Uplink base station cooperation by iterative distributed interference subtraction

Abstract

The capacity of today's cellular mobile communications systems is mainly limited by inter-cell interference. Multi-cell joint transmission or joint detection schemes are means to overcome this limitation and to actively exploit signal propagation across cell borders rather than treating it as noise. A major downside to multi-cell signal processing is the additional backhaul rate that is required to exchange information among cooperating base stations. Hence, cooperation schemes are desired that efficiently utilize the available backhaul rate. In the cellular uplink, one promising option to mitigate interference and thus to significantly increase the efficiency of spectrum usage is the exchange of decoded messages among base station, an information that can be used to subtract interference prior to the decoding of further messages. In this work, this distributed interference subtraction scheme is extended by allowing multiple iterative information exchanges among base stations. Possible gains of this strategy in terms of achievable data rates and required backhaul rates are explored from an information theoretical point of view.