Sequence estimation for class-IV partial-response channels with jitter

An analysis is presented of the output of class-IV partial-response channels corrupted simultaneously by jitter and additive white noise. The authors analyze the behavior of the least-squares (LS) decoder for this channel. They introduce the projection-minimization (P-M) algorithm and demonstrate that, under favorable conditions, its performance, even when not acceptable on its own, could possibly be beneficial when used in conjunction with the LS decoder in enhancing the reliability of the channel. Implementation of the P-M decoder is rather expensive, and it is not at all clear that combining the P-M algorithm with LS decoding and traditional error control schemes is the best way of dealing with channels corrupted by jitter. It may be possible to avoid the P-M algorithm and instead utilize a more aggressive traditional error correction scheme. Alternatively, it may be possible to choose modulation schemes which utilize pulses whose derivatives at the sampled values are small, and perhaps obtain better results than with partial-response class-IV signaling