Outage probability of MISO broadcast systems with noisy channel side information

Transmitter precoding strategies are necessary to achieve the capacity promised in broadcast multiple input single output (MISO) systems. However, these schemes generally require perfect channel information at the transmitter. In this paper, we investigate the impact of Gaussian noise in the channel state information (CSI) of a linear zero forcing transmitter, operating in a fading MISO broadcast channel. We consider a rectangular channel with p users and n transmit antennas such that p ≤ n. System performance is analyzed in terms of the outage probability. Using results from, we give simple two and three dimensional integral formulae of the exact outage probability for an arbitrary number of users and transmit antennas. These integrals can be numerically evaluated, for an arbitrary number of users, with a fixed amount of computational effort. We give some numerical results that afford insight to the performance of broadcast channels under channel uncertainty.