Carl Wijting

Discontinuous Reception (DRX) is one of the mechanisms to reduce User Equipment (UE) power consumption in Long Term Evolution (LTE) systems. In this work, a DRX-aware power and delay optimized scheduling scheme is proposed for downlink transmission of bursty packet data traffic. The UE power consumption is minimized by reducing the time that a UE s...

With the expected increase in data traffic by multiple hundred-folds in the coming years, future networks are likely to experience large densification of small cells, with or without detailed network planning, in order to increase the network capacity. The biggest challenge this densification brings along is very high interference. Thus there is an...

Third generation mobile communication systems are currently being developed. The use of DS-CDMA in these systems leads to a multiple access interference limited system. Due to cross-correlation between the codes used for spreading the system performance is degraded. Multiuser detection techniques have been developed to limit the impact of this inte...

Unlocking the true potential of massive antenna arrays for cellular networks operating in frequency division duplex (FDD) mode is a challenging task as inadequate channel state information (CSI) by conventional limited-size UE feedback forces crude beamforming in downlink. This paper develops a new technique for the CSI acquisition problem of FDD m...

METIS is the EU flagship project with the purpose of developing a 5G system concept that meets the requirements of the beyond-2020 connected information society and emerging applications. Within METIS project, horizontal topics (HTs) are used to build the overall system concept. Direct Device-to-Device (D2D) communication is one of the HTs and rega...

This paper studies the design of a linear precoder and receiver for the downlink of multi-user multiple-input multiple-output (MIMO) systems with imperfect channel state information (CSI). First, we modify the regularized block diagonalization scheme for the case of imperfect CSI, where we assume the variance of the channel estimation error is know...

This paper considers low-complexity multi-user scheduling algorithms for multi-carrier multiple-input multiple-output systems. With large number of active users and transmit antennas, the optimal scheduler is computationally too demanding, therefore more efficient sub-optimal schedulers are of interest. We propose genetic and greedy-based iterative...

With the expected increase in data traffic by multiple hundredfolds in the coming years, future networks will experience more and more deployment of small cells with or without detailed network planning to increase the network capacity. Networks populated with such dense clusters of small cells will likely encounter very high interference. Thus the...

Machine-to-Machine communications has emerged to provide autonomic communications for wide variety of intelligent services and applications. Among various communication technologies, cellular-based systems have gained more attention as the backhaul networks due to ubiquitous coverage and mobility support. The different service requirements as well...

This paper studies the optimization of a dual-hop multi-input single-output (MISO) link with a full-duplex multi-input multi-output (MIMO) relay connecting the end nodes based on the amplify-and-forward or decode-and-forward protocol. The direct end-to-end link is considered weak, hence interpreted as interference by the dual-hop relay link. We obs...

We consider the use of received signal strength based radio fingerprints for energy efficient inter-frequency small cell discovery. The fingerprint data is optimized by removing redundant information and sent to the mobile station by the network on entering a cell for the first time within a specified time period. The fingerprint data is further us...

In this paper we consider the use of an energy efficient, mobility state based flexible scanning mechanism for the discovery of small cells deployed in a different carrier. The evaluated scheme considers the mobility state of the mobile terminal in a heterogeneous network scenario for determining the inter-frequency scanning rate and suspends inter...

The reforms in spectrum management aim toward more efficient, flexible, and shared use of spectrum, while fostering innovation and competition in mobile communications. The goal is to have affordable wireless broadband and make Internet access a human right. To achieve this goal, the regulators need to identify, evaluate, and decide between the dif...

Heterogeneous Network deployments are one of the key enablers in providing ubiquitous coverage and capacity enhancements for satisfying high data rate and Quality of Service requirements for LTE-Advanced networks. In this paper we propose an energy efficient small cell discovery mechanism for heterogeneous networks by means of flexible inter-freque...

We consider the use of received signal strength based radio fingerprints to discover small cells in heterogeneous networks, deployed in a different carrier frequency as compared to a macro-cell network. We propose using a flexible fingerprint matching region around fingerprint reference locations in order to provide energy efficient small-cell disc...

Heterogeneous network, or HetNet, deployments are one of the key enablers in providing ubiquitous coverage and capacity enhancements for LTE-Advanced networks. They play an important role in achieving high data rate and quality of service requirements defined for next generation wireless networks. In this article we evaluate various cell discovery...

In this paper, we construct a practical framework for efficiently allocating long term evolution (LTE) resource blocks (RB) among the users in a device-to-device (D2D) network. For such network that presumably operates under the LTE cellular network, our aim is to improve the overall throughput of D2D connections using opportunistic or fairness-bas...

In heterogeneous cellular scenarios with macrocells, femtocells or picocells users may suffer from significant co-channel cross-tier interference. To manage this interference 3GPP introduced almost blank subframe (ABSF), a subframe in which the interferer tier is not allowed to transmit data. Vulnerable users thus get a chance to be scheduled in AB...

