Joint CFO and Channel Estimation for OFDM-Based Two-Way Relay Networks

Joint estimation of the carrier frequency offset (CFO) and the channel is developed for a two-way relay network (TWRN) that comprises two source terminals and an amplify-and-forward (AF) relay. The terminals use orthogonal frequency division multiplexing (OFDM). New zero-padding (ZP) and cyclic-prefix (CP) transmission protocols, which maintain the carrier orthogonality and ensure low estimation and detection complexity, are proposed. Both protocols lead to the same estimation problem which can be solved by the nulling-based least square (LS) algorithm and perform identically when the block length is large. We present detailed performance analysis by proving the unbiasedness of the LS estimators at high signal-to-noise ratio (SNR) and by deriving the closed-form expression of the mean-square-error (MSE). Simulation results are provided to corroborate our findings.

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

[2]  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.

[3]  Patrick Mitran,et al.  Achievable rate regions for bi-directional relaying , 2008, ArXiv.

[4]  Armin Wittneben,et al.  Achievable Rate Regions for the Two-way Relay Channel , 2006, 2006 IEEE International Symposium on Information Theory.

[5]  Ying-Chang Liang,et al.  Channel Estimation for OFDM Modulated Two-Way Relay Networks , 2009, IEEE Transactions on Signal Processing.

[6]  Feifei Gao,et al.  Scattered Pilots and Virtual Carriers Based Frequency Offset Tracking for OFDM Systems: Algorithms, Identifiability, and Performance Analysis , 2008, IEEE Transactions on Communications.

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

[8]  Didem Kivanc-Tureli,et al.  Experimental and analytical studies on a high-resolution OFDM carrier frequency offset estimator , 2001, IEEE Trans. Veh. Technol..

[9]  Umberto Mengali,et al.  Carrier-frequency estimation for transmissions over selective channels , 2000, IEEE Trans. Commun..

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

[11]  Chintha Tellambura,et al.  Joint Frequency Offset and Channel Estimation Methods for Two-Way Relay Networks , 2009, GLOBECOM 2009 - 2009 IEEE Global Telecommunications Conference.

[12]  Feifei Gao,et al.  Blind maximum likelihood CFO estimation for OFDM systems via polynomial rooting , 2006, IEEE Signal Processing Letters.

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

[14]  Georgios B. Giannakis,et al.  Wireless multicarrier communications , 2000, IEEE Signal Process. Mag..

[15]  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..

[16]  Petre Stoica,et al.  Training sequence design for frequency offset and frequency-selective channel estimation , 2003, IEEE Trans. Commun..

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

[18]  Yonghong Zeng,et al.  Robust subspace blind channel estimation for cyclic prefixed MIMO ODFM systems: algorithm, identifiability and performance analysis , 2008, IEEE Journal on Selected Areas in Communications.

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

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

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

[22]  G. Giannakis,et al.  Wireless Multicarrier Communications where Fourier Meets , 2022 .