Spectrum sensing in MIMO cognitive radio with temporally and spatially correlated signal

An optimal and a low complexity detectors are proposed in this paper for the detection of temporally and spatially correlated signal in cognitive radio (CR), equipped with multiple antennas both at the primary user (PU) transmitter and secondary user (SU) receiver. Both the detectors require a prior knowledge of temporal and spatial correlation information. The detection performance of the proposed optimal detector shows the upper bound for spatially and temporally correlated signals at the cost of higher complexity. The proposed optimal and the proposed low complexity detectors show 32.66% and 6.32% performance improvement, respectively with respect to the maximum-to-minimum eigenvalues (MME), and arithmetic mean to geometric mean (AGM) of eigenvalues of sample covariance matrix based detectors for the values of probability of false-alarm 0.1 and signal-to-noise ratio -10dB. The proposed low complexity detector also shows lesser complexity with respect to the MME and AGM detectors for the number of antennas greater than 3 at SU. The effect of only spatial correlation is also analyzed and observed that the detection performance degrades.