A 16qam modulation optical quadruple frequency millimeter wave rof system
A modulation method, millimeter wave technology, applied in multi-carrier systems, electromagnetic wave transmission systems, transmission systems, etc., can solve the problem of waste of useful signal power, and achieve the effect of pure spectrum and low price
Inactive Publication Date: 2015-08-12
DONGHUA UNIV
View PDF2 Cites 2 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Because it is based on harmonics to generate millimeter waves, often after photoelectric conversion in the base station, there are many harmonic components in the photoelectric current, and the modulation signal will modulate each harmonic component, which will lead to a large number of useful signals. power is wasted
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment
[0013] like figure 1 As shown in the figure, a 16QAM modulation mode optical 4-fold millimeter-wave RoF system provided by the present invention includes a central station 1, a base station 2 and a downlink optical fiber 3, and the central station 1 and the base station 2 are connected by the downlink optical fiber 3, It is characterized in that: the central station 1 includes a laser 1-1, and the laser 1-1 is connected to the input end of the first two-electrode Mach-Zehnder optical modulator 1-14 through a polarization-maintaining pigtail, and the first two-electrode Mach-Zehnder light The RF electrode on one arm of the modulator 1-14 is applied with a cosine microwave signal output by a microwave signal source 1-2, the first bias electrode 1-5 is applied with a voltage V1, and the RF electrode on the other arm is applied by The microwave signal source 1-2 generates a cosine microwave signal phase-shifted by a first π phase shifter 1-3, the second bias electrode 1-6 is groun...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention provides an optical quadrupling millimeter wave radio over fiber system adopting a 16-quadrature amplitude modulation (QAM) way, which comprises a central station, a base station and a downlink optical fiber, wherein the central station and the base station are connected by the downlink optical fiber. The system is characterized in that: the central station comprises a laser, wherein the laser is connected with the input end of a first double-electrode Mach-Zehnder optical modulator by a preserving tail optical fiber; a cosine microwave signal and the cosine microwave signal subjected to the phase shifting of a first phi phase shifter are added to the first double-electrode Mach-Zehnder optical modulator; the first double-electrode Mach-Zehnder optical modulator is connected with a second Mach-Zehnder optical modulator by the preserving tail optical fiber; a sine microwave signal subjected to the phase shifting of a phase shifter is added to the second Mach-Zehnder optical modulator, and the sine microwave signal is added to the other arm; and the second Mach-Zehnder optical modulator is connected in series with a light intensity modulator. The system has the advantages of further reducing the number of harmonic waves, achieving lower cost and making purer the frequency spectrums of generated millimeter waves.
Description
technical field [0001] The invention relates to an optical 4-frequency RoF (RoF, Radio over Fiber) system structure, which generates millimeter waves from light waves and simultaneously realizes the modulation of light waves by signals into modulation of millimeter waves. Background technique [0002] In recent years, optical wireless communication has become a very attractive solution in the field of broadband wireless access network due to its wide frequency band and high flexibility. In order to meet the requirements of future communication, the radio frequency frequency used by the optical carrier wireless system must be developed towards a higher end, so the radio frequency frequency band used by most optical carrier wireless systems is generally the millimeter wave frequency band. The millimeter-wave RoF system based on the optical frequency doubling method is a representative one of the optical carrier wireless system. The RoF system based on the optical frequency do...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/36H04B10/25H04B10/2575H04B10/556
Inventor 陈翔陈小立
Owner DONGHUA UNIV