Design and Implementation of Multi-Rate Wideband General-Purpose Digital Modulator

The architecture for implementing a wideband general-purpose digital modulator is proposed.Key points of its hardware implementation are then analyzed.Methods of realization are given,viz.,baseband PSF(pulse shaping filter),CIC(cascaded integrator comb) filter and clock generator.The implemented wideband modulator is tested by the VSA(vector signal analyzer).Test results showed that the design scheme is correct.The modulator can produce general digital modulation signals with symbol rates from 0.5?MS/s to 50.0?MS/s.Both EVM(error vector magnitude) and spectrum mask meet the requirements of communication standard.