It is now well known that employing channel adaptive signaling in wireless communication systems can yield large improvements in almost any performance metric. Unfortunately, many kinds of channel adaptive techniques have been deemed impractical in the past because of the problem of obtaining channel knowledge at the transmitter. The transmitter in many systems (such as those using frequency division duplexing) can not leverage techniques such as training to obtain channel state information. Over the last few years, research has repeatedly shown that allowing the receiver to send a small number of information bits about the channel conditions to the transmitter can allow near optimal channel adaptation. These practical systems, which are commonly referred to as limited or finite-rate feedback systems, supply benefits nearly identical to unrealizable perfect transmitter channel knowledge systems when they are judiciously designed. In this tutorial, we provide a broad look at the field of limited feedback wireless communications. We review work in systems using various combinations of single antenna, multiple antenna, narrowband, broadband, single-user, and multiuser technology. We also provide a synopsis of the role of limited feedback in the standardization of next generation wireless systems.

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An overview of limited feedback in wireless communication systems

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

The exponential growth and availability of data in all forms is the main booster to the continuing evolution in the communications industry. The popularization of traffic-intensive applications including high definition video, 3-D visualization, augmented reality, wearable devices, and cloud computing defines a new era of mobile communications. The immense amount of traffic generated by today’s customers requires a paradigm shift in all aspects of mobile networks. Ultradense network (UDN) is one of the leading ideas in this racetrack. In UDNs, the access nodes and/or the number of communication links per unit area are densified. In this paper, we provide a survey-style introduction to dense small cell networks. Moreover, we summarize and compare some of the recent achievements and research findings. We discuss the modeling techniques and the performance metrics widely used to model problems in UDN. Also, we present the enabling technologies for network densification in order to understand the state-of-the-art. We consider many research directions in this survey, namely, user association, interference management, energy efficiency, spectrum sharing, resource management, scheduling, backhauling, propagation modeling, and the economics of UDN deployment. Finally, we discuss the challenges and open problems to the researchers in the field or newcomers who aim to conduct research in this interesting and active area of research.

Ultra-Dense Networks: A Survey

As the deployment and commercial operation of 4G systems are speeding up, technologists worldwide have begun searching for next generation wireless solutions to meet the anticipated demands in the 2020 era given the explosive growth of mobile Internet. This article presents our perspective of the 5G technologies with two major themes: green and soft. By rethinking the Shannon theorem and traditional cell-centric design, network capacity can be significantly increased while network power consumption is decreased. The feasibility of the combination of green and soft is investigated through five interconnected areas of research: energy efficiency and spectral efficiency co-design, no more cells, rethinking signaling/control, invisible base stations, and full duplex radio.

Toward green and soft: a 5G perspective

A wireless telecommunication system comprises base stations for communicating with terminal devices. One or more base stations support a power boost operating mode in which a base station's available transmission power is concentrated in a subset of its available transmission resources to provide enhanced transmission powers as compared to transmission powers on these transmission resources when the base station is not operating in the power boost mode. A base station establishes an extent to which one or more base stations in the wireless telecommunications system support the power boost operating mode conveys an indication of this to a terminal device. The terminal device receives the indication and uses the corresponding information to control its acquisition of a base station of the wireless telecommunication system, for example by taking account of which base stations support power boosting and/or when power boosting is supported during a cell attach procedure.

Telecommunications apparatus and methods

An apparatus and method provide MAC logic enabling the use of two or more reverse link rate controls at the same time in one or more sectors of a radio base station. That enables the base station to control reverse link loading via reverse link rate control, while assigning mobile stations to the type of reverse link rate control best suited to their needs. For example, the base station MAC logic may implement both a common rate controller that generates per-sector rate control commands, and a dedicated rate controller that generates per-user rate control commands and assign mobile stations having relatively lax reverse link service needs to the common rate controller, while assigning mobile stations having more demanding reverse link service requirements to the dedicated rate control. More than two rate controls can be implemented, and exemplary choices include per-user, per-sector, per-group, and scheduled rate control in any combination.

