Channel Estimation for OFDM Modulated Two-Way Relay Networks

In this work, we introduce the model of employing orthogonal-frequency-division multiplexing (OFDM) for transmission over time-dispersive channels in the two-way relay network (TWRN), where two source terminals exchange their information through a relay terminal using the amplify-and-forward (AF) relaying scheme. We propose a two-phase training protocol for the channel estimation, which is compatible with the two-phase data transmission scheme. In the first phase, the two source terminals send their individual training sequences concurrently to the relay, while in the second phase the relay amplifies the received training sequences and broadcasts them to both source terminals. We propose two different types of training methods as well as develop their corresponding channel estimation algorithms at each of the two source terminals. The first type of training is block based, for which we first estimate the cascaded source-relay-source channels, and then design algorithms to recover the individual channels between sources and relay. The second type of training is pilot-tone (PT) based, for which we propose to directly estimate the individual channels between sources and relay. Moreover, the identifiability issues on the nonambiguous estimate of the channels in both types of proposed training are carefully addressed. Finally, various numerical examples are presented to corroborate our analytical results.

[1]  Babak Hassibi,et al.  On the sphere-decoding algorithm I. Expected complexity , 2005, IEEE Transactions on Signal Processing.

[2]  A. Wittneben,et al.  Spectral Efficient Signaling for Half-duplex Relay Channels , 2005, Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005..

[3]  Sachin Katti,et al.  Embracing wireless interference: analog network coding , 2007, SIGCOMM '07.

[4]  Claude E. Shannon,et al.  Two-way Communication Channels , 1961 .

[5]  Halim Yanikomeroglu,et al.  Multihop diversity in wireless relaying channels , 2004, IEEE Transactions on Communications.

[6]  Ying-Chang Liang,et al.  Optimal Analogue Relaying with Multi-Antennas for Physical Layer Network coding , 2008, 2008 IEEE International Conference on Communications.

[7]  Petar Popovski,et al.  Physical Network Coding in Two-Way Wireless Relay Channels , 2007, 2007 IEEE International Conference on Communications.

[8]  Hlaing Minn,et al.  Optimal training signals for MIMO OFDM channel estimation , 2004, IEEE Global Telecommunications Conference, 2004. GLOBECOM '04..

[9]  Stephen P. Boyd,et al.  Convex Optimization , 2004, Algorithms and Theory of Computation Handbook.

[10]  Soung Chang Liew,et al.  > Replace This Line with Your Paper Identification Number (double-click Here to Edit) < 1 , 2022 .

[11]  Soung Chang Liew,et al.  Hot topic: physical-layer network coding , 2006, MobiCom '06.

[12]  Georgios B. Giannakis,et al.  Optimal training and redundant precoding for block transmissions with application to wireless OFDM , 2002, IEEE Trans. Commun..

[13]  Tracey Ho,et al.  Distributed Space–Time Coding for Two-Way Wireless Relay Networks , 2008, IEEE Transactions on Signal Processing.

[14]  Ying-Chang Liang,et al.  Optimal beamforming for two-way multi-antenna relay channel with analogue network coding , 2008, IEEE Journal on Selected Areas in Communications.

[15]  C. Tellambura,et al.  An efficient generalized sphere decoder for rank-deficient MIMO systems , 2004 .

[16]  Marc Moonen,et al.  Optimal training design for MIMO OFDM systems in mobile wireless channels , 2003, IEEE Trans. Signal Process..

[17]  Ying-Chang Liang,et al.  Optimal channel estimation and training design for two-way relay networks , 2009, IEEE Transactions on Communications.

[18]  Anna Scaglione,et al.  On the effect of receiver estimation error upon channel mutual information , 2006, IEEE Transactions on Signal Processing.

[19]  Feifei Gao,et al.  Blind Channel Estimation for MIMO OFDM Systems via Nonredundant Linear Precoding , 2007, IEEE Transactions on Signal Processing.

[20]  Feifei Gao,et al.  Blind Channel Estimation for MIMO OFDM Systems via Non-Redundant Linear Precoding , 2006 .

[21]  Jonathan H. Manton,et al.  Optimal training sequences and pilot tones for OFDM systems , 2001, IEEE Communications Letters.

[22]  Ying-Chang Liang,et al.  Two-Way Relaying over OFDM: Optimized Tone Permutation and Power Allocation , 2008, 2008 IEEE International Conference on Communications.

[23]  Georgios B. Giannakis,et al.  Finite-alphabet based channel estimation for OFDM and related multicarrier systems , 2001, IEEE Trans. Commun..

[24]  A. M. Abdullah,et al.  Wireless lan medium access control (mac) and physical layer (phy) specifications , 1997 .

[25]  Vijay K. Bhargava,et al.  Optimal periodic training signal for frequency offset estimation in frequency selective fading channels , 2004, 2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577).

[26]  Jörg Kliewer,et al.  Memoryless Relay Strategies for Two-Way Relay Channels: Performance Analysis and Optimization , 2008, 2008 IEEE International Conference on Communications.

[27]  Gregory W. Wornell,et al.  Cooperative diversity in wireless networks: Efficient protocols and outage behavior , 2004, IEEE Transactions on Information Theory.