Cognitive ALE for HF Radios

This paper presents a novel technique for reducing time delay and improving the performance of Automatic Link Establishment (ALE) in High Frequency (HF)radios. The techniques proposed for Listen Before Transmit(LBT) based on cognitive radio sensing techniques such as energy detection, matched filter detection and cyclostationary feature detection. ALE is a de facto standard for HF radios through which communication is to be carried out by automatically selecting the channel. Current LBT techniques for ALE work fine for good quality channels but it performs pitiable when the channel quality becomes worst.