Large scale field trial results on frequency domain compression for uplink joint detection

The spectral efficiency of cellular communication systems is limited by inter-cell interference. Especially cell edge users will experience bad performance. A potential remedy to inter-cell interference is joint signal processing on the base station (BS) side. In the cellular uplink the received signals of multiple BSs can be processed at a central node, referred to as joint detection (JD). Field trials of this technique verify large improvements in spectral efficiency and fairness which were initially proven in theoretical and simulation studies. Recent studies encourage that JD is even beneficial under stringent backhaul constraints which are likely to occur in real deployments. The general solution in case of limited backhaul capacity is based on the compression of exchanged signals. This paper presents the most significant design criteria of such compression algorithms for an LTE-Advanced system. We focus on the exchange of frequency domain IQ-symbols. The limits and potentials of a comprehensive system solution are evaluated using data from large scale field trials.