Showing papers by "Stefan Parkvall published in 2009"

LTE: the evolution of mobile broadband

Abstract: This article provides an overview of the LTE radio interface, recently approved by the 3GPP, together with a more in-depth description of its features such as spectrum flexibility, multi-antenna transmission, and inter-cell interference control. The performance of LTE and some of its key features is illustrated with simulation results. The article is concluded with an outlook into the future evolution of LTE.

The Evolution of LTE towards IMT-Advanced

Abstract: This paper provides a high-level overview of some technology components currently considered for the evolution of LTE, referred to as LTE-Advanced. First, a brief overview of LTE and some of its technologies are given and then the IMT-Advanced requirements are discussed. One of the targets with the evolution of LTE is to reach or seven surpass these requirements. The technology components considered for LTE-Advanced include extended spectrum flexibility to support up to 100MHz bandwidth, enhanced multi-antenna solutions with up to eight layer transmission in the downlink and up to four layer transmission in the uplink, coordinated multi-point transmission/reception, and the use of advanced repeaters/relaying.

Identifying Multi-Component Carrier Cells

Abstract: Methods and apparatus for generating and determining multi-component carrier cells, without the use of neighbor-cell lists, are described. Methods for generating and informing a communication system terminal about other component carriers belonging to a certain cell identity (ID), and methods and apparatus for a mobile terminal utilizing extended synchronization information for doing multi-component carrier cell search are described. Also, methods for multi-component carrier measurements and methods of reporting such measurements to a network are described.

Methods and arrangements in a telecommunication system

Abstract: There is provided a method in a cellular telecommunications network, the cellular telecommunications network comprising at least a first cell and a second cell. The method comprises the steps of transmitting (302) first periodic physical signals, usable by a device to determine its location, to the first cell; and transmitting (304) second periodic physical signals, usable by a device to determine its location, to the second cell. The second periodic physical signals are synchronized with the first periodic physical signals and have a timing offset, such that the first periodic physical signals and the second periodic physical signals are not transmitted simultaneously. The method is characterized in that transmission of data or control signals to the first cell is inhibited when the second periodic physical signals are transmitted to the second cell.

Methods and devices relating to downlink assignments

Abstract: The invention relates to a method in a first communication device of receiving control information over a radio channel from a second communication device. The first communication device receives a subframe over the radio channel, and determines whether the subframe is a downlink subframe with downlink assignment intended for the first communication device by reading data in the subframe. That being the case, the first communication device decodes data within the subframe, and determines whether any data packet being sent from the second communication device before the subframe has been missed by analysing an indicator associated to the subframe in the data. The indicator provides knowledge about previous downlink subframes with downlink assignment intended for the first communication device.

Uplink scheduling in a cellular system

Abstract: A method for use in a wireless cellular access system, according to which users in a cell in the system receive one or more transmission power control commands on a control channel, where the transmission power control commands comprise an identifier for the intended user or users, said identifier being either an identifier for a specific user or for a group of users. A user disregards one or more predefined control commands if the identifier of the control command is for a group of users in which said user is included.

Method and Apparatus for Transmitting CSI on the PUSCH in an LTE System

Abstract: The present invention relates to allowing configuring CSI reporting (step S-224, 310) on radio resources that are allocated over a plurality of sub frames on Physical Uplink Shared Channel (PUSCH). Allocation of said radio resources (steps S-202, 404) can be performed by semi-persistent allocation or by using Transmission Time Interval (TTI) bundling. By using either semi-persistent scheduling or TTI-bundling as decided by an eNB (104, 204, 600) the UE (102, 202, 500) can be configured to report CSI (step S-224, 310) for a plurality of UL transmissions. By allocating radio resources by using semi-persistent scheduling, the signaling overhead, which can be substantial for dynamic scheduling of radio resources, decreases. By using TTI-bundling the coverage of the CSI-reports increases.

