Transmission capacity of wireless ad-hoc networks with multiple antennas using multi-mode precoding and interference cancelation

The transmission capacity of an ad-hoc network is the maximum density of active transmitters in an unit area, given an outage constraint at each receiver for a fixed rate of transmission. This paper addresses the problem of maximizing the transmission capacity of an ad-hoc network when each node is equipped with multiple antennas. Bounds on the transmission capacity are derived as a function of the number of antennas used for transmission, and the number of antennas used for interference cancellation. Both the transmitter and receiver are assumed to have channel state information (CSI). CSI at the transmitter is used to transmit multiple streams using multi-mode precoding, while CSI at the receiver is used for interference cancellation. Canceling the strongest or the closest interferers, single stream transmission on the best eigenmode together with using all but one receiver antennas for interference cancellation is shown to maximize the transmission capacity.