Sliding window technique for dynamic spectrum sensing of an asynchronous primary user

Dynamic spectrum allocation is the most efficient way of allocating spectrum and reliable spectrum sensing is the core functionality of that idea. While most of the energy detection techniques deal with the additive white Gaussian noise (AWGN) channel, few algorithms have been implemented to recognize vacant spectrum over frequency selective fading channels where the primary and secondary users are not mutually synchronized at the bit level. For that environment, we devise a novel technique that can efficiently detect the presence of a primary user with the help of its known symbols. Sliding window technique is used to combat the effect of interference in a low signal-to-noise ratio (SNR) environment over the fading channels with different number of channel taps. Simulation results are performed to support the analysis.