A high performance satellite data modem using real-time digital signal processing techniques

The techniques employed in the design of a high performance, phase-shift-keyed data modem for satellite communications and the results obtained in trials carried out on a prototype modem over a satellite link are described. Digital signal processing techniques enable a high performance modem to be designed, which is capable of operation close to the theoretical limit. The use of custom designed integrated circuits in the production equipment allows the performance to be achieved without cost penalty relative to currently available products. The digital implementation also offers the user the flexibility of full IEEE 488 or RS232 remote control of all important functions, including CCITT data rates from 32 kbit/s to 4.096 Mbit/s and an intermediate frequency from 52 MHz to 88 MHz.