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  • 1. D, ASTELY
    et al.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Method for determining transmit weights2003Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The transmission weights associated to pilot sequences (p1-p_N) containing symbols with predetermined time, frequency resource and complex transmission weights (W11-W_N_M) are adapted for optimizing the multicast transmission of pilot signal. The multiple information stream are transmitted using adapted transmission weights. USE - For beam-forming data transmission in multi-carrier multi-user communication system such as orthogonal frequency division multiplexing (OFDM) system. ADVANTAGE - Improves downlink channel quality by using feedback information from mobile terminals in response to the received pilot signals, thereby increasing transmission efficiency. DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram of the communication system. communication system (10) access point (11) pilot sequences (p1-p_N) mobile terminals (MS1-MS4) complex transmission weights (W11-W_N_M)

  • 2.
    Frodigh, Magnus
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Parkvall, Stefan
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Roobol, C
    Johansson, Per
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Future-generation wireless networks2001In: IEEE personal communications, ISSN 1070-9916, E-ISSN 1558-0652, Vol. 8, no 5, p. 10-17Article in journal (Refereed)
    Abstract [en]

    Starting with today's 3G standards, future-generation wireless networks are discussed. Two complementing major trends are identified: seamless roaming between different air interfaces, leading to the Always Best Connected concept, and the continuous development of the current third-generation standards. The evolution of WCDMA toward high-speed downlink packet access, aiming for peak rates in the order of 8-10 Mb/s, is described as an example of air-interface evolution., Fourth-generation technologies such as ad hoc networking and multihop networks, still at the research level, are discussed and their impact on wireless communication systems addressed.

  • 3. J, LINDSKOG
    et al.
    G, RYDNELL
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Method for multihop routing for distributed wlan networks2001Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - Involves establishing a multihop route through the wireless network and altering transmission protocol parameters to minimize delays for transmissions over the multihop route. Packets are then transmitted over the multihop route using the altered transmission protocol parameters. USE - For multi-hop routing for distributed wireless local area networks e.g. WLANs conforming to IEE 802.11 standard. ADVANTAGE - Enhances overall performance by allowing effective control of multi-hop packets. DETAILED DESCRIPTION - The transmission protocol parameters can be altered by setting a NAV value at each node of the multi-hop route for a duration of the packet transmissions over the route or by assigning the packets a higher QoS value. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of the type of wireless network in which the method is employed.

  • 4. J, LUNDSJOE
    et al.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    J, BERGSTROEM
    S, SIGNELL
    Method for providing communication device with radio software, involves downloading radio software through available selected radio access technology and storing downloaded software designed for technology in memory.2003Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves selection a radio access technology e.g. wireless local area network (WLAN), wideband code division multiple access (WCDMA) for communication device (9) for downloading radio software from download server (1). The radio software is downloaded through the available access technology and the downloaded software designed for the technology is stored in memory. USE - For providing communication device e.g. mobile terminal such as CDMA phone, GSM phone, lap top, personal computer with modem, pager, personal digital assistant (PDA) with radio software from software download server for providing radio access technologies (RAT) e.g. WCDMA, GSM/GRPS, WLAN, IEEE 802.11a, IEEE.11b . ADVANTAGE - Downloads or upgrades software intended for one radio access technology over an available radio access technology supported by the device. The software download can be performed as a background process that does not have to be coordinated with or blocking other types of traffic including data, control traffic or wireless services. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) communication device; (2) system for providing communication device with radio software; and (3) computer readable medium storing program for providing communication device with radio software. DESCRIPTION OF DRAWING(S) - The figure shows the simplified block diagram of the wireless network. software download server (1) backbone network (3) wireless access networks (5,7) communication device (9)

  • 5.
    Jiansong, Gan
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Qingyu, Miao
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Spatial Filter for MIMO Repeaters with First-Hop Channel State Information and End-to-End SNR2009In: Vehicular Technology Conference Fall (VTC 2009-Fall), 2009 IEEE 70th, 2009Conference paper (Refereed)
    Abstract [en]

    —A repeater is a device that improves the ratecoverage performance of a system by amplifying and forwardingits received signal. When multiple antennas are deployed on arepeater, spatial signal processing becomes possible for betterperformance. In this paper we propose a spatial filter for sucha multi-antenna repeater. This filter is designed based on firsthop channel state information (CSI) and end-to-end signal-tonoise ratio (SNR). The optimal filter matrix is proved to be aproduct of a diagonal matrix and the conjugate transpose of theleft singular matrix of the first-hop channel matrix. The diagonalmatrix is obtained by maximizing an upper bound of the ergodicchannel capacity. Simulation results indicate that the proposedfilter outperforms that without filtering in end-to-end channelcapacity, especially when the number of repeater antennas isgreater than that of the source antennas. As the first-hop CSI andthe end-to-end SNR can be obtained without any modificationof the source or the destination, a repeater with the proposedspatial filter can be easily implemented in a current system.

  • 6. Johansson, Per
    et al.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Frodigh, Magnus
    Wireless ad hoc networking—The art of networking without a network2000In: Ericsson review (English ed.), ISSN 0014-0171, no 04, p. 248-263Article in journal (Other academic)
    Abstract [en]

    Today, many people carry numerous portable devices, such as laptops,mobile phones, PDAs and mp3 players, for use in their professional andprivate lives. For the most part, these devices are used separatelyÑthatis, their applications do not interact. Imagine, however, if they could inter-act directly: participants at a meeting could share documents or presenta-tions; business cards would automatically find their way into the addressregister on a laptop and the number register on a mobile phone; as com-muters exit a train, their laptops could remain online; likewise, incoming e-mail could now be diverted to their PDAs; finally, as they enter the office,all communication could automatically be routed through the wirelesscorporate campus network.These examples of spontaneous, ad hoc wireless communicationbetween devices might be loosely defined as a scheme, often referred toas ad hoc networking, which allows devices to establish communication,anytime and anywhere without the aid of a central infrastructure. Actually,ad hoc networking as such is not new, but the setting, usage and playersare. In the past, the notion of ad hoc networks was often associated withcommunication on combat fields and at the site of a disaster area; now,as novel technologies such as Bluetooth materialize, the scenario of adhoc networking is likely to change, as is its importance.In this article, the authors describe the concept of ad hoc networkingby giving its background and presenting some of the technical challengesit poses. The authors also point out some of the applications that can beenvisioned for ad hoc networking

