Research On Channel Sounding And Parameter Estimation Algorithms In Low SNR

The transmission environment of wireless channel is relatively complex. Channelsounding is always used to do parameter estimation in order to obtain channelcharacteristics. In the dissertation, channel sounding method in low SNR is designedand parameter estimation algorithms are studied.In the paper, characteristics of wireless channel are analyzed in theory. Fadingcharacteristics, mathematical models, Rayleigh channel and Rice channel are studied.For low SNR environment, multicarrier OFDM channel sounding method withde-noising algorithm is given, including the principles of transmitter and receiver, thestructure of data frame, selection of sounding sequences, de-noising algorithm andsounding methods of channel parameters. Based on the measurement designed in lowSNR, channel parameter estimation algorithms are also studied and simulated,including channel impulse response, power delay profile and the correspondingparameters, Doppler spectrum and its corresponding parameters, the power of receivedsignal, path loss and rice factor.