On Base Station Cooperation Schemes for Downlink Network MIMO under a Constrained Backhaul

Next generation mobile communications systems will most likely employ multi-cell cooperative signal processing schemes, often referred to as network MIMO, as these are known to effectively combat inter-cell interference and improve system fairness and spectral efficiency. A major downside of such schemes is, however, the large extent of backhaul infrastructure required for the information exchange between cooperating base stations. In this paper, we observe a cooperative downlink transmission from two base stations to two terminals under different extents of available backhaul capacity. We adapt some well-known concepts from the Gaussian interference channel and observe a variety of possible cooperation schemes. We observe that it is beneficial to use an adaptive cooperation concept, where the base stations exchange either the data to be jointly transmitted itself or partially preceded and compressed signals, depending on the instantaneous channel realization.