WAVEFORM GENERATOR

A WAVEFORM GENERATOR INCORPORATED IN A RADIO TRANSMITTER OF QUADRATURE TYPE FOR BINARY CONTINUOUS PHASE MODULATION (CPM). IT IS PREVIOUSLY KNOWN TO STORE THE WAVEFORMS OF THE TWO QUADRATURE CHANNELS I AND Q IN TWO ADDRESSABLE TABLE UNITS, WHEREIN THE ONE UNIT STORES SIN (THETA) AND THE UNIT STORES COS (THETA), WHERE (THETA) IS THE PHASE ANGLE. THE TABLE UNITS ARE ADDRESSED BY MEANS OF A BIT HISTORY REGISTER (BHR) WHICH STORES THE INSTANTANEOUS PHASE, AND A QUADRANT MEMORY WHICH STORES THE ACCUMULATED PHASE. ACCORDING TO THE INVENTION, THE TWO TABLE UNITS ARE REPLACED WITH A SINGLE TABLE UNIT (SCT) WHICH STORES CURVE SEGMENTS (A-H) SOLELY FOR ONE OF THE WAVEFORMS SIN (THETA) OR COS (THETA). THE TABLE UNIT (SCT) IS ADDRESSED BY MEANS OF AN ADDRESS CONVERSION (ADR) BETWEEN THE BIT HISTORY REGISTER/QUADRANT MEMORY (BHR AND QM RESPECTIVELY) AND THE TABLE UNIT (SCT). THE GENERATOR ALSO INCLUDES A CONTROLLABLE NEGATION UNIT (NP) AND A LATCHING CIRCUIT (LS) UPSTREAM OF D/A-CONVERTERS (DA1, DA2) AND THE MODULATOR CIRCUITS (M1, M2, ADD) OF THE TRANSMITTER. (FIG. 4)