Trade-offs between diversity combining and equalization for wireless LANs

In wireless LAN applications with high transmission rates of up to 10-20 Mbit/s the problem of multipath intersymbol interference (ISI) due to frequency selective fading occurs. Adaptive equalization and diversity combining are two possible techniques for combating multipath ISI. The complexity of digital signal processing on the received signals is one of the main issues of these techniques. We investigate the performance and computational complexity trade-offs between diversity combining and equalization in a quasi-stationary frequency-selective fading with AWGN by means of computer simulations. We consider both MMSE combining and selection diversity combining with up to four diversity antenna branches. The results is useful in determining the number of diversity branches and feedforward and feedback equalization tap weights in the wireless LAN design