A CORRECTED MATCH FOR COHERENT PART OF TIME-VARIANT CHANNEL

The detection performance of the matched filter with the transmitted signal as a reference signal will be degraded in an underwater acoustic channel due to the multipath effect and time variability. Two methods of the channel match are presented in this paper:(1) Pulse-to-pulse correlation method for the channel match. (2) Deeonvolution method. In the first method the received signal is used as a reference signal of the matched filter to improve the detection performance of the matched filter to improve the detection performance of the matched filter. In the second method a short pulse is used to excite the channel. To obtain the response function of the channel, the Wiener-Hopf equation in matrix form is used. The equation can be solved by several deconvolution methods. Then the solved response function of the channel is convoluted with the transmitted signal and the result of the convolution is used as a reference signal of the corrected matched filter. In this paper, with the aid of computer the corrected match for several channel models and for the real underwater acoustic propagation channel is given and the comparison between the conventional and corrected matched filters is illustrated.