CN116015467A - ODL-based M 2 QAM quadruple frequency millimeter wave signal generation and transmission system - Google Patents
ODL-based M 2 QAM quadruple frequency millimeter wave signal generation and transmission system Download PDFInfo
- Publication number
- CN116015467A CN116015467A CN202211618012.1A CN202211618012A CN116015467A CN 116015467 A CN116015467 A CN 116015467A CN 202211618012 A CN202211618012 A CN 202211618012A CN 116015467 A CN116015467 A CN 116015467A
- Authority
- CN
- China
- Prior art keywords
- signal
- optical
- millimeter wave
- qam
- signals
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Optical Communication System (AREA)
Abstract
The invention belongs to the technical field of optical fiber wireless network communication, and particularly relates to an M based on ODL 2 -a QAM quad millimeter wave signal generation and transmission system. In the system of the present invention, the transmitting end includes: the optical fiber transmission device comprises an input module, an optical modulator, an optical coupler, an optical delay line, a polarization beam combiner, an optical fiber transmission module and a photodiode; the input module generates a binary message; the optical modulator modulates the binary message and the clock signal onto an optical carrier; the optical coupler and the optical delay line divide the signal into two paths of orthogonal signals; the optical fiber transmission module transmits the synthesized optical signals; the photodiode square-detects the signal and outputs a vector M 2 -QAM millimeter wave signals; the receiving end comprises a radio frequency source and a signal recovery module; the radio frequency source provides a local oscillation signal for frequency mixing with the received signal to complete the down-conversion of the signal; the signal recovery module recovers the signal received by the oscilloscope. The system does not use DAC and optical filter, and can be the same asTime-realization vector M 2 -QAM millimeter wave signals and wireless communication over optical fiber.
Description
Technical Field
The invention belongs to the technical field of optical fiber wireless network communication, and particularly relates to a vector M based on an ODL modulation format 2 -a QAM quad millimeter wave signal generation and transmission system.
Background
With the development of 5G networks, the demand for mobile data services has greatly driven research on advanced modulation formats with high spectral efficiency. To meet the requirements of high speed, large bandwidth, wide coverage and the like of future access networks
Development of a novel next-generation optical access network technology and an optical fiber wireless fusion technology is imperative. The photon assisted millimeter wave generation is a key technology of the optical fiber wireless network, and the bottleneck of the current electrical equipment is effectively overcome. At present, two types of millimeter wave generation methods are mainly adopted, namely an optical heterodyne method and an optical frequency doubling method. In comparison, the optical frequency multiplication method based on external modulation is more practical in 5G applications due to the characteristics of frequency and phase locking and effective phase noise avoidance. However, since optical filters, wavelength selective switches or splitters, etc., are indispensable in the optical frequency doubling method communication framework, these increase the cost and complexity of the optical wireless communication network. Meanwhile, due to the square monitoring rule of the Photodiode (PD) at the receiving end, the amplitude and phase information of the transmitted QAM signal should be pre-encoded, which greatly increases the computational burden at the receiving end. In addition, methods based on optical frequency multiplication methods for generating millimeter waves typically require a complex transceiver and expensive digital-to-analog converters, which also greatly increase the cost of the system. Furthermore, this presents a potential limiting factor for the development of future high-speed communications due to the limited 3-dB bandwidth and significant bit limit of commercial DACs. To solve the problem of DAC bandwidth, one of the effective methods is to use digital signal transmission, because digital signals have greater noise tolerance and robustness to channel impairments 【1-4】 。
Currently, few studies are made on a method for generating millimeter waves of an optical vector based on digital modulation. In 2014, the publication et al proposed a system without a DAC generating QPSK signal, but the OOK branches were superimposed in free space, so that the phase difference of the two branches could not be precisely controlled 【5】 . Thus, the present invention proposes a method using ODL (optical)delay line) adjusts the phase difference of the two modulated branches, and then generates and transmits an M2-QAM millimeter wave signal by heterodyning beat frequency.
Disclosure of Invention
The object of the present invention is to provide an M based on an ODL modulation conversion format without using a digital-to-analog converter (DAC) and an optical filter 2 A QAM millimeter wave signal generation and transmission system that achieves high-rate and high-reliability communications while achieving the generation of higher-order vector QAM signals.
