The smart grid is conceived of as an electric grid that can deliver electricity in a controlled, smart way from points of generation to active consumers. Demand response (DR), by promoting the interaction and responsiveness of the customers, may offer a broad range of potential benefits on system operation and expansion and on market efficiency. Moreover, by improving the reliability of the power system and, in the long term, lowering peak demand, DR reduces overall plant and capital cost investments and postpones the need for network upgrades. In this paper a survey of DR potentials and benefits in smart grids is presented. Innovative enabling technologies and systems, such as smart meters, energy controllers, communication systems, decisive to facilitate the coordination of efficiency and DR in a smart grid, are described and discussed with reference to real industrial case studies and research projects.

Demand response and smart grids—A survey

This document provides updates to IEEE Std 802.16's MIB for the MAC, PHY and asso- ciated management procedures in order to accommodate recent extensions to the standard.

IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems Draft Amendment: Management Information Base Extensions

With the explosive growth of mobile data demand, the fifth generation (5G) mobile network would exploit the enormous amount of spectrum in the millimeter wave (mmWave) bands to greatly increase communication capacity. There are fundamental differences between mmWave communications and existing other communication systems, in terms of high propagation loss, directivity, and sensitivity to blockage. These characteristics of mmWave communications pose several challenges to fully exploit the potential of mmWave communications, including integrated circuits and system design, interference management, spatial reuse, anti-blockage, and dynamics control. To address these challenges, we carry out a survey of existing solutions and standards, and propose design guidelines in architectures and protocols for mmWave communications. We also discuss the potential applications of mmWave communications in the 5G network, including the small cell access, the cellular access, and the wireless backhaul. Finally, we discuss relevant open research issues including the new physical layer technology, software-defined network architecture, measurements of network state information, efficient control mechanisms, and heterogeneous networking, which should be further investigated to facilitate the deployment of mmWave communication systems in the future 5G networks.

A survey of millimeter wave communications (mmWave) for 5G: opportunities and challenges

Cognitive radio (CR) is the enabling technology for supporting dynamic spectrum access: the policy that addresses the spectrum scarcity problem that is encountered in many countries. Thus, CR is widely regarded as one of the most promising technologies for future wireless communications. To make radios and wireless networks truly cognitive, however, is by no means a simple task, and it requires collaborative effort from various research communities, including communications theory, networking engineering, signal processing, game theory, software-hardware joint design, and reconfigurable antenna and radio-frequency design. In this paper, we provide a systematic overview on CR networking and communications by looking at the key functions of the physical (PHY), medium access control (MAC), and network layers involved in a CR design and how these layers are crossly related. In particular, for the PHY layer, we will address signal processing techniques for spectrum sensing, cooperative spectrum sensing, and transceiver design for cognitive spectrum access. For the MAC layer, we review sensing scheduling schemes, sensing-access tradeoff design, spectrum-aware access MAC, and CR MAC protocols. In the network layer, cognitive radio network (CRN) tomography, spectrum-aware routing, and quality-of-service (QoS) control will be addressed. Emerging CRNs that are actively developed by various standardization committees and spectrum-sharing economics will also be reviewed. Finally, we point out several open questions and challenges that are related to the CRN design.

Cognitive radio networking and communications: an overview

Millimeter wave (mmWave) communications have recently attracted large research interest, since the huge available bandwidth can potentially lead to the rates of multiple gigabit per second per user Though mmWave can be readily used in stationary scenarios, such as indoor hotspots or backhaul, it is challenging to use mmWave in mobile networks, where the transmitting/receiving nodes may be moving, channels may have a complicated structure, and the coordination among multiple nodes is difficult To fully exploit the high potential rates of mmWave in mobile networks, lots of technical problems must be addressed This paper presents a comprehensive survey of mmWave communications for future mobile networks (5G and beyond) We first summarize the recent channel measurement campaigns and modeling results Then, we discuss in detail recent progresses in multiple input multiple output transceiver design for mmWave communications After that, we provide an overview of the solution for multiple access and backhauling, followed by the analysis of coverage and connectivity Finally, the progresses in the standardization and deployment of mmWave for mobile networks are discussed

Millimeter Wave Communications for Future Mobile Networks

For the coexistence management between primary and secondary users in TV white space, a simple propagation model for short range transmission and low antenna height is needed to define the secondary user service area, which can estimate an area with the interference risk to primary user. For calculating the area, the measurement of building penetration losses has been conducted at UHF band, and the propagation model based on free space loss with the penetration loss is proposed.

