IMPACT OF NUMBER OF CHANNELS ON THE CAPACITY OF SINGLE AND MULTI-CHANNEL WIRELESS NETWORKS

Radio Frequency (RF) suffers lot of impairments and perturbations resulting in counterssuch as call drops rate, failure rate and congestion rate on one hand and beam-width, fading,shadowing and attenuation on the other hand. These factors seriously affect systemscapacity. To combat the effect of these impairments on the signal, the information can betransmitted via multiple channels by deploying multiple antennas at both transmitter andreceiver. This antenna configuration is called Multiple-Input-Multiple-Output (MIMO). Inthis paper, the performance of transmission over single channel was first investigated,modelled and compared with that of multiple channels. Also, a mathematical model basedon Shannon capacity formula was used to obtain the capacity of different channels for faircomparison. The results obtained shows that, the capacity from the coherent channel is 1.246times higher than that of single channel. Also, that of non-coherent channel is 1.122 timeshigher than that of single channel. Using the same index, orthogonal channel gives anaverage capacity of n/2 higher than that of single antenna, this implies that, for a givennumber of antennas say eight (n=8) at the same signal to noise ratio, the capacity oforthogonal channel is about four (4) times higher than that of single channel. The resultsindicate that the throughput and the reliability of the link improved more significantly whenthe information is being sent over multiple uncorrelated channels. This can be achieved bythe use of orthogonal MIMO channels.