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US 7,003,055 B2Granted
Systolic equalizer and method of using same
AssigneeNokia Corporation
InventorsThomas A. Sexton, Jari Parviainen
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AssigneeNokia Corporation
InventorsThomas A. Sexton, Jari Parviainen
Estimating the term…
A method and apparatus provide a systolic equalizer for Viterbi equalization of an 8-PSK signal distorted by passage through a communication channel. The systolic equalizer architecture is scalable to process, as examples, four, eight and 16 state received signals. An equalizer in accordance with this invention includes a logical arrangement of a plurality of instantiations of locally coupled processing elements forming a systolic array for processing in common received signal samples having distortion induced by passage through a communication channel. The equalizer outputs soft values for input to a decoder, the soft values representing an approximation of maximum a posteriori (MAP) probabilities. A trellis search procedure is employed to reconstruct estimates of a received signal sequence based on a reduced number of states. The reduced number of states is represented by a plurality of groups determined by partitioning a symbol constellation such that there are fewer groups than possible symbols.
An equalizer, comprising a logical arrangement of a plurality of instantiations of locally coupled processing elements PEs forming a systolic array for processing in common received signal samples having distortion induced by passage through a communications channel, and outputting soft values for input to a decoder, the soft values representing an approximation of maximum a posteriori (MAP) probabilities, the equalizer further comprising a global compares block for comparing a data entry in records operated on by said plurality of instantiations of locally coupled PEs and selectively overwriting said data entry in one of said records based on the comparing.
A method for processing, on a burst by burst basis, received signal samples having distortion induced by passage through a communications channel, comprising:
An equalizer, comprising a logical arrangement of a plurality of instantiations of locally coupled processing elements PEs forming a systolic array for processing in common received signal samples having distortion induced by passage through a communications channel, and outputting soft values for input to a decoder, the soft values representing an approximation of maximum a posteriori (MAP) probabilities, wherein each PE is coupled to a channel lookup table LUT of possible products of channel taps and constellation points.
Dependencies are inferred from the claim text.