PERFORMANCE ANALYSIS OF ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEM IN TRANSIT ANTENNA DIVERSITY TECHNIQUES

The fourth generation and fifth generation mobile communication systems make use of orthogonal frequency division multiplexing technique. Orthogonal frequency division multiplexing technique is a multi-access scheme which aids information splitting among several scarcely spaced sub-channel frequencies in the process of data transmission. Orthogonal frequency-division multiplexing technique can also convert a single wideband signal channels into multiple narrowband channels and then transmits them to the receiver while ensuring no inter-symbol interference. But this technique is sensitive to multipath fading and signal strength can be lost due to shadowing in different radio frequency propagation terrains during practical applications. One way of mitigating this multipath fading problem is by utilizing antenna diversity combining techniques. In this work, MATLAB Simulink software is employed to analytically simulate three antenna diversity techniques, viz; the selection, equal gain and maximum ratio techniques.
Emphasis is laid on Rayleigh fading channels and quadrature phase shift key carrier modulation technique. Symbol error rate and bit error rate are used as performance indicators, the result shows that the MRC having bit error rate performance value of 2.0x-6 and symbol error rate performance value of 1.3x-7. The results indicate that the performance of the three diversity techniques increases as the antenna grows in quantity.