Method applied to an equalizer for reducing ISI and related ISI reduction apparatus

An inter-symbol interference (ISI) reduction apparatus applied to an equalizer comprising:

• a receiver, for receiving an input data-stream having a training sequence component with a first number of symbols and a data component with a second number of symbols, wherein the first number plus the second number equals a third number;
• a training module, coupled to the receiver, for training the training sequence component to generate a first trained coefficient set when a symbol number of the input data-stream is not greater than the first number, and for training a recycled training sequence component to generate a second trained coefficient set when the symbol number of the input data-stream is greater than the first number and not greater than the third number;
• a storage, coupled to the receiver, for storing the training sequence component when the symbol number of the input data-stream is not greater than the first number, and for storing the training sequence component and the data component to generate a delayed input data-stream when the symbol number of the input data-stream is not greater than the third number;
• a recycling module, coupled between the storage and the training module, for recycling the training sequence component to generate a recycled training sequence component when the symbol number of the input data-stream is greater than the first number and not greater than the third number;
• and
• an equalizer, coupled to the receiver, the training module, the storage, and the recycling module, for applying the second trained coefficient set to the equalizer to reduce ISI of the delayed input data-stream when the symbol number of the input data-stream is greater than the third number.