Interference cancellation in multiuser hybrid overlay cognitive radio

In this paper, we consider an overlay cognitive radio (CR) consisting of a primary macro-cell and cognitive small cells of cooperative secondary base stations (SBS).We suggest studying a hybrid CR where a filter bank multicarrier (FBMC) is used for the secondary users (SU) whereas the primary users (PU) are based on orthogonal frequency division multiplexing (OFDM). Compared to OFDM, FBMC has the advantage of reducing the SU interference level that is induced by the differences between the SBS and PU carrier frequency offsets (CFO). Our contribution is threefold: 1/ we derive the interference expression due to SU at the PU receiver, 2/ we propose to use zero forcing beamforming (ZFBF) to cancel the interference, 3/ a comparative study with CR based on OFDM for both the PU and the SU confirms the efficiency of the proposed scheme.

[1]  Andrea J. Goldsmith,et al.  Sum-rate optimal multi-antenna downlink beamforming strategy based on clique search , 2005, GLOBECOM '05. IEEE Global Telecommunications Conference, 2005..

[2]  Andrea J. Goldsmith,et al.  Breaking Spectrum Gridlock With Cognitive Radios: An Information Theoretic Perspective , 2009, Proceedings of the IEEE.

[3]  Wei Yu,et al.  Multi-Cell MIMO Cooperative Networks: A New Look at Interference , 2010, IEEE Journal on Selected Areas in Communications.

[4]  Martin Haardt,et al.  Zero-forcing methods for downlink spatial multiplexing in multiuser MIMO channels , 2004, IEEE Transactions on Signal Processing.

[5]  Hikmet Sari,et al.  A review of OFDMA and single-carrier FDMA , 2010, 2010 European Wireless Conference (EW).

[6]  Leonardo S. Cardoso,et al.  Channel estimation impact for LTE small cells based on MU-VFDM , 2012, 2012 IEEE Wireless Communications and Networking Conference (WCNC).

[7]  Leonardo S. Cardoso,et al.  Vandermonde frequency division multiplexing for cognitive radio , 2008, 2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications.

[8]  Yuanan Liu,et al.  Simplified Semi-Orthogonal User Selection for MU-MIMO Systems with ZFBF , 2012, IEEE Wireless Communications Letters.

[9]  Hong Sun,et al.  Capacity analysis of OFDM / FBMC based Cognitive Radio networks with estimated CSI , 2010, 2010 Proceedings of the Fifth International Conference on Cognitive Radio Oriented Wireless Networks and Communications.

[10]  Mario Tanda,et al.  Data-aided symbol timing and CFO synchronization for filter bank multicarrier systems , 2009, IEEE Transactions on Wireless Communications.

[11]  A. El-Keyi,et al.  Opportunistic interference alignment for multiuser cognitive radio , 2010, 2010 IEEE Information Theory Workshop on Information Theory (ITW 2010, Cairo).

[12]  Witold A. Krzymien,et al.  On the Optimality of Multiuser Zero-Forcing Precoding in MIMO Broadcast Channels , 2009, VTC Spring 2009 - IEEE 69th Vehicular Technology Conference.

[13]  Eric Grivel,et al.  Frequency synchronization and channel equalization for an OFDM-IDMA uplink system , 2012, 2012 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP).

[14]  Aawatif Hayar,et al.  Implementation and performance of an opportunistic cognitive radio system , 2010, 2010 Future Network & Mobile Summit.

[15]  Max H. M. Costa,et al.  Writing on dirty paper , 1983, IEEE Trans. Inf. Theory.