一种针对UWB-PPM多径信号的加权非相干接收机设计方案

Design of weighted non-coherent receiver for UWB-PPM signal in multipath channels

由于实现简单,基于能量检测的非相干超宽带(UWB:Ultra-Wideband)接收机对一些低速数据应用具有很大的吸引力,但另一方面,相对于相干接收机来说其误码性能一般较低。为了提高其误码性能,一种采用子分区积分加权合并的优化措施在文献[4]中被提出。本文针对加权非相干接收机在UWB-PPM多径信号下的情况进行了研究,推导了相应的闭式误码性能表达式,并进一步分析了该接收机的最佳和准最佳加权系数组合。通过计算机仿真对加权非相干接收机的误码性能分析和准最佳加权系数的有效性进行了验证,对子积分区间宽度的影响进行了分析。结果表明,加权非相干接收机在理想情况下至少具有3dB以上的性能提升,并对子积分区间宽度的影响具有一定的强健容忍能力。本文最后提出了一种简单灵活的加权非相干接收机结构设计方案,包括相应的加权系数估计算法和实现结构。

The non-coherent receiver is attractive for UWB system implementation in lower data rate applications due to its simplicity for implementation. However, the performance degradation is the main problem of this receiver, and some optimization approaches, among which is the combining of weighted multi-interval integration, have been proposed to improve its performance. In this paper, a simple yet flexible weighted non-coherent receiver structure based on differential energy detection for UWB-PPM signal is proposed, and the BER performance is derived as well. Subsequently, the optimal weighting coefficients are analytically derived, and two sets of suboptimal weighting coefficients are also proposed and validated. The simulation results demonstrate that the weighted receiver is at least 3dB superior to the conventional non-coherent receiver, and is also robust to the variation of sub-integration width and the timing error. Finally, the detailed implementing scheme is proposed, including the related parameter estimation algorithm and realization structure.