Showing papers by "Stefan Parkvall published in 2011"

4G: LTE/LTE-Advanced for Mobile Broadband

Abstract: Based on the bestseller "3G Evolution - HSPA and LTE for mobile broadband" and reflecting the ongoing success of LTE throughout the world, this book focuses on LTE with full updates including LTE-Advanced to provide a complete picture of the LTE system. Overview and detailed explanations are given for the latest LTE standards for radio interface architecture, the physical layer, access procedures, broadcast, relaying, spectrum and RF characteristics, and system performance. Key technologies presented include multi-carrier transmission, advanced single-carrier transmission, advanced receivers, OFDM, MIMO and adaptive antenna solutions, advanced radio resource management and protocols, and different radio network architectures. Their role and use in the context of mobile broadband access in general is explained. Both a high-level overview and more detailed step-by-step explanations of the LTE/LTE-Advanced implementation are given. An overview of other related systems such as GSM/EDGE, HSPA, CDMA2000, and WIMAX is also provided. This book is a 'must-have' resource for engineers and other professionals in the telecommunications industry, working with cellular or wireless broadband technologies, giving an understanding of how to utilize the new technology in order to stay ahead of the competition. The authors of the book all work at Ericsson Research and have been deeply involved in 3G and 4G development and standardisation since the early days of 3G research. They are leading experts in the field and are today still actively contributing to the standardisation of LTE within 3GPP. Includes full details of the latest additions to the LTE Radio Access standards and technologies up to and including 3GPP Release 10Clear explanations of the role of the underlying technologies for LTE, including OFDM and MIMO Full coverage of LTE-Advanced, including LTE carrier aggregation, extended multi-antenna transmission, relaying functionality and heterogeneous deploymentsLTE radio interface architecture, physical layer, access procedures, MBMS, RF characteristics and system performance covered in detail

Evolution of LTE toward IMT-advanced

Abstract: This article provides a high-level overview of LTE Release 10, sometimes referred to as LTE-Advanced. First, a brief overview of the first release of LTE and some of its technology components is given, followed by a discussion on the IMT-Advanced requirements. The technology enhancements introduced to LTE in Release 10, carrier aggregation, improved multi-antenna support, relaying, and improved support for heterogeneous deployments, are described. The article is concluded with simulation results, showing that LTE Release 10 fulfills and even surpasses the requirements for IMT-Advanced.

Efficient use of reference symbol resources in a hierarchical heterogeneous cell deployment

Abstract: Techniques for collecting channel-state-information, CSI, feedback in a wireless network that comprises a plurality of geographically separated transmission points (110, 120) include methods in which a set of CSI reference symbol, CSI-RS, resources are identified, which correspond to the union of CSI-RS resources used by multiple transmission points (110, 120) in the primary transmission point's coverage area. A mobile station (130) is configured to measure CSI-RS on a subset of the CSI-RS resources, the subset corresponding to CSI-RS resources used by a subset of the transmission points (110, 120). The mobile station (130) is also configured to assume that no downlink data will be transmitted in the remaining portion of the set of CSI-RS resources. CSI feedback is then received from the mobile station (130), based on measurements of the CSI-RS.

Radio base station and user equipment and methods therein

Abstract: Embodiments herein relate to a method in a user equipment (10) for transmitting uplink control information in time slots in a subframe over a radio channel to a radio base station. The radio channel is arranged to carry uplink control information and the user equipment and radio base station are comprised in a radio communications network. The uplink control information is comprised in a block of bits. The user equipment maps the block of bits to a sequence of complex valued modulation symbols. The user equipment also block spreads the sequence of complex valued modulation symbols across Discrete Fourier Transform Spread - Orthogonal Frequency Division Multiplexing (DFTS-OFDM) symbols. This is performed by applying a spreading sequence to the sequence of complex valued modulation symbols, to achieve a block spread sequence of complex valued modulation symbols. The user equipment further transforms the block-spread sequence of complex valued modulation symbols per DFTS-OFDM symbol. This is performed by applying a matrix that depends on a DFTS- OFDM symbol index and/or slot index to the block-spread sequence of complex valued modulation symbols. The user equipment also transmits the block spread sequence of complex valued modulation symbols that has been transformed over the radio channel to the radio base station.

