Power Efficient Communication Research Articles

Design of a passive CMOS implantable continuous monitoring biosensors transponder front-end

This paper presents the design of an implantable passive transponder front-end that can power implantable biosensors and also provide a power-efficient communication means for it with an extracorporeal reader, enabling continuous real-time monitoring of internal body parameters. The implantable passive transponder front-end is composed of power management circuity, demodulator, oscillator, and load-shift keying modulator. To control and power the implantable biosensors we used a 13.56 MHz Pulse Width Modulated signal. A stable DC voltage, data and clock are extracted from this modulated signal. The proposed transponder was designed, simulated and layout in a 40-nm 1P9M TSMC's CMOS technology. The simulation shows that the proposed implantable passive transponder front-end has a total average power consumption of 17.14 μW, with receiving data rate of 142.85 kB/s and transmitting data rate of 50 kB/s.

Optimal 3D-Trajectory Design and Resource Allocation for Solar-Powered UAV Communication Systems

In this paper, we investigate the resource allocation algorithm design for multicarrier solar-powered unmanned aerial vehicle (UAV) communication systems. In particular, the UAV is powered by the solar energy enabling sustainable communication services to multiple ground users. We study the joint design of the 3D aerial trajectory and the wireless resource allocation for maximization of the system sum throughput over a given time period. As a performance benchmark, we first consider an off-line resource allocation design assuming non-causal knowledge of the channel gains. The algorithm design is formulated as a mixed-integer non-convex optimization problem taking into account the aerodynamic power consumption, solar energy harvesting, a finite energy storage capacity, and the quality-of-service requirements of the users. Despite the non-convexity of the optimization problem, we solve it optimally by applying monotonic optimization to obtain the optimal 3D-trajectory and the optimal power and subcarrier allocation policy. Subsequently, we focus on the online algorithm design that only requires real-time and statistical knowledge of the channel gains. The optimal online resource allocation algorithm is motivated by the off-line scheme and entails a high computational complexity. Hence, we also propose a low-complexity iterative suboptimal online scheme based on the successive convex approximation. Our simulation results reveal that both the proposed online schemes closely approach the performance of the benchmark off-line scheme and substantially outperform two baseline schemes. Furthermore, our results unveil the tradeoff between solar energy harvesting and power-efficient communication. In particular, the solar-powered UAV first climbs up to a high altitude to harvest a sufficient amount of solar energy and then descends again to a lower altitude to reduce the path loss of the communication links to the users it serves.

Low-Cost and Secure Communication System for SCADA System of Remote Microgrids

Renewable energy-based local microgrids are gaining popularity despite the unavailability of low-cost, power efficient, and secure communication system for its supervisory control and data acquisition (SCADA) system. This research has been carried out to address this issue along with the additional features such as data uploading to a server through a gateway, local data logging, and alerting the concerned crew in case of any fault to minimize the outage time. This paper presents the design of a communication system for the SCADA system of microgrid. ESP32 with LoRa has been used for communication between two nodes or a node and central SCADA unit. Communication security has been achieved by implementing AES cryptography. Data authenticity has been achieved by introducing a unique message authentication code (MAC) for each message. A mesh-like network has been implemented to improve the LoRa range. ESP32 and dragino-uno based LoRa gateways have been tried for uploading the data to the server, and local data storage has been achieved using an SD card. The main controller working as the SCADA unit has the feature of sending emails. Detailed system design and test results are presented in this paper.

OMUX: Optical Multicast and Unicast-capable interconnection network for data centers

Exponential growth of traffic and bandwidth demands in current data center networks requires low-latency high-throughput interconnection networks, considering power consumption. By considering growth of both multicast and unicast applications, power efficient communication becomes one of the main design challenges in today's data center networks. Addressing these demands, optical networks suggest several benefits as well as circumventing most disadvantages of electrical networks. In this paper, we propose an all-optical scalable architecture, named as OMUX, for communicating intra-data centers. This architecture utilizes passive optical devices and enables optical circuit switching without any switch configuration or path reservation. In addition, it is customized for both unicast and multicast transmissions. It can replace aggregation and core switches in the network, to reduce power consumptions. Simulation results verify its lower latency, higher throughput, and reduced power consumption, compared to conventional electrical or alternative optical solutions.

