Numerical results on capacity bounds for magnetic recording channels

Capacity for magnetic recording channels has been difficult to calculate due to the binary input constraint. We summarize different capacity bounding techniques for channels with media and electronics noise. The performance of existing detectors are computed and compared to the proposed capacity bounds. Simulation results project a less than 3 dB gap between the capacity lower and upper bounds, and a potential coding gain of 4-6 dB for the current read channel detectors.