Timing Synchronization in Distributed Mobile MISO Rayleigh Fading Channels

This paper proposes a novel acquisition technique to improve single-antenna receiver detection performance of signals from multiple transmitters that are distributed spatially. We assume that the distributed transmissions occur simultaneously, but the start time of each of the respective transmissions are not synchronous due to imperfect coordination and non-synchronized clocks across distributed transmitters. First, we propose a robust combining method in mobile channels when there is no feedback or channel knowledge between the receiver and the distributed transmitters. Next, we propose a power control technique, given feedback (and partial channel knowledge) between the receiver and distributed transmitters, to improve the receiver operating characteristic (ROC) performance when re-acquiring multiple distributed transmitters. The ROC performance improvements are demonstrated for multiple distributed transmitter signal detection in a mobile Rayleigh fading channel. Analytical solutions are derived to predict the ROC performance when no channel knowledge is assumed, which is corroborated via simulation. For the power control method, simulation is used to demonstrate performance improvement (over the no feedback case) when the channel is estimated with error and feedback latency. The probability of missed detection is improved by at least a factor of 10 and 100, respectively.