| 摘要 |
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. |
