This paper suggests the use of a prefilter before baud-rate timing recovery (Mueller and Muller 1976). It is shown that the timing phase of the baud-rate timing synchronizer can be set to a desirable timing phase, at which point a digital equalizer performs best, by proper prefiltering. The procedure for the optimal design of such a prefilter is developed under the assumption that the channel impulse response and desirable timing phase for equalization are known. Application of the proposed scheme to the gigabit Ethernet system demonstrated that prefiltering can improve receiver performance.

Based on the fact that the effective bandwidth of regenerated RF signals of high density digital versatile disk (DVD) systems is about 1/4 T where T is the symbol period, we propose a DVD receiver that can recover source data with rate 1/T after 1/2 T sampling. This receiver employs an interpolator that increases the data rate to 1/T. It is shown that the proposed receiver can perform like conventional receivers with a sampling rate 1/T at the expense of a minor increase in computation. Since the proposed receiver can recover the data at twice of the A/D convertor rate, it should be very useful for high-speed data recovery.