Reuse within a cell-interference rejection or multiuser detection?

We investigate the use of an antenna array at the receiver in FDMA/TDMA systems, to let several users share one communication channel within a cell. A decision feedback equalizer which simultaneously detects all incoming signals (multiuser detection) is compared to a set of decision feedback equalizers, each detecting one signal and rejecting the remaining as interference. We also introduce the existence of a zero-forcing solution to the equalization problem as an indicator of near-far resistance of different detector structures. Simulations indicate that multiuser detection in general provides better performance than interference rejection. We have applied the proposed algorithms to experimental measurements from a DCS-1800 antenna array testbed. The results from these experiments confirm that reuse within a cell is indeed possible using an eight-element array antenna at the receiver.