  • 7.
    Koike-Akino, Toshiaki
    et al.
    School of Engineering and Applied Sciences, Harvard University, 33 Oxford Street, Cambridge, MA 02138, U.S.A.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Popovski, Petar
    Department of Communication Technology, Aalborg University, Niels Jernes Vej 12, DK-9220 Aalborg, Denmark.
    Tarokh, Vahid
    School of Engineering and Applied Sciences, Harvard University, 33 Oxford Street, Cambridge MA 02138, U.S..
    Non–linear network coding for two–way discrete channels2009In: International Conference on Wireless Communications & Signal Processing 2009, 2009Conference paper (Refereed)
    Abstract [en]

    In this paper, we present optimal network coding which can maximize achievable rate region in two-way relaying discrete channels, where there are two communicating nodes and one relaying node. We focus on a low-complexity relaying protocol termed the detect-and-forward (DtF) scheme, in which the relaying node does not require channel decoding but detection. We first analyze the achievable rate region of any digital network coding function including non-linear types. We then search for the optimal network code in favor of maximizing two kinds of performance measures: the sum rate and the product rate. For high SNR regimes, linear network codes like the exclusive-or (XOR) function can offer the maximum-achievable rate region. Whereas, for low SNR regimes, it is verified that non-linear network codes like the negate-or (NOR) function can outperform linear codes due to the effect of error occurrence at the intermediate relaying node.

  • 8.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    A multiplicative and constant modulus signal based network coding method applied to CB-Relaying2008In: 2008 IEEE 67TH VEHICULAR TECHNOLOGY CONFERENCE-SPRING, VOLS 1-7, IEEE , 2008, p. 61-65Conference paper (Refereed)
    Abstract [en]

    In this paper, a new, and simple arithmetic operation for network coding (NC) in wireless communication is proposed. It is built on the assumption of constant modulus signals with phase conveyed information such as PSK and employs, in contrast to classical NC finite field additions, a multiplicative NC operation. The benefit of the method is that it decouples the NC operation from forward error correction (FEC) and modulation imposed joint constraints and thus permits for greater flexibility to adapt code and modulation rates to different user. It may further reduce hardware (HW) complexity and cost for NC enabled relays and it may operate directly on (potentially noisy) baseband signals. The performance of the proposed NC method is examined in a three phase NC hi-directional relaying scenario and compared to a traditional four phase non-NC scheme illustrating performance benefits in the high signal to noise (SNR) region and its viability for the former.

  • 9.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    A routing metric for floor acquisition oriented medium access schemes2006In: Proceedings of Scandinavian Wireless Adhoc Workshop 06, 3-4th of May, 2006, Johannesberg, Sweden, 2006Conference paper (Other academic)
    Abstract [en]

    In this paper, a routing metric for shortest pathrouting is described. The metric is particularly crafted for a flooracquisition oriented medium access scheme, such as IEEE 802.11DCF, where nodes around communicating node pairs get blocked. Two variants of the metric are described, one forsystems with and one for systems without rate control. Performance is evaluated and compared to two conventional metrics (minimum hop and inverse rate metrics). Implementation issues related to the metric are also discussed

  • 10.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Advanced multi-sensor processing2003Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - A superposition of signals received from transmitting nodes (10), at receiving nodes (120) is converted to produce soft complex signal information for transmission over network. The signal information transmitted from a subset of transmitting nodes, is collectively detected based on the soft complex signal information. USE - For detecting signal information in digital cellular network of wideband code division multiple access (WCDMA) system. ADVANTAGE - Reduces amount of information to be transported over the network, thereby improving the performance of the network and improving the uplink signal processing efficiency at low cost. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) system for detecting signal information in wireless network; (2) network node. DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram of the centralized architecture and signal processing approach. transmitting nodes (10) receiving nodes (120-1-120-3)

  • 11.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Analysis of multi-user ARQ with multiple unicast flows under non-iid reception probabilities2007In: 2007 IEEE WIRELESS COMMUNICATIONS & NETWORKING CONFERENCE, VOLS 1-9, New York: IEEE , 2007, p. 384-388Conference paper (Refereed)
    Abstract [en]

    This paper presents an analysis of multi-user ARQ for multiple unicast flows with arbitrary reception probabilities. The core idea of multi-user ARQ is to exploit knowledge of previously overheard packets by unintended users, and perform wise selection and joint encoding of any retransmitted information. Intended users may decode the jointly encoded packet by exploiting the previously overheard packets. In this paper, a scheduling approach that balances the traffic shares and maximizes the throughput is proposed and analyzed. It is found that identical reception probabilities among the users yields the best performance and that the sensitivity in throughput efficiency, with respect to changes in reception probabilities, is reduced when the number of user increases.

  • 12.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Closed loop link adjustment method based on a Request To Send-Clear To Send channel access scheme for transmit power control and link adaptation techniques.2001Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves designating a station as an originating station. An RTS frame is transmitted with predetermined transmit power from an originating station, prior to an intended DATA transmission, sounding the channel such that reception characteristics can be evaluated at a designated receiving station. A CTS frame with a predetermined transmit power is transmitted, in response to the originating station, from the receiving station. A DATA frame is transmitted from the originating station to the receiving station. An acknowledge frame is transmitted in response to the originating stations from the receiving station. USE - For transmit power control and link adaptation techniques. ADVANTAGE - Improves overall system performance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (a) a method for open loop group transmit power control in a wireless system; (b) a method for interference mitigation. DESCRIPTION OF DRAWING(S) - The figure shows a tiered TPC in an IBSS-like system.

  • 13.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Cyclic delay diversity for mitigating intersymbol interference in OFDM systems2000Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves splitting a signal along several antenna paths. The signal includes a number of positions, each of the positions includes a sample. The signal is received in an antenna path. The samples of the signal are shifted a predetermined number of positions. Samples shifted beyond the number of positions in the signal are shifted into a number of positions at a beginning or end of the signal. A number of samples from an end of the signal are included in a guard interval. The signal and the guard interval are transmitted. USE - For transmission diversity. ADVANTAGE - Mitigates intersymbol interference in systems which employ delay transmit diversity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for an apparatus for transmitting signals and for a radio transmission system. DESCRIPTION OF DRAWING(S) - The figure shows a transmitter and receiver which operate according to a OFDM transmission scheme using transmission diversity.

