Performance Evaluation of Fast Frequency Hopping OFDM over UWB Channels

The performance of fast frequency hopping OFDM (FFH-OFDM) is evaluated under UWB channels with several types of receivers. It is shown that FFH-OFDM has a significant improvement over a conventional OFDM system. The receiver algorithms for the FFH-OFDM considered in this paper are zero-forcing (ZF), minimum mean square error (MMSE), QR- MMSE and sorted QR-MMSE (SQR-MMSE). Soft-output metric computation is proposed for the coded case that yields further gain over hard-output decision. The simulation results show the advantage of QR-MMSE and sorted QR-MMSE receivers in the uncoded case while MMSE has better performance for the coded case with a convolutional coding scheme. The insight on the performance advantage of MMSE over QR-based receivers for the coded case is also provided.