Downlink scheduling in heterogeneous networks

Abstract: The present invention provides methods to support scheduling of transmissions from a pico base station or micro base station to a mobile terminal operating in a link imbalance zone where interference from macro base station is present. A method is provided to enable the mobile terminal to detect when it is in a link imbalance zone, and for triggering scheduling restrictions when the mobile terminal is in the link imbalance zone.

A method and a user equipment for peer-to-peer communication

Abstract: The exemplary embodiments relate to a method for use in a user equipment (UE), and a cellular infrastructure, for achieving synchronization between UEs for a peer-to-peer or device-to-device (D2D) communication. The method comprising: receiving at a UE a synchronization message from a cell or a RAT or a source of the cellular infrastructure; assembling a message including a list comprising information on the source or cell or RAT, sending the assembled message to a another UE and initiate synchronization between involved UEs based on the information in the assembled message.

Methods providing aided signal synchronization and related network nodes and devices

Abstract: Methods may be providing for signal synchronization at a wireless terminal communicating with a radio access network. For example, a command may be received from the radio access network, and the command may be to add a first carrier on a first frequency as a link for communications from the radio access network to the wireless terminal. Responsive to receiving the command to add the first carrier, the first carrier may be synchronized and/or configured using signals of a second carrier on a second frequency different than the first frequency. Related wireless terminals, network nodes, and network node methods are also discussed.

Point-dependent resource symbol configuration in a wireless cell

Abstract: A high-power point and one or more low-power points transmit signals associated with the same cell-identifier in a heterogeneous cell deployment. Coverage areas corresponding to the low-power points fall at least partly within the coverage area for the high-power point, so that mobile stations within range of a low-power point are also within range of the high-power point. Channel-state-information reference symbols, CSI-RS, are transmitted using different CSI-RS resources on different transmission points within the cell, while configuration of CSI-RS measurement resources is conducted on a UE-specific basis. The choice of measurement resources to be used is determined by the network, based on the properties of the channels from the transmission points to the UE. As the UE moves around within the cell, the network tracks the channel properties and reconfigures the CSI-RS resources measured by the UE, to correspond to the resource of the closest transmission point or points.

Distribution Of Cell-Common Downlink Signals In A Hierarchical Heterogeneous Cell Deployment

Abstract: A high-power point (110) and one or more low-power points (120) transmit signals that are associated with the same cell-identifier in a heterogeneous cell deployment. The coverage areas corresponding to the low-power points (120) fall at least partly within the coverage area for the high-power point (110), so that mobile stations (130) within range of a low-power point are also within range of the high-power point (110), from a downlink perspective. The same CRS signals are transmitted by both the high-power (macro) point (110) and some or all of the low-power (pico) points (120). At the same time, the network transmits CRS-based PDSCH for a particular UE on both the high-power point (110) as well as on some or all of the low-power points (120). In some embodiments only a subset of the points, e.g., those points that the UE hears sufficiently well, participate in the PDSCH transmission using CRS for channel estimation.

Cell searching system and method

Abstract: For wireless networks that transmit synchronization signals allowing user equipment to synchronize to cells within the network and transmit reference signals allowing user equipment to determine cell identities, a method and apparatus taught herein advantageously link the synchronization signal sequences to the reference signal sequences according to a defined mapping. The linking simplifies the cell search process by allowing user equipment to determine cell identities based on mapping detected synchronization signal sequences to the corresponding reference signal or to the corresponding subset of reference signals in embodiments where there are more reference signal sequences than synchronization signal sequences. In at least one embodiment, the network is a 3G LTE network and at least the Primary Synchronization Signal (P-SyS) sequences are linked to the Downlink (DL) reference symbol sequences according to a defined mapping, thereby allowing to user equipment to determine cell identities from detected P-SyS sequences.

