Abstract
Mobile WiMAX, IEEE 802.16 m is a Wireless Metropolitan Area Network offering a mobile broadband internet service. It uses cyclic prefix OFDMA (CP-OFDMA) as a multiple access scheme. CP-OFDMA embeds a large number of pilot subcarriers in OFDMA symbol for channel estimation purpose, reducing the data rate and spectral efficiency of mobile WiMAX system. This paper suggests the application of time-frequency training OFDM (TFT –OFDM) as a modulation and multiplexing technique for IEEE 802.16 m. TFT–OFDM employs a PN sequence as guard interval and grouped pilots for computing channel response. Timefrequency training OFDM scheme along with compressed sensing technique uses less number of pilots for channel estimation, enhancing the data rate and spectral efficiency of mobile WiMAX. This paper provides comparative study of Mobile WiMAX using TFTOFDM with CP-OFDM for different vehicular speed. Simulation results demonstrate that TFT- OFDM outperforms CP-OFDM scheme for bit error rate (BER) performance in a multipath channel conditions. TFT-OFDM improves spectral efficiency by 0.47bps/Hz and the data rate by 4.73Mbps for guard interval 1/4.
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