Estimation of the Doppler spread and time delay spread for the wireless communication channel

Abstract

The performance of the wireless communication channel including HF channel is strongly affected by the short term variations. It is due to the multipath fading which introduces time and frequency selective fading. By characterizing the wireless channel, the information can be used to increase the performance of the wireless communication. Doppler spread and time delay spread are parameters to be investigated where they can be used to characterize the wireless channel. Scattering function via the ambiguity function estimator is adopted in this work. PSK signal with two signal lengths (1 second and 2 seconds) are used in the analysis. The analysis is performed in the absent of the white Gaussian noise. The Doppler spread is estimated from the spread of the scattering plot at the peak of each path while the time delay spread is estimated from the time lag marginal of the scattering function derivation. BPSK having duration of more than 1 second can be used to estimate the Doppler spread and the time delay in the multipath environment. The information on the number of path and their attenuations can also be obtained. Besides, it can give information on the frequency selective fading and the multipath fading condition of the channel.