Adaptive energy detection for cognitive radio: An experimental study

A cognitive radio (CR) is able to sense spectral environment over a wide range of frequencies, and provide opportunistic access to frequency bands temporarily unoccupied by an incumbent. Accurate channel sensing is the first important task for a CR, and energy detector is often used for this purpose. While a normal energy detector works well with well chosen window size based on prior knowledge about possible primary users, it often fails with signals that are narrow compared to the detector window, or if only a fraction of the signal is inside the detector window. We propose an adaptive energy detector that can adjust its detection window, and evaluate such detector´s performance using experimental results obtained through a real time implementation.