Generalized rate control for a wireless communications network

Embodiments of an enhanced Node B (eNB) and method to provide system information (SI) updates to user equipment (UE) in sleep or idle mode with an extending paging cycle are generally described herein. In some embodiments, a paging message configured to include an optional field to indicate whether there has been a system information (SI) update since a last paging occasion for a UE in sleep or idle mode with an extending paging cycle. System information updates are transmitted by the eNB during a system information modification period that is shorter than a period the extending paging cycle. The optional field may indicate whether or not the UE is to acquire the latest SI update during the current paging occasion.

Enhanced node b and methods for providing system information updates to user equipment with extended paging cycles

Machine-to-machine (M2M) communication has received increasing attention in recent year. An M2M network exhibits some salient features such as large number of machines/devices, low data rates, delay tolerant/sensitive, small packets, energy constrained and low or no mobility. A large number of M2M terminals may exist in a small area with many trying to simultaneously and randomly access for channel resources, which will result in overload and access problem. This increased signalling overhead and diverse requirements of machine-type communication (MTC) devices call for the development of flexible and efficient scheduling and random access techniques. In an M2M scenario, where the network is operating at high offered load with a large number of contending transmitters, distributed random access techniques are more appropriate than centralised scheduling techniques because of less control messages and better channel utilisation. There is a need for comparison of various medium access methods that can be used in the development of an efficient hybrid M2M and human to human network. In this article, we review and compare various scheduling and random access techniques in cellular networks, particularly in Long-Term Evolution. We also discuss how successful they are to fulfill the unique requirements of M2M communication and networking. Resource management in M2M networks with a large number of MTC devices is also discussed from the access point of view. Energy efficiency, being one of the main challenges of quality-of-service-constrained M2M communication, is also discussed. Minimisation of the energy consumption is tightly bound to channel access and hence considered in the comparison of various medium access control protocols. Finally, some potential research directions related to access control and resource allocation are presented for future work. Copyright © 2014 John Wiley & Sons, Ltd.

Medium access control techniques in M2M communication: survey and critical review

Systems and methods are disclosed for communicating enhanced user equipment (UE) assistance information between nodes in wireless communication systems. The UE achieves power savings and latency requirements more effectively by communicating its preferences, constraints and/or requirements to an evolved Node B (eNodeB) in the form of UE assistance information. The UE assistance information may include, for example, an indication of a preferred set of discontinuous reception (DRX) settings, current data traffic conditions, expected data traffic conditions, power or performance preferences, and/or an indication of the UE's mobility between cells.

Systems and methods for enhanced user equipment assistance information in wireless communication systems

As future Machine-to-Machine (M2M) communications aim at supporting wireless networks with large coverage range and a huge number of devices without human intervention, energy-efficient protocol design for M2M communications networks becomes notably significant. The emerging energy harvesting technology, allowing devices to harvest energy from external sources automatically without human intervention, is promisingly applied to M2M communications networks, which can therefore operate permanently. However, currently available IEEE 802.11 protocols do not consider supporting energy-harvesting devices efficiently. Our research focuses effort in enhancing IEEE 802.11 power saving mode (PSM) with widely-deployed numerous devices powered by energy-harvesting modules so as to realize an energy-efficient M2M communications network. We propose DeepSleep with the aim of improving energy-efficiency and reducing the overall outage probability, application layer loss rate and collision probability. The effectiveness of DeepSleep is demonstrated by NS-2 platform. An analytical model is provided to select DeepSleep parameters. Applying DeepSleep, an energy-harvesting device can have less energy wastage on idle listening and overhearing, and have a higher channel access priority when waking up from a relatively longer period of sleeping. In addition, the channel access fairness is considered in DeepSleep design. In addition, all devices benefit when DeepSleep and 802.11 PSM co-exist in the network, which implies DeepSleep has potential to be deployed in existing WLANs.

Rath Vannithamby

Papers

Generalized rate control for a wireless communications network

Enhanced node b and methods for providing system information updates to user equipment with extended paging cycles

Medium access control techniques in M2M communication: survey and critical review

Systems and methods for enhanced user equipment assistance information in wireless communication systems

DeepSleep: IEEE 802.11 enhancement for energy-harvesting machine-to-machine communications