IEICE Transactions on Communications
Online ISSN : 1745-1345
Print ISSN : 0916-8516
E100.B 巻, 3 号
選択された号の論文の9件中1~9を表示しています
Regular Section
  • Shujuan WANG, Chunting YAN
    原稿種別: PAPER
    専門分野: Fundamental Theories for Communications
    2017 年 E100.B 巻 3 号 p. 407-416
    発行日: 2017/03/01
    公開日: 2017/03/01
    [早期公開] 公開日: 2016/09/12
    ジャーナル 認証あり

    In this work, we study efficient scheduling with network coding in a scalable video coding (SVC) multicast system. Transmission consists of two stages. The original SVC packets are multicasted by the server in the first stage and the lost packets are retransmitted in the second stage. With deadline constraint, the consumer can be only satisfied when the requested packets are received before expiration. Further, the hierarchical encoding architecture of SVC introduces extra decoding delay which poses a challenge for providing acceptable reconstructed video quality. To solve these problems, instantly decodable network coding is applied for reducing the decoding delay, and a novel packet weighted policy is designed to better describe the contribution a packet can make in upgrading the recovered video quality. Finally, an online packet scheduling algorithm based on the maximal weighted clique is proposed to improve the delay, deadline miss ratio and users' experience. Multiple characteristics of SVC packets, such as the packet utility, the slack time and the number of undelivered/wanted packets, are jointly considered. Simulation results prove that the proposed algorithm requires fewer retransmissions and achieves lower deadline miss ratio. Moreover, the algorithm enjoys fine recovery video quality and provides high user satisfaction.

  • Stephane KAPTCHOUANG, Hiroki TAHARA, Eiji OKI
    原稿種別: PAPER
    専門分野: Internet
    2017 年 E100.B 巻 3 号 p. 417-425
    発行日: 2017/03/01
    公開日: 2017/03/01
    [早期公開] 公開日: 2016/10/06
    ジャーナル 認証あり

    Link duplication is widely used in Internet protocol networks to tackle the network congestion increase caused by link failure. Network congestion represents the highest link utilization over all the links in the network. Due to capital expenditure constraints, not every link can be duplicated to reduce congestion after a link fails. Giving priority to some selected links makes sense. Meanwhile, traffic routes are determined by link weights that are configured in advance. Therefore, choosing an appropriate set of link weights reduces the number of links that actually need to be duplicated in order to keep a manageable congestion under failure. A manageable congestion is a congestion under which Service Level Agreements can be met. The conventional scheme fixes link weights before determining links to duplicate. In this scheme, the fixed link weights are optimized to minimize the worst network congestion. The worst network congestion is the highest network congestion over all the single non-duplicated link failures. As the selection of links for protection depends on the fixed link weights, some suitable protection patterns, which are not considered with other possible link weights, might be skipped leading to overprotection. The paper proposes a scheme that considers multiple protection scenarios before optimizing link weights in order to reduce the overall number of protected links. Simulation results show that the proposed scheme uses fewer link protections compared to the conventional scheme.

  • Huaning WU, Yalong YAN, Chao LIU, Jing ZHANG
    原稿種別: PAPER
    専門分野: Antennas and Propagation
    2017 年 E100.B 巻 3 号 p. 426-432
    発行日: 2017/03/01
    公開日: 2017/03/01
    [早期公開] 公開日: 2016/10/06
    ジャーナル 認証あり

    This paper introduces and uses spider monkey optimization (SMO) for synthesis sparse linear arrays, which are composed of a uniformly spaced core subarray and an extended sparse subarray. The amplitudes of all the elements and the locations of elements in the extended sparse subarray are optimized by the SMO algorithm to reduce the side lobe levels of the whole array, under a set of practical constraints. To show the efficiency of SMO, different examples are presented and solved. Simulation results of the sparse arrays designed by SMO are compared with published results to verify the effectiveness of the SMO method.