Managing energy consumption of base stations

Abstract: A base station includes an emulation controller (20) configured to receive signals indicating that another base station in an active mode managing a cell, having a predetermined cell identity and coverage area, will go into an idle mode and no longer manage the cell, and to determine terminal activity in the cell. A baseband processing unit (18) is connected to the emulation controller (20) and configured to emulate the active mode of the other base station by taking over management of the cell, in at least part of its coverage area, using the same cell identity.

Method and apparatus in a telecommunications network

Abstract: According to the present invention, a receiving node of a telecommunications network (20) (e.g. a radio base station (22) in uplink, or a mobile terminal (24) in downlink) transmits a single acknowledgement message to a transmitting node (e.g. a mobile terminal (24) in uplink, or a radio base station (22) in downlink) in respect of signals received over a plurality of frequency-aggregated carriers (component carriers) (10) between the transmitting and receiving nodes. If all signals are decoded correctly in the receiving node, a positive acknowledgement message (ACK) is sent to the transmitting node; if not all signals are decoded correctly, a negative acknowledgement message (NACK) is sent, or no acknowledgement message is sent. In this way, a single acknowledgement message can be sent for signals received over multiple carriers. The acknowledgement message can have the same format as legacy standards (for example, as specified in Release 8 of the 3GPP specifications), providing compatibility with existing equipment. The number of messages is also reduced compared with the straightforward approach of transmitting individual acknowledgement messages per component carrier.

Controlling Energy Consumption of a Wireless Network Node

Abstract: An arrangement for controlling energy consumption of a network node associated with a cell includes a terminal activity monitor (16) configured to detect active terminals served by the cell. A transmission controller (18) is connected to the terminal activity monitor and is configured to restrict transmission downlink in the cell during time periods when there are no active terminals served by the cell. During these time periods transmission is restricted to inermittent transmission of information assisting active terminals not served by the cell in finding the cell.

Uplink link adaption at the user equipment

Abstract: Method and arrangement in a user equipment for link adaptation of signals sent from the user equipment to a base station. The base station and the user equipment are comprised within a wireless communication system. The method comprises receiving information from the base station, comprising an indication of resource blocks available for transmission of signals from the user equipment to the base station, obtaining at least one of a user equipment related parameter or a link related parameter, and selecting a subset of the indicated available resource blocks received from the base station, based on at least one of the measured user equipment related parameter or the measured link related parameter, to be used for sending signals to the base station. Also, a method and arrangement in a base station for assisting a user equipment in performing link adaptation of signals is presented.

3G Radio Access Evolution : HSPA and LTE for Mobile Broadband

Abstract: This paper provides an overview of the 3GPP radio-access technologies for mobile broadband — HSPA and its evolution, and LTE. The paper also discusses the current stage of the 3GPP activities on evolving LTE towards LTE-Advanced and full IMT-Advanced compliance.

Data packet transmission scheduling in a mobile communication system

Abstract: A communication device has a first transceiver that operates in a first communication system in the presence of a second transceiver that operates in a second communication system that is unrelated to the first communication system. A scheduler of packets for transmission by the first transceiver uses information about when the second communication system will be transmitting a signal that will interfere with reception by the first transceiver, and schedules data for which re-transmission is not essential in those time slots in which an implicit NACK is expected due to the second transceiver's operation.

Communications Engineering Desk Reference

Abstract: A one-stop Desk Reference, for RD this is a book that will not gather dust on the shelf. It brings together the essential professional reference content from leading international contributors in the field. Material covers a wide scope of topics including voice, computer, facsimile, video, and multimedia data technologies * A hard-working desk reference, providing all the essential material needed by communications engineers on a day-to-day basis * Fundamentals, key techniques, engineering best practice and rules-of-thumb together in one quick-reference sourcebook* Definitive content by the leading authors in the field, including Erik Dahlman, Steven Parkvall, Claude Oestges, Alan Bovik, Bruce Fette and Keith Jack

Method and arrangement in a radio communications system for dynamic carrier mode switching

Abstract: A method in a radio network node for dynamic carrier mode switching is provided. The radio network node is comprised in a radio communications system. The radio network node is configured to operate in a legacy mode and is further configured to operate in a non legacy mode. At least one carrier is operated so that it switches (602) from non legacy mode to legacy mode. When operating the carrier in the legacy mode, the radio network node signals (603) with a user equipment. The user equipment operates in legacy mode, but can not operate in non legacy mode. The radio network node then operates the at least one carrier so that it switches (604) from legacy mode back to non legacy mode.

