Wavelet analysis of signal through space-time channel

This paper applies wavelet theory to analyze space-time channel. Signals through space-time channel have fractal, singular and multi-resolution characteristics. Space-time channel has fractal characteristic according to dynamics mechanism of multipath fading. The local singularity exists in received signal through space-time channel according to the suddenly changed channel parameters in the space-time channel. Singularity plays an important role in the channel estimation and signal reconstruction. Received signals through space-time channel have multi-resolution characteristics, because different DOAs correspond to different multi-resolution in the fixed array range. The received signals through space-time channel are regarded as the addition of multi-resolution. Signals through space-time channel are processed with wavelet. Mathematics model of singularity is expressed with Lipschitz exponent. The singularity can be detected with wavelet, and received signals can be reconstructed with wavelet transform. Simulation results reveal that the reconstructed signals with wavelet have better denoising ability. When received signals through space-time channel are processed by wavelet transform the wavelet coefficients under the different scales have self-similarity, which proves that signals through space-time channel have fractal characteristic. Simulation results also prove that signals through space-time channel have multi-resolution characteristic.