Patent ID: 6968016

Claim:
A device for modulating a carrier signal comprising: (a) a mapper generating a first data signal at a selected one of a plurality of baud rates, the first data signal comprises an I-channel first data signal and a Q-channel first data signal; (b) a scaler multiplying the first data signal by one of a plurality of predetermined scaler values selected to correspond to the baud rate to generate a scaled data signal, the scaled data signal comprises an I-channel scaled data signal and a Q-channel scaled data signal and wherein the complex mixer includes: (i) a first multiplier and a second multiplier each multiplying the I-channel scaled data signal by a sine waveform and a cosine waveform respectively; (ii) a third and fourth multiplier each multiplying the Q-channel scaled data signal by the sine waveform and a cosine waveform respectively; (iii) a first summer adding the result of the second multiplier to the result of the third multiplier multiplied by negative one to generate the I-channel frequency shifted scaled data signal; and (iv) a second channel summer adding the result of the first multiplier and the result of the fourth multiplier to generate the Q-channel frequency shifted scaled data signal; (c) a complex mixer for generating a frequency shifting scaled data signal, the frequency shifted scaled data signal comprises an I-channel frequency shifted scaled data signal and a Q-channel frequency shifted scaled data signal; (d) an upsampler circuit for increasing the sampling frequency of the frequency shifted scaled data signal; and (e) a pulse shaper circuit for generating a digital representation of a modulated carrier signal in accordance with the frequency shifted scaled data signal, wherein the pulse shaper circuit includes a finite impulse response filter and a coefficient matrix storing a set of coefficients for each of the I-channel and the Q-channel.