Modified OFDM Model Based on Sub-Sliding Window Technique

In modern wireless communication systems, Doppler frequency reduction is employed for efficient transmission of data in noisy environments. Achieving a very less bit error rate (BER) has been the major task in the orthogonal frequency division multiplexing (OFDM), which is a popular multicarrier modulation technique in IEEE 802.11a wireless systems and is currently being used in the IEEE 802.16e (WiMax) standard. This paper presents a modified sub-sliding window (SSW) technique that is used to improve the performance of OFDM modem for the physical layer of IEEE 802.11a standard. To carry out the simulations, the bit error rate performance of the modified and standard models is compared under the additive white Gaussian noise (AWGN) and flat fading channel. The simulation results show that the combination of SSW and OFDM technology is superior to the OFDM standard technology.

[1]  Babak Daneshrad,et al.  Detailed OFDM modeling in network simulation of mobile ad hoc networks , 2004, 18th Workshop on Parallel and Distributed Simulation, 2004. PADS 2004..

[2]  Cai Jue-ping.  Doppler spread estimation for mobile OFDM systems in rayleigh fading channels , 2004 .

[3]  R. van Nee.  A new OFDM standard for high rate wireless LAN in the 5 GHz band , 1999 .

[4]  Ahmed Nori,et al.  Improvement Model of MC-CDMA in Frequency Selective Fading Channel , 2007, 2007 2nd International Conference on Cognitive Radio Oriented Wireless Networks and Communications.

[5]  Jack M. Holtzman,et al.  Adaptive averaging methodology for handoffs in cellular systems , 1995 .

[6]  Yoshikuni Onozato,et al.  Performance Study for STC-OFDM Systems Based on IEEE802.11a Standard , 2009, 2009 5th International Conference on Wireless Communications, Networking and Mobile Computing.

[7]  B. Floch,et al.  Coded orthogonal frequency division multiplex , 1995 .

[8]  Sandeep Chennakeshu,et al.  Doppler spread estimation in mobile radio systems , 2001, IEEE Communications Letters.

[9]  Jean-Philippe Javaudin,et al.  Pilot-aided channel estimation for OFDM/OQAM , 2003, The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring..

[10]  KyungHi Chang,et al.  A novel channel estimation scheme for OFDM/OQAM-IOTA system , 2007 .

[11]  Huaping Liu,et al.  A Maximum Likelihood Doppler Frequency Estimator for OFDM Systems , 2006, 2006 IEEE International Conference on Communications.

[12]  Svante Signell,et al.  Novel Preamble-Based Channel Estimation for OFDM/OQAM Systems , 2009, 2009 IEEE International Conference on Communications.

[13]  Ramjee Prasad,et al.  OFDM for Wireless Multimedia Communications , 1999 .

[14]  Chen Wei,et al.  Doppler spread estimation for nonRayleigh fading channel , 2009, 2009 4th IEEE Conference on Industrial Electronics and Applications.

[15]  R. Michael Buehrer,et al.  Mobile Radio Communications , 2003 .

[16]  T. Yucek,et al.  Doppler spread estimation for wireless OFDM systems , 2005, IEEE/Sarnoff Symposium on Advances in Wired and Wireless Communication, 2005..