A new amplitude and phase compensation scheme under fast fading environment for OFDM packet transmission systems

This paper proposes a new amplitude and phase compensation scheme for OFDM packet transmission systems in order to compensate severe and time-variant fluctuation of the received signal amplitude and phase under fast fading environment. The proposed scheme, in addition to the conventional scheme that averages and updates the estimated propagation characteristics on each subchannel, detects subchannels that are momentarily distorted by noise and inter-carrier-interference (ICI) over the fast frequency-selective channels, or by the sudden intercept owing to the shadowing effects. The information of the detected subchannel is used to improve accuracy of the compensation when update the estimated propagation characteristics. The performance of the proposed OFDM packet transmission system was evaluated from several aspects by computer simulation. As a result, by using the proposed scheme, packet error rate (PER) is improved under a high-mobility environment in comparison with the conventional scheme