Design and Implementation of a STANAG 5066 Data Rate Change Algorithm for High Data Rate Autobaud Waveforms

High Frequency (HF) communication systems have been used for more than a century. However, solutions have to be designed to facilitate data communication over HF. STANAG (NATO Standardisation Agreement) 5066 is one such solution which provides an application independent ARQ (Automatic Repeat Request) bearer service for client applications. This paper describes the design and simulation of a new Data Rate Change (DRC) algorithm that uses the SNR (Signal to Noise Ratio) and the BER (Bit Error Rate) estimate to make a data rate choice. The DRC algorithm was implemented in a commercial STANAG 5066 system and tested using HF data modems and a simulated HF channel. The results of the implementation and testing show that the designed DRC algorithm gives a better performance, is quicker to adapt and is more robust than previous DRC algorithms. This is also the first DRC algorithm that has been designed to use channel information, such as the SNR and BER, to make a data rate choice.