The Experts below are selected from a list of 1428 Experts worldwide ranked by ideXlab platform

Stefan Parkvall - One of the best experts on this subject based on the ideXlab platform.

  • evolving 3g mobile systems broadband and broadcast services in wcdma
    IEEE Communications Magazine, 2006
    Co-Authors: Stefan Parkvall, E Englund, M Lundevall, Johan Torsner
    Abstract:

    The third-generation WCDMA standard has been Enhanced to offer significantly increased performance for packet data and broadcast services through the introduction of high-speed downlink packet access (HSDPA), Enhanced Uplink, and multimedia broadcast multicast services (MBMS). This article provides an overview of the key technologies used, the reasons behind their selection, and their integration into WCDMA. Performance results are also included to exemplify the performance possible in an evolved WCDMA network.

  • end to end performance of wcdma Enhanced Uplink
    Vehicular Technology Conference, 2005
    Co-Authors: Janne Peisa, Hannes Ekstrom, Hans Hannu, Stefan Parkvall
    Abstract:

    In this paper we study the end-to-end performance of the Enhanced Uplink of WCDMA. We present results for latency and TCP performance on both Uplink and downlink when using the Enhanced Uplink. The results show that the Enhanced Uplink can significantly improve the end-to-end performance of both for up- and downlink oriented traffic when compared to the Uplink provided by 3GPP R5. The expected performance depends strongly on the configuration of the Enhanced Uplink, especially on the HARQ operating point.

  • system performance of wcdma Enhanced Uplink
    Vehicular Technology Conference, 2005
    Co-Authors: Ke Wang Helmersson, Stefan Parkvall, Eva Englund, Maria Edvardsson, Christer Edholm, M Samuelsson, Yipin Wang, Jungfu Cheng
    Abstract:

    We present the potential performance improvements attainable by new enhancements to the WCDMA Uplink. Improvements can be expected in both system capacity and end-user perceived performance. In this paper we focus on the capacity gains of short TTI, hybrid ARQ and scheduling in node-B. The performance is studied from both the link-level and system-level perspectives. The link performance results focus on the gains obtained by the introduction of short TTI and hybrid ARQ with soft combining in node-B. In the system performance results, we also evaluate node-B based rate scheduling for both 2 ms TTI and 10 ms TTL. Our studies indicate that with the introduction of Enhanced Uplink the gain in Uplink capacity can be in the order of 70-100%.

  • wcdma Enhanced Uplink principles and basic operation
    Vehicular Technology Conference, 2005
    Co-Authors: Stefan Parkvall, Janne Peisa, Johan Torsner, Mats Sagfors, Peter Malm
    Abstract:

    The WCDMA Uplink has recently been Enhanced with hybrid ARQ, scheduling, and shorter TTI to provide improved performance for packet data services in terms of reduced delays, improved availability of high data rates, and increased capacity. This paper gives an overview of the design targets, the basic principles, and how they are integrated into WCDMA.

Janne Peisa - One of the best experts on this subject based on the ideXlab platform.

  • end to end performance of wcdma Enhanced Uplink
    Vehicular Technology Conference, 2005
    Co-Authors: Janne Peisa, Hannes Ekstrom, Hans Hannu, Stefan Parkvall
    Abstract:

    In this paper we study the end-to-end performance of the Enhanced Uplink of WCDMA. We present results for latency and TCP performance on both Uplink and downlink when using the Enhanced Uplink. The results show that the Enhanced Uplink can significantly improve the end-to-end performance of both for up- and downlink oriented traffic when compared to the Uplink provided by 3GPP R5. The expected performance depends strongly on the configuration of the Enhanced Uplink, especially on the HARQ operating point.

  • wcdma Enhanced Uplink principles and basic operation
    Vehicular Technology Conference, 2005
    Co-Authors: Stefan Parkvall, Janne Peisa, Johan Torsner, Mats Sagfors, Peter Malm
    Abstract:

    The WCDMA Uplink has recently been Enhanced with hybrid ARQ, scheduling, and shorter TTI to provide improved performance for packet data services in terms of reduced delays, improved availability of high data rates, and increased capacity. This paper gives an overview of the design targets, the basic principles, and how they are integrated into WCDMA.

Johan Torsner - One of the best experts on this subject based on the ideXlab platform.

  • evolving 3g mobile systems broadband and broadcast services in wcdma
    IEEE Communications Magazine, 2006
    Co-Authors: Stefan Parkvall, E Englund, M Lundevall, Johan Torsner
    Abstract:

    The third-generation WCDMA standard has been Enhanced to offer significantly increased performance for packet data and broadcast services through the introduction of high-speed downlink packet access (HSDPA), Enhanced Uplink, and multimedia broadcast multicast services (MBMS). This article provides an overview of the key technologies used, the reasons behind their selection, and their integration into WCDMA. Performance results are also included to exemplify the performance possible in an evolved WCDMA network.

  • wcdma Enhanced Uplink principles and basic operation
    Vehicular Technology Conference, 2005
    Co-Authors: Stefan Parkvall, Janne Peisa, Johan Torsner, Mats Sagfors, Peter Malm
    Abstract:

    The WCDMA Uplink has recently been Enhanced with hybrid ARQ, scheduling, and shorter TTI to provide improved performance for packet data services in terms of reduced delays, improved availability of high data rates, and increased capacity. This paper gives an overview of the design targets, the basic principles, and how they are integrated into WCDMA.

Hailiang Yang - One of the best experts on this subject based on the ideXlab platform.

