Optimizing MIMO multipoint wireless networks assuming Gaussian other-user interference

This paper shows how network information theory can lead to practical algorithms for optimizing multipoint wireless networks, whose transceivers are equipped with multiple-antenna elements. Modeling the other-user interference as colored Gaussian noise, it is demonstrated that network capacity can be realized using linear transmit and receive beamforming. Moreover, to optimize the mutual information for all the multiple-input-multiple-output (MIMO) channels, it suffices to consider a much simpler objective function that considers each data link in the network separately, treating all other transmitters as interference. This, in turn, leads to a network objective function, which fully exploits channel reciprocity, exploits MIMO channels, and simplifies the optimization of transmit beamformers across the network. A numerical example is provided showing more than an order of magnitude performance improvement over a conventional network.