Hybrid DCO-OFDM, ACO-OFDM and PAM-DMT for dimmable LiFi

This paper proposes a hybrid orthogonal frequency division multiplexing (OFDM) modulation termed as hybrid DC-biased asymmetrically-clipped pulse-amplitude-modulated OFDM (HDAP-OFDM) for providing power efficient communication and dimming control for light fidelity (LiFi) schemes. The proposed HDAP-OFDM is a combination of three OFDM formats: DC-biased optical OFDM (DCO-OFDM), asymmetrically clipped optical OFDM (ACO-OFDM) and pulse amplitude modulated discrete multitone (PAM-DMT). In HDAP-OFDM, the lower-index subcarriers carry DCO-OFDM, while the remaining higher subcarriers carry ACO-OFDM on the odd-index subcarriers and PAM-DMT on the even-index subcarriers. Mathematical analysis shows that the required DC bias for HDAP-OFDM is a function of the required dimming levels and the root mean square of the three of its components. Furthermore, an algorithm is presented to simulate the dimming control of HDAP-OFDM. Simulations results indicate that by adjusting the proportion of subcarriers for the three OFDM/DMT elements, HDAP-OFDM can have a wide dimming range, a low peak to average power ratio, and high power efficiency. Results also show that at a bit error rate of 10−3 and a dimming range of 3%–97%, HDAP-OFDM exhibits 8 dB more optical and electrical power efficiency than existing asymmetrical hybrid optical OFDM.

Optimal hops for minimal route power under SINR constraints in wireless sensor networks

This study attempts to deduce the optimal hops in a multi-hop wireless sensor network (WSN) ensuring power-efficient communication under signal-to-interference noise ratio (SINR) constraints. The authors model the total route power consumption under wireless channel quality constraints. WSNs usually employ a multiple-source, single-sink structure for information transfer, necessitating data aggregation. The authors calculate optimal hops for three different data aggregation schemes. They further propose a robust hybrid data aggregation strategy that demonstrates an improved performance with respect to minimal power consumption when compared with employing individual data aggregation schemes. The data aggregation scheme employing optimal hops has been implemented and results have been verified for an illustrative application in water supply and drainage monitoring system. The authors have formulated the problem as a standard convex optimisation problem. They employ Karush-Kuhn-Tucker optimality conditions to derive the analytical expressions of the globally optimal hops, which incorporate the influence of route power, receiver noise, and SINR thresholds. The transmit power and hop count are varied simultaneously until an optimised hop count is achieved. The relation between the node transmit power and the number of hops in the route is derived and the condition for feasible optimal hops is presented.

Reconfigurable on-chip communication link for efficient communication

Application specific reconfiguration of On-chip communication link is a fast growing research area in system on chip (SoC) based system design. Optimization of the communication link is important to achieve a trade-off between efficient communication and low power consumption. So achieving both efficient communication and low power consumption requires a special optimization mechanism. Such Optimization problems can be solved using a genetic algorithm. Here, in this paper genetic algorithm based On-chip communication link reconfiguration is presented. The algorithm will optimize efficiency of communication link with constrain of low power consumption. The parameters involved in power consumption and efficient communication link are coded in the chromosomes. By evolutionary iteration the optimal parameters of the communication link are derived that is used for the communication link successfully in the simulated system. The performance of the simulated system is analyzed which shows the out performance of the proposed system.

