Patent ID: 7117234

Claim:
A waveform generator ( 100 ) for use in IQ modulation, comprising: digital frequency modulation waveform generator means ( 104 ) for generating digital values representative of any of a predetermined range of desired frequency modulation schemes; digital accumulator means ( 108 , 110 , 112 ) for accumulating digital values produced by said digital frequency modulation waveform generator means; first look-up means for receiving only a most significant group of bits produced by the digital accumulator means and for looking up in a first look-up table ( 114 ) phase-space values (cos (φMSB) , sin (φMSB) ) associated with the received most significant group of bits; second look-up means for receiving only a least significant group of bits produced by the digital accumulator means and for looking up in a second look-up table ( 116 ) phase-space values (cos (φLSB) , sin (φLSB) ) associated with the received least significant group of bits; and combining means ( 130 , 140 ) for combining the phase-space values produced by the first and second look-up means to produce in-phase and quadrature-phase values (I, Q) for transmission modulation.