  • 14.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Data packets scheduling and encoding method for multicast automatic repeat request communication system, involves transmitting one of composite data packets to two receivers by sender.2006Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves obtaining feedback information from two receivers indicating received data packets, and forming a composite data packet as a weighted linear combination of regular data packets. Coding weights of a weight vector are adapted based on the feedback information for each of the composite data packet, such that the composite packet represents a linear combination of the regular packets for the receivers of the data packet previously received by the receivers during a multicast session. One of the composite data packets is transmitted to the receivers by a sender. USE - Method for scheduling and encoding data packets for transmission in a multicast session from a sender to two receivers in a multicast automatic repeat request (ARQ) communication system. Can also be used in a cellular system with a base station in communication with a set of mobile terminals. ADVANTAGE - The method effectively schedules and encodes the data packets for transmission in the multicast session from the sender to the receivers in the multicast automatic repeat request (ARQ) communication system. The method enables improved throughput efficiency for the reliable multicast, and provides deterministically decodable re-transmission scheme. The method provides highly throughput-efficient strategy for reliable multicasting. The method efficiently provides the multicast strategy that enables enhanced throughput, reduced delay and/or reduced energy consumption. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a sender for use in a multicast automatic repeat request (ARQ) communication system, comprising an arrangement for scheduling and encoding data packets for transmission in a multicast session from the sender to two receivers. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic flow diagram of a method for scheduling and encoding regular data packets into a composite data packet.

  • 15.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Exchange unit for multiplex speech and data signal transmission in communications network.1997Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The device includes an alternative path arrangement for preparing a connection between two arbitrary time slots, in the event that the control device can set up no regular path over the time module and space module. The space modules and time modules are provided for preparing connections between arbitrary time slots at inputs and outputs corresponding to connection demands, which are ascertained through the control device. USE - For control of blocked switching unit in communication network. ADVANTAGE - Provides communication network with low costs and high level of access. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method controlling the exchange unit. DESCRIPTION OF DRAWING(S) - The figure shows time and space modules, and alternative path arrangements, providing sequences different from time-space-time sequence. space module (SM) time module (TM) multiplexer (M) alternative path arrangement (AP) subscriber (A) control (C) connections (T)

  • 16.
    Larsson, Peter
    KTH, School of Electrical Engineering and Computer Science (EECS), Centres, ACCESS Linnaeus Centre.
    Golden Angle Modulation2018In: IEEE Wireless Communications Letters, ISSN 2162-2337, E-ISSN 2162-2345, Vol. 7, no 1, p. 98-101Article in journal (Refereed)
    Abstract [en]

    Quadrature amplitude modulation (QAM), with its uniform distribution, exhibits an asymptotic shaping-loss of pi e/6 (approximate to 1.53 dB) with increasing signal-to-noise-ratio compared to the additive white Gaussian noise Shannon capacity. With inspiration gained from special (leaf, flower petal, and seed) packing arrangements (spiral phyllotaxis) found among plants, a novel, shape-versatile, circular symmetric, modulation scheme, the golden angle modulation (GAM) is introduced. Disc-shaped, and complex Gaussian approximating bell-shaped, GAM-signal constellations are considered. For bell-GAM, a high-rate approximation, and a mutual information optimization formulation, are developed. Bell-GAM overcomes the asymptotic shaping-loss seen in QAM, and offers Shannon capacity approaching performance. Transmitter resource limited links, such as space probe-to-earth, and mobile-to-basestation, are cases where GAM could be particularly valuable.

  • 17.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Implicit Signaling for Link Adaptation2005Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - A designated originating node sends a message including an indication of current transmit duration corresponding to a currently assumed data link rate for transfer of predetermined amount of information to a designated receiving node. The designated receiving node selects a desired data link rate and determines an updated transmit duration according to desired data link rate. The designated receiving node sends a message indicating updated transmit duration to designated originating node that determines an updated data link rate. USE - For supporting link adaptation in wireless network such as cellular networks. ADVANTAGE - Efficient support for link adaptation in wireless networks, improved exploitation of the communication medium are achieved where changes in existing communication standards and additional overhead are eliminated. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) system for supporting link adaptation in wireless network; (2) receiving node in wireless network; and (3) transmitting node in wireless network. DESCRIPTION OF DRAWING(S) - The figure shows the flow diagram of the method for supporting link adaptation in wireless network.

  • 18.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Information transfer method for transferring information over link between two nodes, in which frame containing link data is transmitted between nodes such that receiving node can determine link mode.2001Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - A frame containing link data containing link mode for future transmissions is transmitted between nodes. The receiving node determines the link mode using the link data in the frame. Transmissions can then be made from the receiving node to the first node using the determined link node. USE - Link adaptation without transferring link mode information between communicating nodes. ADVANTAGE - Controls link adaptation without explicit link mode signaling. DETAILED DESCRIPTION - The method for transferring information between first and second nodes involves transmitting a frame from the first node to the second node. The frame contains link data enabling the determination of a link mode. Upon receipt of the frame at the second node, a determination is made of a link mode using the link data contained in the frame. Data is transmitted from the second node to the first node using the determined link node. INDEPENDENT CLAIMS are included for; a communications system; DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of the method of the invention.

  • 19.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Joint power and rate control for delay tolerant traffic in a wireless system2007In: 2007 IEEE 65TH VEHICULAR TECHNOLOGY CONFERENCE, VOLS 1-6, IEEE , 2007, p. 2822-2826Conference paper (Refereed)
    Abstract [en]

    A power and rate control scheme especially crafted for delay tolerant traffic under interfering link conditions is presented in this paper. Specifically, an iterative distributed algorithm, based on a sum-power constrained sum-rate maximization with upper (and lower) power and rate constraints, is developed. The feasibility and performance of the algorithm is demonstrated by simulation in a cellular system, where it is applied both for SISO and MIMO links. Simulations show significant improvement of the sum-rate vs. sum-power relation compared to both HSDPA-like "fixed power adaptive rate" and GSM-like "fixed rate adaptive power" radio resource management. Also, the method offers automatic re-use handling by silencing sub-optimal links. In a MIMO scenario, the sum-rate scales near linearly with the number of antenna elements.

