Author Affiliations
Key Laboratory for Information Science of Electromagnetic Waves (MoE), Department of Communication Science and Engineering, Fudan University, Shanghai 200433, Chinashow less
Fig. 1. 8-QAM constellation design.
Fig. 2. BER versus average SNR.
Fig. 3. Frequency response of a commercial LED.
Fig. 4. BER versus baud rate under high-frequency attenuation.
Fig. 5. U–I curve of the red chip of a commercial RGB–LED (LZ4-00MA00).
Fig. 6. CCDF of PAPRs for single-carrier, special-shaped 8-QAM signals.
Fig. 7. Experimental setup of single-carrier, special-shaped 8-QAM VLC system.
Fig. 8. BER versus different bias voltage and signal vpp for (a) circular (7,1), (b) circular (4,4), (c) rectangular, and (d) triangular.
Fig. 9. BER versus signal vpp (a) at bias voltage=1.8 V, (b) at bias voltage=2.0 V, and (c) at bias voltage=2.3 V.
Fig. 10. Q-factor comparison for different 8-QAM constellations.
Fig. 11. Baud rate comparison for different 8-QAM constellations.
Fig. 12. Highest baud rate versus transmission for different 8-QAM.
Constellation | Min_Euclidean |
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Circular (7,1) | 0.9277 | Circular (4,4) | 0.9194 | Rectangular | 0.8165 | Triangular | 0.8729 |
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Table 1. Minimum Euclidean Distances of Special-Shaped 8-QAM Constellations
Constellation | PAPR |
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Circular (7,1) | 1.1429 | Circular (4,4) | 1.5774 | Rectangular | 1.3333 | Triangular | 1.5238 |
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Table 2. PAPRs of Different Special-Shaped 8-QAM Constellations
Constellation | Circular (7,1) | Circular (4,4) |
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Dynamic range | | 0.40 V (0.30 V–0.70 V) | | 0.14 V (0.48 V–0.62 V) | | 0.60 V (0.22 V–0.82 V) | | 0.46 V (0.32 V–0.78 V) | | 0.37 V (0.41 V–0.78 V) | | 0.12 V (0.48 V–0.60 V) | Constellation | Rectangular | Triangular | Dynamic range | | 0.22 V (0.48 V–0.70 V) | | 0.23 V (0.4 V–0.63 V) | | 0.48 V (0.32 V–0.8 V) | | 0.46 V (0.32 V–0.78 V) | | 0.34 V (0.45 V–0.79 V) | | 0.34 V (0.48 V–0.82 V) |
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Table 3. Dynamic Range of Signal VPP Under Different Bias Voltage