  • Zedong XIE, Xihong CHEN, Xiaopeng LIU, Lunsheng XUE, Yu ZHAO
    原稿種別: PAPER
    専門分野: Wireless Communication Technologies
    2017 年 E100.B 巻 3 号 p. 433-439
    発行日: 2017/03/01
    公開日: 2017/03/01
    [早期公開] 公開日: 2016/09/12
    ジャーナル 認証あり

    The impact of intersymbol interference (ISI) on single carrier frequency domain equalization with multiple input multiple output (MIMO-SCFDE) systems is severe. Most existing channel equalization methods fail to solve it completely. In this paper, given the disadvantages of the error propagation and the gap from matched filter bound (MFB), we creatively introduce a decision feedback equalizer with frequency-domain bidirectional noise prediction (DFE-FDBiNP) to tackle intersymbol interference (ISI) in MIMO-SCFDE systems. The equalizer has two-part equalizer, that is the normal mode and the time-reversal mode decision feedback equalization with noise prediction (DFE-NP). Equal-gain combining is used to realize a greatly simplified and low complexity diversity combining. Analysis and simulation results validate the improved performance of the proposed method in quasi-static frequency-selective fading MIMO channel for a typical urban environment.

  • Lengchi CAO, Satoshi DENNO
    原稿種別: PAPER
    専門分野: Wireless Communication Technologies
    2017 年 E100.B 巻 3 号 p. 440-448
    発行日: 2017/03/01
    公開日: 2017/03/01
    [早期公開] 公開日: 2016/09/20
    ジャーナル 認証あり

    This paper proposes novel nonlinear precoding for XOR-physical layer network coding (XOR-PNC) to improve the performance of bi-directional MIMO relay systems. The proposed precoder comprises a pre-equalizer and a nonlinear filter, which we also propose in the paper. We theoretically analyze the performance of the XOR-PNC with the proposed nonlinear precoding. As a result, it is shown that the proposed pre-equalizer improves the distribution of the received signals at relays, while the nonlinear precoder not only improves the transmission power efficiency but also simplifies the receiver at the relays. The performance is confirmed by computer simulation. The XOR-PNC with the proposed precoding achieves almost the lower bound in BER performance, which is much better than the amplify-and-forward physical layer network coding (AF-PNC).

  • Hidekazu MURATA, Makoto MIYAGOSHI, Yuji OISHI
    原稿種別: PAPER
    専門分野: Wireless Communication Technologies
    2017 年 E100.B 巻 3 号 p. 449-455
    発行日: 2017/03/01
    公開日: 2017/03/01
    [早期公開] 公開日: 2016/10/12
    ジャーナル 認証あり

    The end-to-end packet error rate (PER) performance of a multi-hop cooperative relaying system is discussed in this paper. In this system, the end-to-end PER performance improves with the number of hops under certain conditions. The PER performance of multi-hop cooperative networks is analyzed with the state transition technique. The theoretical analysis reveals that the PER performance can be kept almost constant, or even improved, as the number of hops is increased. Computer simulation results agree closely with the analysis results. Moreover, to confirm this performance characteristic in an actual setup, an in-lab experiment using a fading emulator was conducted. The experimental results confirm the theoretical end-to-end PER performance of this system.

  • Hiraku OKADA, Shuhei SUZAKI, Tatsuya KATO, Kentaro KOBAYASHI, Masaaki ...
    原稿種別: PAPER
    専門分野: Terrestrial Wireless Communication/Broadcasting Technologies
    2017 年 E100.B 巻 3 号 p. 456-464
    発行日: 2017/03/01
    公開日: 2017/03/01
    [早期公開] 公開日: 2016/09/20
    ジャーナル 認証あり

    We proposed to apply compressed sensing to realize information sharing of link quality for wireless mesh networks (WMNs) with grid topology. In this paper, we extend the link quality sharing method to be applied for WMNs with arbitrary topology. For arbitrary topology WMNs, we introduce a link quality matrix and a matrix formula for compressed sensing. By employing a diffusion wavelets basis, the link quality matrix is converted to its sparse equivalent. Based on the sparse matrix, information sharing is achieved by compressed sensing. In addition, we propose compressed transmission for arbitrary topology WMNs, in which only the compressed link quality information is transmitted. Experiments and simulations clarify that the proposed methods can reduce the amount of data transmitted for information sharing and maintain the quality of the shared information.

