The Experts below are selected from a list of 41985 Experts worldwide ranked by ideXlab platform

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

  • offset estimation for clock synchronization in Mobile molecular communication system
    Wireless Communications and Networking Conference, 2016
    Co-Authors: Zhan Luo, Lin Lin
    Abstract:

    Nano communication is a novel communication paradigm. The nano-devices communicate with each other by molecular communication at the nano- or micro-scale. Clock synchronization is an essential issue for the collaboration of the nano-devices. How to synchronize the nanomachine in a Mobile Scenario is a challenge. This paper propose a method to estimate the clock offset in Mobile molecular communication systems. First, we introduce a simple model of clock synchronization in Mobile molecular communication system. Next, we propose a method to estimate the clock offset base on Maximum-Likelihood Estimation (MLE) in Mobile molecular communication system. Finally, simulations by MATLAB are performed and the results show that the mean square error (MSE) of the estimated clock offsets can be reduced and converges after a number of rounds of message exchange, which manifests the effectiveness of the proposed solution.

Ove Edfors - One of the best experts on this subject based on the ideXlab platform.

  • performance characterization of a real time massive mimo system with los Mobile channels
    IEEE Journal on Selected Areas in Communications, 2017
    Co-Authors: Paul Harris, Steffen Malkowsky, Joao Vieira, Erik Bengtsson, Fredrik Tufvesson, Wael Boukley Hasan, Liang Liu, Mark A Beach, Simon Armour, Ove Edfors
    Abstract:

    The first measured results for massive multiple input, multiple-output (MIMO) performance in a line-of-sight (LOS) Scenario with moderate mobility are presented, with 8 users served in real-time using a 100 antenna base Station (BS) at 3.7 GHz. When such a large number of channels dynamically change, the inherent propagation and processing delay has a critical relationship with the rate of change, as the use of outdated channel information can result in severe detection and precoding inaccuracies. For the downlink (DL) in particular, a time division duplex (TDD) configuration synonymous with massive MIMO deployments could mean only the uplink (UL) is usable in extreme cases. Therefore, it is of great interest to investigate the impact of mobility on massive MIMO performance and consider ways to combat the potential limitations. In a Mobile Scenario with moving cars and pedestrians, the massive MIMO channel is sampled across many points in space to build a picture of the overall user orthogonality, and the impact of both azimuth and elevation array configurations are considered. Temporal analysis is also conducted for vehicles moving up to 29km�h and real-time bit error rates (BERs) for both the UL and DL without power control are presented. For a 100 antenna system, it is found that the channel state information (CSI) update rate requirement may increase by 7 times when compared to an 8 antenna system, whilst the power control update rate could be decreased by at least 5 times relative to a single antenna system. (Less)

Zhan Luo - One of the best experts on this subject based on the ideXlab platform.

  • offset estimation for clock synchronization in Mobile molecular communication system
    Wireless Communications and Networking Conference, 2016
    Co-Authors: Zhan Luo, Lin Lin
    Abstract:

    Nano communication is a novel communication paradigm. The nano-devices communicate with each other by molecular communication at the nano- or micro-scale. Clock synchronization is an essential issue for the collaboration of the nano-devices. How to synchronize the nanomachine in a Mobile Scenario is a challenge. This paper propose a method to estimate the clock offset in Mobile molecular communication systems. First, we introduce a simple model of clock synchronization in Mobile molecular communication system. Next, we propose a method to estimate the clock offset base on Maximum-Likelihood Estimation (MLE) in Mobile molecular communication system. Finally, simulations by MATLAB are performed and the results show that the mean square error (MSE) of the estimated clock offsets can be reduced and converges after a number of rounds of message exchange, which manifests the effectiveness of the proposed solution.

Paul Harris - One of the best experts on this subject based on the ideXlab platform.

  • performance characterization of a real time massive mimo system with los Mobile channels
    IEEE Journal on Selected Areas in Communications, 2017
    Co-Authors: Paul Harris, Steffen Malkowsky, Joao Vieira, Erik Bengtsson, Fredrik Tufvesson, Wael Boukley Hasan, Liang Liu, Mark A Beach, Simon Armour, Ove Edfors
    Abstract:

    The first measured results for massive multiple input, multiple-output (MIMO) performance in a line-of-sight (LOS) Scenario with moderate mobility are presented, with 8 users served in real-time using a 100 antenna base Station (BS) at 3.7 GHz. When such a large number of channels dynamically change, the inherent propagation and processing delay has a critical relationship with the rate of change, as the use of outdated channel information can result in severe detection and precoding inaccuracies. For the downlink (DL) in particular, a time division duplex (TDD) configuration synonymous with massive MIMO deployments could mean only the uplink (UL) is usable in extreme cases. Therefore, it is of great interest to investigate the impact of mobility on massive MIMO performance and consider ways to combat the potential limitations. In a Mobile Scenario with moving cars and pedestrians, the massive MIMO channel is sampled across many points in space to build a picture of the overall user orthogonality, and the impact of both azimuth and elevation array configurations are considered. Temporal analysis is also conducted for vehicles moving up to 29km�h and real-time bit error rates (BERs) for both the UL and DL without power control are presented. For a 100 antenna system, it is found that the channel state information (CSI) update rate requirement may increase by 7 times when compared to an 8 antenna system, whilst the power control update rate could be decreased by at least 5 times relative to a single antenna system. (Less)

Rui Zhang - One of the best experts on this subject based on the ideXlab platform.

  • cognitive uav communication via joint maneuver and power control
    IEEE Transactions on Communications, 2019
    Co-Authors: Yuwei Huang, Weidong Mei, Ling Qiu, Rui Zhang
    Abstract:

    This paper investigates a new Scenario of spectrum sharing between unmanned aerial vehicle (UAV) and terrestrial wireless communication, in which a cognitive/secondary UAV transmitter communicates with a ground secondary receiver (SR), in the presence of a number of primary terrestrial communication links that operate over the same frequency band. We exploit the UAV’s mobility in three-dimensional (3D) space to improve its cognitive communication performance while controlling the co-channel interference at the primary receivers (PRs), such that the received interference power at each PR is below a prescribed threshold termed as interference temperature (IT). First, we consider the quasi-stationary UAV Scenario, where the UAV is placed at a static location during each communication period of interest. In this case, we jointly optimize the UAV’s 3D placement and power control to maximize the SR’s achievable rate, subject to the UAV’s altitude and transmit power constraints, as well as a set of IT constraints at the PRs to protect their communications. Second, we consider the Mobile UAV Scenario, in which the UAV is dispatched to fly from an initial location to a final location within a given task period. We propose an efficient algorithm to maximize the SR’s average achievable rate over this period by jointly optimizing the UAV’s 3D trajectory and power control, subject to the additional constraints on UAV’s maximum flying speed and initial/final locations. Finally, numerical results are provided to evaluate the performance of the proposed designs for different Scenarios, as compared to various benchmark schemes. It is shown that in the quasi-stationary Scenario the UAV should be placed at its minimum altitude while in the Mobile Scenario the UAV should adjust its altitude along with horizontal trajectory, so as to maximize the SR’s achievable rate in both Scenarios.