Cache-Enabled Physical Layer Security for Video Streaming in Backhaul-Limited Cellular Networks

In this paper, we propose a novel wireless caching scheme to enhance the physical layer security of video streaming in cellular networks with limited backhaul capacity. By proactively sharing video data across a subset of base stations (BSs) through both caching and backhaul loading, secure cooperative joint transmission of several BSs can be dynamically enabled in accordance with the cache status, the channel conditions, and the backhaul capacity. Assuming imperfect channel state information (CSI) at the transmitters, we formulate a two-stage non-convex mixed-integer robust optimization problem for minimizing the total transmit power while providing quality of service (QoS) and guaranteeing communication secrecy during video delivery, where the caching and the cooperative transmission policy are optimized in an offline video caching stage and an online video delivery stage, respectively. Although the formulated optimization problem turns out to be NP-hard, low-complexity polynomial-time algorithms, whose solutions are globally optimal under certain conditions, are proposed for cache training and video delivery control. Caching is shown to be beneficial as it reduces the data sharing overhead imposed on the capacity-constrained backhaul links, introduces additional secure degrees of freedom, and enables a power-efficient communication system design. Simulation results confirm that the proposed caching scheme achieves simultaneously a low secrecy outage probability and a high power efficiency. Furthermore, due to the proposed robust optimization, the performance loss caused by imperfect CSI knowledge can be significantly reduced when the cache capacity becomes large.

Evaluation of Signal Regeneration Impact on the Power Efficiency of Long-Haul DWDM Systems

Abstract Due to potential economic benefits and expected environmental impact, the power consumption issue in wired networks has become a major challenge. Furthermore, continuously increasing global Internet traffic demands high spectral efficiency values. As a result, the relationship between spectral efficiency and energy consumption of telecommunication networks has become a popular topic of academic research over the past years, where a critical parameter is power efficiency. The present research contains calculation results that can be used by optical network designers and operators as guidance for developing more power efficient communication networks if the planned system falls within the scope of this paper. The research results are presented as average aggregated traffic curves that provide more flexible data for the systems with different spectrum availability. Further investigations could be needed in order to evaluate the parameters under consideration taking into account particular spectral parameters, e.g., the entire C-band.

Proficient Car Parking System Based on Cluster Head Routing Protocol Utilizing IEEE 802.15.4

The paper discusses a proposed model for car parking system based on cluster head routing protocol utilizing a low cost and power efficient communication technology, ZigBee (IEEE 802.15.4). The model is designed in a way that car parking is divided into different clusters and each cluster has a head which acts a messenger for transmitting information to other heads and the coordinator of the network. Each cluster head is a ZigBee Host (Router) which collects the information of car presence in the parking slot. This information is then passed to the coordinator of the network which is used to display the information of available parking slots in a specific car parking area. Since there is only one coordinator in the network, so heads can transmit information to the coordinator using multi-hop communication if direct communication is not possible. Several simulations were performed to gauge the efficiency of the proposed model, and results show that the proposed model is reliable in communication and efficient in its operation.

Underwater acoustic communication using orthogonal signal division multiplexing scheme with time diversity

In this paper, an underwater acoustic (UWA) communication scheme for mobile platforms is proposed. The proposed scheme is based on the orthogonal signal division multiplexing (OSDM) scheme, which offers highly reliable UWA communication. However, OSDM is not suitable for mobile platforms as it is — it requires a receiver array and a large calculation cost for equalization. To establish a reliable link with small communication platforms, we design OSDM that can perform reliable communication without the need for an array and can reduce receiver complexity using the time-diversity technique (TD), and evaluate its performance in experiments. The experimental results suggest that OSDM-TD can simultaneously achieve power-efficient communications and receiver complexity reduction, and can realize small-scale communication platforms. In detail, OSDM-TD achieved almost the same communication quality as conventional OSDM, in exchange for an effective data rate. Moreover, the power efficiency of OSDM-TD was almost the same as that of conventional OSDM with two receiver array elements, although the calculation cost of OSDM-TD was far below that of conventional OSDM. As a result, it was found that OSDM-TD is suitable for UWA communication for mobile nodes whose capacity and computational resources are severely limited.

