Real-Time Multi-User Video Optical Wireless Transmission Based on a Parallel Micro-LEDs Bulb

Abstract

In this work, we experimentally achieved a real-time video optical wireless transmission which can broadcast two users in different positions, simultaneously. Firstly, a single-pixel 50-μm micro-LED is designed and fabricated on a GaN-based wafer and then two micro-LED chips are connected as parallel form in a single bulb. The transceiver based on two FPGA boards is used to generate quadrature amplitude modulation-orthogonal frequency division multiplexed (QAM-OFDM) signals and measure the communication performance of the VLC system. The low-power micro-LEDs bulb emits 0.8 mW optical power through two optical paths at 20 mA driving current, and the modulation bandwidths for two users' access are 90 MHz and 73 MHz, respectively. In this two-user real-time video transmission system, the total data rate exceeds 105.54 Mbps without naked eye discernable distortion over 2-m free-space distance. Different from traditional point-to-point links, this work demonstrates the possibility of flexible high-speed multi-user real-time video optical wireless transmission based on a parallel micro-LEDs bulb.

Encapsulation-Enabled Perovskite–PMMA Films Combining a Micro-LED for High-Speed White-Light Communication

“…In the previous work, we have realized the high-speed parallel VLC link based on μLED with a high output power, and this parallel scheme can be combined with color converters for further practical application. 46 After the study of illumination characteristics for SSL, the 3 dB modulation bandwidth of the QD-based films and whitelight VLC system have been further tested for communication. The normalized frequency response of RPNC-PMMA and YPNC-PMMA are shown in Figure 4d.…”

“…A too small transmittance will cause a sharp drop on the signal-to-noise ratio (SNR) of the communication system because the capacity is mainly attributed to the light from μLED, while a too large one will affect the quality of white light. In the previous work, we have realized the high-speed parallel VLC link based on μLED with a high output power, and this parallel scheme can be combined with color converters for further practical application …”

FPGA-Based Visible Light Communications Instrument for Implementation and Testing of Ultralow Latency Applications

“…Software defined radio (SDR) systems supporting calculation-intensive applications in real time are available [20], [21], but they do not include a programmable VLC front-end. As a consequence, VLC experiments where a real-time link is demonstrated and latency is evaluated are a small minority [22], [23], [24], [25]; in the most cases, data…”

Performance enhancement of visible light communication (VLC) system incorporating WMZCC‐OCDMA codes and PDM‐QPSK‐DSP data encoding

“…Orthogonal frequency division multiplexing (OFDM)‐based VLC has an advantage due to its ultranarrow spectrum and the resistance to intersymbol interference (ISI) but a disadvantage of nonlinear distortions because of its high peak‐to‐average‐power ratio (PAPR) 42 . VLC is also demonstrated for quadrature phase shift keying (37 Mbps and 1.5 m), 43 16‐QAM‐OFDM (50 Mbps and 3 m), 44 64‐QAM‐OFDM (4.8 m and 1.45 Gbps), 45 QAM‐OFDM (0.1 Gbps and 2 m) and 46 QAM‐OFDM (35 Gbps and 4 m) 47 . Standard QAM modulations such as 16, 64, and 256‐QAM have substantial signal‐to‐noise ratio (SNR) gaps because they can only reach certain data rates.…”