Measured performance of tandem digital troposcatter links

A measurement program was conducted to obtain performance data at the digital voice user level (32 Kb/s) on tandem digital microwave tropospheric-scatter (troposcatter) radio links. Error performance in terms of errored seconds and 15 min average bit-error-rate (BER) was measured by using a single link with a time-delayed loopback configuration to simulate two through ten tandem links. Error performance degradation due to tandeming is shown. Results show small additive error contributions with an increasing number of tandem links. The end-to-end tandem link system performance is dominated by the poorest performing link. A description of the measurement instrumentation, path, and RF equipment is given