Technique for transmitting on multiple frequency resources in a telecommunication system

Abstract: The present disclosure relates to a technique for transmitting modulation symbols on multiple frequency resources. A method aspect of this technique includes applying a Discrete Fourier Transform (DFT) coding per set of modulation symbols of two or more sets of modulation symbols, wherein a first set of modulation symbols from the two or more sets of modulation symbols is transmitted on a set of frequency resources handled by the same power amplifier. Then, Orthogonal Frequency Division Multiplexing (OFDM) modulation is applied to the sets of DFT coded modulation symbols to output a first set of OFDM symbols for transmission on the set of frequency resources, and output another set of OFDM symbols for transmission on at least one additional frequency resource distinct from the set of frequency resources. Power amplification is then applied per set of frequency resources at the power amplifier.

Methods and apparatuses for resource allocation for random access in wireless telecommunication systems with carrier-aggregation

Abstract: The embodiments of the present invention relate to apparatuses and methods for resource allocation for random access in wireless telecommunication systems with carrier-aggregation wherein a plurality of component carriers (CCs) is defined per cell. According to a method for use in an apparatus corresponding to a radio base station (31), a message is assembled comprising information on the structure of the cell served by the radio base station; the information including one or more CCs used in the cell that is/are available for a user equipment for performing initial access in the cell. The method also comprises, transmitting the assembled message to the user equipment (30) and indicating to the user equipment which resources to use for random access in the cell. The exemplary embodiments of the present invention also relates to a method in the user equipment, to a radio base station and to a user equipment.

Error control in multi-carrier wireless systems

Abstract: Methods and apparatus for signaling scheduling information in a multi-carrier wireless communications system (700), as well as corresponding methods and apparatus for processing such signaling information, are disclosed. An exemplary method comprises scheduling (610) first and second transport blocks for simultaneous transmission during a first transmission interval on first and second component carriers, and transmitting (620) a common re-transmission process identifier for the first transmission interval. The method further comprises scheduling (640) at least one of the first and second transport blocks for re-transmission during a second transmission interval, along with a third transport block, and transmitting (660) second scheduling information for the second transmission interval, the second scheduling information comprising the same common re-transmission process identifier.

Method for improved mixing automatic re-transmission request, receiver and transmitter

Abstract: The present invention relates to methods and a transmitter and a receiver for a mobile communication system. The basic idea of the present invention is to recursively derive from previous HARQ feedback the number of HARQ transmissions that is required to be able to decode the transmitted data successfully and to only transmit explicit HARQ feedback information if the decoding result differs from the derived result.

A transmitter stage and a corresponding method for signal transmission on mutiple compenent carriers in a telecommunication system

Abstract: The present disclosure relates to a technique for transmitting modulation symbols on multiple frequency resources. A method aspect of this technique includes applying a Discrete Fourier Transform (DFT) coding per set of modulation symbols of two or more sets of modulation symbols, wherein a first set of modulation symbols from the two or more sets of modulation symbols is transmitted on a set of frequency resources handled by the same power amplifier. Then, Orthogonal Frequency Division Multiplexing (OFDM) modulation is applied to the sets of DFT coded modulation symbols to output a first set of OFDM symbols for transmission on the set of frequency resources, and output another set of OFDM symbols for transmission on at least one additional frequency resource distinct from the set of frequency resources. Power amplification is then applied per set of frequency resources at the power amplifier.