Yinghui Ye

Improved Energy Detection With Laplacian Noise in Cognitive Radio

Contaminated by Laplacian noise, the performance of energy detection (ED) degrades. To address this problem, an improved energy detection (i-ED) is proposed. Instead of the square of the received signal amplitude in the ED, an arbitrary exponent varying from 0 to 2 is adopted in the proposed algorithm. By deriving the expressions of the false alarm probability and detection probability, we propose an approach to determine the optimal exponent for a given cognitive radio system scenario. Both theoretical analysis and simulation results demonstrate that, by selecting the optimal exponent, the proposed i-ED outperforms ED and the absolute-value cumulating detection in terms of detection performance and robustness to the noise uncertainty.

Dynamic Asymmetric Power Splitting Scheme for SWIPT-Based Two-Way Multiplicative AF Relaying

Power splitting (PS) scheme design is one of the most important challenges in simultaneous wireless information and power transfer-based two-way multiplicative amplify-and-forward relay networks. In this letter, we propose a novel dynamic asymmetric PS (DAPS) scheme to minimize the system outage probability by exploiting the asymmetric instantaneous channel gains between the relay node and the destination nodes. As the formulated optimization problem is a nonconvex problem and difficult to solve, we reformulate it as a fractional programming problem and propose a Dinkelbach-based iterative algorithm to obtain the optimal asymmetric PS ratios. Both the analytical and simulation results demonstrate that the proposed DAPS scheme with the same channel state information overhead can significantly reduce the system outage probability as compared with the existing static symmetric PS scheme.

Power splitting protocol design for the cooperative NOMA with SWIPT

In this paper, we consider the simultaneous wireless information and power transfer assisted cooperative nonorthogonal multiple access (SWIPT-CNOMA) system, in which the near NOMA users with strong channel conditions serve as energy harvesting (EH) relays to help the far NOMA users with poor channel conditions. For the considered system, a new power splitting (PS) protocol for EH relay is proposed and its impact on the outage performance of both near and far NOMA users is studied. The analytical expressions of both outage probability and system throughput are further derived for delay-sensitive transmission mode. Simulation results are provided to verify the derived results and reveal the advantages of the proposed protocol.

Performance analysis of cooperative NOMA with a shared AF relay

Non-orthogonal multiple access (NOMA) has been proposed as a promising technique for the fifth generation wireless networks. In this study, the authors investigate the performance of a cooperative relaying scheme using NOMA (termed NOMA-AF-CRS), where two sources communicate with their corresponding destinations over the same frequency simultaneously through a shared amplify-and-forward (AF) relay. First, the closed-form approximations are derived for the outage probability. The analytical results are further evaluated in the high signal-to-noise ratio region to characterise the diversity order achieved by the system. Then, the ergodic sum capacity of NOMA-AF-CRS is analysed and an upper bound to the ergodic sum capacity is derived. Finally, simulation results are presented to verify the proposed analysis and demonstrate the advantages of NOMA-AF-CRS over the conventional orthogonal multiple access techniques.