Identification of spectrum holes using energy detector based spectrum sensing

Abstract

Spectrum sensing is the key factor of cognitive radio for efficient utilization of the spectrum resources by identifying and making use of spectrum holes. An attempt has been made to implement a transmitter and receiver section for efficient spectrum sensing in cognitive radio environment. A primary user detection algorithm using energy detector-based spectrum sensing technique is designed to analyze the effect of message length on the identification of primary user. Input message of variable length have been modulated using binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK) before transmission. Additive white Gaussian noise (AWGN) is added as it possesses wide range of frequency over the channel. The presence/absence of primary user has been identified by determining the received signal energy amplitude using Welch Periodogram based power spectral density approach. Simulation results reveal that better detection of primary user takes place in QPSK instead of BPSK for similar message lengths. The precise identification of primary users may lead to enhancement of spectrum utilization under variable network traffic load.