Abstract
The term Cognitive Radio (CR) is an intelligent technique for opportunistic access of idle radio resources. In Cognitive Radio, spectrum sensing is one of its important attributes which is used to sense the unused spectrum in an opportunistic fashion. Energy detection constitutes a preferred approach for spectrum sensing due to its simplicity and ease of applicability. The conventional energy detection technique, which is based on fixed threshold is susceptible to noise uncertainty, which in practical sense, is actually unavoidable – this noise uncertainty makes the fixed threshold energy sub-optimal in its performance. In this paper, wavelet packet transform is proposed as a preferred energy detection technique for optimal CR performance. Simulation results show that the proposed Wavelet Packet Transform Energy Detection technique (WPT-ED) gave higher probability of detection Pd than the conventional type, which implies that the WPT-ED would give a more accurate detection of the primary user’s presence in the channel compared to the conventional technique.