| Visible light communication?VLC?,as one of potential solutions for future high-speed short-range wireless access,has become a research hotspot in the field of wireless communication in recent years.The waveform technology in VLC is an important part of high-speed data transmission.This paper studies the waveform technology in high-speed VLC and designs a VLC waveform with throughput of10Gbps,and carries out numerical simulation verification and hardware implementation verification.The main work of this paper is as follows:Firstly,this paper analyzes the waveform requirements and designs the waveform scheme.Under a channel condition with a bandwidth of 2GHz,a SNR of more than30dB,and a model of AWGN,a waveform scheme suitable for high-speed VLC is designed in combination with hardware resource limitations.The waveform scheme uses technologies such as OFDM,QAM,and RS code to achieve a throughput rate of10Gbps or more and a bit error rate of 10-6 or less.Using a parallel structure implementation scheme of multiplex unit channel,16 channels of 287.5MSPS signals are synthesized into 4.6GSPS signals.Compared with the traditional multiphase parallel architecture,there is only a small amount of data crossover and the implementation complexity is significantly reduced.Secondly,this paper conducts numerical simulation and analysis of the waveform.The key parts of the waveform and the overall solution are verified by simulation.Symbol synchronization simulation shows that the algorithm accuracy is within 4sampling points.Channel equalization simulation shows that the SNR loss of the algorithm is about 3dB.Floating-point performance simulation shows that when the SNR of the channel is about 25dB,the waveform has a BER of less than 10-6.The parallel structure simulation shows that the parallel structure scheme does not affect the performance.Thirdly,this paper contains waveform hardware implementation and waveform test results.FPGA platform is used to code and design waveforms.Waveform test shows:In a cable-coupled direct-connect scenario,the waveform meets the needs of throughput rate greater than 10Gbps and BER lower than 10-6.In the visible-light-coupled scenario,since the SNR of the visible light channel does not meet the requirements of the scheme design,the BER does not meet the needs.Sacrificing throughput performance in exchange for BER performance,the modified waveform throughput rate is 3.6Gbps and the BER is 10-6 or less.This paper analyzes,designs,simulates,implements,and tests a high-speed VLC waveform.The waveform uses a low-complexity parallel implementation scheme in its implementation,which has practical engineering significance in high-speed parallel signal processing. |
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