We show that polar codes asymptotically achieve the whole capacity-equivocation region for wiretap channel when wiretapper's is degraded with respect to main channel, and weak secrecy notion used. Our coding scheme also achieves capacity of physically receiver-orthogonal relay channel. simulation results moderate block length binary erasure comparing two edge type LDPC codes.

We consider the symmetric discrete memoryless relay channel with orthogonal receiver components and show that polar codes are suitable for decode-and-forward compress-and-forward relaying. In first case we prove capacity achieving physically degraded channel; stochastically channels our construction provides an achievable rate. second construct sequences of achieve rate by nesting source compression into coding. both cases constructions inherit most properties codes. particular, encoding...

We investigate energy-efficient cooperation for secrecy in cognitive radio networks. In particular, we consider a four-node scenario where the secondary receiver is treated as potential eavesdropper with respect to primary transmission. The transmitter should ensure that message not leaked user by using cooperative jamming. optimal power allocation and splitting at our model maximize energy efficiency (EE) under constraints. formulate analyze an important EE Stackelberg game between two...

State estimation is routinely being performed in high-voltage power transmission grids order to assist operation and detect faulty equipment. In low- medium-voltage distribution grids, on the other hand, few real-time measurements are traditionally available, often conducted based predicted historical data. Today, many parts of world, smart meters have been deployed at customers, their could principle be shared with operators real time enable improved state estimation. However, customers may...

Mushroom-type electromagnetic bandgap (EBG) structures are known to operate as high-impedance surfaces at low-frequency bands. They broadly used in the microwave regime. However, one of main drawbacks mushroom-type EBG is their narrow bandwidth. In this article, we propose a structure with glide-symmetric edge vias increase operational This bandwidth increment explained by physical insight provided an equivalent circuit model well description field behavior. Simulation and measurement...

We study the detection and delay performance impacts of a feature-based physical layer authentication (PLA) protocol in mission-critical machine-type communication (MTC) networks. The PLA uses generalized likelihood-ratio testing based on line-of-sight (LOS), single-input multiple-output channel-state information order to mitigate impersonation attempts from an adversary node. performance, develop queueing model that captures erroneous decisions (i.e., false alarms missed detections), three...

Abstract Background Whether early fluid accumulation is a risk factor for adverse renal outcomes in septic intensive care unit (ICU) patients remains uncertain. We assessed the association between cumulative balance and major kidney events within 30 days (MAKE30), composite of death, dialysis, or sustained dysfunction, such patients. Methods performed multicenter, retrospective observational study 1834 admitted to five ICUs three hospitals Stockholm, Sweden. used logistic regression analysis...

We present a novel symbol-based soft-input posteriori probability (APP) decoder for packetized variable-length encoded source indexes transmitted over wireless channels where the residual redundancy after encoding is exploited error protection. In combination with mean-square or maximum APP estimation of reconstructed data, whole decoding process close to optimal. Furthermore, solutions proposed reduced complexity are discussed and compared near-optimal solution. When, in addition, channel...

In this paper, we propose a new family of rate-compatible regular low-density parity-check (LDPC) convolutional codes. The construction is based on graph extension, i.e., the codes lower rates are generated by successively extending base code with highest rate. Theoretically, proposed can cover all rational from 0 to 1. addition, regularity degree distributions simplifies optimization. We prove analytically that LDPC different in capable achieving capacity binary erasure channel (BEC)....

We consider transmission over a wiretap channel where both the main and wiretapper's are binary erasure channels (BEC). A code construction method is proposed using two edge-type low-density parity-check (LDPC) codes based on coset encoding scheme. Using single LDPC ensemble with given threshold BEC, we give for same threshold. If has degree variable nodes, our gives rise to one nodes in used channel. This results zero In order circumvent this problem, distribution of numerically optimized....

We consider an extension of the cognitive radio channel model in which secondary transmitter has to obtain (``learn") primary message a first phase rather than having non-causal knowledge it. propose achievable rate region that combines elements decode--and--forward relaying w

In this letter, we present an improved index-based a-posteriori probability (APP) decoding approach for the error-resilient transmission of packetized variable-length encoded Markov sources. The proposed algorithm is based on a novel two-dimensional (2D) state representation which leads to three-dimensional trellis with unique transitions. APP realized by employing 2D version BCJR where all available source statistics can be fully exploited in decoder. For additional use channel codes...