Disclosed herein is a method comprising detecting, by a relay node in a wireless network, an inner automatic repeat request (ARQ) error on a local link of the wireless network, and sending, in response to the detecting, an outer ARQ status report identifying one or more packets that were not successfully received, the outer ARQ status report includ...

The demand for spectrum is growing rapidly as data intensive mobile communications and high-definition television are getting more popular. The spectrum regulators are preparing for flexible spectrum use and the implementation of new technologies. To make the appropriate decisions, the regulators need to identify and evaluate the different alternat...

Mobile broadband data usage in Long Term Evolution (LTE) networks is growing exponentially and capacity constraint is becoming an issue. Heterogeneous network, WiFi offload, and acquisition of additional radio spectrum can be used to address this capacity constraint. Licensed spectrum, however, is limited and can be costly to obtain. This paper inv...

Cognitive radio provides an opportunity for more efficient use of spectrum and features that improve and increase services in mobile business. This paper analyzes the economic impact of cognitive radio with a three-player oligopoly model. The three players represent the three markets of the industry: devices, connectivity and services. We examine h...

Cognitive radio will bring changes to the mobile wireless business ecosystem and value creation in it. This paper introduces two ways to estimate the value of cognitive radio for society on a high level, resulting in values of the order of 100 billion euro annually, like 120 B euro. Half of this could be consumer surplus. If the remaining 60 B euro...

Cognitive radio devices dynamically share unused sections of the radio spectrum. Under current spectrum regulations different secondary users accessing these unused sections have equal access rights, and they will interfere when operating on the same spectrum resources at the same time instance. A coexistence solution between secondary users is nee...

In this article device-to-device (D2D) communication underlaying a 3GPP LTE-Advanced cellular network is studied as an enabler of local services with limited interference impact on the primary cellular network. The approach of the study is a tight integration of D2D communication into an LTE-Advanced network. In particular, we propose mechanisms fo...

This paper presents novel spectral resource management (SRM) functionalities of WINNER ‡ The WINNER project is a major European research activity to develop a flexible and scalable radio access interface for future wireless communication systems. project. The proposed SRM spectrum architecture uses more efficient resource allocation techniques wher...

This article presented a platform for awareness networking, targeted for distribution of locally relevant control information between nodes in heterogeneous wireless environments. This concept can be leveraged in many different ways and purposes, as shown with the examples given, which range from network discovery, to functionalities required in co...

IntroductionSpectrum Technologies FrameworkDetailed Design of a Spectrum Assignment Negotiation MechanismSpectrum Assignment Enabling MechanismsWINNER Sharing with FSSPerformance Evaluation of Spectrum Assignment MechanismsConclusion AcknowledgementsReferences

WINNER is an ambitious research project aiming at identification, development, and assessment of key technologies for IMT-advanced mobile communication systems. WINNER has devised an OFDMA-based system concept with excellent system-level performance for flexible deployments in a wide variety of operating conditions. The WINNER system provides a s...

This paper investigates different functionalities that are needed in cognitive radio systems. Cognitive radio systems have the ability to observe their surrounding, become of aware of the particular needs in that surrounding and can adjust their operation to those needs. The paper presents a basic toolbox of functions that are needed to allow for b...

In this paper we present an interference aware phased scheduling strategy for a soft frequency reuse (SFR) interference coordination scheme in an Orthogonal Frequency Division Multiple Access (OFDMA) network. It groups the active user terminals (UT) in a low and high signal-to-interference plus noise ratio (SINR) group and picks UTs from both group...

The IST 6^th framework WINNER project defines spectrum sharing techniques for future wireless communication systems. This paper addresses spectrum sharing capabilities between different radio technologies. More particularly, spectrum sharing between WINNER system and the Fixed Satellite Service (FSS) community is at stake. The goal is to...

WINNER has been an ambitious research project aiming at identification and assessment of key technologies for Beyond 3G mobile systems. The WINNER mobile radio access network provides a system that is highly flexible and efficient and can provide a wide range of services to a multitude of users in many different environments. This paper provides...

Operation in multiple frequency bands simultaneously is an important enabler for future wireless communication systems. This article presents a new concept for scheduling transmissions in a wireless radio system operating in multiple frequency bands: the Multiband Scheduler (MBS). The MBS ensures that the operation in multiple bands is transparent...

This paper presents a new concept for scheduling transmissions in a wireless radio system operating at multiple frequency bands: the multi-band scheduler (MBS). The MBS ensures transparency of the operation on multiple bands for the higher network layers. Special attention is paid to achieve low delay and latency when operating the system in the mu...

