scholarly journals Design and Performance Evaluation for a Non-Line of Sight VLC Dimmable System Based on SC-LPPM

IEEE Access ◽  
2018 ◽  
Vol 6 ◽  
pp. 52393-52405 ◽  
Author(s):  
Nazmi A. Mohammed ◽  
Kareem A. Badawi
Keyword(s):  
Performance Evaluation ◽  
Line Of Sight ◽  
And Performance ◽  
Non Line Of Sight

scholarly journals Experimental Performance Evaluation of Multihop IEEE 802.15.4/4g/4e Smart Utility Networks in Outdoor Environment

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Chin-Sean Sum ◽  
Ming-Tuo Zhou ◽  
Fumihide Kojima ◽  
Hiroshi Harada
Keyword(s):  
Performance Evaluation ◽  
Ieee 802.15.4 ◽  
Outdoor Environment ◽  
Line Of Sight ◽  
The Sun ◽  
Experimental Performance ◽  
Low Energy Consumption ◽  
Extended Range ◽  
And Control ◽  
Non Line Of Sight

This paper presents the experimental performance evaluation results of the IEEE 802.15.4/4g/4e Smart Utility Networks (SUN) in applications suited for outdoor environment. SUN is an advanced wireless communications network designed for reliable, low data rate, and low energy consumption networks for command-and-control applications like utility service, sensor network, and so on. IEEE 802.15.4g/4e is the international standard for SUN supported by multiple utility providers and product vendors. In this paper, a comprehensive field test was conducted by employing the implementation we have developed to evaluate the performance of the SUN devices based on IEEE 802.15.4/4g/4e standard. The output power of the implementation is 250 mW for extended range, reducible to 20 mW for short-range scalability and battery preservation. Results showed that in an outdoor line-of-sight environment, the achievable one-hop range of a 50 kbps SUN device was 450 m. Next, in a non-line-of-sight environment involving typical residential concrete building, the communications could be established penetrating obstructions to reach above the 11th storey, reaching the performance degradation limits at the 20th storey. Next, the network of the SUN system was proven to be capable of supporting a typical multihop tree network in a dense populated building, meeting the required performance by the standard.

scholarly journals Measurement-Based LoS/NLoS Channel Modeling for Hot-Spot Urban Scenarios in UMTS Networks

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Jiajing Chen ◽  
Xuefeng Yin ◽  
Li Tian ◽  
Nan Zhang ◽  
Yongyu He ◽  
...  
Keyword(s):  
Hot Spot ◽  
Channel Modeling ◽  
Line Of Sight ◽  
Parameter Estimates ◽  
Deterministic Models ◽  
System A ◽  
Universal Mobile Telecommunications System ◽  
And Performance ◽  
Existence Probability ◽  
Non Line Of Sight

A measurement campaign is introduced for modeling radio channels with either line-of-sight (LoS) or non-line-of-sight (NLoS) connection between user equipment (UE) and NodeB (NB) in an operating universal mobile telecommunications system. A space-alternating generalized expectation-maximization (SAGE) algorithm is applied to estimate the delays and the complex attenuations of multipath components from the obtained channel impulse responses. Based on a novel LoS detection method of multipath parameter estimates, channels are classified into LoS and NLoS categories. Deterministic models which are named “channel maps” and fading statistical models have been constructed for LoS and NLoS, respectively. In addition, statistics of new parameters, such as the distance between the NB and the UE in LoS/NLoS scenarios, the life-distance of LoS channel, the LoS existence probability per location and per NB, the power variation at LoS to NLoS transition and vice versa, and the transition duration, are extracted. These models are applicable for designing and performance evaluation of transmission techniques or systems used by distinguishing the LoS and NLoS channels.

Sign in / Sign up

Export Citation Format

Share Document