Microwave Data Transmission Test Program - QPSK Modems.

The objective of the Microwave Data Transmission Test Program - QPSK Modem, was to design, construct, and conduct systems tests on a 70 MHz Quadriphase Shift Keyed ModulatorDemodulator Modem. The modem is designed to permit the conveyance of digital data traffic over conventional frequency division multiplex radios with a 70 MHz intermediate frequency. Data rates from 1.536 Mbps to 12.95 Mbps, in 1 Kbps increments can be accommodated by the QPSK Modem. This program was performed concurrently with a program to develop a modem with a baseband interface Quaternary Baseband Modem. Of particular interest are the system test results including bit error rate as a function of received signal level and transmitted spectral occupancy.