Arrangement and method for identifying PUCCH format 3 resources

Abstract: The disclosure relates to a user equipment for a wireless communications system, and to a related method for identifying a resource to use for a transmission of control information on a physical uplink control channel, PUCCH, format 3. The method comprises receiving (610) a resource index from a serving radio base station, and identifying (620) the resource to use for the transmission of the control information in a subframe based on the received resource index, wherein the identified resource is within a same confined set of physical resource blocks regardless of if a normal or a shortened PUCCH format 3 is used in the subframe.

Method and apparatus for reducing co-channel interference

Abstract: A method for providing co-channel interference information by a network node includes receiving information for at least one user equipment (UE) connected to an adjacent network node, determining a co-channel interference list for user equipment (UE) connected to the network node wherein the co-channel interference list is based on the received information and transmitting the co-channel interference list to a UE connected to the network node.

Control channel configuration in a wireless communications system

Abstract: The present invention is directed to methods in a wireless communication network for allocating resource elements of a transmission resource to a control channel. The invention also relates to different nodes of a wireless communication network. The transmission resource comprises a first number of resource blocks each comprising one or a plurality of subsets of resource elements. One method in a control node comprises the steps: obtaining a bitmap for configuration of the transmission resource, wherein the bitmap is adapted to identify at least one subset of resource elements within the transmission resource (S1); allocating the at least one identified subset of resource elements to the control channel (S2); and transmitting control data on the at least one subset of resource elements allocated to the control channel to a receiving node (S3).

Methods and Devices for Managing Radio Access in a Communication System

Abstract: A method for managing radio access comprises sending of a radio access technology (RAT) resource aggregation request from a first radio access network (RAN) to a second RAN concerning communication with a user equipment connected to a source RAN, and returning a response to the first RAN. The source RAN is the first or second RAN. The first and second RANs use different radio access technologies. Radio resources of a base station in a target RAN, the RAN to which the user equipment is not connected, are reserved. A report of the reserved radio resources is sent to the source RAN. A RAT resource aggregation command is transmitted to the user equipment. The RAT resource aggregation command comprises that a RAT resource aggregation shall be used and the reserved radio resources. The base stations have at least partly overlapping coverage areas.

Methods and Devices for Transmission of Control Data to a User Equipment

Abstract: A method for transmission of control data to a user equipment in a mobile telecommunication system, wherein the method comprises sending control data to the user equipment in a data transmission, and performing, by the user equipment, a blind decoding of transmission elements within the data transmission in order to detect the control data in a data region in the data transmission.

Adaptation of receiver settings in a heterogenous network

Abstract: Techniques are described for adapting receiver settings used by a mobile terminal operating in a heterogeneous network comprising macro cells and pico cells with overlapping coverage areas. A first set of subframes is allocated to the pico cells for downlink transmissions to a mobile terminal in a link imbalance zone. The mobile terminal acquires information about the subframe allocation and uses the subframe allocation information to select the signals used for adapting receiver settings used when operating in the link imbalance zone.

Cell search and measurement in heterogeneous networks

Abstract: An extended cell search procedure enables more inclusive measurement reports by mobile terminals operating in a heterogeneous network. The mobile terminal may be configured to conduct an extended cell search to enable better detection of signals transmitted from weaker cells. For mobile terminal with extended cell search capabilities, the network sends an extended cell search message to the mobile terminal when there is a need for an extended cell search. In response to the extended cell search message, the mobile terminal uses an extended cell search procedure rather than the normal cell search procedure (as specified in Rel-8 of the LTE standard) when performing cell searches.

