IEEE SmartGridComms ConferenceIEEE

The following tutorials will be given at PIMRC 2011. All tutorials will be given on September 11, 2011.

T1: Interference Management in Femtocell Networks

Presenters: Ekram Hossain, Long Bao Le
Duration: half day
The evolving femtocell networks are envisioned to provide improved capacity and coverage in next generation cellular wireless systems. A recent study estimates that by 2012, there could be around 70 million femto access points (FAPs) installed in homes or offices around the world, serving more than 150 million customers. However, femtocell deployments pose many challenges among which interference management is the most significant one. The aim of this tutorial is to provide an extensive overview of the interference management problem in femtocell networks considering both CDMA (e.g., 3G) and OFDMA (e.g., LTE, WiMAX) femtocells, and the state-of-the-art research on this topic. After a brief overview of the femtocell networks, we outline the major challenges in successful deployment of femtocells in next generation cellular wireless systems. In particular, the challenges related to co-tier and cross-tier interference management, mobility and handoff management, auto-configuration, timing and synchronization, and security are discussed. Then we provide a comprehensive overview of the different state-of-the-art techniques for interference management in femtocell networks. In this context, the interference modeling approach based on the shot-noise theory is also discussed. We consider both CDMA and OFDMA femtocells and two different approaches for these systems are described in detail. To this end, we outline several major open research issues and directions for future research on interference management and self-reconfiguration in femtocell networks.

T2: Interference Alignment : A New Look at Signal Dimensions in Interference Networks

Presenters: Syed Ali Jafar
Duration: half day
Interference is the primary bottleneck on the data rate capacity of most wireless and many wired networks. The recent emergence of the idea of interference alignment has shown that the throughput  limits of interference networks may be orders of magnitude higher than previously imagined. In a relatively short period of three years since its emergence, the idea has gained tremendous momentum in research pursued by industry as well as the academia within the network information theory, communication theory, signal processing, and network coding communities and has produced an array of surprising and fundamental insights into the number of accessible signaling dimensions in both wired and wireless communication networks. A diversity of tools from linear algebra, algebraic geometry, diophantine approximation theory as well as coding and traditional Shannon theory continue to be the basis for an increasing variety of interference alignment schemes that include spatial alignment, lattice alignment, asymptotic alignment, asymmetric complex signal alignment, opportunistic alignment, ergodic alignment, aligned interference neutralization, blind alignment and retrospective align- ment schemes. Applications include wireless interference networks, X networks, cellular networks, two- way communication networks, multicast and compound networks, multihop multiflow networks, tactical communication networks with secrecy and jamming issues, cooperative communication networks, cognitive radio networks, distributed data storage networks, index coding networks, and wired multiple unicast networks.This tutorial introduces the audience to the idea of interference alignment, traces its origins, reviews a variety of interference alignment schemes, summarizes the diverse settings where the idea of interference alignment is applicable and highlights the common principles that cut across these diverse applications.

T3: Localization and Communication - Theory, Algorithms and Benefits of Localization in Wireless Networks

Presenters Giuseppe Abreu, Giuseppe Destino, Davide Macagnano
Duration: half day
This Tutorial offers a comprehensive view of technological and theoretical aspects of localization algorithms in connection with wireless communication
networks. We start under the motivation of recent trends in wireless communications which point to an increasingly important role of location information
both as the key parameter for new applications (such as personal navigation) and as a universal token of cognitivity which can be exploited to optimize wireless communication systems. After a brief categorization the localization problem according to the two major mathematical formulation paradigms, we discuss in concrete strategies to apply location information to the advantage of efficient communications, as well as analytical tools utilized to quantify the corresponding benefits and costs.

Amongst other topics, the utilization of stochastic geometric tools in network models, novel results on the statistics of multihop distances, auctiontheoretic
location-aware relay selection mechanisms, and global network performance metrics such as transport capacity, transmit capacity and information
efficiency are covered. Having clearly established the potential benefits of the utilization of location information in wireless systems, and quantified the corresponding communication costs involved, we then turn our attention to a deep discussion of state-of-the-art and further advanced localization algorithm.
In particular, the elementary types of data that can be exploited to produce location information, namely, connectivity, spatial correlation measures,
angle information and finally, distance information are first addressed.

Next, we review the most common and best-performing class of localization methods, namely distance-based algorithms, with a particular focus on the
network localization application where devices are able to communicate with several other devices in their neighborhood (mesh topologies), such as in ad
hoc, sensor, and future cooperative networks. Several of the most important and recently proposed approaches are described in detail, including the
semidefinite and linear programming methods, gradient-based smoothed and majorized methods, as well as algebraic methods. In the sequel, the most
relevant additional issues afflicting network localization systems, such as flip-ambiguity, LOS/NLOS conditions, the lack of absolute reference, and the choice between centralized and distributed approaches, are discussed.

