OFDM-based wireless system for H.263 video communication on frequency selective fading channels

Abstract

Future wireless and personal communication systems are expected to provide high quality service to a wide variety of users demands using the minimum possible resources, in terms of power consumption, bandwidth utilization and hardware complexity. The big challenge in designing the wireless communication system is the technique used to overcome the impairment caused by the unpredictability of the wireless channel itself. We know that most wireless channels are characterized as frequency selective fading (FSF) channels. And one of the effective techniques to mitigate major impairments in FSF channels is orthogonal frequency division multiplexing ( OFDM). This paper addresses the problem of the OFDM application in frequency selective fading for H.263 video codec transmission. A solution for channel estimation based on the transmission of a short training signal is adopted, and processing with a cross correlation algorithm is also devised. The simulation of the proposed technique is applied on seven QCIF sequences with different characteristics for several types of the wireless channel, namely: reference channel, AWGN channel, moderate FSF channel, and bad FSF channel.