Covert communication aims to hide the existence of transmissions guarantee security in wireless communications. In this letter, channel uncertainty is exploited achieve covert relay networks. The transmitter Alice sends messages legitimate receiver Bob with help a relay, while warden Willie wants detect transmission. introduces confusions degrade performance Willie's detection. We show that can transmit ${O}$ (${n}$ ) bits ${n}$ uses covertly and uncertainty. Numerical results are shown...

We propose a robust transceiver design for covert integrated sensing and communications (ISAC) system with imperfect channel state information (CSI). Considering both bounded probabilistic CSI error models, we formulate worst-case outage-constrained optimization problems of joint beamforming radar waveform to balance the performance multiple targets while ensuring covertness system. The are challenging due non-convexity arising from semi-infinite constraints (SICs) coupled variables. In an...

This letter proposes a generalised propulsion energy consumption model (PECM) for rotary-wing unmanned aerial vehicles (UAVs) under the consideration of practical thrust-to-weight ratio (TWR) with respect to velocity, acceleration and direction change UAVs. To verify effectiveness proposed PECM, we consider UAV-enabled communication system, where UAV serves multiple ground users as an base station. We aim maximize efficiency (EE) by jointly optimizing user scheduling trajectory variables....

In the rapidly advancing landscape of 6G, characterized by ultra-high-speed wideband transmission in millimeter-wave and terahertz bands, our paper addresses pivotal task enhancing physical layer security (PLS) within near-field communications. We introduce true-time delayer (TTD)-incorporated analog beamfocusing techniques designed to address interplay between propagation beamsplit, an uncharted domain existing literature. Our approach maximizing secrecy rates involves formulating...

This work employs an unmanned aerial vehicle (UAV) as a jammer to aid covert communication from transmitter Alice receiver Bob, where the UAV transmits artificial noise (AN) with random power deliberately create interference warden Willie. In considered system, UAV's trajectory is critical performance, since AN transmitted by also generates Bob. To maximize system we formulate optimization problem jointly design and Alice's transmit power. The formulated non-convex normally solved...

In this paper, we study the beamforming schemes via novel frequency diverse array (FDA) on enhancing covert communications performance. We first consider ideal scenario where channel state information (CSI) is perfectly known at transmitter. Then characterize key role of minimizing correlation communication and detection channels in boosting covertness system, which also provides a theoretical design principle for FDA-specific carrier scheduling. By exploiting optimization framework block...

The increasing demand in 5G wireless systems has brought significant improvement transmission speed with lower latency, especially ultra-dense networks. of privacy and security are becoming more critical such large scale Different from traditional encryption methods, this paper, we discussed the physical layer features social opportunities networks summarized physical, link upper using cross optimization, will meet new problems pending to be tackled. Also, challenges due some ideal...

Internet of Things (IoT) as a prospective platform to develop mobile applications, is facing with significant challenges posed by the tension between resource-constrained smart devices and low-latency demanding applications. Recently, edge computing (MEC) emerging cornerstone technology address such in IoT. In this paper, leveraging social ties human networks, we investigate optimal dynamic computation offloading mode selection jointly minimize total tasks' execution latency devices' energy...

In this letter, we analyze the performance of covert communications under <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">faster-than-Nyquist</i> (FTN) signaling in Rayleigh block fading channel. Both maximum likelihood criterion- and xmlns:xlink="http://www.w3.org/1999/xlink">Kullback-Leibler</i> (KL) divergence-based covertness constraints are considered. Especially, for KL one, prove that both transmit power rate FTN higher than those...

This letter considers amplify-and-forward (AF) cognitive relay networks with interference power constraint and transmit in a spectrum-sharing context. In particular, we impose the on secondary source node, node. We derive exact outage probability lower bound symbol error rate (SER) of transmission over Rayleigh fading channels. Our results show that SER saturation phenomenons occur when or reaches specified value. Monte Carlo simulations are shown to validate accuracy analytical results.

In this article, we investigate device-to-device (D2D) relay enabled covert communications. Safety zone is employed to isolate the eavesdroppers from transmitters and receivers. Different majority of existing studies considering fixed relays, dynamic selection first considered for communications in article. Additionally, formulate power allocation into an infinite-horizon time-average renewal-reward problem subject time average constraint on a collection penalty processes. Furthermore, novel...