  • 20.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Large-Scale cooperative relaying network with optimal coherent Combining under Aggregate Relay Power Constraints2003In: Proc. of the Future Telecommunications Conference (FTC2003), Beijing, China, Dec. 2003, 2003, p. 166-170Conference paper (Refereed)
    Abstract [en]

    Communication schemes exploiting cooperating relay nodes can enable significant SNR and diversity order enhancements. In this paper, a communicating pair of nodes with support from an arbitrary number of relay nodes cooperating in parallel is considered, and the optimal weighting parameters for coherent combining based non-regenerative relaying are derived under aggregate relay power constraint. The analysis demonstrates that each relay merely requires multiplying the received signal with an individual phase and amplitude factor and a common amplitude normalization factor. It is illustrated that the resulting SNR is substantially enhanced compared to direct communication and that SNR improves with increasing relay station density.

  • 21.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Lattice array receiver and sender for spatially orthonormal MIMO communication2005In: VTC2005-SPRING: 2005 IEEE 61ST VEHICULAR TECHNOLOGY CONFERENCE, VOLS 1-5, PROCEEDINGS, IEEE , 2005, p. 192-196Conference paper (Refereed)
    Abstract [en]

    In this paper, Line-of-Sight (LoS) oriented Multiple Input Multiple Output (MIMO) communication is examined. It is shown, that two opposing rectangular (as well as square and linear) lattice antenna arrays achieves the maximum attainable channel capacity, when a certain distance-wavelength condition is fulfilled. A relationship for large number of antenna elements is derived that connects LoS MIMO with US SISO channel capacity, through array aperture, wavelength and number of array antenna elements. Furthermore, a sensitivity study is performed for the proposed MIMO array arrangement that reveals high robustness against various array and antenna element position errors. Sensitivity against reflections is also examined, with the conclusion that the studied MIMO scheme appears less sensitive to reflections than a SISO system.

  • 22.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Method and architecture for wireless communication networks using cooperative relaying2003Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves determining specific and common transmission parameters for relay station based on which the signals are forwarded from one link between transmitter (210') and relay station, to another link between relay station and receiver (220'). USE - For communication in two hop wireless communication network. ADVANTAGE - Ensures more precise and reliable characterization of individual radio paths, and optimizes different transmission parameter, so as to fully exploit the network. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) relay station adapted in two hop wireless communication network; (2) system for communication in two hop wireless communication network; (3) receiver; (4) base station; and (5) mobile station. DESCRIPTION OF DRAWING(S) - The figure shows a schematic model used to describe the parameters and terms used in data communication. relay stations (215:1-215:k) transmitter (210') receiver (220')

  • 23.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Method and Arrangement for Arq Data Transmission2003Patent (Other (popular science, discussion, etc.))
  • 24.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Method and Arrangement for Improved Relaying2005Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - An orthogonal frequency division multiplexing (OFDM) symbol is formed and a signal comprising the OFDM symbol is transmitted to a relay node (20) and directly to a receiving node (30). The transmitted symbol is received, amplified and transmitted by the relay node with latency smaller than OFDM symbol duration, to the receiving node as relay signal in same frequency band. The superimposition of the direct and relay signal are concurrently received to enable constructive interference of OFDM symbol and the OFDM symbol free from inter symbol interference is provided. USE - For wireless communication relay system (claimed) such as cellular system, etc. ADVANTAGE - The quality of the signal is enhanced by the receiver by combining the direct and relayed signal and hence the overall communication performance is improved. A predictable and reliable constructive interference is provided between the direct and relayed signals in the receiving node. The signal to noise ratio (SNR) is enhanced and higher data rates are supported. 100% data rate increase is obtained. Different cooperative relaying (CR) schemes relying on the constructive interference, can be used. DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a wireless communication relay system. Transmitting node (10) Relay node (20) Receiving node (30)

  • 25.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Method and system for wireless communication networks using cooperative relaying2003Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves selecting relay channels (530:1-530:k) associated with the relay stations (415) having spatial overlap coverage at the mobile station, for establishing communication session between the base station and mobile station. USE - For communication such as multiple input-multiple output (MIMO) communication between base station (claimed) and mobile station in two-hop wireless communication network such as radio access network and cellular network. ADVANTAGE - The MIMO communication between the base station and mobile station is optimized using the relay stations without any increase in excessive control signaling over the air interface. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) system for communication in two-hop wireless network; (2) receiver; and (3) base station. DESCRIPTION OF DRAWING(S) - The figure shows a logical block diagram of the wireless communication system. relay station (415) base station transmitter (510) transmit antennas (513) mobile station receiver (520) relay channels (530:1-530:k) transmit channel (535)

  • 26.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Method for forwarding in multi-hop networks2000Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - An acknowledgement of a message is transmitted to originating node from candidate relay node that receives message from the originating node. A candidate node is selected to which a forwarding order is transmitted. An acknowledgement of forwarding order is transmitted from the selected node which is designed as the originating node. USE - For forwarding information through multihop networks. ADVANTAGE - Improves robustness by increasing transmission speed of the nodes. Maximizes efficiency by reducing high transmission power levels and hence reduces energy consumption. Supports concurrent, space-coinciding transmissions with enhanced reliability. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) Information forwarding system; and (2) Communication node. DESCRIPTION OF DRAWING(S) - The figure shows signaling procedure for forwarding information.

  • 27.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Method of encoding and scheduling data packets in communication system, involves forming composite data packets by combining two regular multicast data packets, when automatic repeat request is transmitted from receiving node.2006Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves transmitting the multicast data packets (A,B) from the sending node (105) to the receiving nodes (110,120). The acknowledgement message is transmitted from the receiving node to the sending node, when the transmitted data packets are received by the receiving node. The composite data packets are formed by combining two regularly transmitted multicast data packets, when an automatic repeat request (ARQ) is transmitted from the receiving node. USE - Method of encoding and scheduling data packets in sending node of communication system (both claimed). ADVANTAGE - Since the composite data packets are formed by combining two regularly transmitted multicast data packets, the transmission capability of the sending node can be improved. And the data packet loss in the communication system can be prevented. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) sending node; and (2) communication system. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the data transmission sequence in the communication system. Sending node (105) Receiving nodes (110,120) Multicast data packets (A,B)

  • 28.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Method, system and device for ARQ data transmission2003Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves transmitting several protocol data units (PDUs) in partially overlapped state, at different power levels. USE - For automatic repeat request of radio communication device (claimed) e.g. mobile terminal and radio base station in cellular radio communication system using universal mobile telecommunication system (UMTS) technique. ADVANTAGE - Ensures reliable user data transfer and data sequence integrity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) computer program product comprising computer storage medium for storing automatic repeat request program; (2) automatic repeat request system; and (3) radio communication device. DESCRIPTION OF DRAWING(S) - The figure shows a message sequence chart explaining the automatic repeat request method.

