A New Adaptive OFDM System with Precoded Cyclic Prefix for Dynamic Cognitive Radio Communications

Recent development in cognitive radio (CR) communications brings significant technical challenges in the design of adaptive and robust transmission techniques in hostile communication environments due to the dynamic channel transitions and strong co-channel interference. A novel adaptive Orthogonal Frequency Division Multiplexing (OFDM) system with a precoded cyclic prefix (PCP) is proposed in this paper to provide a dynamic CR communication platform with fast transmitter-receiver interaction capability. Besides the basic function as a guard interval for the OFDM system, the PCP, combined from two oversampled precoded Kasami sequences, provides an efficient way of sending the system parameters without the requirement of additional signaling or feedback channels. Overall system and network efficiency is substantially improved due to the simplification of the preambles and handshaking signaling required when there is any change in the CR transmission parameters. Meanwhile, the real part of the PCP is uniquely assigned to each CR transceiver as identification label for spectrum sensing. The receiver design particularly the hybrid domain equalization and PCP induced interference cancellation for the proposed OFDM system is presented in this paper. Implementation related issues including exploitation of the PCP structure and complexity reduction are investigated. The performance of the proposed PCP-OFDM system is analyzed and verified through numerical simulations.

[1]  M. Reuter,et al.  Cyclic code shift keying: a low probability of intercept communication technique , 2003 .

[2]  Hüseyin Arslan,et al.  OFDM for cognitive radio: merits and challenges , 2009, IEEE Wireless Communications.

[3]  Zhu Han,et al.  Replacement of spectrum sensing in cognitive radio , 2009, IEEE Transactions on Wireless Communications.

[4]  Xianbin Wang,et al.  On the design and performance analysis of multisymbol encapsulated OFDM systems , 2006, IEEE Transactions on Vehicular Technology.

[5]  Xianbin Wang,et al.  Robust channel estimation and ISI cancellation for OFDM systems with suppressed features , 2005, IEEE Journal on Selected Areas in Communications.

[6]  Preston F. Marshall.  Extending the Reach of Cognitive Radio , 2009, Proceedings of the IEEE.

[7]  Georgios B. Giannakis,et al.  Cyclic prefixing or zero padding for wireless multicarrier transmissions? , 2002, IEEE Trans. Commun..

[8]  David G. Daut,et al.  Spectrum Sensing for OFDM Systems Employing Pilot Tones and Application to DVB-T OFDM , 2008, 2008 IEEE International Conference on Communications.

[9]  Xianbin Wang,et al.  Transmitter identification using embedded pseudo random sequences , 2004, IEEE Transactions on Broadcasting.

[10]  Joseph Mitola,et al.  Cognitive Radio An Integrated Agent Architecture for Software Defined Radio , 2000 .

[11]  Alessio Filippi,et al.  OFDM Symbol Synchronization Using Frequency Domain Pilots in Time Domain , 2007, 2007 IEEE 66th Vehicular Technology Conference.

[12]  Seyed Masoud Sadjadi,et al.  Service Clouds: Distributed Infrastructure for Adaptive Communication Services , 2007, IEEE Transactions on Network and Service Management.

[13]  Ying-Chang Liang,et al.  Sensing-Based Spectrum Sharing in Cognitive Radio Networks , 2008, IEEE Transactions on Vehicular Technology.

[14]  Michele Zorzi,et al.  A distributed network coded control channel for multihop cognitive radio networks , 2009, IEEE Network.

[15]  Xianbin Wang,et al.  A New Adaptive OFDM System with Precoded Cyclic Prefix for Cognitive Radio , 2008, 2008 IEEE International Conference on Communications.

[16]  MoscibrodaThomas,et al.  White space networking with wi-fi like connectivity , 2009 .

[17]  Lei Hu,et al.  Generalized Kasami Sequences: The Large Set , 2005, IEEE Transactions on Information Theory.

[18]  H. Vincent Poor,et al.  Autocorrelation-Based Decentralized Sequential Detection of OFDM Signals in Cognitive Radios , 2009, IEEE Transactions on Signal Processing.

[19]  Kwang-Cheng Chen,et al.  Spectrum Sensing of OFDMA Systems for Cognitive Radio Networks , 2009, IEEE Transactions on Vehicular Technology.

[20]  Jyrki Lahtonen,et al.  On the odd and the aperiodic correlation properties of the Kasami sequences , 1995, IEEE Trans. Inf. Theory.

[21]  Simon Haykin,et al.  Cognitive radio: brain-empowered wireless communications , 2005, IEEE Journal on Selected Areas in Communications.

[22]  M.B. Pursley,et al.  Crosscorrelation properties of pseudorandom and related sequences , 1980, Proceedings of the IEEE.

[23]  Pierre Duhamel,et al.  A pseudorandom postfix OFDM modulator - semi-blind channel estimation and equalization , 2006, IEEE Transactions on Signal Processing.

[24]  Marina Petrova,et al.  ARQ-based cross-layer optimization for wireless multicarrier transmission on cognitive radio networks , 2008, Comput. Networks.

[25]  Tung-Sang Ng,et al.  Blind Symbol Synchronization Based on Cyclic Prefix for OFDM Systems , 2009, IEEE Transactions on Vehicular Technology.

[26]  Xianbin Wang,et al.  Robust Spectrum Sensing of OFDM signal without noise variance knowledge , 2009, 2009 11th Canadian Workshop on Information Theory.

[27]  D.J. Edwards,et al.  Multipath Effects in Ultrawideband Rake Reception , 2008, IEEE Transactions on Antennas and Propagation.

[28]  Yuh-Ren Tsai,et al.  Kasami Code-Shift-Keying Modulation for Ultra-Wideband Communication Systems , 2007, IEEE Transactions on Communications.

[29]  Paramvir Bahl,et al.  White space networking with wi-fi like connectivity , 2009, SIGCOMM '09.

[30]  Kyung Sup Kwak,et al.  Code Shift Keying Impulse Modulation for UWB Communications , 2008, IEEE Transactions on Wireless Communications.

[31]  Geoffrey Ye Li,et al.  Soft Combination and Detection for Cooperative Spectrum Sensing in Cognitive Radio Networks , 2008, IEEE GLOBECOM 2007 - IEEE Global Telecommunications Conference.

[32]  Ian F. Akyildiz,et al.  NeXt generation/dynamic spectrum access/cognitive radio wireless networks: A survey , 2006, Comput. Networks.

[33]  J.-Y. Chouinard,et al.  Modified channel estimation algorithms for OFDM systems with reduced complexity , 2004, Proceedings 7th International Conference on Signal Processing, 2004. Proceedings. ICSP '04. 2004..

[34]  Hang Su,et al.  Cross-Layer Based Opportunistic MAC Protocols for QoS Provisionings Over Cognitive Radio Wireless Networks , 2008, IEEE Journal on Selected Areas in Communications.

[35]  Anatoliy A. Platonov.  Optimization of Adaptive Communication Systems with Feedback Channels , 2009, 2009 IEEE Wireless Communications and Networking Conference.