Pulse or digital communications – Receivers – Particular pulse demodulator or detector
Reexamination Certificate
2006-08-29
2006-08-29
Kumar, Pankaj (Department: 2611)
Pulse or digital communications
Receivers
Particular pulse demodulator or detector
Reexamination Certificate
active
07099410
ABSTRACT:
The present invention involves demodulation of radio signals modulated with M-ary modulation in the presence of intersymbol interference distortion. The invention presents a method for reducing the number of multiplications needed to implement a maximum-likelihood-sequence-estimation (MLSE) equalizer for signals modulated with M-ary modulation. In exemplary embodiments of the present invention, the number of multiplications is reduced by pre-computing certain values needed for the determination of the branch metric and storing these pre-computed values in a product table. When a branch metric computation is to be made, whether it is an Euclidean branch metric computation or an Ungerboeck branch metric computation, certain multiplication operations are replaced by simple table look-up operations. As a result, the power efficiency and speed of the system are increased. Any receiver that demodulates signals that are modulated with M-ary modulation can be implemented using the present invention. The resulting demodulator will have a lower complexity than existing demodulators.
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Bottomley Gregory E.
Chennakeshu Sandeep
Zangi Kambiz
Ericsson Inc.
Kumar Pankaj
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