A Real-Time Visible Light Communication System on Chip Design for High Speed Wireless Communication

The increasing demand of wireless communication bandwidth due to advancement of IoT and smartphone technology, requires the new wireless communication technology that can provide high speed wireless communication. The Visible Light Communication (VLC) has been proven can provide multi gigabit wireless communication throughput using unlicensed visible light spectrum. Therefore, VLC is a promising technology to solve bandwidth limitation problem. In order to achieve high speed throughput, VLC signal processing has to be implemented using Application Specific Integrated Circuits (ASICs) technology. In this research, we develop a baseband processor architecture for VLC application. We use System on Chip (SoC) design approach to reduce design time and easy system integration to various applications. In order to increase spectrum efficiency, we utilize OFDM modulation scheme. Several OFDM processing blocks, such as synchronizer, FFT/IFFT, modulator, demodulator, are designed in the system. The real-time system performance is verified in FPGA based system prototyping. The design includes optical wireless front end module, baseband processing and network layer. The developed prototype shows a real-time performance for high speed internet access

Comparison of Non Chirped Nrz, Chirped Nrz and Alternate-chirped Nrz Modulation Techniques for Free Space Optic (Fso) Systems

Free Space Optics (FSO) is the technology where transmission occurs through optical waveform that contains datatransformed at the transmitter from electrical signal. Since the transmission medium of FSO is atmosphere, atmosphericscattering is the major cause for interruption of FSO link. Non return zero (NRZ) modulation is the dominant modulationscheme employed in commercial terrestrial Free Space Optic (FSO) communication systems. This research are requiredto investigate three viable modulation techniques; NRZ pulse formats, non-chirped NRZ, chirped NRZ, and alternatechirpedNRZ at 10 Gb/s and 40 Gb/s data rate. The 1550 nm of continuous wave (CW) laser is modulated with threedifferent modulation formats over 1 km of FSO channel. The signal is propogated at different attenuation value based onMalaysia weather conditions. In this paper we have successfully compared the three modulation techniques in FSOsystem due to the Malaysia weather and the performance is accessed at bit error rate (BER) of 1x10-9. The presentedsimulation of these three modulation shows that alternate-chirped NRZ has slightly better performance compared to thenon-chirped NRZ and chirped NRZ modulation format at clear weather, haze, light rain, medium rain and heavy rain.We believe that, this system is an alternative for the future optical wireless network that has a potential to be installed inthe urban and sub-urban area

Performance of the wavelet-transform-neural network based receiver for DPIM in diffuse indoor optical wireless links in presence of artificial light interference

Artificial neural network (ANN) has application in communication engineering in diverse areas such as channel equalization, channel modeling, error control code because of its capability of nonlinear processing, adaptability, and parallel processing. On the other hand, wavelet transform (WT) with both the time and the frequency resolution provides the exact representation of signal in both domains. Applying these signal processing tools for channel compensation and noise reduction can provide an enhanced performance compared to the traditional tools. In this paper, the slot error rate (SER) performance of digital pulse interval modulation (DPIM) in diffuse indoor optical wireless (OW) links subjected to the artificial light interference (ALI) is reported with new receiver structure based on the discrete WT (DWT) and ANN. Simulation results show that the DWT-ANN based receiver is very effective in reducing the effect of multipath induced inter-symbol interference (ISI) and ALI

Deep Learning Framework for Wireless Systems: Applications to Optical Wireless Communications

Optical wireless communication (OWC) is a promising technology for future wireless communications owing to its potentials for cost-effective network deployment and high data rate. There are several implementation issues in the OWC which have not been encountered in radio frequency wireless communications. First, practical OWC transmitters need an illumination control on color, intensity, and luminance, etc., which poses complicated modulation design challenges. Furthermore, signal-dependent properties of optical channels raise non-trivial challenges both in modulation and demodulation of the optical signals. To tackle such difficulties, deep learning (DL) technologies can be applied for optical wireless transceiver design. This article addresses recent efforts on DL-based OWC system designs. A DL framework for emerging image sensor communication is proposed and its feasibility is verified by simulation. Finally, technical challenges and implementation issues for the DL-based optical wireless technology are discussed.Comment: To appear in IEEE Communications Magazine, Special Issue on Applications of Artificial Intelligence in Wireless Communication