Scheduling of a User Equipment in a Radio Communication System

Abstract: A radio base station (110) and a method in a radio base station (110) for scheduling a transmission to be transmitted between a user equipment (120) and the radio base station (110) are provided. Moreover, a user equipment (120) and a method in a user equipment (120) for obtaining information about the transmission are provided. The radio base station (110) operates an aggregated carrier in a subframe structure comprising a plurality of subframes. The aggregated carrier comprises a plurality of carriers. The radio base station (110) encodes information about a subframe out of said plurality of subframes and a carrier out of said plurality of carriers into a message indicating scheduling information to the user equipment (120). The radio base station (110) sends the message to the user equipment (120), which decodes the message to obtain the information about the transmission. The information about the transmission is indicative of the subframe and the carrier on which the transmission is scheduled.

Methods and arrangements for transmitting and receiving sub-frame specific power offset information

Abstract: In one embodiment, a method in a network node is provided. The network node is configured to use a first power level for transmitting data in subframes of a first type, and to use a second power level for transmitting data in subframes of a second type. The method comprises signaling (520) first and second information to a network entity. From the first information, a power offset for subframes of the first type is derivable. The first power offset represents a relation between a power level for transmitting reference signals and the first power level. From the second information, a power offset for subframes of the second type is derivable. The second power offset represents a relation between the power level for transmitting reference signals, and the second power level.

Background of LTE

Abstract: This chapter provides a historical overview of the evolution of mobile communication from the first generation of analog cellular systems, through second generation (2G) systems such as GSM and 3G systems including WCDMA/HSPA, into 4G LTE. ITU and its activities related to IMT and IMT-Advanced are described, as is the process in 3GPP, the organization responsible for developing the GSM, WCDMA/HSPA, and LTE technical specifications.

Synchronization of pico-nodes in a heterogeneous cellular network deployment

Abstract: A high-power point (110) and one or more low-power points (120) transmit signals associated with the same cell-identifier in a heterogeneous cell deployment. Coverage areas corresponding to the low-power points (120) fall at least partly within the coverage area for the high-power point, so that mobile stations (130) within range of a low-power point are also within range of the high-power point (110). A low-power point (120) measures timing or frequency, or both, of one or more signals received at the low-power point (120) from the high-power point (110), and adjusts the timing or frequency, or both, of a transmission from the low-power point (120) to a mobile station (130), to align the transmission with signals received by the mobile station (130) from the high-power point (110).

Signaling mechanism for inter-rat carrier aggregation

Abstract: A signaling mechanism informs a Radio Network Controller (700) of the radio access technology associated with data packets forwarded to the Radio Network Controller (700) from base stations (600) supporting multiple radio access technologies. With this information, the Radio Network Controller (700) can associate received data with the corresponding radio access technologies, and thus manage differing physical layer procedures, such as outer-loop power control, for the radio access technologies. In an example method, first and second data units transmitted by a mobile station over first and second radio access technologies, respectively, are forwarded (430) from one or more base stations to a network control node for further processing. A control message associated with at least some of the data units is also sent (440) to the network control node, the control message indicating the radio access technology over which the associated data units were transmitted.

Method and Device for Truncating Location Information

Abstract: The embodiments herein relate to a method in a first device (101) for informing a second device (105) that an identity associated with the first device (101) is at a certain location. The first device (101) obtains information about the location of the first device (101). The first device (101) broadcasts, by means of device to device, D2D, communication, a message to be received by the second device (105). The message comprises the location information and an identity information associated with a user of the first device (101). The location information is transmitted on a first communications resource and the identity information is transmitted on a second communications resource.

TDD time slot splitting

Abstract: The invention discloses a method for a cellular communications system, in which traffic is sent in frames, each frame comprising a first number of subframes, with a second number of said subframes being available for at least either uplink or downlink traffic. At least one of said second number of subframes is made to comprise at least three parts, as follows: One part which is utilized for uplink traffic, One part which is utilized for downlink traffic, One part which is utilized as a guard period, with said guard period part being scheduled between the uplink and the downlink parts. The duration of at least two of said three parts may be varied to fit the current system need.

