Title :
Distributed power allocation strategies for parallel relay networks
Author :
Chen, Min ; Serbetli, Semih ; Yener, Aylin
Author_Institution :
Pennsylvania State Univ., University Park
fDate :
2/1/2008 12:00:00 AM
Abstract :
We consider a source-destination pair assisted by parallel regenerative decode-and-forward relays operating in orthogonal channels. We investigate distributed power allocation strategies for this system with limited channel state information at the source and the relay nodes. We first propose a distributed decision mechanism for each relay to individually make its decision on whether to forward the source data. The decision mechanism calls for each relay that is able to decode the information from the source to compare its relay-to-destination channel gain with a given threshold. We identify the optimum distributed power allocation strategy that minimizes the total transmit power while providing a target signal-to-noise ratio at the destination with a target outage probability. The strategy dictates the optimum choices for the source power as well as the threshold value at the relays. Next, we consider two simpler distributed power allocation strategies, namely the passive source model where the source power and the relay threshold are fixed, and the single relay model where only one relay is allowed to forward the source data. These models are motivated by limitations on the available channel state information as well as ease of implementation as compared to the optimum distributed strategy. Simulation results are presented to demonstrate the performance of the proposed distributed power allocation schemes. Specifically, we observe significant power savings with proposed methods as compared to random relay selection.
Keywords :
probability; radio networks; relays; distributed decision mechanism; distributed power allocation strategies; limited channel state information; optimum distributed strategy; orthogonal channels; outage probability; parallel regenerative decode-and-forward relays; parallel relay networks; passive source model; random relay selection; relay-to-destination channel gain; signal-to-noise ratio; single relay model; source-destination pair; Antenna arrays; Channel state information; Decoding; Digital relays; Laboratories; Power system relaying; Signal to noise ratio; Transmitting antennas; Wireless communication; Wireless sensor networks;
Journal_Title :
Wireless Communications, IEEE Transactions on
DOI :
10.1109/TWC.2008.051002