Adjacent and Co-Channel Interferences Effect on AWGN and Rayleigh Channels Using 8-QAM Modulation for Data Communication

Abstract

In wireless communication systems the interference is an essential nature of that is several transmissions frequently take place instantaneously over a common communication channel. In the cellular radio systems, a major limiting factor for their performance is interference. It is severely effects the system due to the notable increase in dropped calls as well as limit their capacity and hence degrades the system quality. Therefore, this problem must be carefully taken into account when designing wireless cellular communication systems. Interference sources are added mobiles in a similar cell, a call being in development in nearby cell, as well as another nearby base station having the same frequency band. This kind of interference can be divided into two main categories Adjacent Channel Interference (ACI) and Co-Channel Interference (CCI). To investigate the effect of ACI and CCI on AWGN and Rayleigh channels for data communication. The 8-Quadrature Amplitude Modulation (8-QAM) technique is used because it is well known technique in communication systems. These two signals are applied on both AWGN and Rayleigh channels. In this paper the interference effect is investigated, and simulated using Simulink. The obtained results in terms of Bit Error Rate (BER) against the bit energy to noise energy ratio (E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b</sub> /N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sub> ), indicate that the 8-QAM modulation performs fairly well under these conditions.