Network MIMO in the Presence of Transmit Desynchronization

In this paper, we study the performance of Network MIMO in the presence of transmit desynchronization between the base stations (BS), in Rayleigh fading radio environments. We model the transmit desynchronization using lower shift matrices and we explain how a receiver can reliably detect space-time codewords while mitigating synchronization errors. Subsequently, we derive a closed form of the system capacity and bounds on the capacity scaling. Interestingly, we find out that maximum capacity scaling can be preserved even in the presence of desynchronization, provided that the latter be uniformly distributed over [0,T-1], where T is the codeblock length. Thus, our work suggests that, rather than synchronizing all BSs to a common clock, it would be more beneficial, from a capacity scaling perspective, to have their signal clocks independent from each other.