SINR Improvement in OFDM Systems Using VSB-VBL Technique for High Mobility Applications

OFDM based wireless system provides high spectral efficiency but they are very sensitive to Doppler shift. High mobility causes the channel to be fast fading channel. The rapid variation of the channel can induce inter carrier interference (ICI). ICI due to carrier frequency offset can be mitigated by accurate frequency synchronization but ICI due to fast fading channel is more difficult to handle. Thus ICI reduces the throughput and increases the BER. In this paper we proposed an OFDM system which will use variable sub carrier bandwidth (VSB) with variable bit loading (VBL) to minimize the effect of ICI due to high mobility. We investigate the performance of such VSB-VBL OFDM system with fixed sub carrier bandwidth (FSB-OFDM) system based on signal interference to noise ratio (SINR).