Two-Track Reading With a Wide-Track Reader for Shingled Track Recording

In order to avoid the requirement for a narrow track reader in high track density shingled recording, decoding schemes for two-track simultaneous reading, which allows a wide-track reader to be used, are investigated. The strong intertrack interference (ITI) is a major difficulty to be overcome. To avoid ITI, the recorded magnetization in the two tracks should be staggered. Two possible 2-D decoding techniques are provided: 1) recursive decoding by oversampling and 2) Partial Response Maximum Likelihood (PRML) detection. Because data in two track are read simultaneously, the data transfer rate is two times higher than in regular single-track reading. Despite the high data rate, the requirement on the reader for high readback resolution, such as a small shield gap length, magnetic spacing, can be mitigated.