On the Performance Gain of Harnessing Non-Line-of-Sight Propagation for Visible Light-Based Positioning

The mitigation of NLOS (non-line-of-sight) propagation conditions is one of main challenges in wireless signals based indoor localization. When RFID localization technology is applied in applications, RSS fluctuates frequently due to the shade and multipath effect of RF signal, which could result in localization inaccuracy. In particularly, when tags carriers are walking in LOS (line-of-sight) and NLOS hybrid environment, great attenuation of RSS will happen, which would result in great location deviation. The paper proposes an IMU-assisted (Inertial Measurement Unit) RFID based indoor localization in LOS/NLOS hybrid environment. The proposed method includes three improvements over previous RSS based positioning methods: IMU aided RSS filtering, IMU aided LOS/NLOS distinguishing and IMU aided LOS/NLOS environment switching. Also, CRLB (Cramér-Rao Low Bound) is calculated to prove theoretically that indoor positioning accuracy for proposed method in LOS/NLOS mixed environment is higher than position precision of only use RSS information. Simulation and experiments are conducted to show that proposed method can reduce the mean positioning error to around 3 meters without site survey.

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Long distance non-line-of-sight (NLOS) visible light signal detection based on rolling-shutter-patterning of mobile-phone camera

Optics Express ◽

10.1364/oe.25.010103 ◽

2017 ◽

Vol 25 (9) ◽

pp. 10103 ◽

Cited By ~ 21

Author(s):

Wei-Chung Wang ◽

Chi-Wai Chow ◽

Liang-Yu Wei ◽

Yang Liu ◽

Chien-Hung Yeh

Keyword(s):

Visible Light ◽

Signal Detection ◽

Mobile Phone ◽

Light Signal ◽

Line Of Sight ◽

Long Distance ◽

Mobile Phone Camera ◽

Non Line Of Sight

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Analisis Performansi Multi User Detection pada Kanal NLOS untuk Sistem NOMA-VLC

ELKOMIKA Jurnal Teknik Energi Elektrik Teknik Telekomunikasi & Teknik Elektronika ◽

10.26760/elkomika.v9i2.482 ◽

2021 ◽

Vol 9 (2) ◽

pp. 482

Author(s):

BIMA SURYA PRATAMA ◽

NACHWAN MUFTI ADRIANSYAH ◽

BRIAN PAMUKTI

Keyword(s):

Wireless Communication ◽

Visible Light ◽

Interference Cancellation ◽

Multiple Access ◽

Data Rate ◽

Line Of Sight ◽

Optical Wireless Communication ◽

Optical Wireless ◽

Better Than ◽

Non Line Of Sight

ABSTRAKNon-orthogonal multiple access (NOMA), mulai diteliti untuk dapat digunakan sebagai teknik multiple access yang efektif pada jaringan 5G karena teknik ini dapat menghemat bandwidth modulasi. Pada penelitian ini, NOMA diterapkan untuk sistem downlink Visible Light Communivation (VLC). Kami telah melakukan analisis performansi Multi-User Detection (MUD) pada kanal propagasi Non-Line of Sight (NLOS) dengan mempertimbangkan efek reflektor dan efek bayangan (shadowing). Kami juga mempertimbangkan teknik MUD yang digunakan pada penelitian ini yaitu Succesive Interference Cancellation (SIC). Setelah simulasi yang ekstensif, kami menemukan bahwa dengan penerapan SIC sebagai MUD pada sistem NOMA-VLC lebih baik dibandingkan dengan tanpa NOMA. Selain itu, kami juga memperoleh peningkatan data rate sebesar 72 %.Kata kunci: VLC, NOMA, NLOS, MUD, Optical Wireless Communication. ABSTRACTNon-orthogonal multiple access (NOMA), began to be studied to be used as an effective multiple access technique on 5G networks because this technique can save modulation bandwidth. In this research, NOMA is applied to the Visible Light Communivation (VLC) downlink system. We have performed a Multi-User Detection (MUD) performance analysis on Non-Line of Sight (NLOS) propagation channels by considering the reflector and shadowing effects. We also consider the MUD technique used in this study, namely Successive Interference Cancellation (SIC). After extensive simulations, we found that the application of SIC as MUD to the NOMA-VLC system is better than without NOMA. In addition, we also achieve an increase in data rate of 72%.Keywords: VLC, NOMA, NLOS, MUD, Optical Wireless Communication.

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