The Application of Cross Correlation Technique for Estimating Impulse Response and Frequency Response of Wireless Communication Channel

Abstract

Cross correlation technique is one of the most commonly used methods to estimate the channel impulse response such as a wireless communication channel. This paper looks at the use of two different types of signals that is applied in the cross correlation technique. The signals are phase shift keying (PSK) and linear FM signals (Chirps). Pseudo random sequence (PRS) is used in the generation of the PSK signals. The parameters of the PRS are varied according to the sequence lengths, sampling frequency and bit rate. From the cross correlation functions and the cross spectrum, the channel impulse response and channel frequency response are respectively estimated. Besides PSK signals, linear FM signal is also used as an input to estimate the channel impulse response. Both PSK and linear FM signals are chosen due to their auto correlation properties that are similar to an impulse function. Thus, the channel impulse response can be estimated based on the cross correlation between the output and the input signals. The desired and the estimated channel impulse responses and channel frequency response are respectively estimated and compared based on the mean squared error (MSE).