A New Automatically Adjustable Signal Detection Method Using the Second Difference

Abstract

In many digital VTR systems, the playback signal is equalized to the Nyquist criterion and then detected using integrated detection. We digitized the playback signal after equalization at four times the synchronous clock frequency. Using computer analysis, we then investigated the error occurring waveform and the number of errors. From this investigation, we developed a new signal detection method that uses the second difference between each bit. The threshold level is controlled with the value of the second difference to increase the signal-noise ratio. Detection erros near the threshold level in integrated detection are significantly reduced. Some new parameters are required for this method, but they can be automatically adjusted using the zero forcing algorithm.