MAP Detection with Soft Information in an Estimate and Forward Relay Network
Serediuc, Corina Ioana
Master of Science
One proven solution for improving the reliability of a wireless channel is to use relays. We analyze the three-node relay network, focusing on the estimate-and-forward (EF) relay protocol, where the relay node estimates the source symbol and then forwards it to the destination. For an uncoded system in a path-loss model for the cooperative three-node wireless network, we show that EF with minimum mean square error (MMSE) estimate outperforms other common relay protocols such as amplify-and-forward (AF) and detect-and-forward (DF). Since the probability density function required by the optimal maximum a posteriori (MAP) detector at the destination does not have an analytical form, we provide a solution to bypass its numerical approximation. We show that EF with a piecewise linear approximation of the MMSE estimate provides an analytical form of the detector at the destination and its performance is similar to the case when a MMSE estimate is used.
Applied sciences; Pure sciences; Statistics; Electrical engineering