NOVEL TECHNIQUES IN HIGH-SPEED MODEM IMPLEMENTATION USING PROGRAMMABLE DSPS

We present the design and performance of a high speed MSK modem that i ncorporates digital heterodyne processing. A novel table look-up proce dure for direct IF/RF modulation, based on a suitable maximal-length s hift register sequence, is described. High performance, linear phase, low-complexity mixing and filtering in the receiver is achieved using multirate IFIR filters, where the shaping filter may possibly be Mth-b and. The configuration of the IFIR filters is chosen based on the carr ier frequency and the filtering requirements.