Bi-directional timing recovery for magnetic recording systems

Magnetic recording systems employ conventional timing recovery to synchronize the sampler with the readback signal. However, conventional timing recovery does not perform well when the timing error is large. This paper proposes the bidirectional timing recovery, which utilizes conventional timing recovery to sample the readback signal both in forward direction and in backward direction. The outputs of these two operations are averaged and sent them to the Viterbi detector to determine the most likely input sequence. Results indicate that the bidirectional timing recovery performs better than conventional timing recovery, especially when the timing error is large.