Sequence detection device using maximum likelihood sequence detection with programmable branch metric computation reduction and associated sequence detection method

A sequence detection device comprising:

• a sequence detection circuit, configured to perform sequence detection upon a received signal to generate and output a symbol sequence, wherein the received signal is an output signal of an analog-to-digital converter (ADC), and the sequence detection circuit comprises:
• a region estimation circuit, configured to categorize each of a plurality of samples included in the received signal into one of a plurality of regions;
• and
• a trellis selection circuit, configured to select one of a plurality of trellis schemes for branch metric calculation according to region estimation results of two of the plurality of samples output from the region estimation circuit.

A sequence detection method comprising:

• obtaining a data signal, comprising:
• receiving an output of an analog-to-digital converter (ADC) as the data signal;
• or
• performing a feed-forward filtering operation upon the output of the ADC to generate an equalized signal as the data signal;
• performing a sequence detection operation upon the data signal to generate and output a symbol sequence, wherein the sequence detection operation comprises:
• performing a region estimation operation to categorize each of a plurality of samples included in the data signal into one of a plurality of regions;
• and
• performing a trellis selection operation to select one of a plurality of trellis schemes for branch metric calculation according to region estimation results of two of the plurality of samples output from the region estimation operation.