A study of SNR and BER in Heat Assisted Magnetic Recording (HAMR)

As Perpendicular Magnetic Recording (PMR) technology reaches its areal density limit, Heat-Assisted Magnetic Recording (HAMR) becomes one of the most promising candidates for the next generation recording technology that could allow continued areal density growth up to 4 Tb/in². However, as the areal density increases, it will bring many challenges to the recording system, such as increased non-linear bit shift and transition noise, and could lower the SNR . In this work, we focused on the factors that could affect the signal-to-noise ratio (SNR) and hence bit error rate (BER) of the HAMR system: we try to determine which one is more important . We then studied SNR vs BER by processing the readback signal with a 1D minimum mean square error (MMSE) equalizer and an improved Viterbi detector.