信息管理中UWB系统信道估计与均衡算法及实现
2014-10-14鲁海蓉
鲁海蓉
摘 要: 通过介绍UWB技术的发展现状,着重阐述了MB?OFDM UWB通信系统的物理层帧结构和信道模型。在分析最小二乘(LS)信道估计算法和基于快速傅里叶变换(FFT)信道估计算法的基础上,针对MB?OFDM UWB信号帧结构特征提出了一种基于FFT变换和Hannan?Quinn(HQ)准则的改进算法,即FFT?HQ信道估计算法。该文也提出了一种基于信道估计的自适应均衡算法,利用仿真可以看出此均衡算法在性能上优于传统的基于LS算法调整均衡器系数的方法。
关键词: 超宽带; 正交频分复用; 信道估计; 均衡算法
中图分类号: TN911?34 文献标识码: A 文章编号: 1004?373X(2014)20?0041?03
Channel estimation, equalization algorithm and realization of UWB system in information management
LU Hai?rong
(Business School, Hohai University, Nanjing 211100, China)
Abstract: The development situation of UWB technology is introduced. The frame structure in physical layer and the channel model of the MB ? OFDM UWB communication system are elaborated emphatically. Based on the analysis of the least?squares (LS) channel estimation algorithm and FFT?based channel estimation algorithm, FFT ? HQ channel estimation algorithm, which is an improved algorithm based on FFT and Hannan?Quinn (HQ) criterion, is put forward according to the structural features of MB?OFDM UWB signal frame. An adaptive equalization algorithm based on channel estimation is also proposed in this paper. It can be seen by simulation that the performance of the equalization algorithm is superior to the traditional method based on LS algorithm to adjust the equalizer coefficients.
Keywords: ultra wideband; OFDM; channel estimation; load?balancing algorithm
0 引 言
无线通信系统及产品已成为人们日常生活中必不可少的一部分,迅速增长的无线设备使用户享受便利,也使可利用的频谱资源日趋饱和。因此,超宽带(Ultra Wideband,UWB)技术凭借其更高的数据传输速率、更低的成本和功耗、更强的抗干扰能力,逐渐成为无线通信领域研究和开发的热点,被视为是下一代无线通信的关键技术之一。解决码间干扰和串扰,降低系统的误码率,提高接收系统的性能,就要对已经失真的传输信道进行均衡。国外研究者提出了基于频域的复系数滤波均衡方法,局限在于:
(1) 必须测量的相频特性和幅频特性,实际测量时由于仪器精度和测量方法的限制不可能做到很准确;
(2) 实际的复系数滤波器针对的对码元的每一个采样点数据进行均衡滤波,对高码率资源消耗无法接收;
(3) 针对特定信道进行均衡,当信道特性改变时不能做到自适应。……
