Pulse or digital communications – Receivers – Angle modulation
Patent
1996-02-23
1999-07-27
Chin, Stephen
Pulse or digital communications
Receivers
Angle modulation
375329, 329304, H04L 2722, H03D 322
Patent
active
059303050
ABSTRACT:
For combining diversity path signals comprising symbols each modulated in accordance with one of a plurality of orthogonal (e.g. Walsh) functions, a diversity combiner includes, for each path, a demodulator to demodulate each modulated signal symbol in accordance with a selected one of the orthogonal functions, a phase estimator to estimate a phase rotation and amplitude of the diversity path signal from the demodulated signal, and a complex signal multiplier to derotate the phase and weight the amplitude of the diversity path modulated signal in dependence upon the estimated phase rotation and amplitude. The combiner sums real parts of the phase-derotated and weighted modulated signals of the diversity paths, demodulates the combined signal in accordance with all of the orthogonal functions, and selects the maximum demodulated signal for each symbol thereby to determine for the symbol the selected one of the orthogonal functions.
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Chin Stephen
Deppe Betsy L.
Haley R. John
Northern Telecom Limited
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