| The implementation of mobile multimedia services has been a topic of great interest for some years. This thesis explores modem designs for video transmission that are well-suited to implementation with commercial digital signal processing (DSP) technology. In particular, a new phasor-based algorithm is developed for carrier recovery in coherent, M-PSK digital DSP modems. Efficient, requiring at most 3 complex multiplies per detected symbol, the method is based entirely upon the manipulation of phasors, or complex baseband data strobes, and is applicable to both stream and burst transmission. The intended application is a high rate, DSP-based video-coded modem.; Phase estimation is performed over short, non-overlapping sets of complex data strobes known as windows. An estimate from a previous window is used for initial phase correction on each symbol, followed by a data decision. Two variations of the technique then proceed differently.; These and other methods are extensively examined in terms of complexity, BER performance, and quality of the phase estimator. (Abstract shortened by UMI.)... |
