Patent ID: 8229040

Claim:
A feedforward receiver for reducing inter-symbol interference in a received symbol, said receiver comprising: an equalizer that determines and outputs a joint soft value which includes joint information of a modem bit x and a previous modem bit x′, wherein determining the joint soft value comprises computing the equation: E ″( x′,x )= F k−2 ( j″ x′,x )= f k−1 ( j″ x′,x ,j′ x )= f k ( j′ x ,φ), wherein E″(x′,x) defines a cumulative metric candidate, F k−2 (j″ x′,x ) defines a cumulative metric for index k−2, k defines a time index, f k−1 (j″ x′,x ,j′ x ) defines a branch metric at index k−1, f k−1 (j′ x ,φ) defines a branch metric at index k; wherein x comprises a modem bit labeling a branch from stage k−1 to stage k, φ comprises a value corresponding to a best state at index k, j′ x comprises a value corresponding to a state at index k−1, j′ x′,x comprises a value corresponding to a state at index k−2; a fusion function that receives the joint soft value and outputs an input soft value for the previous modem bit x′; a decoder that receives the input soft value for the previous modem bit x′ and outputs an output soft value for the previous modem bit x′; and a modification unit that uses the input soft value for the previous modem bit x′ and the output soft value for the previous modem bit x′ to generate side information which is in a form of a bias about the previous modem bit x′; wherein said fusion function receives the side information and processes the side information and the joint soft value to generate an improved single soft value for modem bit x.