Carrier Suppression Mode Optical Carrier Vector Wave System Based on Phase Factor Optimization

Abstract

The invention belongs to the technical field of radio over fiber transmission and particularly relates to a carrier suppression mode radio on fiber vector wave system based on phase factor optimization. The system is mainly composed of a laser, a Mach-Zehnder intensity modulator and a photoelectric detector, and is featured by simple structure and low cost. A vector signal in the system through the photoelectric detector causes the signal phase distribution imbalance, and in the case of low signal to noise ratio, the constellation points of the vector signal are closer and increase the signal error rate. By optimizing the vector signal phase factor in the precoding at the sending terminal, the recovered vector signal is enabled to symmetric on the phase distribution, thereby improving the system performance. The optimization method can greatly reduce the error rate of the system under a condition that the algorithm complexity is not increased and the structural complexity is not increased. The optimization scheme has a wide application prospect in the radio on fiber vector wave systems of different frequency multiplication numbers and different modulation formats.

Description

technical field [0001] The invention belongs to the technical field of optical transmission, and in particular relates to an optical wireless vector wave system. Background technique [0002] With the explosive growth of the amount of mobile data connected to the Internet, the need for ultra-high-speed wireless signals is imminent. In response to this demand, how to generate ultra-high-speed wireless signals has become a difficult problem. High-frequency wireless waves have become a research hotspot for solving problems because they can provide sufficient transmission bandwidth. In terms of generating high-frequency wireless waves, the bandwidth of electronic devices is limited, and it is difficult to generate high frequencies. Photon-assisted wireless signal technology can overcome the bandwidth bottleneck of electronic devices and become an effective method for generating high-frequency waves. Radio-over-fiber signaling is seen as a viable technology for future 5G wirele...

AI Technical Summary

Problems solved by technology

However, the vector signal in the system passes through the square-law photodetector, which will cause the signal phase distribution to be unbalanced. In the case of low signal-to-noise ratio, the constellation points between the vector signals will be closer to increase the error rate of the signal.

[0006] In order to overcome the main shortcomings of the above three technologies, including: the limited bandwidth of the direct laser modulator, the frequency instability of the wireless signal generated by the mutual shooting of different source optical signals, and the unbalanced phase distribution of the vector signal constellation points at the receiving end

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