  • 29.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Methods and arrangements in a telecommunications system2000Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves providing multiple channel estimation in the field of space time coding in a radio communication system. Space time coding includes transmitter diversity, space(-time) multiplexing and other complex use of signal coding in time and space. USE - For wireless communication ADVANTAGE - Pilot signals are sent concurrently instead of consecutively in order to increase bandwidth efficiency during a multitude of channel transfer functions in OFDM and doing so, guaranteeing non-interfering channel estimates at low processing cost for both transmitter and receiver side. Provides channel estimation technique, which is very bandwidth efficient DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a wireless communication system, and an arrangement in a wireless communication system DESCRIPTION OF DRAWING(S) - The figure shows a schematic view illustrating pilot signal being sent concurrently.

  • 30.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Multicast multiuser ARQ2008In: WCNC 2008: IEEE WIRELESS COMMUNICATIONS & NETWORKING CONFERENCE, VOLS 1-7, 2008, p. 1985-1990Conference paper (Refereed)
    Abstract [en]

    In this paper, multiuser ARQ is extended to multicasting. The core idea is that the sender, based on feedback from users regarding successfully received transmissions, adapts code weights for data packet linear combinations that are then sent. Each user exploits its previously received information in decoding the linearly combined packets. Specifically, a throughput optimal, low en-/decoding complexity enabling, low overhead and on-line multicast coding and scheduling algorithm is devised based on a per user rank increase criterion. For throughput optimality, a minimum field size criterion is derived. Relative previous work, which adaptively identifies sets of users suited to receive linearly combined packets and uses GF(2) and XOR coding, the proposed method adaptively select weights from a sufficient large finite field for optimality instead. Throughput is analyzed and simulated, and en-/decoding complexity, signaling overhead, and latency etc. are studied through realistic simulations. Overall, it is found that the throughput is significantly higher than multicast Selective Repeat ARQ, and that the optimal throughput for an erasure channel is attained.

  • 31.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Multiplexing communicating method, involves partitioning signal constellation of signal modulation such that intra-subset distances decreases for increased resolution levels, and scheduling communication data flows.2004Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves allocating communications to resolution levels of a signal modulation based on propagation conditions. A particular user is allocated to a particular resolution level based on time averaged channel quality information. A signal constellation of the modulation is partitioned such that intra-subset distances decreases for increased resolution levels, and communication data flows are scheduled. USE - Used for communicating multiplexing. ADVANTAGE - The method effectively provides channel resources without causing excessive interference between user`s individual communications, and achieves spectrum efficient multiplexing. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a radio communication system comprising radio communication equipment. DESCRIPTION OF DRAWING(S) - The drawing shows a communication situation.

  • 32.
    Larsson, Peter
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    On Performance Analysis of Retransmission Schemes with Fading Channels2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Future wireless communication systems and services bring increased performance demands, with respect to data-rate(s), reliable communication, (stochastic) real-time guarantees, and more. In this context, not only new communication schemes are needed, but also more capable performance analysis methods are essential. Digital wireless communication systems convey information (digital messages, as data packets) inherently susceptible to errors when communicated. In this respect, fading channels, receiver noise, and interference, are often the main causes of errors. State-of-the-art wireless systems use, e.g., retransmissions (and channel coding) to correct possible remaining errors in communicated message. Retransmissions of erroneous messages are generally known, under the umbrella-term, as automatic repeat request. Adopting a modern terminology (see Chapter 2.2), the three main schemes are here denoted; automatic repeat request (ARQ), repetition redundancy hybrid-ARQ (RR-HARQ), and incremental redundancy hybrid-ARQ (IR-HARQ). There are at least three factors that motivate further performance studies of the ARQ-, RR-, and IR-schemes. First, many commercially important and extensively deployed wireless systems, e.g. cellular systems, use those (H)ARQ-schemes as core system components. Second, those schemes are often integrated with various (recently invented) communication schemes, such as multiple-antenna systems, which promote the need of further studies. Third, the information theoretically-based performance characterization of those (H)ARQ-schemes is, in our view, only in its infancy, and only a few closed-form expressions for very basic (H)ARQ-cases exists in the literature. The thesis deals, on a high level, with the problem of developing performance analysis methods for (H)ARQ-schemes, and, on a more detailed level, studying particularly important (H)ARQ-cases, i.e. with respect to (wrt) (H)ARQ-scheme, fading statistics, antenna-scheme, etc. In doing so, the thesis addresses tools and models that support, ease, or strengthen the analysis.

