US PATENT SUBCLASS 329 / 304
PHASE SHIFT KEYING OR QUADRATURE AMPLITUDE DEMODULATOR

Current as of: June, 1999
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329 /   HD   DEMODULATORS

304PHASE SHIFT KEYING OR QUADRATURE AMPLITUDE DEMODULATOR {3}
305  DF  .~> Including discrete semiconductor device
306  DF  .~> Input signal combined with local oscillator or carrier frequency signal {1}
310  DF  .~> Including logic element (e.g., logic gate or flip-flop)

DEFINITION

Classification: 329/304

PHASE SHIFT KEYING OR QUADRATURE AMPLITUDE DEMODULATOR:

(under the class definition) Subject matter where the demodulator extracts the modulating signal from a signal which has undergone phase shift keying modulation or quadrature amplitude modulation.

(1) Note. Phase shift keying modulation occurs when the phase of a carrier is shifted among a plurality of discrete angles in accordance with the modulating signal.

(2) Note. Quadrature amplitude modulation occurs when the phase and amplitude of a carrier is simultaneously shifted among a plurality of discrete angle/magnitude pairs.

(3) Note. This subclass includes phase shift keying demodulators or quadrature amplitude demodulators, per se. See the SEARCH CLASS notes below for combinations with the subject matter of this subclass.

SEE OR SEARCH THIS CLASS, SUBCLASS:

300+, for a frequency shift keying demodulator.

SEE OR SEARCH CLASS 375, Pulse or Digital Communications,

261, for a quadrature amplitude modulation system (i.e., transmitter and receiver), subclasses 279+ for a phase shift keying system, and subclasses 322+ for a phase shift keying demodulator combined with receiving structure.