The Necessity of LED to Ambient Light Ratio Optimization for Vehicular Optical Camera Communication
In vehicular optical camera communication (VOCC) systems, LED panels are used to transmit visible light signals which are captured by cameras. The logic bits 1 and 0 are represented by the On and Off status of the LEDs in the panel. The bit error rate (BER) of the system is directly proportional to...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-01-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/20/1/292 |
| _version_ | 1818001059736453120 |
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| author | Trong-Hop Do Myungsik Yoo |
| author_facet | Trong-Hop Do Myungsik Yoo |
| author_sort | Trong-Hop Do |
| collection | DOAJ |
| description | In vehicular optical camera communication (VOCC) systems, LED panels are used to transmit visible light signals which are captured by cameras. The logic bits 1 and 0 are represented by the On and Off status of the LEDs in the panel. The bit error rate (BER) of the system is directly proportional to the distinguishability of the On and Off LEDs in the received LED panel images. The signal quality is commonly believed in telecommunications to improve with a higher transmitted power. Therefore, one might expect to get a lower BER in VOCC systems by simply using more powerful LED lights. However, this is not the case with VOCC systems. This paper shows that the LED distinguishability is simultaneously determined by two factors: The LED extinction ratio and LED interference. The former needs to be kept high and the latter kept low for better LED distinguishability. The problem is that both the extinction ratio and interference increase with the ratio of LED light to ambient light (L2A). Consequently, an optimal L2A ratio exists to achieve the optimal balance between the positive impact of the extinction ratio and the negative impact of the interference. This can bring about the lowest BER without changing the system’s data rate. In addition, this paper shows that the optimal L2A ratio varies according to the interval between the LEDs in a panel. We analyze the effect of the L2A ratio and LED interval on LED distinguishability. We then formulate a constrained optimization problem to find the optimal L2A ratios corresponding to different LED intervals. The simulation results verify the necessity of LED to ambient light ratio optimization as it can bring about the lowest BER without scarifying other aspects of the VOCC system. |
| first_indexed | 2024-04-14T03:28:44Z |
| format | Article |
| id | doaj.art-0f0e706cda2d4872821563904e31826c |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-14T03:28:44Z |
| publishDate | 2020-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-0f0e706cda2d4872821563904e31826c2022-12-22T02:15:01ZengMDPI AGSensors1424-82202020-01-0120129210.3390/s20010292s20010292The Necessity of LED to Ambient Light Ratio Optimization for Vehicular Optical Camera CommunicationTrong-Hop Do0Myungsik Yoo1School of Electronic Engineering, Soongsil University, Seoul 06978, KoreaSchool of Electronic Engineering, Soongsil University, Seoul 06978, KoreaIn vehicular optical camera communication (VOCC) systems, LED panels are used to transmit visible light signals which are captured by cameras. The logic bits 1 and 0 are represented by the On and Off status of the LEDs in the panel. The bit error rate (BER) of the system is directly proportional to the distinguishability of the On and Off LEDs in the received LED panel images. The signal quality is commonly believed in telecommunications to improve with a higher transmitted power. Therefore, one might expect to get a lower BER in VOCC systems by simply using more powerful LED lights. However, this is not the case with VOCC systems. This paper shows that the LED distinguishability is simultaneously determined by two factors: The LED extinction ratio and LED interference. The former needs to be kept high and the latter kept low for better LED distinguishability. The problem is that both the extinction ratio and interference increase with the ratio of LED light to ambient light (L2A). Consequently, an optimal L2A ratio exists to achieve the optimal balance between the positive impact of the extinction ratio and the negative impact of the interference. This can bring about the lowest BER without changing the system’s data rate. In addition, this paper shows that the optimal L2A ratio varies according to the interval between the LEDs in a panel. We analyze the effect of the L2A ratio and LED interval on LED distinguishability. We then formulate a constrained optimization problem to find the optimal L2A ratios corresponding to different LED intervals. The simulation results verify the necessity of LED to ambient light ratio optimization as it can bring about the lowest BER without scarifying other aspects of the VOCC system.https://www.mdpi.com/1424-8220/20/1/292opticalvisible lightcameravehiclecommunicationledambient lightoptimization |
| spellingShingle | Trong-Hop Do Myungsik Yoo The Necessity of LED to Ambient Light Ratio Optimization for Vehicular Optical Camera Communication Sensors optical visible light camera vehicle communication led ambient light optimization |
| title | The Necessity of LED to Ambient Light Ratio Optimization for Vehicular Optical Camera Communication |
| title_full | The Necessity of LED to Ambient Light Ratio Optimization for Vehicular Optical Camera Communication |
| title_fullStr | The Necessity of LED to Ambient Light Ratio Optimization for Vehicular Optical Camera Communication |
| title_full_unstemmed | The Necessity of LED to Ambient Light Ratio Optimization for Vehicular Optical Camera Communication |
| title_short | The Necessity of LED to Ambient Light Ratio Optimization for Vehicular Optical Camera Communication |
| title_sort | necessity of led to ambient light ratio optimization for vehicular optical camera communication |
| topic | optical visible light camera vehicle communication led ambient light optimization |
| url | https://www.mdpi.com/1424-8220/20/1/292 |
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