Power Efficient Communication for Joint Detection Receivers in Rician Channels

In a multipoint to point link, where multiple streams from geographically separated points co-existing in time and frequency are jointly detected, the relative powers at which the signals are received play an important role in deciding the sum rate. Unlike Rayleigh fading, where decreasing the power of any of the streams will result only in decrease in the sum rate, Rician fading exhibits an interesting behavior where one can actually improve the sum rate by decreasing the power of one or more of the transmitted streams. This gives rise to the possibility of power efficient communications under Rician channel conditions. In this paper, the authors discuss a power control scheme where the receiver, based on the present received powers and k-factor, feeds back the optimal powers to be transmitted so that the total transmitted power is minimized without any loss in the sum rate. It can be shown that by employing such a power control scheme, considerable amount of power can be saved on the transmit side, paving way to greener communications, for LoS or near LoS links.

Scaling hierarchical clustering and energy aware routing for sensor networks

Abstract Energy efficiency in wireless sensor networks (WSNs) is of a primary concern due to the limited energy capacity of sensor nodes. Since most power dissipation occurs in wireless communication, it becomes imperative to reduce the energy costs of communication by developing power efficient communication protocols. To that end, this paper presents scaling hierarchical power efficient clustering with energy aware routing (SHEAR), which offers a clustering based scalable topology control coupled with an energy aware path selection scheme. By selecting cluster heads based on the maximum local residual energy of neighboring nodes, the topology control of SHEAR distributes energy dissipation evenly among all clusters. Additionally, routes for packet flows are allocated such that the aggregate energy consumption along a chosen path is minimized while avoiding the nodes with low energy levels. Simulation results demonstrate the effectiveness of SHEAR in attaining reasonably long-lived WSNs.

Distributed resource allocation in ultra-dense networks via belief propagation

Ultra-dense networking is widely accepted as a promising enabling technology to realize high power and spectrum efficient communications in future 5G communication systems. Although joint resource allocation schemes promise huge performance improvement at the cost of cooperation among base stations, the large numbers of user equipment and base station make jointly optimizing the available resource very challenging and even prohibitive. How to decompose the resource allocation problem is a critical issue. In this paper, we exploit factor graphs to design a distributed resource allocation algorithm for ultra dense networks, which consists of power allocation, subcarrier allocation and cell association. The proposed factor graph based distributed algorithm can decompose the joint optimization problem of resource allocation into a series of low complexity subproblems with much lower dimensionality, and the original optimization problem can be efficiently solved via solving these subproblems iteratively. In addition, based on the proposed algorithm the amounts of exchanging information overhead between the resulting subprob-lems are also reduced. The proposed distributed algorithm can be understood as solving largely dimensional optimization problem in a soft manner, which is much preferred in practical scenarios. Finally,the performance of the proposed low complexity distributed algorithm is evaluated by several numerical results.

Optical Multilevel Signaling for High Bandwidth and Power-Efficient On-Chip Interconnects

The scalability of high-performance computing systems is increasingly dependent on high-bandwidth and power-efficient communication between a growing number of processing cores on- and off-chip. Recent developments in silicon photonics technology can potentially alleviate many of the challenges associated with these stringent interconnection demands. In this letter, we propose the use of an optical multilevel signaling technique for on-chip interconnects in conjunction with wavelength division multiplexing to double the aggregate communication bandwidth without increasing the number of waveguides and wavelengths used, thereby reducing scaling costs.

Iterative Quantum-Assisted Multi-User Detection for Multi-Carrier Interleave Division Multiple Access Systems

With the proliferation of smart-phones and tablet PCs, the data rates of wireless communications have been soaring. Hence, the need for power-efficient communications relying on low-complexity multiple-stream detectors has become more pressing than ever. As a remedy, in this paper we design low-complexity soft-input soft-output quantum-assisted multi-user detectors (QMUD), which may be conveniently incorporated into state-of-the-art iterative receivers. Our design relies on extrinsic information transfer charts. Our QMUDs are then employed in multi-carrier interleave-division multiple-access (MC-IDMA) systems, which are investigated in the context of different channel code rate and spreading factor pairs, whilst fixing the total bandwidth requirement. One of our QMUDs is found to operate within 0.5 dB of the classical maximum a posteriori probability MUD after three iterations between the MUD and the decoders, while requiring only half its complexity, at a BER of $10^{-5}$ in the uplink of a rank-deficient MC-IDMA system relying on realistic imperfect channel estimation at the receiver, while supporting 14 users transmitting QPSK symbols.

