In this paper, a backscatter cooperation (BC) scheme is proposed for non-orthogonal multiple access (NOMA) downlink transmission. The key idea to the surplus power of received signals at one user enhance reception who cannot recover its information. To evaluate performance BC-NOMA scheme, three benchmark schemes are introduced, which include non-cooperation (NC)-NOMA conventional relaying (CR)-NOMA and incremental (IR)-NOMA scheme. For all these schemes, outage performance, expected rate,...

This letter investigates the limit covert rate of ambient backscatter communications over additive white Gaussian noise channel, where Alice expects to reliably transmit information Bob via reflecting incident signals from an radio frequency (RF) source without being detected by Willie. The RF is not dedicatedly deployed for communication and has its own data stream send. Our analyses show that subject well-known square root law (i.e., <inline-formula...

In this letter, a reconfigurable intelligent surface (RIS)-based passive covert communication scheme is proposed, where source node Alice covertly transmits information to receiver Bob by using RIS and reflecting the incident signals from an ambient radio frequency source. The key idea adjust phase shifts of align phases received reflected at meanwhile reflection amplitude satisfy constraint. detection error probability warden Willie decoding in Rayleigh fading channels are derived...

This paper proposes a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) segmented symbiotic ambient backscatter system. The elements of the STAR-RIS are into an enhancing primary-signal (EP) zone backscatter-device (BD) zone, which adjusted to enhance receivers' reception primary signal from S convey STAR-RIS's information, respectively. With aid proposed Max-Min rule, optimal reflection coefficients achieve maximum sum ergodic capacity derived. A...

This paper investigates the limit covert rate of backscatter communication systems based on undecodable ambient radio frequency (RF) signals over additive white Gaussian noise channel. In considered network, source node Alice expects to transmit information receiver Bob without being detected by warden Willie, backscattering RF signals. this case, it is challenging for recover from Alice, since result in both unknown and multiplicative interference. A subtle strategy proposed alleviate...

In this paper, an impartial simultaneous wireless information and power transfer (SWIPT)-assisted cooperation mechanism is proposed for a non-orthogonal multiple access (NOMA) downlink scenario. The key idea of the user (IUCM) that not only cell-center but also cell-edge applies power-splitting architecture utilizes harvested energy to forward other user's information. Analytical results show IUCM outperforms traditional partial in terms outage probability, diversity order...

In this paper, to perform an energy-efficient and high-throughput time-switching (TS)-based energy-harvesting (EH) relaying in a practical block-by-block manner, adaptive discrete TS-based EH scheme is proposed. Specifically, focusing on both dual-hop amplify-and-forward (AF) decode-and-forward (DF) systems, we make full use of the channel state information (CSI) at relay determine power as well TS factor based relay's current accumulated energy. For such, effective analytical framework...

ABSTRACT Existing research in the field of reconfigurable intelligent surface (RIS)‐aided physical layer security assumed Gaussian signal inputs, which is inapplicable to practical communication systems, where finite‐alphabet inputs are used. This paper considers an RIS‐aided secure multiple‐input multiple‐output wireless system with artificial noise (AN) invoked at transmitter enhance performance. In order maximize secrecy rate (SR), data precoder, AN and RIS's reflection coefficients...

In this paper, a robust adaptive fuzzy control for class of nonlinear uncertain systems preceded by an unknown dead-zone and with upper bound uncertainties is developed. The dead-zones are quite commonly encountered in many (e.g., DC servosystem, robot, machine tools), usually poorly known, may severely limit the performance control. addition, system parameter variations, or external load, unmodeled dynamics) often exist. Therefore, controllers required to deal stability presence...

Uncertainty about noise variance is unavoidable. Many existing works exploited the uncertainty for covert communication and meanwhile assumed that adversary third party Willie adopts a radiometer detector, in which case positive reliable rate O(N) bits/N channel uses achievable. Nonetheless, not optimal general. The limit based on against detector remains unknown. To shed light this problem, letter proves when suffers from but has two or more antennas detection, over additive white Gaussian...

In this paper, we propose an impartial simultaneous wireless information and power transfer (SWIPT)-assisted cooperation mechanism for a non-orthogonal multiple access (NOMA) downlink scenario. Specifically, both cell-center user cell-edge apply the power-splitting technique utilize harvested energy to forward other user's on premise of successful decoding their own information. Both analytical numerical results show that proposed (IUCM) outperforms traditional partial in terms outage...

A reconfigurable intelligent surface (RIS)-based passive secure communication scheme is proposed, where the RIS uses part of power incident signals from an ambient radio frequency source to transmit its own confidential information, and remaining used passively generate jamming confuse eavesdropper. Each RIS’s reflection coefficient responsible for both jamming. The coefficients are jointly optimized maximize secrecy rate (SR). Numerical results show that proposed algorithm can approach...