Data storage device including a recording channel, a detector, and a noise prediction circuit, and method of processing a signal in a data storage device

A data storage device comprising:

• a recording channel configured to carry a signal;
• a detector configured to detect the signal from the recording channel;
• a noise prediction circuit configured to predict noise affecting the recording channel and the detected signal based on a noisy channel model;
• and
• a decoder configured to decode the detected signal based on the predicted noise;
• wherein the detector and the decoder form a joint detector/decoder circuit;
• and
• wherein the noisy channel model comprises at least one of:
• a single channel graph model, wherein the joint detector/decoder circuit has a layered structure comprising check nodes of low-density parity-check codes, low-density parity-check bit nodes, and channel check nodes;
• or
• a concatenated channel graph model, wherein the joint detector/decoder circuit has a layered structure comprising a serial concatenation of a rowwise binary channel graph, a columnwise non-binary channel graph, and a low-density parity-check code graph.