  • Takayuki MASUO, Fang SHANG, Shouhei KIDERA, Tetsuo KIRIMOTO, Hiroshi S ...
    原稿種別: PAPER
    専門分野: Sensing
    2017 年 E100.B 巻 3 号 p. 465-472
    発行日: 2017/03/01
    公開日: 2017/03/01
    [早期公開] 公開日: 2016/10/12
    ジャーナル 認証あり

    Doppler lidar (LIght Detection And Ranging) can provide accurate wind velocity vector estimates by processing the time delay and Doppler spectrum of received signals. This system is essential for real-time wind monitoring to assist aircraft taking off and landing. Considering the difficulty of calibration and cost, a single Doppler lidar model is more attractive and practical than a multiple lidar model. In general, it is impossible to estimate two or three dimensional wind vectors from a single lidar model without any prior information, because lidar directly observes only a 1-dimensional (radial direction) velocity component of wind. Although the conventional VAD (Velocity Azimuth Display) and VVP (Velocity Volume Processing) methods have been developed for single lidar model, both of them are inaccurate in the presence of local air turbulence. This paper proposes an accurate wind velocity estimation method based on a parametric approach using typical turbulence models such as tornado, micro-burst and gust front. The results from numerical simulation demonstrate that the proposed method remarkably enhances the accuracy for wind velocity estimation in the assumed modeled turbulence cases, compared with that obtained by the VAD or other conventional method.

  • Kyunghoon LEE, Dong Hun LEE, Wonjun HWANG, Hyung-Jin CHOI
    原稿種別: PAPER
    専門分野: Space Utilization Systems for Communications
    2017 年 E100.B 巻 3 号 p. 473-483
    発行日: 2017/03/01
    公開日: 2017/03/01
    [早期公開] 公開日: 2016/10/12
    ジャーナル 認証あり

    3GPP (3rd Generation Partnership Project) has started to discuss D2D (Device-to-Device)-aided OTDOA (Observed Time Difference Of Arrival) as one of the mobile positioning enhancement techniques for LTE (Long Term Evolution) systems. It is a kind of multi-node based OTDOA which directly receives D2D signals from adjacent multiple UEs (User Equipment) to measure RSTD (Reference Signal's Time Difference). D2D signals provide valuable advantages in terms of OTDOA positioning because it can guarantee more reference nodes and high SNR (Signal-to-Noise Ratio) of PRS (Positioning Reference Signal). Two typical methods for multi-node based OTDOA can be applied to D2D-aided OTDOA. Multiple OTDOA positioning is one of the multi-node based methods that averages multiple results from OTDOA; however, it cannot always guarantee high accuracy due to the non-uniform geometry of UEs. OTDOA positioning based on TSE (Taylor Series Expansion) algorithm may be one of the solutions; however, it has the initial value problem and high computational complexity due to its iterative procedure. Therefore, in this paper, we propose a novel D2D-aided OTDOA positioning method which utilizes UEs not as reference node of OTDOA but as assisting node for RSTD error reduction. The proposed method can reduce RSTD error of eNB based hyperbola by using multiple hyperbola bands. The hyperbola band indicates the possible range in which a hyperbola can occur due to RSTD error. Then, by using principal axes of hyperbolas, we estimate a modified hyperbola from the overlap area of hyperbola bands, which has less RSTD error. We verify that the proposed method can effectively reduce RSTD error and improve positioning performance with lower computational complexity.

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