Some results on channel capacity when using multiple antennas

Recent research has demonstrated that the capacity of a multipath-rich channel (such as indoor channel) is dramatically increased when antenna arrays are used at both transmitter and receiver. This is achieved by using the multipath to create parallel sub-channels. This ability to achieve parallelism in the channel is influenced by how much information about the channel is known at the transmitter, the structure of the channel, and the structure of the arrays. This paper discusses the influence of the transmitter´s knowledge of the channel on capacity, presents closed-form solutions for capacity when there are two paths in the channel, and then presents numerical results based on simulations. For the two-path case, the simulation data compare capacity based on differing assumptions about the transmitter, and compare different array structures. Simulation results are also presented for random channels generated using a statistical model for indoor multipath propagation