Hybrid Tropo Transmission System
Abstract
This document describes the design, development, laboratory testing, and over-the-air testing of a Digital Data Tropo Transmission System and Hybrid Tropo Transmission System (HTTS). Digital transmission was accomplished at data rates of 1.75, 3.5 and 7.0 Mbps by using the Raytheon Distortion Adaptive Receiver (DAR-IV) modulation/demodulation (modem) technique. Testing of the DAR- IV was performed using the RADC troposcatter media simulator and comfirmed by actual over-the-air tests on the AN/MRC-98, AN/TRC-97 and AN/TRC-132 radio equipments in both modes. The test results showed that the DAR-IV technique has the potential to provide quality digital data transmission on both tactical and DCS troposcatter links. Within its multipath spread capabilities, the DAR-IV was shown to typically operate within 3 dB of theoretical. The extent of multipath spread accommodated was found to be approximately equal to the inverse of the transmission bit rate. Design improvements are identified to achieve greater multipath spread capacity at the higher data rates. Hybrid transmission was accomplished by using separate analog and digital subcarriers with conventional FDM/FM modulation for analog traffic of up to 60 voice channels. Testing in the hybrid transmission mode revealed that a dual subcarrier approach was feasible but somewhat inefficient in power utilization.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1976
- Accession Number
- ADA032000
Entities
People
- Manfred Unkauf
- Robert Bagnell
Organizations
- RTX