摘要
针对超宽带信号采样速率过高难以实现的问题,利用信道稀疏性提出一种基于压缩感知的信道估计算法。将信号重复送入随机滤波器后发送,对接收信号进行欠采样,利用调制信号、滤波器、信道的圆周卷积关系建立压缩感知的数学模型,最后采用基追踪（BP）算法得到信道估计值,同时通过分析得到了估计算法的克拉美-罗界（CRB）。算法节省大量的模数转换（ADC）资源,使系统实现成为可能。仿真结果表明,算法仅需不超过1/3的采样点数就可达到很优的估计效果,而且估计信道的均方误差（MSE）在高信噪比下接近于CRB。
It is difficult to design an ultra-high rate Analog-to-Digital Converter which can sample the UWB pulses with a huge bandwidth.To reduce the sampling rate,a novel channel estimation algorithm is proposed exploiting compressed sensing（CS） based random filter.Firstly,the repetition of the modulated signals gets across a random filter.Then the measurement sequence is gained by sub-sampling of the received signals.The mathematicalmodelofCScan be established exploitingthe cyclicconvolution propertyofthe modulated signals,the filter and the channel.The basic pursuit（BP）algorithm isutilized to get the estimated channel.And the Cramer-Rao bound ofthe sparse UWB channel estimation isderived.The number ofthe measurementsismuch smaller than the number ofsamplesin the originalsignalthat reducesuse ofADC resources.The computer simulation showsthat the proposed algorithm can get an excellent estimation performance using just not more than 1/ 3 of the sampling rate,and the Mean Square Error（MSE） approachesthe CRB under high Signal-Noise Ratio（SNR） conditions.
出处
《通信对抗》
2010年第2期3-6,11,共5页
Communication Countermeasures
基金
国家自然科学基金(60672157
60672158)
关键词
超宽带
信道估计
压缩感知
随机滤波器
基追踪
克拉美-罗界
Ultra Wide-Band（UWB）
channel estimation
compressed sensing
random filter
basic pursuit
Cramer-Rao bound