Power Control, Scheduling, and Interference Handling

Abstract: Publisher Summary This chapter deals with some radio-resource-management issues, including uplink power control, downlink and uplink scheduling, and different means for intercell interference coordination to handle/avoid severe interference between different cells including cells of different layers in heterogeneous network deployments. Uplink power control for LTE is the set of algorithms and tools by which the transmit power for different uplink physical channels and signals are controlled to ensure that they, if possible, are received at the cell site with appropriate power. This means that the transmission should be received with sufficient power to allow for proper demodulation of the corresponding information. At the same time, the transmit power should not be unnecessarily high as that would cause unnecessary interference to other cells. The transmit power will thus depend on the channel properties, including the channel attenuation and the noise and interference level at the receiver side. This chapter begins with elaborating the basic rules of uplink power control, power control for PUCCH, power control for PUSCH and SRS. It then discusses the downlink scheduling, uplink scheduling, semipersistent scheduling, and scheduling for half-duplex FDD. The chapter concludes with a discussion on intercell interference coordination and heterogeneous network deployments.

Method and arrangement for reporting channel state information in a telecommunication system

Abstract: A method and an arrangement (800) in a user equipment (420) for reporting Channel State Information, CSI, and a method and an arrangement (1000) in a base station (410) for obtaining CSI are provided. The user equipment (420) is in connection with the base station (410) in a cellular communication network (400). After receiving a receiving (702) a grant in a subframe n to be used for CSI reporting, from the base station, the user equipment determines (703) subframe type of a subframe n+p. The user equipment then reports (704) to the base station, CSI reflecting channel conditions in the subframe type of subframe n+p. p is a variable value.

Methods and nodes in a radio communication system

Abstract: The present invention generally relates to radio communication systems, relay nodes, controller nodes, user equipment (user terminals), software and methods for said systems and nodes. In one embodiment, a method for operating a control node for a wireless communication system is provided. The method comprises the steps: creating a data frame comprising an early part and a later part, wherein the early part comprises first control data for controlling a receiving node; checking whether second control data are to be put into the later part; scheduling payload data for the receiving node into the later part if second control data are not to be put into the later part; and transmitting the data frame to the receiving node.

Chapter 14 – Access Procedures

Abstract: Publisher Summary This chapter describes the procedures necessary for a terminal to be able to access an LTE-based network. Before an LTE terminal can communicate with an LTE network, it has to find and acquire synchronization to a cell within the network; and receive and decode the information, also referred to as the cell system information, needed to communicate with and operate properly within the cell. The first of these steps, simply referred to as cell search, includes acquisition of frequency and symbol synchronization to a cell; acquisition of frame timing of the cell; and determination of the physical-layer cell identity of the cell. There are 504 different physical-layer cell identities defined for LTE, where each cell identity corresponds to one specific downlink reference-signal sequence. The set of physical-layer cell identities is further divided into 168 cell-identity groups, with three cell identities within each group. This chapter begins with an overview of LTE cell search, PSS structure and SSS structure. The chapter then discusses the basic concepts of MIB and BCH transmission and system-information blocks. The chapter concludes with a discussion on terminal identification, contention resolution, and paging.

Downlink Physical-Layer Processing

Abstract: This chapter provides a detailed description of the LTE downlink physical-layer functionality, including transport-channel processing, downlink reference signals, details on downlink multi-antenna transmission, and control signaling.

Methods and nodes in a radio communication system with efficient control channel use

Abstract: The present invention generally relates to radio communication systems, relay nodes, controller nodes, user equipment (user terminals), software and methods for said systems and nodes. In one embodiment, a method for operating a control node for a wireless communication system is provided. The method comprises the steps: creating a data frame comprising an early part and a later part, wherein the early part comprises first control data for controlling a receiving node; checking whether second control data are to be put into the later part; scheduling payload data for the receiving node into the later part if second control data are not to be put into the later part; and transmitting the date frame to the receiving node.