity and significance in the fast Fourier transform domain even at the sub-Nyquist sampling rate. Based on those properties, the subspace of the NBI is estimated. An orthogonal ma- trix for projecting the discrete-time NBI signal into a zero vector is designed. Simulation results show that with an acceptable UWB signal energy loss, the proposed scheme can greatly improve the received signal-to interfer- ence-plus-noise ratio.