Cooperative and distributed receiver processing based on message passing

Cooperative communications in wireless multiuser systems, e.g., cellular systems, can improve the spectral efficiency. Through cooperation between distributed receivers, a better performance can be obtained by exploiting the spatial diversity gain. In this paper, we derive distributed iterative receiver (DIR) algorithms using a factor graph. DIR algorithms are message-passing algorithms where messages are exchanged through an intracommunication network between distributed receivers. To take into account the limited bandwidth of the intracommunications, we also derive DIR algorithms with quantized messages and partial connections between distributed receivers. Through simulations, we show that the performance is improved as more collaboration (i.e., iteration) takes place.