Effective Generalized Partial Response Target and Serial Detector for Two-Dimensional Bit-Patterned Media Recording Channel Including Track Mis-Registration

Abstract

With the development of 5G technology, programs are gradually moving to cloud services. This leads to an increasing demand for storage. In the field of high-density data storage, bit-pattern media recording (BPMR) is considered a promising approach, as it can expand the data density to 4 Tb/in2. However, in high-density BPMR, bits or magnetic islands are very close to each other, leading to significant intertrack interference (ITI) from the cross-track direction and intersymbol interference (ISI) from the down-track direction. To minimize two-dimensional interference, including ITI and ISI, the serial detector method has been highly effective. However, in this method, the signal at the output of the first decoder is still a hard output. Therefore, we suggest methods to convert the output of the first detector into a soft output. Additionally, we have developed a new form of generalized partial response target to overcome the track mis-registration. The results show that our proposed methods apparently improve bit error rate performance.

Improving Serial Detection Using MAP Algorithm for Bit-Patterned Media Recording

“…With Equation ( 2), the signal b[j,k] is a hard decision value. To create a soft output for the signal b[j,k], we applied the feedback in [11]…”

“…This is presented in Figure 3. [10], soft output serial detection [11], and our proposed model. This is presented in Figure 4.…”

“…In Figure 4, we can see that the probability of R 2 in our proposed model has the largest value (0.28). We can choose R 2 for applying the method in [11] and create a soft output similar to [11]. This soft output is supplied to the vertical detection.…”

“…This helped in the development of several detection algorithms. Serial detection for the BPMR systems based on the coefficient estimation was also introduced using the GPR target [10,11]. Serial detection is inspired by the 2D soft-output Viterbi algorithm (SOVA) for BPMR systems [12].…”

Iterative Signal Detection Scheme Using Multilayer Perceptron for a Bit-Patterned Media Recording System

“…In addition, when the read head cannot continue at the center of the main data track, the system performance is degraded owing to track misregistration (TMR). To overcome performance degradation from these error factors, signal processing schemes such as signal detection, error control coding, and modulation coding schemes must be employed [4][5][6][7]. To mitigate ISI and ITI effects, a 2D equalizer and one-dimensional (1D) partial response (PR) target based on the minimum mean square error (MMSE) criterion was proposed for the BPMR system [4].…”