    We start our study with a basic throughput analysis of (H)ARQ (Chapter 4). A general throughput expression for HARQ is given in terms of the Laplace-transform (LT) for the probability density function (pdf) of a so called effective-channel. Here, the effective-channel represents the signal-to-noise-ratio (SNR), or mutual information (MI), after signal processing. We then focus on some important (H)ARQ-cases and give closed-form throughput expressions in a general diversity (GD) channel, accounting for space-time-block coding (STC), maximal ratio combining (MRC), and Nakagami-m fading. The throughput of (H)ARQ can, in many cases, be maximized by tuning the initial transmission rate. However, analytical throughput optimization has proven challenging to solve even for the simplest (H)ARQ-cases. We propose a parametric optimization approach, based on judiciously chosen parameter, that allows expressions for the optimal throughput, and the optimal rate point, to be given in closed-forms (Chapter 5). The method is demonstrated for several important, but previously not handled, (H)ARQ-cases. An inherent assumption in this thesis, shared with many other works in wireless communication analysis, is the assumption of that the average symbol MI equals the additive white Gaussian noise (AWGN) channel capacity. The underlying assumption is that the communication symbol can be modeled as an independent and identically distributed (iid) complex Gaussian random variable (r.v). However, practical systems use discrete modulation, not a continuous r.v. Quadrature amplitude modulation (QAM) is the most common (discrete) modulation format in communication systems. Unfortunately, QAM exhibits an asymptotic 1.53 dB SNR-gap relative to the AWGN channel capacity. We substantiate the assumption, of modeling the communication signal as iid complex Gaussian, and close the SNR-shaping-gap, by proposing a novel modulation framework inspired from packing arrangements (spiral-phyllotaxis) among plants (Chapter 6). Much work on wireless performance analysis focus on specialized fading channel gain models, such as exponentially- or gamma-distributed fading. We introduce the idea of a matrix exponential (ME) distributed effective channel SNR (Chapter 7). The ME-distribution is dense on the positive axis, and includes the exponential- and gamma-distribution as special cases. With the ME-distributed channel at hand, we develop an overall ME-distribution-based framework that simplifies the performance analysis and directly express performance measures in the ME-distributed (effective) channel parameters. It has proven hard to analyze (H)ARQ with interference via standard methods, and only special cases have previously been handled successfully. With the ME-distribution-based performance analysis framework, we can now analyze interferers with ME-distributed SNRs. Numerous closed-form throughput expressions are also given in terms of ME-distribution-based channels. Up to this point, the performance measure of choice has been throughput. However, communication systems may impose delay requirements. For this purpose, the effective capacity, giving an indication of communication rate for a given maximum delay and delay violation probability, is a more suitable performance measure. We formulate a very general retransmission system model (allowing for multiple transmissions, multiple communication modes, and multiple rate increments), going beyond classical ARQ-, RR-, and IR-models, and develop a powerful recurrence-based effective capacity performance analysis framework (Chapter 8).

    Thus, to summarize on a high-level, we introduce a simplifying LT-based performance analysis framework, develop a powerful auxiliary-parameterized throughput optimization method, propose a novel AWGN channel capacity approaching (golden angle) modulation scheme, introduce the ME-distributed channel, develop the ME-distribution-based performance analysis framework, design a highly general retransmission system model, and propose a recurrence-based (effective capacity) performance analysis framework. Throughout the thesis, numerous new closed-form performance expressions are given built on the tools and models introduced in the preceding chapters.

  • 33.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Packet data transmission method for wireless communication system, involves comparing sensitivity value for each modulated packet data unit per flow based on measured modulated packet data units.2004Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves determining value of sensitivity related to non-ideal characteristics of transmitter for each modulated packet data unit (PDU). The determined sensitivity value for each of modulated PDU per flow is compared, based on measured modulated PDUs. The modulated PDU with the lowest sensitivity value is selected and transmitted. USE - For base station of cellular communication system using orthogonal frequency division multiplexing (OFDM) technique. ADVANTAGE - The transmission performance is improved. The errors in the transmitted packet data unit are minimized. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) transmitter; and (2) computer program product for packet data transmission. DESCRIPTION OF DRAWING(S) - The figure shows a flow diagram of the packet data transmission process.

  • 34.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Selection diversity forwarding in a multihop packet radio network with fading channel and capture2001In: MobiHoc '01 Proceedings of the 2nd ACM international symposium on Mobile ad hoc networking & computing, 2001, p. 279-282Conference paper (Refereed)
    Abstract [en]

    Recent and increased interest of wireless mobile ad hoc networking motivates detailed examination of routing schemes specifically targeted for the demanding constraints that an unreliable, time varying and braodcast like wireless medium imposes. Incorporation and exploitation of radio characteristics are fundamental keys to successful and near optimal operation of routing schemes in a wireless environment. In this paper, for warding methods for wireless mobile multihop networking in Rayleigh fading and non-fading channels are examined. An adaptive forwarding scheme denoted Selection Diversity Forwarding (SDF) is introduced and compared with two classical forwarding methods. It is shown that SDF presents significant peformance improvements. In particular and in constrast to the reference methods NFP and MFR, the performance of SDF is enhanced under fading channel conditions. It is found that local path adaptation has potential to perform better than routing approaches along a single path

  • 35.
    Larsson, Peter
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Selection diversity forwarding in a multihop packet radio network with fading channel and capture2001In: ACM SIGMOBILE Mobile Computing and Communications Review, Vol. 5, no 4, p. 47-54Article in journal (Refereed)
    Abstract [en]

    Recent and increased interest of wireless mobile ad hoc networking motivates detailed examination of routing schemes specifically targeted for the demanding constraints that an unreliable, time varying and broadcast like wireless medium imposes. Incorporation and exploitation of radio characteristics are fundamental keys to successful and near optimal operation of routing schemes in a wireless environment. In this paper, forwarding methods for wireless mobile multihop networking in Rayleigh fading and non-fading channels are examined. An adaptive forwarding scheme denoted Selection Diversity Forwarding (SDF) is introduced and compared with two classical forwarding methods. It is shown that SDF presents significant performance improvements. In particular and in contrast to the reference methods NFP and MFR, the performance of SDF is enhanced under fading channel conditions. It is found that local path adaptation has potential to perform better than routing approaches along a single path.

  • 36.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    E, DAHLMAN
    Method and system of radio communications of traffic with different characteristics2003Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The traffic from at least two information sources is divided into two or more categories, for transfer with different characteristics such as time scale of power control adjustments. The traffic is transmitted on physically wholly or partially separated channels. USE - For communicating data traffic or voice traffic in cellular radio communication system (claimed). ADVANTAGE - Provides increased immunity to interference from communication channels, thereby increasing system performance and data rate. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) radio communication equipment; and (2) cellular radio communication system. DESCRIPTION OF DRAWING(S) - The figure shows the radio communication cells with base station. base stations (BS1,BS2)

  • 37.
    Larsson, Peter
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Gross, James
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Al-Zubaidy, Hussein
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Rasmussen, Lars Kildehöj
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Effective Capacity of Retransmission Schemes: A Recurrence Relation Approach2016In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 64, no 11, p. 4817-4835Article in journal (Refereed)
    Abstract [en]

