Frequency domain equalization for OFDM systems with insufficient guard interval using null subcarriers

Frequency domain equalizers (FEQs) have been applied extensively in multicarrier systems to enhance transmission rate by reducing transmit redundancy in the form of guard interval. The proposed equalization algorithm is able to remove intersymbol and intercarrier interference (ISI and ICI) incurred by the reduction or the absence of this redundancy by properly exploiting null subcarriers that are inherent in standardized multicarrier systems. Unlike previous proposed schemes, the proposed algorithm does not require additional temporal nor spatial diversity at the receiver to mitigate the channel-induced interferences. Simulation results show that our approach outperforms those of other schemes in terms of bit error rate.

[1]  Ieee Microwave Theory,et al.  Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems — Amendment for Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands , 2003 .

[2]  Tanja Karp,et al.  Frequency domain equalization of DMT/OFDM systems with insufficient guard interval , 2002, 2002 IEEE International Conference on Communications. Conference Proceedings. ICC 2002 (Cat. No.02CH37333).

[3]  Ta-Sung Lee,et al.  A Near-Optimal Low-Complexity Transceiver for CP-Free Multi-Antenna OFDM Systems , 2006, IEICE Trans. Commun..

[4]  Yung-Fang Chen,et al.  Adaptive Antenna Arrays for Interference Cancellation in OFDM Communication Systems With Virtual Carriers , 2007, IEEE Transactions on Vehicular Technology.

[5]  Cenk Toker,et al.  Joint Transceiver Design for MIMO Channel Shortening , 2007, IEEE Transactions on Signal Processing.

[6]  P. Vaidyanathan.  Multirate Systems And Filter Banks , 1992 .

[7]  Charles E. Rohrs,et al.  Impulse response shortening for discrete multitone transceivers , 1996, IEEE Trans. Commun..

[8]  Brian L. Evans,et al.  Equalization for discrete multitone transceivers to maximize bit rate , 2001, IEEE Trans. Signal Process..

[9]  Jacob Benesty,et al.  Separating ISI and CCI in a two-step FIR Bezout equalizer for MIMO systems of frequency-selective channels , 2004, 2004 IEEE International Conference on Acoustics, Speech, and Signal Processing.

[10]  B.L. Evans,et al.  DMT bit rate maximization with optimal time domain equalizer filter bank architecture , 2002, Conference Record of the Thirty-Sixth Asilomar Conference on Signals, Systems and Computers, 2002..

[11]  P. P. Vaidyanathan,et al.  A low-complexity eigenfilter design method for channel shortening equalizers for DMT systems , 2003, IEEE Trans. Commun..

[12]  John Thompson,et al.  A comparison of the MMSE detector and its BLAST versions for MIMO channels , 2001 .

[13]  Steven Kay,et al.  Fundamentals Of Statistical Signal Processing , 2001 .

[14]  Tianren Yao,et al.  FEQ for OFDM systems with insufficient CP , 2003, 14th IEEE Proceedings on Personal, Indoor and Mobile Radio Communications, 2003. PIMRC 2003..

[15]  Rui Dinis,et al.  A Reduced-CP Approach to SC/FDE Block Transmission for Broadband Wireless Communications , 2007, IEEE Transactions on Communications.

[16]  Harry L. Van Trees,et al.  Optimum Array Processing , 2002 .

[17]  Marc Moonen,et al.  Bitrate-maximizing time-domain equalizer design for DMT-based systems , 2004, IEEE Trans. Commun..

[18]  Yoshitaka Hara,et al.  A novel OFDM adaptive antenna array for delayed signal and Doppler-shifted signal suppression , 2001, ICC 2001. IEEE International Conference on Communications. Conference Record (Cat. No.01CH37240).