A Cooperative System Using an Adaptive Relaying Protocol and Rateless Codes

In this paper, a full-duplex compress-and-forward (CF) protocol for cooperative communication systems using Raptor codes is first investigated. It is verified that the throughput of the full-duplex CF protocol is superior to that of the full-duplex decode-and-forward (DF) protocol when the relay-to- destination channel has a much higher quality compared to the source-to-relay channel, while the full-duplex DF protocol works more effectively than the full-duplex CF protocol in the reverse situation. A full-duplex adaptive relaying protocol that is devised based on both CF and DF protocols is then proposed. In the proposed protocol, the CF and DF protocols are adaptively switched, depending on the channel conditions of the wireless links. In addition, the throughput of the overall system is enhanced using an outer Raptor code. Simulation results show that the proposed scheme smoothly switches between the two conventional protocols to cope with different channel conditions.

[1]  Norman C. Beaulieu,et al.  Achievable Rates and Fairness in Rateless Coded Relaying Schemes , 2008, IEEE Transactions on Wireless Communications.

[2]  Elza Erkip,et al.  User cooperation diversity. Part I. System description , 2003, IEEE Trans. Commun..

[3]  Lajos Hanzo,et al.  Reconfigurable Rateless Codes , 2009, VTC Spring 2009 - IEEE 69th Vehicular Technology Conference.

[4]  Yongyi Mao,et al.  Rateless coding for wireless relay channels , 2005, ISIT.

[5]  Michael Luby,et al.  LT codes , 2002, The 43rd Annual IEEE Symposium on Foundations of Computer Science, 2002. Proceedings..

[6]  Omid Etesami,et al.  Raptor codes on binary memoryless symmetric channels , 2006, IEEE Transactions on Information Theory.

[7]  Zixiang Xiong,et al.  Compress-forward coding with BPSK modulation for the half-duplex Gaussian relay channel , 2009, IEEE Trans. Signal Process..

[8]  Xiaodong Wang,et al.  A Rateless Coded Protocol for Half-Duplex Wireless Relay Channels , 2011, IEEE Trans. Signal Process..

[9]  Ashutosh Sabharwal,et al.  Low density parity check codes for the relay channel , 2007, IEEE Journal on Selected Areas in Communications.

[10]  Elza Erkip,et al.  User cooperation diversity. Part II. Implementation aspects and performance analysis , 2003, IEEE Trans. Commun..

[11]  A. Robert Calderbank,et al.  On Maximizing Coverage in Gaussian Relay Channels , 2008, IEEE Transactions on Information Theory.

[12]  Robert G. Gallager,et al.  Low-density parity-check codes , 1962, IRE Trans. Inf. Theory.