    We consider the effective capacity performance measure of persistent-and truncated-retransmission schemes that can involve any combination of multiple transmissions per packet, multiple communication modes, or multiple packet communication. We present a structured unified analytical approach, based on a random walk model and recurrence relation formulation, and give exact effective capacity expressions for persistent hybrid automatic repeat request (HARQ) and for truncated-retransmission schemes. For the latter, effective capacity expressions are given for systems with finite (infinite) time horizon on an algebraic (spectral radius-based) form of a special block companion matrix. In contrast to prior HARQ models, assuming infinite time horizon, the proposed method does not involve a non-trivial per case modeling step. We give effective capacity expressions for several important cases that have not been addressed before, e.g., persistent-HARQ, truncated-HARQ, network-coded ARQ, two-mode-ARQ, and multilayer-ARQ. We propose an alternative quality-of-service-parameter (instead of the commonly used moment generating function parameter) that represents explicitly the target delay and the delay violation probability. This also enables the closed-form expressions for many of the studied systems. Moreover, we use the recently proposed matrix-exponential distributed modeling of wireless fading channels to provide the basis for numerous new effective capacity results for HARQ.

  • 38.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    H, SAHLIN
    Methods and arrangements in a wireless communication system for producing signal structure with cyclic prefix2008Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The processing method involves transmitting a first symbol of sequence preceded by first cyclic-prefix. A second symbol of the sequence preceded by a second cyclic-prefix is transmitted. The second symbol comprises the samples of the first symbol shifted so that the last sample of the first symbol and the first sample of the second cyclic prefix are cyclically consecutive. USE - Processing method for producing signal structure with cyclic prefix in wireless communication system. ADVANTAGE - Allows handling of very large signal delay spreads in any system using cyclic-prefix insertion. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) a transmitting unit; and (2) a receiving unit. DESCRIPTION OF DRAWING(S) - The drawing shows the schematic diagram of the placement of two Fast Fourier transform windows giving signal to noise ratio enhancements of the signal through combining. Extended symbol (500) Effective cyclic-prefix duration (501) Fast Fourier transform windows (502,503) Extracted signals (504,505) Combines extracted signals (506)

  • 39.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    J, GUEY
    Method for calibrating transmission portion of node in wireless communication network, involves compensating radio transmission from radio node using correction factor based on exchanged representation of radio channel characteristics.2003Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves compensating radio transmissions from a radio node using correction factor that is based on the representation of radio channel characteristics exchanged between the radio nodes. USE - For calibrating transmission portion of node in wireless communication network. ADVANTAGE - Enables achieving reciprocity between radio nodes, thereby optimizing coding and mapping at the transmitter which requires an accurate forward channel estimation hence communication performance is improved. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) communication system; (2) radio node; and (3) computer program comprising calibration program. DESCRIPTION OF DRAWING(S) - The figure shows the message sequence chart.

  • 40.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    J, JOHANSSON N
    Beacon message transmission method between radio nodes in ad-hoc or multihop network, involves determining beacon transmit power at which radio node transmits beacons, based on estimate of network dynamics.2003Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves determining the beacon transmit power at which a radio node transmits the beacons, based on the estimate of network dynamics. USE - For transmitting beacon messages between mobile radio nodes such as cellular phone, laptop computer and personal digital assistant (PDA) in ad-hoc or multihop networks. ADVANTAGE - Enables increasing the accuracy of topology map, and maintaining connections efficiently when topology changes, also enables reducing the power consumption of radio nodes, thereby improving the durability of battery of mobile radio nodes. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) radio node; (2) computer program product comprising computer storage medium storing beacon message transmission program; and (3) system of radio nodes. DESCRIPTION OF DRAWING(S) - The figure shows a flowchart explaining the beacon message transmission process.

  • 41.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Johansson, Niklas
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Multi-User ARQ2006In: 2006 IEEE 63RD VEHICULAR TECHNOLOGY CONFERENCE, VOLS 1-6, IEEE , 2006, p. 2052-2057Conference paper (Refereed)
    Abstract [en]

    This paper presents a novel ARQ scheme for multiple unicast flows in a multi-user system, which enhances the aggregate throughput efficiency. The core idea is to exploit knowledge of previously overheard packets by unintended users, and perform wise selection and joint encoding of any retransmitted information. Intended users may decode the jointly encoded packet by exploiting the previously overheard packets. It is found that the throughput efficiency in a K-user system approaches, the fairly remarkable result of, unit value when K goes to infinity. Moreover, complexity and overhead of the scheme is studied and a link to (feedback free) network coding is established.

  • 42.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Johansson, Niklas
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Multiuser diversity forwarding in multihop packet radio networks2005In: 2005 IEEE Wireless Communications and Networking Conference, Vols 1-4: WCNC 2005: BROADBAND WIRELESS FOR THE MASSES READY FOR TAKE-OFF., IEEE , 2005, p. 2188-2194Conference paper (Refereed)
    Abstract [en]

    Multihop packet radio networking promises increased data rates and enhanced coverage in wireless networks. In this paper, we propose a new high performing low complexity multihop forwarding scheme, denoted multi-user diversity forwarding (MDF), that efficiently exploits inherent radio channel characteristics. The scheme is founded on a crosslayer paradigm, which enables a transmitting node to perform instant rate adaptation as well as to select among relays and among flows, thereby taking full advantage of the inherent multiuser diversity. The relative performance of MDF is benchmarked against two reference schemes, Nearest with Forward Progress (NFP) and Selection Diversity Forwarding (SDF). The simulations indicate that the proposed scheme yields a substantial throughput increase.

  • 43.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Johansson, Niklas
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Sunell, Kai-Erik
    Coded Bi-directional Relaying2006In: 2006 IEEE 63RD VEHICULAR TECHNOLOGY CONFERENCE, VOLS 1-6, 2006, p. 851-855Conference paper (Refereed)
    Abstract [en]

    In this paper, bi-directional traffic between two nodes communicating via a relay node is considered. A novel relaying method based on joint data packet encoding in conjunction with exploitation of a priori known information is presented. Moreover, a specially crafted method for combining of the direct and relayed radio signal is suggested. The proposed scheme enables a reduced number of transmissions, whereby enhancing aggregate throughput. Evaluation, where optimal power and rate settings are derived, shows that the proposed method enhances the throughput up to 33% as compared to a (traditional) four-phase bi-directional protocol under a system energy constraint, both with and without the proposed combining method.

