Minimum Common Outage Probability for the Broadcast Relay Channel

In this paper the broadcast relay channel (BRC) is studied. In the BRC model, the source communicates with two destinations with the help of a single relay. The minimum common outage probability for four different transmission protocols, direct transmission (DT), multihop (MH), path selection (PS) and link combination with path selection (LCPS) is investigated under long-term power constraint for constant rate transmission. In addition, the epsilon-outage rate region for a fixed common outage probability is computed. Based on the cut-set bound (CSB), a lower bound on the minimum common outage probability and an upper bound on the epsilon-outage rate region are also found. Numerical results suggest that enforcing the relay to help both destinations simultaneously is limiting. The dominant factor in the gains obtained with respect to DT is due to path selection and link combination is not necessary when the relay is close to the source

Transmission strategies and resource allocation for fading broadcast relay channels

In this paper the broadcast relay channel, where the source communicates with multiple destinations with the help of a single relay is studied. Five different transmission protocols, direct transmission, multihop (MH), multihop with link combination (MHLC), path selection (PS) and path selection with link combination (PSLC) are investigated. In MH and MHLC, the relay decodes the source message and assists both destinations. In PS and PSLC, the relay can perform partial decoding and has the option to help only one of the destinations. Under long-term power constraint, power allocation for delay-limited transmission is performed to minimize common outage probability and individual outage probability region. For comparison, lower bounds on both common and individual outage probabilities are found. Numerical results suggest that path selection significantly lowers outage probabilities, while enforcing the relay to help both destinations simultaneously is limiting the system performance. (C) 2014 Elsevier GmbH. All rights reserved.This material is based upon work supported by the Scientific and Technological Research Council of Turkey, TUBITAK, under Grant No. 112E059. The material in this paper was presented in part at the 7th International Wireless Communications and Mobile Computing Conference, Istanbul, Turkey, July 2011

A Low-Complexity Policy for Outage Probability Minimization With an Energy Harvesting Transmitter

Outage probability in an energy harvesting (EH) block-fading communication system is studied in the finitehorizon online setting. First, the offline version of the problem is considered, and formulated as a mixed integer linear program (MILP). Then, the infinite-horizon online problem (IIL) is considered relaxing the battery constraints. Solutions of these two problems provide lower bounds on the finite-horizon online problem, for which we provide a low-complexity heuristic scheme, called the fixed threshold transmission (FTT) scheme. Numerical results show that the FTT scheme achieves an outage performance close to the MILP lower bound for a wide range of operation regimes, and close to IIL when the EH rate is low. It is also observed that the power allocated by the FTT scheme resembles the optimal offline solution with high probability, despite the lack of information about future channel states and energy arrivals.This work was supported in part by the Scientific and Technological Research Council of Turkey, TUBITAK, under Grant 112E059 and by British Council Institutional Links Program under Grant 173605884. The associate editor coordinating the review of this letter and approving it for publication was K. K. Wong

Power Scheduling in Privacy Enhanced Microgrid Networks with Renewables and Storage

13th IEEE Annual Consumer Communications and Networking Conference (CCNC) (2016 : Las Vegas, NV)As many countries embark on a major transitioning to the Smart Grid (SG), realizing the benefits of the new paradigm depends on generation, collection, and usage of unprecedented amount of data. With such proliferated data processing, there are legitimate concerns that call for sound privacy measures to ensure proper safekeeping. A significant portion of the potential benefits of the SG initiative, thus, relies on devising convincing mechanisms to strengthen the privacy. As a new distribution subsystem, microgrids are expected to play a crucial role in the SG. In this paper, we develop a privacy-aware microgrid power scheduling formulation with renewable sources and energy storage where five different classes of appliances are prioritized by smart meters. Our analysis shows that there is a tradeoff between maximizing the power usage and privacy levels. Hence, it is not possible to find a solution that maximizes both objectives simultaneously. However, it is possible to achieve significantly higher levels of privacy preservation with moderate sacrifice from the power usage, especially when the number of users is high

Joint phase noise estimation and data detection in coded multi-input-multi-output systems

The problem of joint oscillator phase noise (PHN) estimation and data detection for multi-input multi-output (MIMO) systems using bit-interleaved-coded modulation is analysed. A new MIMO receiver that iterates between the estimator and the detector, based on the expectation-maximisation (EM) framework, is proposed. It is shown that at high signal-to-noise ratios, a maximum a posteriori (MAP) estimator can be used to carry out the maximisation step of the EM algorithm. Moreover, to reduce the computational complexity of the proposed EM algorithm, a soft decision-directed extended Kalman filter-smoother (EKFS) is applied instead of the MAP estimator to track the PHN parameters. The numerical results show that by combining the proposed EKFS-based approach with an iterative detector that employs low-density parity check codes, PHN can be accurately tracked. The simulations also demonstrate that compared to the existing algorithms, the proposed iterative receiver can significantly enhance the performance of MIMO systems in the presence of PHN