System for generating single side band high-frequency optical fiber millimeter wave and reusing wavelength

Abstract

The invention belongs to a method for generating a single high-frequency side band millimeter wave signal by using a smaller-bandwidth intensity modulator and a lower-frequency radio-frequency signal The invention belongs to a method for generating a single high-frequency side band millimeter wave signal by using a smaller-bandwidth intensity modulator and a lower-frequency radio-frequency signalin the technical field of Radio-over-Fiber (abbreviated as ROF). The system makes full use of the reliability and low cost characteristics of double-side-band modulation and the excellent signal perfoin the technical field of Radio-over-Fiber (abbreviated as ROF). The system makes full use of the reliability and low cost characteristics of double-side-band modulation and the excellent signal performance and fiber dispersion of single-side-band modulation. At a central station, multiple double-frequency technology is adopted to generate high-frequency millimeter microwaves, so the requirementsrmance and fiber dispersion of single-side-band modulation. At a central station, multiple double-frequency technology is adopted to generate high-frequency millimeter microwaves, so the requirementsof the central station on element bandwidth are reduced and the configuration of the central station is simple and easy to realize, and the cost of the central station is reduced. A base station usesof the central station on element bandwidth are reduced and the configuration of the central station is simple and easy to realize, and the cost of the central station is reduced. A base station usesa filter to acquire a single-side-band signal having a bandwidth which is two times of that of the conventional single-side-band. Therefore, a higher direct current component at a central carrier wavea filter to acquire a single-side-band signal having a bandwidth which is two times of that of the conventional single-side-band. Therefore, a higher direct current component at a central carrier waveposition generated when the single-side-band modulation is used directly is avoided and the influence of the fiber dispersion on the signal is reduced. In addition, the method can filter the central position generated when the single-side-band modulation is used directly is avoided and the influence of the fiber dispersion on the signal is reduced. In addition, the method can filter the centralcarrier waves of the ROF millimeter waves from a down link and be used for reusing the wavelength of an up link, and simplifies the base station.carrier waves of the ROF millimeter waves from a down link and be used for reusing the wavelength of an up link, and simplifies the base station.

Description

(1) Technical field [0001] The invention belongs to the technical field of a radio-over-fiber (abbreviated as ROF) system. The system can generate a single sideband millimeter wave signal with high frequency and strong anti-dispersion effect, and reuse the wavelength at the base station. (2) Background technology [0002] With the development of communication technology, wireless communication has developed from narrowband services mainly based on voice to multimedia broadband services such as voice, video and data. In addition, with the continuous increase of new wireless users, the existing available wireless spectrum resources are approaching the limit. On the other hand, a large number of fiber optic cables that have been laid have not been fully utilized, and the currently used bandwidth is less than one thousandth of the fiber bandwidth, which results in serious idle bandwidth resources. Therefore, how to make full use of these cheap idle resources and solve the probl...

AI Technical Summary

Problems solved by technology

Due to the influence of dispersion, the transmission distance is limited, and SSB is better than DSB because it can better resist pulse broadening caused by fiber dispersion; and if OCS is used, the center carrier cannot be reused in the base station

However, the SSB modulation that has been proposed so far has a large DC component of the signal at the center carrier, and the receiver sensitivity of the SSB signal is lower than that of the DSB signal; and the signal bandwidth of the SSB modulation is only double-band and half the bandwidth of the carrier-suppressed modulated signal

[0006] In order to solve the above problems, we propose a new scheme, which only uses a single-arm external modulator with narrow bandwidth to generate double-sideband signals but only uses single-sideband, so that it not only overcomes the fiber dispersion, but also at the center carrier There is also no large DC component

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