Performance Analysis of OFDM Systems with Adaptive Sub Carrier Bandwidth

Orthogonal frequency division multiplexing based wireless systems are spectrally efficient, but they are vulnerable to inter-carrier interference (ICI). In a wide area scenario, users will experience varying signal strength due to different individual path loss and also varying amount of Doppler spread because of their independent velocities. Therefore, the ICI among users will vary over a wide range. It is proposed in this work to use dynamically adaptive sub carrier bandwidth (ASB) along with adaptive bit loading to mitigate ICI in such conditions, which will keep receivers simple while maintaining maximum throughput in each situation. Results show that ASB can provide higher throughput than its fixed sub carrier bandwidth counterpart when both may use adaptive bit loading per sub carrier.