Adaptive information rate performance on bandlimited meteor burst channels: empirical results

An investigation is conducted of the throughput performance of two adaptive information rate schemes on the bandlimited meteor-burst communications channel. The first technique, called adaptive symbol rate, uses a fixed waveform modulation and adapts the channel symbol rate to match the received signal-to-noise ratio. The second technique, called adaptive trellis-coded modulation (adaptive TCM), uses the familiar M-ary PSK (phase-shift-key) signal sets with TCM and varies the information rate by adapting the number of information bits per channel symbol to the channel conditions. Experimental data from the USAF High Latitude Greenland Test Bed are used to validate previously derived theoretical performance predictions. Theoretical predictions show that adaptive-symbol-rate improvement over conventional fixed-rate technique is bounded by a factor of 2 and that adaptive TCM improvement exceeds a factor of 3. Data from the Greenland Test Bed show close agreement with these theoretical predictions and confirm the superiority of adaptive TCM for bandlimited meteor-burst channels