室内环境下超宽带信号具有丰富的多径分量,在时域中这些分量表现出簇(cluster)的形式,簇在时域上类似于幅度调制,可采用包络分析法对其进行分析.介绍了利用小波变换进行超宽带信号包络分析的方法,给出了接收信号包络的时域表达式,并对低信噪比下超宽带信号进行了包络提取,结果显示该方法实现了簇内多径分量的合并,并具有很强的去噪作用.包络分析方法对于那些难以建立模型的传输环境以及能够建立模型但难以提取参数的场合下超宽带信号的采集具有重要的意义,它指出了传统的包络分析技术可用于超宽带信号的采集.
Ultra-wideband(UWB) signal has rich multi-path components in indoor environment, and the clustering phenomenon is observed in the receiver. In order to fit the measurement data, some UWB channel models are established to describe this property. In this paper a method is introduced to extract the envelope of UWB signal utilizing wavelet transform. The expressions in time domain are given and the envelope is extracted in low signal noise ratio (SNR). The simulation results show that the method of envelope analysis can be fit for both parameterized channel model and nonparameterized. It is of significance for the realization of UWB systems and it implies that conventional envelope analysis could be used in acquisition of UWB signal.