A change-detection approach to monitoring fading channel bandwidth

The statistics of mobile communications over frequency nonselective fading channels are determined largely by fading bandwidth, which is related to vehicle speed. On-line estimation of fading bandwidth can be used to optimize coherent signal transmission, as well as improve handoff algorithms. The level crossing rates of the received signal amplitude, combined with on-line change detection techniques are used to estimate the fading bandwidth. The proposed estimator takes AGWN into account and has low complexity and processing delay. Applied to adaptive on-line tracking of fast fading channel parameters, significant BER reduction is demonstrated, particularly in situations where vehicle speed increases abruptly