Performance of Interpolated Timing Recovery in Perpendicular Magnetic Recording Channel

Magnetic recording systems employ conventional VCO-based timing recovery to synchronize the readback signal and the sampler, which is expensive to implement. To get rid of this VCO, a fully digital timing recovery known as interpolated timing recovery (ITR) is utilized. This paper investigates the performance of the ITR architecture in magnetic recording channels with and without error-control codes (ECCs). First, we focus on the system without ECC and compare the performance of ITR and conventional timing recovery. Simulation results show that ITR has a performance comparable to conventional timing recovery. Then, we propose an iterative scheme for the system with ECC to jointly perform timing recovery and turbo equalization. This scheme is achieved by introducing the ITR module within the turbo equalizer to refine the samples for each iteration. Results show that the proposed iterative scheme outperforms a conventional receiver with separate timing recovery and turbo equalization.