Multiple Beacon Based Robust Cooperative Spectrum Sensing in MIMO Cognitive Radio Networks under CSI Uncertainty

Abstract

This paper presents multiple beacon vectors based robust detection schemes for cooperative spectrum sensing (CSS) in multiple-input multiple-output (MIMO) cognitive radio (CR) networks under channel state information (CSI) uncertainty. The inaccuracies in the estimate of the CSI are modeled as the standard ellipsoidal uncertainty set. We develop a multiple beacon vector based linear discriminant framework to obtain robust detectors for the problem of primary user detection in MIMO cognitive radio networks under ellipsoidal CSI uncertainty. Next, we employ this framework to develop signaling scheme based application specific detectors, namely the antipodal signaling based robust detector and on-off signaling based robust detector, along with their closed form expressions. Further, for the two signalling schemes, we even present allied detectors that are advantageous under low signal-to-noise ratio (SNR) conditions. Simulation results demonstrate a superior detection performance of the proposed robust detection schemes in comparison to the uncertainty agnostic matched filter detector for CSS in MIMO cognitive radio networks.