Format efficiency and ECC design
To make efficient use of the magnetic recording system and reliably read back the user data, the bit stream written onto the magnetic medium includes redundancy and synchronization patterns. The goal is to introduce as little overhead as possible, while ensuring proper operation of the data acquisition and timing loops and meeting the 10-17 bit error rate requirement of tape recording systems.
Our team has extended the principle of reverse concatenation (RC) to tape and proposed a new capacity-efficient RC scheme with a modulation code of less than 1% redundancy [1], [5]. This new format supports novel ECC techniques based on turbo and low-density parity-check (LDPC) codes. Innovative code design techniques and the theory of iterative decoding have made significant progress in the past few years moving signal-to-noise ratio (SNR) gains very close to the theoretical limit. However, these techniques are still in their infancy in terms of implementation.
Our team is exploring the potential applicability of novel coding techniques to magnetic recording. In addition to optimizing the coding system proper, careful designs of the detection and timing schemes are critical to ensure optimal signal quality.
