Pulse or digital communications – Receivers – Particular pulse demodulator or detector
Patent
1995-12-13
1999-03-30
Pham, Chi H.
Pulse or digital communications
Receivers
Particular pulse demodulator or detector
375340, 375261, 375264, 371 432, 371 434, 371 437, H03D 100, H04L 2302, G06F 1110
Patent
active
058898239
ABSTRACT:
A method and apparatus for decoding a signal in the presence of linear or nonlinear interference, correlated noise or a combination thereof. The method involves a concatenated decoder comprising an inner decoder and a postprocessor. N most likely paths are generated by the inner decoder, or a combination of the inner decoder and an error event generator. These paths are then presented to the postprocessor which computes metrics for each path based on information about the signal, not considered by the inner decoder. These metrics can be based on linear or nonlinear model of the channel and optionally, a noise whitened signal for noise decorrelation. The path with the best metric is selected as the concatenated decoder output. The postprocessor can also be implemented in the presence of channel codes. It is also shown that the postprocessor is especially suited for a trellis implementation. When applied to magnetic recording channels, the method of the present invention allows for increased recording capacity. In addition, the present invention requires less computation and results in a reduction of the power dissipation of about two orders of magnitude compared to alternative approaches.
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Agazzi Oscar E.
Seshadri Nambirajan
Lucent Technologies - Inc.
Pham Chi H.
Tran Khai
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