TABLE OF CONTENTS We consider a communication system, where N signals are transmitted from N transmitters simultaneously. For example, in a wireless communication system, at each time slot t, signals C t , n, n = 1, 2, , N are transmitted simultaneously from N transmit antennas. The signals are the inputs of a multiple-input multiple-output (MIMO) channel with M outputs. Each transmitted signal goes through the wireless channel to arrive at each of the M receivers. In a wireless communication system with M receive antennas, each output of the channel is a linear superposition of the faded versions of the inputs perturbed by noise. Each pair of transmit and receive antennas provides a signal path from the transmitter to the receiver. The coefficient ? n , m is the path gain from transmit antenna n to receive antenna m. Figure 2.1 depicts a baseband discrete-time model for a flat fading MIMO channel. Based on this model, the signal r t , m, which is received at time t at antenna m, is given by
| (2.1) |  |
where ? t , m is the noise sample of the receive antenna m at time t. Based on (2.1), a replica of the transmitted signal from each transmit antenna is added to the signal of each receive antenna. Although the faded versions of different signals are mixed at each...
