FIR Noise Prediction Algorithm and Simulation Model of Read/Write Channel in Hard Disk
硬盘读写通道的FIR噪声预测算法与仿真模型

Because of the improvement of the storage density in the hard disk, and the decreased space between bits to bits, the noises in the read back signals of magnetic head have been nonstationary and correlative colored noises, which can not adapt to Viterbi detect algorithm. By embedding FIR Noise Prediction Maximum Likelihood (NPML) algo- rithm to the computing process of the branch metric in Viterbi, the colored noises can be effectively whiten. So it can be used to reduce the bit error rate (BER) and improve the system performance. In this paper the comparing analysis of the ordinary Viterbi detector, the noise prediction with FIR is given respectively. Furthermore a SIMULINK simula- tion model of read/write channel, a fast approaching way to acquire the FIR taps, and a method to verify the correction of the model have been constructed to analyze the different noise prediction algorithms. Simulation results show that under the same storage density NPML detector can attain SNR which is xxdb higher and BER which is xxdb lower than PRML detector.