Cognitive radio describes a promising concept for improving the utilization of spectrum. It allows secondary users to access licensed spectrum in an opportunistic fashion, given that quality service primary is maintained. In this scenario, detection unused main obstacle: it requires recognition low- power signals noisy environment. Therefore, we consider case where cognitive are supported by wireless sensor network (WSN) providing beliefs on event user active. The provided WSN nodes then...

In this paper, we investigate the wiretap channel in presence of a cooperative relay node. We analyze and compare outage performance three cooperatives schemes: jamming (CJ), decode-and-forward (DF), amplify-and-forward (AF) for Rayleigh slow fading channel. particular, derive closed-form expression probability DF CJ strategies, which allows an optimal strategy selection terms performance. schemes through numerical simulations.

In this paper we present bilayer LDPC convolutional codes for half-duplex relay channels. Two types of codes, expurgated and lengthened are proposed decode-and-forward (DF) relaying. the case binary erasure channel, prove analytically that both code constructions achieve capacities source-relay link source-destination simultaneously, provided channel conditions known when designing codes. Meanwhile, enable highest transmission rate possible with DF relaying a wide range parameters. addition,...

We consider the coexistence of a multiple-input multiple-output secondary system with single-output primary link different degrees coordination between systems. First, for uncoordinated underlay cognitive radio scenario, we fully characterize optimal parameters that maximize rate subject to constraint transmission strategy combines splitting and interference cancellation. Second, establish model coordinated overlay scenario consists message-learning phase followed by communication phase....

In this paper, we investigate cooperative secure communications in a four-node cognitive radio network where the secondary receiver is treated as potential eavesdropper with respect to primary transmission. The user allowed transmit his own signals under condition that user's secrecy rate and transmission scheme are intact. Under setting, derive achievable rates related constraints guarantee weak rate, when Gelfand-Pinsker coding used at transmitter. addition, propose multiphase include: 1)...

Feature-based physical layer authentication (PLA) schemes, using position-specific channel characteristics as identifying features, can provide lightweight protection against impersonation attacks in overhead-limited applications like e.g., mission-critical and low-latency scenarios. However, with PLA-aware attack strategies, an attacker maximize the probability of successfully impersonating legitimate devices. In this paper, we worst-case detection performance bounds under such strategies...

In this article, we propose a new variational approach to learn private and/or fair representations. This is based on the Lagrangians of formulation privacy and fairness optimization problems that propose. formulation, aim generate representations data keep prescribed level relevant information not shared by or sensitive data, while minimizing remaining they keep. The proposed (i) exhibits similarities problems, (ii) allows us control trade-off between utility through Lagrange multiplier...

In this paper, we present a novel packetized bit-level decoding algorithm for variable-length encoded Markov sources, which calculates reliability information the decoded bits in form of posteriori probabilities (APPs). An interesting feature proposed approach is that symbol-based source statistics transition are exploited as priori on trellis. This method especially well-suited long input blocks, since contrast to other APP approaches, number trellis states does not depend packet length....

In this paper, we address the design of distributed coding schemes for 3-node relay channel with half-duplex constraint. We first discuss general problem optimally re-encoding noisy data at and summarize recently proposed approximations. Based on an analysis extrinsic information transfer characteristics component codes investigate potential ldquoweakrdquo turbo or LDPC which are employed by source node in order to increase reliability when decoding is not possible. The results show that can...

This paper explores the trade-off between cooperation and secrecy in cognitive radio networks. We consider a scenario consisting of primary secondary system. In simplest case, each system is represented by pair transmitter receiver. assume constraint on transmission sense that message has to be concealed from Both situations where aware unaware are investigated compared. first helps allocating power for jamming, which increases message. latter it can also act as relay message, thus improving...

In this paper, typical uplink scenarios in a cellular system are considered, where two cooperating mobile stations (serving, for example, as relays) transmitting the some information to base station by using distributed space-time coding scheme. Due nature of system, transmitted signals typically subject different average path losses. For fixed distances between and station, error performance scheme is determined analytically. Then, based on considerations concerning spatial distribution...

In this paper we consider the coexistence of a single-input single-output (SISO) primary link with multiple-input (MISO) secondary user pair that has non-causal knowledge message. We study an achievable rate region exploits by combining selfless relaying to maintain supported dirty coding pre-cancel interference at receiver. find optimal choice power allocation between these operating modes transmitter as well beamforming vectors. Moreover, address robustness solution uncertainties in...