Research On Dual-band Optical Orthogonal Frequency Division Multiplexing System Based On Adaptive Technology

In recent years,optical fiber communication technology plays an important role in China's data communication network.Because optical fiber communication has the characteristics of large transmission capacity and long transmission distance,it has been well applied.However,the transmission process of the optical fiber may have a dispersion effect due to factors such as modal dispersion and wavelength dispersion.The dispersion effect of the optical fiber is similar to the multipath interference in wireless communication,and the problem of multipath interference can be solved by orthogonal frequency division multiplexing.So the introduction of orthogonal frequency division multiplexing technology in optical fiber communication systems has attracted people's attention,and finally for ied the technology of optical orthogonal frequency division multiplexing(OFDM).Optical Orthogonal Frequency Division Multiplexing(OOFDM)has become a widely used optical transmission technology due to its better dispersion tolerance and higher spectrum utilization.In addition to the features of high spectrum utilization and anti-code interference,the OFDM system also has flexible modulation capabilities,because the fiber communication will be different due to different application scenarios(such as multimode fiber LAN,single-mode fiber backbone transmission,access networks,etc.)and the distance of the transmission distance produce different dispersion effects and frequency selective fading.Therefore,in the optical orthogonal frequency division multiplexing technology,adaptive modulation can be used to optimize system performance to achieve flexible and efficient data transmission.The dual-band adaptive optical orthogonal frequency division multiplexing system studied in this paper combines the baseband signal transmission and the upper sideband to the frequency band signal transmission at the transmitting end to perform optical fiber communication,and then the signals on the two bands are respectively perform independent adaptive modulation.This has the advantage of being able to flexibly and efficiently increase the spectrum utilization of the system according to the channel conditions,and can double the signal transmission capacity in the system without worrying about the minimum quantization bit number and the sampling precision of the digital-to-analog converter.And increase the cost of the entire system.The main work of this paper can be summarized as:Theoretically analyze the working principle of OFDM system and the components of the system,for some key technologies such as constellation mapping(QAM technology),OFDM modulation and demodulation principle implementation(IFFT/FFT),encountered during transmission The peak-to-average ratio(PAPR)and other techniques were analyzed.Through MATLAB programming to build the various components of the system,and finally construct a complete orthogonal frequency division multiplexing transmission system model,in which the transmission medium is fiber channel,the spectral characteristics of the fiber channel can obtain the discrete data through the time domain unit impulse response of the channel.The entire transmission system will have different dispersion effects due to the transformation of the channel application scene and the distance of the transmission distance.This paper proposes an adaptive modulation technique to eliminate the influence of different channel dispersion.The proposed technology can significantly improve the transmission performance of the entire system.In order to improve the transmission capacity of the system and reduce the transmission cost of the system,this paper further proposes a dual-band optical orthogonal frequency division multiplexing system model,and then verifies the design of the dual-band system through MATLAB simulation,and transmits it through the fiber channel.The signal-to-noise ratio quality of the data signal and the error performance of the data verify the efifectiveness of the dual-band system design.Finally,the effectiveness of each module in the whole system and the feasibility of the adaptive cyclic prefix modulation technique and the dual-band system design proposed in this paper are verified by MATL AB simulation results.In general,the dual-band adaptive optical orthogonal frequency division multiplexing(PSO)proposed in this paper can ensure better spectrum utilization,anti-fiber channel dispersion interference,and network structure expansion compared with traditional multiplexing technology.At the same time,it has flexible adaptive modulation capability and low-cost requirements.And the technical application scenario can be used for the transmission of big data of the data center network in the enterprise now.