Finally, fundamental limits are reviewed and used to compare and assess the accuracies of the algorithms described. Through a comprehensive review of both theory and practical algorithms, and a keen eye on the interconnections between localization and communication, the tutorial addresses the subject with timely and solid review of contributions in the area of localization for and in wireless communication networks.

T4: Mobile Radio Channel Sounding, Data Analysis and Radio Channel Modelling

Presenters Robert Bultitude, Sana Salous
Duration: half day

This tutorial has the objective of outlining methods, measurement equipment, data analysis, and modelling procedures used by experts in the field to make mobile radio channel models available for use by systems engineers. The target audience is one composed of both students and practicing engineers considering the conduct of research in the field and/or systems engineers who use the results from such work and are seeking better knowledge of how information of importance to them is compiled.

The tutorial will begin with an overview by Dr. Bultitude of the basics, including the representation of radio channels as linear filters, the making of measurements to estimate radio channel impulse response functions, and applications for such results. This is to be followed by a short discussion of methods for triggering data collection and the advantages/disadvantages of each. Most of the time in the first half of the tutorial will be devoted to an outline of best practices for the analysis of channel sounding data, including: estimation and reporting of channel impulse response functions and static rms delay spreads; the selection of appropriate intervals for dynamic channel analysis; estimation of average power delay profiles and dynamic channel rms delay spreads; estimation of 1-D and 2-D frequency correlation functions and coherence bandwidths; and application of rms delay spread and coherence bandwidth results. A brief overview of more advanced research work in the area of double directional channel sounding and spatial channel modelling will then be given, with emphasis on directing participants to appropriate references for further reading. Attention will then be then turned to narrowband channel modelling for a discussion of the extraction of narrowband results from channel impulse response estimates, removal of the influence of long term fading from measured time series, and the modelling of short term fading via cumulative distribution functions for envelope fading, including the estimation of Rician K ratios, and determining goodness of fit to hypothesised model fading distributions. The first part of the tutorial will end with some observations concerning the reporting of measurement and data analysis results, and some application examples concerning the modelling of relay channels, a topic of much current new interest.

In the second part of the tutorial, Professor Salous will discuss passive and active measurement techniques using both standard test and measurement equipment such as network analysers and spectrum analysers and custom designed radio channel sounders. The discussion of passive techniques will include observations on the assessment of radio coverage for possible placement of relay stations and spectral sensing for cognitive radio. Various aspects that need to be considered to design and implement both narrowband and wideband radio channel measurement equipment will be discussed in terms of the requirements of wideband measurements for both indoor and outdoor environments. This will include consideration of: the choice of waveform (for wideband applications in particular); processing gains associated with the use of wideband sounding signals; time and frequency synchronisation; stability and phase noise of reference sources; as well as time delay window and Doppler coverage. Resolution in both time delay and Doppler shift will be related to the radar ambiguity function; a number of techniques for the calibration of sounders from back to back tests and for the calibration of antennas with single and multiple elements in anechoic environments will be described and compared. Suitable sounder architectures for probing single band as well as multiple band radio links, with both single antenna and multi-antenna sounders for use during both active and passive measurements will be discussed. The tutorial will end with the presentation of examples showing measured data from the GSM and UMTS bands as well as from higher frequencies ranging up to 6 GHz, which were recorded in indoor environments such as shopping centres, TV studios and large office buildings, as well as outdoors in both rural/semi-rural and dense urban environments.

T5: Enabling Opportunistic Spectrum Access: White Space Databases and Spectrum Sensing

Presenters: Claudio da Silva, Marina Petrova
Duration: half day
Opportunistic spectrum access (OSA) – also commonly referred to as Dynamic Spectrum Access – is a new concept that offers the potential for more efficient use of the radio spectrum and improved spectrum sharing. In OSA systems, users first identify idle or underutilized spectrum with the use of white space databases and/or spectrum sensing and then, following pre-defined rules, dynamically access the “best” frequency bands on an opportunistic and non-interfering basis. This tutorial gives an introduction to both enabling techniques supporting OSA, namely white space databases and spectrum sensing.

The first part of the tutorial is dedicated to OSA systems based on white space databases. In these systems, OSA devices access through the Internet a database containing data on protected services and obtain the channels that may be used at their locations. Such an approach was adopted in the U.S. for the opportunistic access of the TV bands. Spectrum sensing, a technique that according to the FCC “holds promise to further improvements in spectrum efficiency in the TV spectrum in the future and will be a vital tool for providing opportunistic access to other spectrum bands” is covered in the second part of the tutorial. We present in this tutorial the major efforts and trends in the development of these two techniques, as well as identify and discuss their main design and implementation challenges and open research problems. Relevant regulatory and standardization efforts will also be discussed.







home   about   committee   call for papers   submission   registration   program   hotel&travel   nondiscrimination policy             © 2010 IEEE Communications Society

Register now