Distributed precoding with centralized power allocation techniques for multicell OFDM systems

In this paper we propose and compare several distributed linear precoding schemes for the downlink of multicell OFDM based systems. The precoders are designed in two phases: first the precoder vectors are computed in a distributed manner at each BS considering several criteria; then the system is further optimized through power allocation. Two centralized power allocation algorithms with per-BS power constraint and different complexity tradeoffs are proposed: minimization of the instantaneous average BER and minimization of the sum of inverse of signal-to-interference noise ratio. The performance of the proposed schemes is compared considering typical pedestrian scenarios based on LTE specifications. The numerical results show that the performance of the DVSINR and DZF precoders with the proposed power allocation schemes is close.