Pulse or digital communications – Spread spectrum – Direct sequence
Reexamination Certificate
2007-01-09
2007-01-09
Fan, Chieh M. (Department: 2611)
Pulse or digital communications
Spread spectrum
Direct sequence
C375S316000, C375S332000
Reexamination Certificate
active
10306917
ABSTRACT:
A method for multi-user detection includes receiving a complex input signal due to a superposition of waveforms encoding symbols in a constellation of fixed magnitude and variable phase, which symbols are transmitted respectively by a plurality of transmitters in a common frequency band. The complex input signal is sampled at sampling intervals over the duration of an observation period to provide a sequence of complex samples. The sequence of complex samples is processed to determine soft decision values corresponding to the symbols transmitted by the plurality of the transmitters in the observation period, while constraining the soft decision values to a circle in a complex plane. The soft decision values are projected onto the constellation to estimate the transmitted symbols.
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Ben-David Shay
Karnin Ehud
Sheinvald Jacob
Ejaz Naheed
Fan Chieh M.
International Business Machines - Corporation
Kaufman Stephen C
LandOfFree
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