Achievable rates for discrete memoryless relay channels with generalised feedback

Abstract

This paper considers three-node discrete memoryless relay channels with generalised feedback. In particular, two generalised feedback configurations are investigated. In the first configuration, the source is assumed to be able to actively collect feedback signals from the channel, whereas in the second one, the destination is assumed to be able to actively transmit feedback signals to the relay. For both configurations, new coding schemes that are based on the notions of decode and forward and compress and forward are developed to exploit the feedback, and corresponding achievable rates are derived. For the first configuration, the proposed coding schemes exploit the feedback by allowing the source to cooperate with the relay in the process of forwarding the compressed version of the channel output sequence at the relay to the destination. For the second configuration, the proposed coding schemes allow the destination to perform compress and forward to enhance the decoding power at the relay which applies partial decode and forward, thereby improving the overall transmission rate. The derived achievable rates are also shown to generalise several existing results for corresponding settings with perfect feedback as special cases. Copyright © 2012 John Wiley and Sons, Ltd.