Transmission of intra-cellular genetic information: A system proposal

One of the great challenges of the scientific community on theories of genetic information, genetic communication and genetic coding is to determine a mathematical structure related to DNA sequences. In this paper we propose a model of an intra-cellular transmission system of genetic information similar to a model of a power and bandwidth efficient digital communication system in order to identify a mathematical structure in DNA sequences where such sequences are biologically relevant. The model of a transmission system of genetic information is concerned with the identification, reproduction and mathematical classification of the nucleotide sequence of single stranded DNA by the genetic encoder. Hence, a genetic encoder is devised where labelings and cyclic codes are established. The establishment of the algebraic structure of the corresponding codes alphabets, mappings, labelings, primitive polynomials (p(x)) and code generator polynomials (g(x)) are quite important in characterizing error-correcting codes subclasses of G-linear codes. These latter codes are useful for the identification, reproduction and mathematical classification of DNA sequences. The characterization of this model may contribute to the development of a methodology that can be applied in mutational analysis and polymorphisms, production of new drugs and genetic improvement, among other things, resulting in the reduction of time and laboratory costs.

Wearable Antenna for Power Efficient On-Body and Off-Body Communications

A novel dual-band and diverse radiation pattern antenna is proposed for power efficient on-body and off-body communications intended for various applications in healthcare and sport monitoring. The antenna is dual band at 2.45 GHz (ISM band) with omnidirectional radiation pattern over the body surface to communicate power efficiently with other co-located body worn devices and at 1.9 GHz (PCS band), it has directive radiation pattern towards off the body to communicate from on-body device to off-body devices. The free space and on-body performances of the antenna are investigated by both simulation and experiment. The antenna shows very good on-body radiation efficiency of 58% at 2.45 GHz and 61% at 1.9 GHz. Good on-body gain is noticed at both frequency bands. Results show that the gain of the proposed antenna increases by 4.7% at 2.45 GHz and 3.2% at 1.9 GHz when placed on the body.

Power Efficient Group Communication in Small Cell Networks

Small Cell Networks (SCNs) constitute a new promising way for increasing coverage, boosting data rates and lowering capital and operating expenditures (CAPEX and OPEX) of today's mobile networks. In this paper, we deal with the problem of efficient power control in SCNs. We propose and evaluate an efficient power control mechanism for SCNs, which efficiently controls the available power resources of the network, while on the other hand guarantees home users’ Quality of Service. We introduce the methodology of Priority Grouping, in which home users in the topology, are assigned to one of a number of predefined groups, with different priorities, in terms of traffic requirements. Furthermore, the mechanism dynamically updates the power setting of home base stations, based on the topology of the macro and home users in real time.

Spatial Modulation for Generalized MIMO: Challenges, Opportunities, and Implementation

A key challenge of future mobile communication research is to strike an attractive compromise between wireless network's area spectral efficiency and energy efficiency. This necessitates a clean-slate approach to wireless system design, embracing the rich body of existing knowledge, especially on multiple-input-multiple-ouput (MIMO) technologies. This motivates the proposal of an emerging wireless communications concept conceived for single-radio-frequency (RF) large-scale MIMO communications, which is termed as SM. The concept of SM has established itself as a beneficial transmission paradigm, subsuming numerous members of the MIMO system family. The research of SM has reached sufficient maturity to motivate its comparison to state-of-the-art MIMO communications, as well as to inspire its application to other emerging wireless systems such as relay-aided, cooperative, small-cell, optical wireless, and power-efficient communications. Furthermore, it has received sufficient research attention to be implemented in testbeds, and it holds the promise of stimulating further vigorous interdisciplinary research in the years to come. This tutorial paper is intended to offer a comprehensive state-of-the-art survey on SM-MIMO research, to provide a critical appraisal of its potential advantages, and to promote the discussion of its beneficial application areas and their research challenges leading to the analysis of the technological issues associated with the implementation of SM-MIMO. The paper is concluded with the description of the world's first experimental activities in this vibrant research field.