Symmetric capacity of multi-user MIMO downlink under per-base station power constraints

We consider a multiuser multiple-input multiple output (MIMO) Gaussian broadcast channel (BC). Assuming a sum-power constraint over all transmit antennas, the sum capacity of such a system can be achieved with dirty paper coding (DPC) which has been found as a very promising strategy. Rather than the usual sum-power constraint, in this paper we focus on the downlink of a cooperative multicellular network where each transmit antenna has an individual power constraint. This scenario is much more realistic than the case where a sum power constraint is considered, since in practical systems transmit antennas have their own power amplifiers. We extend this approach to the scenario where each base station (BS) is assumed to have an individual power constraint. We propose a capacity calculation algorithm which is able to take both per-BS and per-antenna power constraints into account.