Designing and comparative analysis for BER of selection, Equal gain and maximal ratio combining diversity techniques

This paper provides a brief introduction to the various types of Diversity systems in wireless systems. Stepping into the new generation of mobile communication it is of concern to increase the performance of the mobile terminals and their antennas to be able to answer to the demand of faster and more various communicational services. Still, the issue of signal fading in a multi-path environment stands as an obstacle today. The purpose of this work is to introduce diversity techniques as a promising way of improving the performance at the mobile terminals. The goal is more profound, dealing with analysis of the correlation between received signals and the propagation environments that diversity improvement depends on, and putting together a repeatable method for measuring the improvement. The work resulted in simulated and measured diversity performance for three different, antenna diversity concepts created for the purpose of this work. The results confirmed by using Rayleigh fading in AWGN noisy channel and with the BPSK modulation, presented the best diversity technique out of three and also provide a comparison between all. An analytical expression for the signal-to-bit-error-rate (BER) at the output of a threediversity technique is given. The three branches are assumed to be Rayleigh fading, correlated with the BPSK modulation. Measurements of the bit-error-rate with the Eb/N0 after selection, equal gain combining and maximal ratio combining were made in Rayleigh fading channels and compared with the analytical results.