Propagation model based on building penetration loss measurement in UHF band

A low spurious SiGe-MMIC direct conversion transceiver using 2fLO LO switching configuration for cognitive radio is described. In the proposed configuration, LO signals for Tx and Rx blocks are generated by frequency divider behind switching circuits. By applying this configuration to the transceiver, the offset frequency of maximum Tx spurious in FDD mode is doubled compared to the conventional configuration. Also, theoretical analysis shows that the proposed configuration can lower LO signal spurious level by 12 dB. Through these effects, receiver sensitivity degradation by Tx signal can be avoided and required characteristics of Tx BPF is relaxed. The direct conversion transceiver MMIC using 2fLO LO switching configuration is fabricated in 0.18 mum SiGe-BiCMOS process. Measured results show a high modulation accuracy over 400 M-6 GHz, and low Tx spurious characteristics.

A low spurious 400M–6GHz SiGe-MMIC Direct Conversion Transceiver using 2ƒ LO LO switching configuration for cognitive radio

Calculating current distributions along conducting straight wires reveals that the electric influence of the wires is more effectively reduced by loading reactances than it is by disconnecting the loading ports. With the electric influence almost eliminated, a sheet consisting of reactively loaded straight wires can almost perfectly transmit a radio wave of a frequency determined by the interval between the loading ports and the reactance value. The frequency responses of radio wave transmissions for a normal incident plane wave are numerically calculated, and it is shown that by controlling the reactance value, the transmission can be changed more than 30 dB. Thus, a sheet by which radio wave transmission can be electronically controlled is proposed, and its operation is experimentally examined.

Periodically Loaded Straight Wires for Radio Wave Transmission Control

Frequency shift keying (FSK) is a widely-used transmission scheme for Internet of things (IoT) due to the merits of simple implementation and low power consumption. To expand IoT systems, higher data rate is expected for massive IoT or new IoT application scenarios. In this paper, a novel design of a data rate enhancement is proposed for IEEE 802.15.4 based 2-FSK transmission scheme while satisfying the regulations of spectrum usage by ARIB STD-T108 in Japan. Computer simulation and experiments with software-defined receiver (SDR) are conducted progressively to evaluate the performance of FSK with enhanced data rate parameters. Moreover, a prototype of integrated circuit (IC) is developed and experiments with ICs are conducted to demonstrate the effectiveness of the proposed scheme. Evaluation results show that the proposed scheme enhances the data rate to 600 kbps with a required input power increase of 7.0 dB in comparison with the conventional data rate of 100 kbps. Also, the effects of adopting IC are analyzed by contrast experiments.

Data Rate Enhancement for IEEE 802.15.4 Based FSK Transmission Scheme

The multi-Gbps wireless personal area network (WPAN) operating at 60-GHz is being standardized in the task group of IEEE 802.15.3c. To deal with the multi-path delay spread in non-line-of-sight (NLOS) environments, single-carrier frequency-domain equalization (SC-FDE), a.k.a., single-carrier block transmission (SCBT), is used in the physical (PHY) layer design. The low-density parity-check (LDPC) coding is considered as the high-performance channel coding scheme due to its good tradeoff between performance and complexity. A series of structured LDPC designs with very short codeword length of 576 are being adopted in one of the major proposals for IEEE 802.15.3c. The short codeword length helps to reduce the decoding complexity of LDPC. We evaluated the 576- length structured LDPC codes in SC-FDE system and found they have very good fixed point decoding performance. They are very promising in supporting ultra high-data-rate transmission with low complexity in 60-GHz WPAN (IEEE 802.15.3c).

Hiroshi Harada

Papers

Propagation model based on building penetration loss measurement in UHF band

A low spurious 400M–6GHz SiGe-MMIC Direct Conversion Transceiver using 2ƒ LO LO switching configuration for cognitive radio

Periodically Loaded Straight Wires for Radio Wave Transmission Control

Data Rate Enhancement for IEEE 802.15.4 Based FSK Transmission Scheme

Fixed Point Decoding Performance of Short-Length Structured LDPC Codes for SC-FDE Based 60-GHz WPAN (IEEE 802.15.3c)