TY - JOUR

T1 - Spectrum sensing algorithms via finite random matrices

AU - Zhang, Wensheng

AU - Abreu, Giuseppe

AU - Inamori, Mamiko

AU - Sanada, Yukitoshi

PY - 2012/1

Y1 - 2012/1

N2 - We address the Primary User (PU) detection (spectrum sensing) problem, relevant to cognitive radio, from a finite random matrix theoretical (RMT) perspective. Specifically, we employ recently-derived closed-form and exact expressions for the distribution of the standard condition number (SCN) of uncorrelated and semi-correlated random dual central Wishart matrices of finite sizes in the design Hypothesis-Testing algorithms to detect the presence of PU signals. In particular, two algorithms are designed, with basis on the SCN distribution in the absence (H 0) and in the presence (H 1) of PU signals, respectively. Due to an inherent property of the SCN's, the H 0 test requires no estimation of SNR or any other information on the PU signal, while the H 1 test requires SNR only. Further attractive advantages of the new techniques are: a) due to the accuracy of the finite SCN distributions, superior performance is achieved under a finite number of samples, compared to asymptotic RMT-based alternatives; b) since expressions to model the SCN statistics both in the absence and presence of PU signal are used, the statistics of the spectrum sensing problem in question is completely characterized; and c) as a consequence of a) and b), accurate and simple analytical expressions for the receiver operating characteristic (ROC) - both in terms of the probability of detection as a function of the probability of false alarm (P D versus P F) and in terms of the probability of acquisition as a function of the probability of miss detection (P A versus P M) -are yielded. It is also shown that the proposed finite RMT-based algorithms outperform all similar alternatives currently known in the literature, at a substantially lower complexity. In the process, several new results on the distributions of eigenvalues and SCNs of random Wishart Matrices are offered, including a closed-form of the Marchenko-Pastur's Cumulative Density Function (CDF) and extensions of the latter, as well as variations of asymptotic the distributions of extreme eigenvalues (Tracy-Widom) and their ratio (Tracy-Widom-Curtiss), which are simpler than those obtained with the "spiked population model".

AB - We address the Primary User (PU) detection (spectrum sensing) problem, relevant to cognitive radio, from a finite random matrix theoretical (RMT) perspective. Specifically, we employ recently-derived closed-form and exact expressions for the distribution of the standard condition number (SCN) of uncorrelated and semi-correlated random dual central Wishart matrices of finite sizes in the design Hypothesis-Testing algorithms to detect the presence of PU signals. In particular, two algorithms are designed, with basis on the SCN distribution in the absence (H 0) and in the presence (H 1) of PU signals, respectively. Due to an inherent property of the SCN's, the H 0 test requires no estimation of SNR or any other information on the PU signal, while the H 1 test requires SNR only. Further attractive advantages of the new techniques are: a) due to the accuracy of the finite SCN distributions, superior performance is achieved under a finite number of samples, compared to asymptotic RMT-based alternatives; b) since expressions to model the SCN statistics both in the absence and presence of PU signal are used, the statistics of the spectrum sensing problem in question is completely characterized; and c) as a consequence of a) and b), accurate and simple analytical expressions for the receiver operating characteristic (ROC) - both in terms of the probability of detection as a function of the probability of false alarm (P D versus P F) and in terms of the probability of acquisition as a function of the probability of miss detection (P A versus P M) -are yielded. It is also shown that the proposed finite RMT-based algorithms outperform all similar alternatives currently known in the literature, at a substantially lower complexity. In the process, several new results on the distributions of eigenvalues and SCNs of random Wishart Matrices are offered, including a closed-form of the Marchenko-Pastur's Cumulative Density Function (CDF) and extensions of the latter, as well as variations of asymptotic the distributions of extreme eigenvalues (Tracy-Widom) and their ratio (Tracy-Widom-Curtiss), which are simpler than those obtained with the "spiked population model".

KW - Cognitive radio

KW - Hypothesis test

KW - Random matrix

KW - Spectrum sensing

KW - Standard condition number

UR - http://www.scopus.com/inward/record.url?scp=84857366909&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84857366909&partnerID=8YFLogxK

U2 - 10.1109/TCOMM.2011.112311.100721

DO - 10.1109/TCOMM.2011.112311.100721

M3 - Article

AN - SCOPUS:84857366909

SN - 1558-0857

VL - 60

SP - 164

EP - 175

JO - IEEE Transactions on Communications

JF - IEEE Transactions on Communications

IS - 1

M1 - 6094130

ER -