Multiantenna spectrum sensing: Detection of spatial correlation among time-series with unknown spectra

One of the key problems in cognitive radio (CR) is the detection of primary activity in order to determine which parts of the spectrum are available for opportunistic access. This detection task is challenging, since the wireless environment often results in very low SNR conditions. Moreover, calibration errors and imperfect analog components at the CR spectral monitor result in uncertainties in the noise spectrum, making the problem more difficult. In this work, we present a new multiantenna detector which is based on the fact that the observation noise processes are spatially uncorrelated, whereas any primary signal present should result in spatial correlation. In particular, we derive the generalized likelihood ratio test (GLRT) for this problem, which is given by the quotient between the determinant of the sample covariance matrix and the determinant of its blockdiagonal version. For stationary processes the GLRT tends asymptotically to the integral of the logarithm of the Hadama...

• Type: Conference
• Year: 2010
• Where: ICASSP
• Authors: David Ramírez, Javier Vía, Ignacio Santamaría, Roberto López-Valcarce, Louis L. Scharf
• Keywords: CR Spectral Monitor, ICASSP 2010, Low Snr, Low Snr Conditions, Signal Processing