Simulation of telephone mobile networks

Abstract

The goal for the next generation of mobile communication system is to seamlessly integrate a wide variety of communication services such as high speed data, video and multimedia traffic as well as voice signals. The technology needed to make these services available is popularly known as the Third Generation (3G) Cellular Systems.

In the radio environment, transmitted signals arrive at the receiver via a direct, unobstructed path or via multiple paths from the reflection, diffraction and scattering of surrounding objects such as buildings and trees. The received signal at the WCDMA Receiver Antenna subsystem is the sum of attenuated and delayed versions of the transmitted signals due to the so-called multipath propagation introduced by the channel. At the receiver side, a RAKE receiver is implemented to resolve and compensate for such effect. This thesis is mainly focus on the WCDMA concept, RAKE receiver and Handover process.

In this thesis, bit error rate (BER) simulation was carried out to study different modulation techniques and the contribution of RAKE receiver in WCDMA system for the overall system performance. Next, evaluation on BER for RAKE receiver at different conditions such as varying number of spreading factor, time delaying and using different spreading codes (Walsh and Kasami codes). Important parameters are selected and their influences on RAKE receiver performance are investigated by means of simulations. Performance improvements due to RAKE receiver important parameters are studied. RAKE receiver simulation is implemented by using Matlab.

Moreover, this thesis also simulates Handover process – one of the most important processes in any cellular mobile system to maintain calling - under Network Simulator 2 (NS2) program. This simulation gives general view about Handover processing of a Mobile Equipment in mobile system.