Spatiotemporal propagation characteristics of non-line-of-sight using low antenna-height base station in microcellular environment

In this paper, a localization scenario that the home base station (BS) measures time of arrival (TOA) and angle of arrival (AOA) while the neighboring BSs only measure TOA is investigated. In order to reduce the effect of non-line of sight (NLOS) propagation, the probability weighting localization algorithm based on NLOS identification is proposed. The proposed algorithm divides these range and angle measurements into different combinations. For each combination, a statistic whose distribution is chi-square in LOS propagation is constructed, and the corresponding theoretic threshold is derived to identify each combination whether it is LOS or NLOS propagation. Further, if those combinations are decided as LOS propagation, the corresponding probabilities are derived to weigh the accepted combinations. Simulation results demonstrate that our proposed algorithm can provide better performance than conventional algorithms in different NLOS environments. In addition, computational complexity of our proposed algorithm is analyzed and compared.

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Implementation and evaluation of a 2.4 GHz multi-hop WSN: LoS, NLoS, different floors, and outdoor-to-indoor communications

International Journal of Electrical and Computer Engineering (IJECE) ◽

10.11591/ijece.v11i6.pp5170-5179 ◽

2021 ◽

Vol 11 (6) ◽

pp. 5170

Author(s):

Vasin Chaoboworn ◽

Yoschanin Sasiwat ◽

Dujdow Buranapanichkit ◽

Hiroshi Saito ◽

Apidet Booranawong

Keyword(s):

Ieee 802.15.4 ◽

Base Station ◽

Sensor Nodes ◽

Line Of Sight ◽

Delivery Ratio ◽

Packet Delivery ◽

Communication Reliability ◽

Ieee 802.15.4 Standard ◽

Test Scenarios ◽

Non Line Of Sight

In this paper, the communication reliability of a 2.4 GHz multi-hop wireless sensor network (WSN) in various test scenarios is evaluated through experiments. First, we implement an autonomous communication procedure for a multi-hop WSN on Tmote sky sensor nodes; 2.4 GHz, an IEEE 802.15.4 standard. Here, all nodes including a transmitter node (Tx), forwarder nodes (Fw), and a base station node (BS) can automatically work for transmitting and receiving data. The experiments have been tested in different scenarios including: i) in a room, ii) line-of-sight (LoS) communications on the 2nd floor of a building, iii) LoS and non-line-of-sight (NLoS) communications on the 1st floor to the 2nd floor, iv) LoS and NLoS communications from outdoor to the 1st and the 2nd floors of the building. The experimental results demonstrate that the communication reliability indicated by the packet delivery ratio (PDR) can vary from 99.89% in the case of i) to 14.40% in the case of iv), respectively. Here, the experiments reveal that multi-hop wireless commutations for outdoor to indoor with different floors and NLoS largely affect the PDR results, where the PDR more decreases from the best case (i.e., the case of a)) by 85.49%. Our research methodology and findings can be useful for users and researchers to carefully consider and deploy an efficient 2.4 GHz multi-hop WSN in their works, since different WSN applications require different communication reliability level.

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Simulation and analysis of UWB propagation characteristics in the indoor Non-Line-of-Sight environment

2016 IEEE International Conference on Computational Electromagnetics (ICCEM) ◽

10.1109/compem.2016.7588626 ◽

2016 ◽

Author(s):

Shuangde Li ◽

Yuanjian Liu ◽

Xiaojun Zhang ◽

Guanyun Wang

Keyword(s):

Line Of Sight ◽

Propagation Characteristics ◽

Non Line Of Sight

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Combination linear lines of position and neural network for mobile station location estimation

International Journal of Distributed Sensor Networks ◽

10.1177/1550147717717387 ◽

2017 ◽

Vol 13 (7) ◽

pp. 155014771771738 ◽

Cited By ~ 1

Author(s):

Chien-Sheng Chen

Keyword(s):

Mobile Station ◽

Base Station ◽

Location Estimation ◽

Base Stations ◽

Line Of Sight ◽

Time Of Arrival ◽

Angle Of Arrival ◽

Marquardt Algorithm ◽

Station Location ◽

Non Line Of Sight

To enhance the effectiveness and accuracy of mobile station location estimation, author utilizes time of arrival measurements from three base stations and one angle of arrival information at the serving base station to locate mobile station in non-line-of-sight environments. This article makes use of linear lines of position, rather than circular lines of position, to give location estimation of the mobile station. It is much easier to solve two linear line equations rather than nonlinear circular ones. Artificial neural networks are widely used techniques in various areas due to overcoming the problem of exclusive and nonlinear relationships. The proposed algorithms employ the intersections of three linear lines of position and one angle of arrival line, based on Levenburg–Marquardt algorithm, to determine the mobile station location without requiring a priori information about the non-line-of-sight error. The simulation results show that the proposed algorithms can always provide much better location estimation than Taylor series algorithm, hybrid lines of position algorithm as well as the geometrical positioning methods for different levels of biased, unbiased, and distance-dependent non-line-of-sight errors.

