| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a universal modulator architecture for generating various band efficient waveforms, such as QPSK 8 PSK, 16 PSK, 16 QAM, 12/4 QAM, 32 QAM and 64 QAM and higher. <P>SOLUTION: The modulator includes one or more biphase modulators coupled to one or more QPSK modulators. Each of the biphase modulators includes a pair of switchable attenuators for varying the degree of phase shift of the symbols to form the various constellations for the 8 PSK, 16 PSK, 16 QAM, 12/4 QAM, 32 QAM and 64 QAM and higher signals. The architecture is expandable to generate higher order modulation formats, such as 256 QAM, 512 QAM and 1024 QAM and above. The architecture is also expandable to support nonlinear predistortion. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
