International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The design, implementation, and performance of a digital modem employing Gaussian minimum shift keying (GMSK) is described. The GMSK modem is implemented in field programmable gate array (FPGA) chips, and a laboratory test setup was developed to validate its performance for a signal BT value of 1/5. The measured spectrum of the GMSK modem and its bit error rate (BER) performance, which are found in very close agreement with those of theory and simulation, are presented in this paper.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / A data-aided approach to symbol time and carrier phase synchronization applicable to general continuous phase modulation (CPM) signals with modulation index 0.5 is described. Simulated BER performance of two receivers equipped with these synchronizers is presented for a GMSK BT=1/5 signal received in noise with constant and dynamic synchronization errors. Results demonstrate that these synchronizers provide a very promising and yet simple solution to the tracking problem in the design of coherent CPM receivers.