In this paper, we consider unmanned aerial vehicle (UAV)-enabled two-way relaying communications between two robot swarms in the absence of communication infrastructures remote areas or post-disaster rescues. To be more specific, UAV is employed as relay to expand range disconnected ground swarms, due its high maneuverability and flexible deployment. Meanwhile, mode adopted can improve transmission performance terms delay throughput comparison conventional one-way relaying, owing ability...

This paper explores downlink multi-antenna covert communications using rate-splitting multiple access (RSMA). Specifically, RSMA is utilized to enhance covertness and address the challenge of integrating services while maintaining concealment from regular subscribers. The formulates an optimization problem aimed at maximizing minimal communication rate among all users. An iterative algorithm proposed, employing matrix lifting fractional programming. Our scheme also applicable space division...

Cooperative spectrum sensing (CSS) can improve the performance by introducing spatial diversity in cognitive radio networks (CRNs). However, such cooperation also introduces delay for reporting data. Conventional scheme assumes that cooperative secondary users (SUs) report their local data to fusion center sequentially. This causes increase with number of SUs, and ultimately affects CSS. In this article, we consider formulate optimization problem CSS user selection maximize average...

In this paper, we investigate the joint optimization of sensing and power allocation for cooperative relay in cognitive radio networks (CRNs). Specifically, time slot, source secondary user (SU) SUs individually sense channel, then send their results to SU, which a fusion rule is employed determine whether primary (PU) idle or not on channel. data transmission selective amplify-and-forward (S-AF) scheme considered assist SU transmission. By jointly considering two slots, problems are...

This paper discuss the term threats, attacks and vulnerabilities in Wireless Sensor Networks followed by a model that relates three entities. Based on model, framework of Trusted node is presented consisting two major sections which are platform security enhancement Authentication protocol to enhance sensor nodes features confirm fidelity joining network respectively. The design line with Computing Group specifications toward trusted implementation. Finally, brief analysis proposed presented.

The physical layer security problem with a passive eavesdropper is considered in this letter. We propose method to obtain everlasting secrecy by exploiting inter-symbol interference (ISI) eavesdropper. In the proposed method, pulse shaping filter transmitter changes time faster-than-Nyquist (FTN) signaling structure. hopping pattern pre-shared between and legitimate receiver. Knowing pattern, receiver can mitigate ISI as that FTN. Otherwise, will experience severe interference. results show...

Linear frequency modulated (LFM) signal is widely applied in many fields for its excellent characteristic of long time interval and wide band. The chirp rate the key parameter LFM signal. traditional search-based estimation algorithms have contradiction between performance complexity. phase-based good case high SNR, but complexity high. In order to solve these problems, a new algorithm by multiple discrete polynomial phase transform (DPT) weighted combination proposed. this algorithm,...

In this paper, we investigate multi-antenna covert communications, where the transmitter Alice equips multiple antennas, legitimate receiver Bob and eavesdropper Willie single antenna. Through analyzing detection performance rate, prove that a positive rate is achievable with certain number of antennas in Alice. Numerical results are shown to illustrate correctness our MISO communication.

Cooperative spectrum sensing (CSS) is a promising technology in cognitive radio (CR) networks. Among the many existing CSS methods, cooperation single channel studied extensively. However, CR networks usually deal with multiple channels, therefore multi-channel needs be studied. In this paper, we investigate problems that how to optimally assign secondary users (SU) cooperatively sense channels and set time thresholds. An optimization problem of formulated maximize average throughput subject...

Interpolators are widely employed in the frequency estimation of sinusoidal signals. However, for a real-valued signal, existing interpolators do not consider negative component, which leads to error floor. To solve this problem and further improve accuracy, three new proposed paper. These consist two initial one fine interpolator. In algorithm, both positive components utilized first eliminate floor obtain an estimate. Then, interpolator complex sinusoid is exploited accuracy The...

Dynamic spectrum access to the unused licensed has been proposed as a solution scarcity problem. However, efficient sensing techniques are crucial on way towards systems, which use idle bands opportunistically and increase overall spectral efficiency. The occupancy measurement is very important for sensing. Current was evaluated in few campaigns. This paper describes about TV source performed Chengdu. Through analysis result, we can find band be used by Cognitive Radio.