Turning our attention in this chapter to a general receiver-receiver protocol, we address the synchronization problem in which a master node sends reference broadcasts to the neighboring nodes (e.g., RBS). As discussed earlier, the main advantage of adopting such an approach is that all the deterministic and non-deterministic delay components on the sender side (such as send time, transmission time, channel access time) are eliminated and hence the clocks of the beacon-receiving nodes can be very tightly synchronized. The importance of RRS increases due to the fact that the channel access time at the MAC layer is the largest source of error in solving a synchronization problem. This chapter applies both classical and Bayesian estimation approaches to synchronize a set of nodes receiving timing messages from a master node.

The main topics in this chapter are as follows. First, the JMLE for clock phase offset and skew under the exponential noise model is formulated and found via a direct algorithm. Second, the Gibbs sampler is proposed for joint clock phase offset and skew estimation and is shown to provide superior performance relative to JMLE. Finally, lower and upper bounds for the MSE of JMLE and Gibbs sampler are introduced in terms of the MSE of the MVUE and the conventional BLUE, respectively.