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Study on the Propagation Characteristics of Radio Wave for Indoor Non-Line-of-Sight

Journal of Computer and Communications ◽

10.4236/jcc.2015.33007 ◽

2015 ◽

Vol 03 (03) ◽

pp. 40-43

Author(s):

Feng Chen ◽

Yuanjian Liu ◽

Pengfei Wang

Keyword(s):

Radio Wave ◽

Line Of Sight ◽

Propagation Characteristics ◽

Non Line Of Sight

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On Channel Estimation and Power Control for Multi-cell Multi-path Massive MIMO TDD System

10.21203/rs.3.rs-454402/v1 ◽

2022 ◽

Author(s):

Jamal AMADID ◽

Abdelfettah Belhabib ◽

Mohamed Boulouird ◽

Moha M’Rabet Hassan ◽

Abdelouhab Zeroual

Keyword(s):

Channel Estimation ◽

Power Control ◽

Large Scale ◽

Mimo System ◽

Base Station ◽

Line Of Sight ◽

Cell Edge ◽

Mmse Estimator ◽

Time Division ◽

Non Line Of Sight

Abstract Some more practical channels that model the networks in a real environment is the multi-path communication channels. In order to investigate these communications channels. This work addressed Channel Estimation (CE) in the Uplink (UL) phase for a multi-cell multi-user massive multipleinput multiple-output (M-MIMO) system that studies multi-path communication between each user and its serving Base Station (BS). We suppose that the network operates under Time-Division Duplex (TDD) protocol. We studied and analyzed the multi-path channels and their benefit over CE since it presents a more realistic channel that displays a real propagation circumstance. on the flip side, we evaluated the CE quality using ideal MinimumMean Square Error (MMSE). This latter relies on an impractical property that can be explicated since the MMSE estimator considers foreknowledge on Large-Scale Fading (LSF) coefficients of interfering users. Thus, the suggested estimator is introduced to overcome this issue, where the suggested estimator tackled this problem and presented result asymptotic approaches to the performance of the MMSE estimator. Besides, we considered a more real communication in which the multi-path channels are either realized using Non-Line-of-Sight (NLoS) only or using both Line-of-Sight (LoS) and NLoS path depending on the distance at which the user is located from his serving BS. Otherwise, in numerous scenarios, users at the cell edge are strongly affected by Pilot Contamination (PC). Hence, we introduced a Power Control (PoC) policy so that the users at the cell edge are less affected by the PC problem. In the simulation results segment, the analytic and simulated results are introduced to assert our theoretical study.

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Topology Optimization of Interactive Visual Communication Networks Based on the Non-Line-of-Sight Congestion Control Algorithm

Complexity ◽

10.1155/2020/6699515 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11

Author(s):

Boya Liu ◽

Xiaobo Zhou

Keyword(s):

Congestion Control ◽

Visual Communication ◽

Relay Node ◽

Base Station ◽

Line Of Sight ◽

Data Generation ◽

Channel State ◽

Network Resource ◽

Routing Problem ◽

Non Line Of Sight

In this paper, an in-depth study of interactive visual communication of network topology through non-line-of-sight congestion control algorithms is conducted to address the real-time routing problem of adapting to dynamic topologies, and a delay-constrained stochastic routing algorithm is proposed to enable packets to reach GB within the delay threshold in the absence of end-to-end delay information while improving network throughput and reducing network resource consumption. The algorithm requires each sending node to select an available relay set based on the location of its neighbor nodes and channel state and computes transfer probabilities for each node in the relay set combining the remaining delay of the packet with the distance from the relay node to GB. Based on the obtained transfer probability and local channel state, the sending node passes the packet to the relay node. The convergence of the algorithm is proved and its performance is verified by simulation. The first part of the algorithm is based on the greedy algorithm to deploy and locate the network flying platform nodes with the goal of efficient coverage of the network flying platform nodes, considering the ground base station services. As the delay on each link varies due to the change of channel state, the source and relay nodes asynchronously update the data generation rate and the pairwise parameters based on the received local information and use the obtained optimal values to pass the packets to GB.

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