DocumentCode :
76576
Title :
Sum-Rate Optimization in a Two-Way Relay Network with Buffering
Author :
Huaping Liu ; Popovski, Petar ; de Carvalho, Elisabeth ; Yuping Zhao
Author_Institution :
State Key Lab. of Adv. Opt. Commun. Syst. & Networks, Peking Univ., Beijing, China
Volume :
17
Issue :
1
fYear :
2013
fDate :
Jan-13
Firstpage :
95
Lastpage :
98
Abstract :
A Relay Station (RS) uses a buffer to store and process the received data packets before forwarding them. Recently, the buffer has been exploited in one-way relaying to opportunistically schedule the two different links according to their channel quality. The intuition is that, if the channel to the destination is poor, then RS stores more data from the source, in order to use it when the channel to the destination is good. We apply this intuition to the case of half-duplex two-way relaying, where the interactions among the buffers and links become more complex. We investigate the sum-rate maximization problem in the Time Division Broadcast (TDBC): the users send signals to the RS in different time slots, the RS decodes and stores messages in the buffers. For downlink transmission, the RS re-encodes and sends using the optimal broadcast strategy. The operation in each time slot is not determined in advance, but depends on the channel state information (CSI). We derive the decision function for adaptive link selection with respect to CSI using the Karush-Kuhn-Tucker (KKT) conditions. The thresholds of the decision function are obtained under Rayleigh fading channel conditions. The numerical results show that the sum-rate of the adaptive link selection protocol with buffering is significantly larger compared to the reference protocol with fixed transmission schedule.
Keywords :
Rayleigh channels; decoding; optimisation; protocols; relay networks (telecommunication); scheduling; CSI; KKT conditions; Karush-Kuhn-Tucker conditions; RS; Rayleigh fading channel conditions; TDBC; adaptive link selection; adaptive link selection protocol; buffering; channel quality; channel state information; decision function threshold; downlink transmission; fixed transmission schedule; half-duplex two-way relaying; message decoding; message stroage; one-way relaying; opportunistic scheduling; optimal broadcast strategy; reference protocol; relay station; sum-rate maximization problem; sum-rate optimization; time division broadcast; two-way relay network; Buffer storage; Educational institutions; Fading; Optimization; Protocols; Relays; Schedules; Two-way relaying; opportunistic link selection; relay-aided buffering;
fLanguage :
English
Journal_Title :
Communications Letters, IEEE
Publisher :
ieee
ISSN :
1089-7798
Type :
jour
DOI :
10.1109/LCOMM.2012.112012.122101
Filename :
6362133
Link To Document :
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