An LDPC coded adaptive amplify-and-forward scheme based on the EESM model

Abstract

Cooperative communication is a promising technology to obtain diversity gain at terminals. According to the traditional amplify-and-forward (AF) scheme, relay node helps transmit source node’s information with fixed transmission power all the time. It is not optimal in view of power efficiency, especially when the channel state is good. This paper introduces the adaptive AF scheme based on the minus exponential effective-SNR mapping (EESM) model. The optimal power to relay is predicted accurately. The reliability requirement is satisfied, and the power is saved for transmitting new information. Theoretical analysis and simulation results indicate that the adaptive AF scheme improves the power efficiency significantly.