Application of full-duplex wireless communication system on echo cancellation

Abstract

In this paper, we intend to realize the data trading between the mobile station and the base station with only one frequency and in simultaneous process. Until now for transmitting and receiving the data, the mobile station and the base station have been used two different frequencies. This is obvious that by using two different frequencies in transceivers side there would be no interferences in transceiver itself. Therefore, utilization of different frequencies in transceiver was common. However, in these days due to the rapid increase of mobile station users, utilized frequencies between mobile and base stations should be allocated efficiently. Otherwise, it would reduce the speed of data sending in mobile stations. In order to get rid of this problem utilization of the same frequency in transmitter and receiver side is suggested. In this research utilization of the same frequency is considered for the mobile and the base station. However, there are near end echo occurs in system. Meanwhile, the echo canceller is implemented in the suggested system in order to cancel near end signal. In this paper, the considered algorithms of Echo canceller are Least Mean Square, Normalized Mean Square and Recursive Least Square. As a consequence, Normalized Least Mean Square Algorithm performed sufficiently to maintain an adequate low learning curve of normalized mean square error.