Fast packet transmission to a receiver with an adaptive antenna array

We consider fast packet transmission in a multi-user system to a receiver with an adaptive antenna array. A packet length of 53 bytes is assumed and the preamble length is usually 5 bytes. Each packet is taken to be from a different user and thus the array weights for beamforming must be determined from the preamble for each unique packet. The array weights are determined using the direct matrix inversion algorithm and are held fixed over the data portion of the packet to provide a nearly uniform error distribution to each data bit in the packet. Both Gaussian noise and fading channels are considered. The major findings are as follows: (a) for a fixed preamble length, there are an optimum number of array elements to provide the minimum bit-error-probability, (b) performance losses due to adaptive operation are less on fading channels than on Gaussian noise channels and (c) on fading channels the performance can improve with an increase in fading bandwidth