  • Enhanced Uplink resource allocation in non orthogonal multiple access systems
    IEEE Transactions on Wireless Communications, 2018
    Co-Authors: Rukhsana Ruby, Shuxin Zhong, Hailiang Yang
    Abstract:

    Non-orthogonal multiple access (NOMA) is envisioned to be one of the most beneficial technologies for next generation wireless networks due to its Enhanced performance compared with other conventional radio access techniques. Although the principle of NOMA allows multiple users to use the same frequency resource, due to decoding complication, the information of users in practical systems cannot be decoded successfully if many of them use the same channel. Consequently, assigned spectrum of a system needs to be split into multiple subchannels in order to multiplex that among many users. Uplink resource allocation for such systems is more complicated compared with the downlink ones due to the individual users’ power constraints and the discrete nature of subchannel assignment. In this paper, we propose an Uplink subchannel and power allocation scheme for such systems. Due to the NP-hard and non-convex nature of the problem, the complete solution, that optimizes both subchannel assignment and power allocation jointly, is intractable. Consequently, we solve the problem in two steps. First, based on the assumption that the maximal power level of a user is subdivided equally among its allocated subchannels, we apply many-to-many matching model to solve the subchannel-user mapping problem. Then, in order to enhance the performance of the system further, we apply iterative water-filling and geometric programming two power allocation techniques to allocate power in each allocated subchannel-user slot optimally. Extensive simulation has been conducted to verify the effectiveness of the proposed scheme. The results demonstrate that the proposed scheme always outperforms all existing works in this context under all possible scenarios.

  • Enhanced Uplink resource allocation in non orthogonal multiple access systems
    arXiv: Information Theory, 2017
    Co-Authors: Rukhsana Ruby, Shuxin Zhong, Hailiang Yang
    Abstract:

    Non-orthogonal multiple access (NOMA) is envisioned to be one of the most beneficial technologies for next generation wireless networks due to its Enhanced performance compared to other conventional radio access techniques. Although the principle of NOMA allows multiple users to use the same frequency resource, due to decoding complication, information of users in practical systems cannot be decoded successfully if many of them use the same channel. Consequently, assigned spectrum of a system needs to be split into multiple subchannels in order to multiplex that among many users. Uplink resource allocation for such systems is more complicated compared to the downlink ones due to the individual users' power constraints and discrete nature of subchannel assignment. In this paper, we propose an Uplink subchannel and power allocation scheme for such systems. Due to the NP-hard and non-convex nature of the problem, the complete solution, that optimizes both subchannel assignment and power allocation jointly, is intractable. Consequently, we solve the problem in two steps. First, based on the assumption that the maximal power level of a user is subdivided equally among its allocated subchannels, we apply many-to-many matching model to solve the subchannel-user mapping problem. Then, in order to enhance the performance of the system further, we apply iterative water-filling and geometric programming two power allocation techniques to allocate power in each allocated subchannel-user slot optimally. Extensive simulation has been conducted to verify the effectiveness of the proposed scheme. The results demonstrate that the proposed scheme always outperforms all existing works in this context under all possible scenarios.

Rahim Tafazolli - One of the best experts on this subject based on the ideXlab platform.

  • integrated radio resource allocation for multihop cellular networks with fixed relay stations
    IEEE Journal on Selected Areas in Communications, 2006
    Co-Authors: Yajian Liu, Reza Hoshyar, Xinjie Yang, Rahim Tafazolli
    Abstract:

    Recently, the notion that a logical next step towards future mobile radio networks is to introduce multihop relaying into cellular networks, has gained wide acceptance. Nevertheless, due to the inherent drawbacks of multihop relaying, e.g., the requirement for extra radio resources for relaying hops, and the sensitivity to the quality of relaying routes, multihop cellular networks (MCNs) require a well-designed radio resource allocation strategy in order to secure performance gains. In this paper, the optimal radio resource allocation problem in MCNs, with the objective of throughput maximization, is formulated mathematically and proven to be NP-hard. Considering the prohibitive complexity of finding the optimal solution for such an NP-hard problem, we propose an efficient heuristic algorithm, named integrated radio resource allocation (IRRA), to find suboptimal solutions. The IRRA is featured as a low-complexity algorithm that involves not only base station (BS) resource scheduling, but also routing and relay station (RS) load balancing. Specifically, a load-based scheme is developed for routing. A mode-aware BS resource-scheduling scheme is proposed for handling links in different transmission modes, i.e., direct or multihop. Moreover, a priority-based RS load balancing approach is presented for the prevention of the overloading of RSs. Within the framework of the IRRA, the above three functions operate periodically with coordinated interactions. To prove the effectiveness of the proposed IRRA algorithm, a case study was carried out based on Enhanced Uplink UMTS terrestrial radio access/frequency-division duplex with fixed RSs. The IRRA is evaluated through system level simulations, and compared with two other cases: 1) nonrelaying and 2) relaying with a benchmark approach. The results show that the proposed algorithm can ensure significant gains in terms of cell throughput

  • on the radio resource allocation in Enhanced Uplink utra fdd with fixed relay stations
    Personal Indoor and Mobile Radio Communications, 2005
    Co-Authors: Yajian Liu, Reza Hoshyar, Xinjie Yang, Rahim Tafazolli
    Abstract:

    In this paper, an integrated radio resource allocation (IRRA) algorithm is proposed for Enhanced Uplink UTRA-FDD with fixed relay stations (RSs). It comprises three entities: load based route manager (LBRM), base station resource scheduler (BSRS), and relay station load balancer (RSLB). LBRM is responsible for the selection of user transmission routes, BSRS is for the scheduling of user transmission time and rates based on the available base station (BS) capacity, and RSLB is for the fine-tuning of user resource assignments (e.g. assigned rates) so as to prevent the overloading of RSs. The three entities operate periodically, synchronously, and with coordinated interactions. By system level simulations, the proposed algorithm is evaluated and compared with two other cases: 1) non-relaying, 2) relaying with a benchmark approach. The results show that IRRA can ensure significant gains in terms of cell throughput