Distributed Iterative Detection Based on Reduced Message Passing for Networked MIMO Cellular Systems

摘要

This paper considers base station cooperation (BSC) strategies for the uplinkof a multi-user multi-cell high frequency reuse scenario where distributediterative detection (DID) schemes with soft/hard interference cancellationalgorithms are studied. The conventional distributed detection scheme exchanges{soft symbol estimates} with all cooperating BSs. Since a large amount ofinformation needs to be shared via the backhaul, the exchange of hard bitinformation is preferred, however a performance degradation is experienced. Inthis paper, we consider a reduced message passing (RMP) technique in which eachBS generates a detection list with the probabilities for the desired symbolthat are sorted according to the calculated probability. The network thenselects the best {detection candidates} from the lists and conveys the index ofthe constellation symbols (instead of double-precision values) among thecooperating cells. The proposed DID-RMP achieves an inter-cell-interference(ICI) suppression with low backhaul traffic overhead compared with {theconventional soft bit exchange} and outperforms the previously reportedhard/soft information exchange algorithms.