The Design Of HF ALE Signal Detection Devices

As communications technology continues to evolve and be improved, high frequency (HF) communications become more and more popular because they are low-cost, easy to be setup, and require minimum equipment. Automatic link establishment (ALE) technology is one of the advanced communications technologies. In this thesis, the concept of ALE technology is introduced first on the basis of MTL-STD-188-141A and thus the system design is proposed. The basic content of ALE is described. Details of communication protocols and full words structures are presented, For LQA functions and the situations describe, the meaning of ASCII38 are explained by figures. By using the VC++6.0 programming tools, the ALE demodulation, interleaving, and convolution functions are designed and implemented. A signal waveform display is accomplished by using signal LAB controls, including a remote control of WJ8711 and NI broadband receiver functions, a spectrum display, and a waveform display. Finally, the ability of the ALE signal system is successfully tested through the computer audio access. The effect of the demodulation is compared with the current green software. The result is better than expected. As the progress of the project is underway, the current system only includes the initial model construction. The future work will focus on the design and development of the system.