In this paper we present an adaptive radio resource management scheme for relay enhanced cells based on soft resource partitioning. Power masks varying in the time or frequency domain are assigned to each radio access point (RAP). Thus, soft resource partitioning enables frequency reuse one and at the same time each RAP has high power resources wit...

This report provides the baseline assumption related to environment, deployment, system design, and algorithms for the three test scenarios "base coverage urban", "microcellular", and "indoor" in which the WINNER system is exemplified and evaluated. Associated key assessment criteria are defined. The WINNER radio interface provides a versatile...

In recent years WLAN technology has become the common wireless access technology for mobile computing. Additional to infrastructure access to WLAN networks, peer-to-peer and mesh networking are currently gaining in interest. Mesh networking techniques using WLAN are being standardized in IEEE 802.11s. This article describes use cases, the main tech...

In this paper we advocate the use of multiple base stations for providing wireless link to an OFDM-based terminal and thus obtain macro diversity, in particular site diversity. The wireless link to a terminal is defined through a subset of sub-carriers that is optimized in a greedy manner over the union of base stations. The wireless terminal is un...

Wireless Personal Area Networking (WPAN) is introduced as a new concept for next generation wireless systems. WPANs are short-range wireless systems operating in the direct surrounding of the user. A reference architecture for short-range wireless communications has been designed covering the end-to-end system design. Traditional protocol stack imp...

Short-range wireless systems have recently gained a lot of attention to provide seamless, multimedia communications around a user-centric concept in so called wireless personal area networks (WPAN). Ultra-wideband (UWB) technology presents itself as a good candidate for the physical layer (PHY) of WPAN, both for high and low data rate applications....

The general requirements for a 4G system will mainly be derived from the types of service a user will require in the future. An information transport platform must provide high-speed, large volume, good quality, global coverage and flexibility to roam. To ensure this effective global coverage, we propose to derive the benefits of mobile ad-hoc netw...

The paper considers the application of forward error correction (FEC) and automatic repeat request (ARQ) schemes over correlated wireless channels. In particular, the depth of the interleaver and its influence on the frame-error-rate and transmission delay in the presence of correlated fading and delay constraints is investigated. It is found that...

This paper considers the application of Forward Error Correction (FEC) and Automatic Repeat reQuest (ARQ) schemes over correlated wireless channels. In particular the depth of the interleaver and its influence on the frame-error-rate and transmission delay in the presence of Correlated fading and delay constraints is investigated. It is found that...

An inter-layer scheduling structure that achieves a coupling between the IP and data link layer is proposed. Based upon the QoS requirements from the network layer and the available resources at link layer the optimal bearer is selected. The combination of information from different layers in the protocol stack allows for a more optimised and accur...

The next generation of wireless mobile networks will apply IP to offer a mixed set of services, varying from real time voice-over-IP and videoconferencing, to best effort transmission of E-mail messages. This paper investigates the coupling between the queuing mechanism on the IP and data link layer to be able to offer end users a guaranteed QoS. P...

This paper describes a network simulator for IPv6 networks. Such a network can consist of both fixed and wireless components, like routers, nodeBs, computers, mobile nodes, etc. The simulator can be used to analyse the performance of the TCP/IP protocol suite in wireless and wired networks

A mobile ad hoc network (MAN) consists of mobile nodes, which are free to move around arbitrarily. These mobile nodes incorporate routing functionality, due to which a backbone network is no longer essential. The ad hoc topology may change with time as the nodes move or adjust their transmission and reception parameters. A MAN is an autonomous syst...

This paper presents the performance of groupwise successive interference cancellation (GSIC) in a DS-CDMA system with multiple data rates (multirate). The performance is evaluated both in AWGN and Rayleigh fading channels. In the GSIC scheme users with the same data rate are grouped and detected, using either a matched filter or a parallel interfer...

Future-generation communication systems need to cope on a global scale with new forms of personal communications as well as man-machine interaction. This demand will be also helped by delivering IP-based, real-time, person-to-person multimedia communications, integrating real-time person-to-person with non real-time person-to-machine, providing the...

The content of this deliverable is twofold. Firstly, the work done within WINNER II project towards the World Radiocommunication Conference 2007 is described and a summary of the conference outcome is given. From the ITU-R WP 8F point of view spectrum estimate results and candidate bands are shortly summarised and the results of the sharing study a...

Wireless ad-hoc networks, or mobile distributed multi-hop wireless networks, have gained a lot of attention during the last years. Ad-hoc architectures have many properties, such as self-reconfiguration and adaptability to highly variable mobile characteristics including power and transmission conditions, traffic distribution variations and load ba...

6 Abstract: The radio resource management is crucial for the performance of a 7 cellular network in general and for relay based deployments in particular. In this 8 paper we study different interference coordination schemes for low cost relay 9 networks in a metropolitan area with high user and traffic density, which we then 10 evaluate in dynamic...