Analysis of Cyclostationary CR Detector for OFDM signals

Abstract

he cyclostationary based spectrum sensing algorithm is especially suitable for detection
of orthogonal frequency division multiplexing (OFDM) signals that exhibit strong periodic
correlation due to insertion of cyclic prefix between OFDM blocks. Normally, the cyclic
prefix is used to remove the Intersymbol interference (ISI) and intercarrier interference (ICI)
of the OFDM signal and so it eliminates a need for complex equalizer.
In this paper, simulation results demonstrate the normalized spectrum correlation
function of the primary OFDM signal used in cognitive radio systems with different values of
cyclic frequency. Two techniques are assumed to be used as PAPR reduction of OFDM
transmitted signal. The results show that only one of them has no apparent effect on the
correlation performance of the cyclostationary detector. Finally, it is found that a reduction of
30% in the implementation complexity can be taken by suitable choice of detector cyclic
frequency.