  • 44.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Johansson, Niklas
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Sunell, Kai-Erik
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Coded Bi-directional Relaying2005In: Proceedings of the Scandinavian Wireless Adhoc Workshop 05, Johannesberg, 3-4 May, 2005, 2005Conference paper (Other academic)
    Abstract [en]

    In this summary, we consider bi-directional communication between a transmitter and receiver communicating via a relay station. We present a novel communication method based on joint data packet encoding in conjunction with exploitation of a priori known information that enables reduced number of transmissions, whereby enhancing aggregate throughput.

  • 45.
    Larsson, Peter
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Kronander, Jonas
    Ericsson Research, Kista, Sweden.
    Joint power, Rate, and Channel Allocation in Multilink (Cognitive) Radio System2009In: Milcom 2009, Boston USA, Nov. 2009, IEEE , 2009Conference paper (Refereed)
    Abstract [en]

    We consider multi-constrained power, rate and channelallocation crafted for low power consumption, delaytolerant traffic, and under interfering link conditions thatmay be used in a cognitive radio system. Specifically, aniterative distributed algorithm, based on a sum-powerconstrained sum-rate maximization with upper (andlower) per user and channel power and rate constraints,as well as upper per user sum-power and sum-rateconstraints is developed. The feasibility and performanceof the algorithm is demonstrated by simulation in acellular system. Simulations show that the multipleconstraints are handled while improving the sum-rate vs. sum-power relative an “equal power adaptive rate” RRM approach.

  • 46.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    M, LARSSON
    Method and apparatus for discarding packets in a data network having automatic repeat request1998Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - A receiver in the data network is commanded to receive data packet having sequence number by inputting ARQ scheme in data network. The erroneous or unreceived data packets are then discarded. Then, sequence numbers are assigned to the non-discarded packets, that are yet to be received, so that transmitted stream of data packets will have consecutive sequence numbers. USE - For discarding data packet in wireless data network. Also used for telephony, video conferencing system. ADVANTAGE - Ensures reliable data transfer to protect data sequence integrity, as ARQ technique is used. Since the delayed or outdated data packets are transmitted correctly, bandwidth minimization is achieved and hence data packet life time is prolonged. DESCRIPTION OF DRAWING(S) - The figure shows receiver packet enforcement bit in data packet discharging method.

  • 47.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    M, LARSSON
    Transmission method for sender and receiver information in wireless asynchronous data transfer system.1998Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The data word of a PDU is encoded as a function of an identification vector, without increasing the bandwidth required for transmission of the PDU from the sender to the receiver. The vector includes a priori identification information regarding the sender and the receiver, and a corresponding data frame is sent from the sender to the receiver. USE - For transmitting sender and receiver information such as access point and wireless terminal identifier data in a wireless asynchronous data transfer system. ADVANTAGE - Ensures that the wireless terminal receives and decodes only intended downlink transmissions. The data integrity and the transmission security are enhanced, without diminishing the bandwidth efficiency. Permits wireless terminal or access point to recognize an unintended data, and enables the discarding of the transmission. DETAILED DESCRIPTION - A protocol data unit (PDU) with a data word is generated at the sender side. An INDEPENDENT CLAIM is also included for receiver status determination method. DESCRIPTION OF DRAWING(S) - The figure indicates the transportation of sender and receiver identification information.

  • 48.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    M, LARSSON
    G, Malmgren
    H, LI
    Mobile terminal initiated and assisted antenna selection2003Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves transmitting sector messages from the base station, where each sector message is associated with a corresponding sector of the cell. The sector messages transmitted by the base station are received at a mobile terminal and a signal quality associated with each receiver sector messages is determined. At the mobile terminal one of multiple antennas is selected as a function of the signal quality determination. An antenna selection request message is transmitted from the mobile terminal to the base station. USE - For cellular network. ADVANTAGE - Improves the BS antenna selection process in cellular, broadband access network which employs multiple antennas per BS. Improves signal quality of communication links between MTs and corresponding BS which employs multiple antennas. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for an apparatus for selecting one of the multiple antennas. DESCRIPTION OF DRAWING(S) - The figure shows a technique for selecting in accordance with an embodiment of the invention.

  • 49.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    M, LARSSON
    P, LJUNGGREN
    Packet loss tolerant reshaping method1999Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves receiving data packets from a source. The transmission time for each received data packet is calculated based on the automatic repeat request (ARQ) sequence number of the received data packet and peak packet rate (PR). The time intervals between data packets, transported in a local area network (LAN) system with data link control (DLC) layer, are then restored. USE - For reshaping streams of data packets or cells in a communications network. ADVANTAGE - Restores or maintains proper time intervals between packets of cells in a stream to efficiently and effectively detect and handle situations where one or more packets are lost or discarded. Ensures that output stream of packets or cells from DLC reshaper is not slipped or shifted in phase and does not include jitters. Determines specific transmission times for packets or cells in the stream based on peak cell rate (PCR), ARQ sequence numbers and reference time e.g. transmission time or first packet or cell. Improves performance of synchronous application e.g. codec, and copes with packet loss by repeating preceding packet or inserting background noise in output stream in lieu of lost packet. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for the LAN system with DLC layer. DESCRIPTION OF DRAWING(S) - The figure shows the DLC reshaper in a wireless asynchronous transfer mode (WATM) network.

  • 50.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    N, JOHANSSON
    Cost determination method for multihop communication network, involves determining simultaneously potential next hop nodes for one node from source node to destination node, so that potential node jointly optimizes preset cost function.2003Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - Several simultaneously potential next hop nodes are determined for one of multiple nodes from a source node (S) to destination node (d) in the network, such that the potential node jointly optimizes preset cost function. The optimal cost for multiple nodes, is determined to be equal to the optimized value of the preset cost function. USE - For determination of cost in multihop communication network. ADVANTAGE - Provides robustness under node failure, varying node availability and node mobility. Provides robustness under varying channel quality due to fading and interference. Supports multipath routing. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) system for cost determination in multihop communication network; (2) method for cost optimization in routing protocol; and (3) node in multihop communication network. DESCRIPTION OF DRAWING(S) - The figure shows the multihop network schematically. destination node (d) node (i) source node (S) subset (S')

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