On Reducing Call Drop Outs By Improving Bit Error Rate Performance In A GSM Mobile Communications System

Abstract

Call Drop Out is one of the most annoying problems in Mobile Communications. It is one of the most important Quality of Service (QoS) indicators for a mobile carrier. Over the years, many strategies have been proposed to solve the problem of call drop out. But the problem is still prevalent. One of the important reasons for call drop outs is high Bit Error Rate (BER). In general, many existing wireless systems set a threshold BER before a call is dropped. In this work, our intent is to reduce the call drop out due to high BER. Towards that end, we simulated the overall block diagram for a typical mobile communication system and measured its BER. Thereafter, we introduced a new signal processing subsystem at the receiver section to improve the BER and thereby improve the end-to -end performance of the system. In particular, the calculation of un-mixing matrix and automated identification for distinguishing separated signals was carried out. Our simulation is valid specifically for Global Systems for Mobile (GSM), although it can be extended to a Code Division Multiple Access (CDMA). Our simulation proved that the new signal processing subsystem did indeed improve the BER. The implication of this is that the existing network will see a reduction in call drops outs.