Time-Slotted Round-Trip Carrier Synchronization

We consider the problem of synchronizing the carriers of two sources in a wireless communication system with one destination. Carrier synchronization has been considered recently in cooperative communication systems where the sources wish to pool their antenna resources and transmit as a "distributed beamformer". Based on the concept of round-trip carrier synchronization first described in [1], we propose a new time-slotted round-trip carrier synchronization system and describe its implementation in systems with single-path or multi- path channels. The performance of the time-slotted round-trip carrier synchronization system is investigated in terms of the phase offset at the destination and the expected beamforming time before resynchronization is required. Our results suggest that the synchronization overhead can be small with respect to the potential beamforming gains.