Non-orthogonal multiple access-aided MIMO cognitive radio networks with selective reporting

In this article, we investigate the performances of conventional cooperative sensing (CCS)- and superior selective reporting (SSR)-based cooperative sensing schemes in a multiple-input, multiple-output (MIMO)-aided non-orthogonal multiple access (NOMA)-driven cognitive radio (CR) networks. First, we derive expressions for the probabilities of false-alarm and signal detection for an optimal detector in the considered MIMO-NOMA CR setup. Next, we study a constrained optimization problem that maximizes the sum rates of CCS and SSR schemes, with a constraint on the power allocation at SUs. This problem is shown to be a constrained convex optimization problem. Later, we analytically characterize and compare the sum rate performances of CCS and SSR schemes in MIMO-NOMA CR and MIMO-based orthogonal multiple access (MIMO-OMA) CR networks. Extensive computer simulation results are presented which corroborate our analysis, which also quantifies the gain in performance of the proposed MIMO-NOMA CR network employing SSR scheme when compared to conventional MIMO-OMA CR systems. Furthermore, we present an experimental study based on RTL-SDR setup, which supports our theory and also paves way towards a practical implementation of the proposed framework.