The M based on ODL provided by the invention 2 -a QAM four-frequency millimeter wave signal generation and transmission system whose structure is divided into a signal transmitting end and a signal receiving end, wherein:
the signal transmitting terminal comprises:
a distributed feedback semiconductor laser (DFB-LD) for outputting a continuous light wave as a light source and modulating it thereafter;
a pseudo random code (PRBS) generator for generating a binary signal;
a radio frequency source (RF 1) for generating a clock signal;
two Electronic Amplifiers (EA), wherein a first electronic amplifier (EA 1) is used for amplifying the binary signal and a second electronic amplifier (EA 2) is used for amplifying the clock signal;
two cascaded optical modulators (MZM), wherein the first optical modulator (MZM 1) is used for modulating the amplified binary signal onto the optical carrier, the second optical modulator (MZM 2) uses the amplified clock signal as driving voltage to modulate the output signal of the first optical modulator (MZM 1), and the modulation index is controlled to ensure that the optical carrier has larger optical power in + -2 order subcarriers;
an optical coupler (PM-OC) for dividing the cascade modulated signal into upper and lower identical paths;
two attenuators (ATT 1, ATT 2) for matching the amplitude gain of the upper and lower optical signals;
an optical extension line (ODL) for changing the phase of one optical signal of the upper and lower optical signals so as to make the upper and lower optical signals orthogonal;
a polarization combiner (PBC) for combining the optical signals of the two branches;
a Dispersion Shifted Fiber (DSF) for transmitting the Polarization Beam Combiner (PBC) output optical signal to a next portion of the system;
an Erbium Doped Fiber Amplifier (EDFA) for enhancing the signal after optical fiber transmission;
an attenuator (ATT 3) for adjusting the power of the optical signal to avoid saturation effects of the photodiode;
a Photodiode (PD) for generating M by square-rate detection 2 -QAM millimeter wave signals;
an Electronic Amplifier (EA) for increasing M 2 -power of QAM millimeter wave signals;
a transmitting antenna for obtaining M 2 -transmitting out QAM millimeter wave signals;
a lens (lens) for focusing the optical signal power between the antennas;
and (II) the signal receiving terminal comprises:
a receiving antenna for receiving M 2 -QAM millimeter wave signals;
a radio frequency source (RF 2) providing a local oscillation source;
a Mixer (Mixer) for down-converting the signal received by the antenna;
an Oscilloscope (OSC) captures the amplified signal and observes time and frequency domain plots of the signal.
The working flow of the sending end is as follows:
first, the laser source generates a center frequency f c Through two intensity modulators MZM1 and MZM2 in cascade. MZM1 is driven by digital signal data amplified by EA, modulated to obtain an optical baseband signal, and input to MZM2. The DC bias point of MZM2 is set at zero bias point and is controlled by clock signal f s And (5) driving. Meanwhile, the output voltage of the clock source input to the MZM2 is regulated through EA, so that the modulated + -2-order subcarrier has larger optical power.
And then dividing the optical signal obtained by the MZM2 modulation into an upper branch and a lower branch through an optical coupler, and adjusting the amplitude of the optical signal through attenuators ATT1 and ATT2 of the upper branch and the lower branch respectively to realize amplitude matching. Meanwhile, the optical signal phase information of the upper branch is changed by the ODL, so that the phase quadrature of the two signals is realized.
And then combining the two paths of signals by using a polarization beam combiner, transmitting the optical signals through a dispersion shift optical fiber, and adjusting the signal power by using an erbium-doped optical fiber amplifier and an attenuator.
Finally, the vector M can be generated by passing the optical signal transmitted by the optical fiber through PD 2 -QAM quad millimeter wave signals. After the power is regulated by the amplifier, millimeter wave signals can be transmitted through the antenna. Here, the millimeter wave signal after passing through the PD is:
κ＝πV drive /V pp (2)。
wherein R is the sensitivity of the photodiode; kappa is the modulation index; g 0 The power gain of the upper optical signal and the lower optical signal is obtained; phi is the phase delay. J (J) -2 (κ)，J 2 (kappa) is a second order Bessel function, data upper 、data lower The signals to be modulated are respectively the upper branch and the lower branch. V (V) drive Is the MZM driving voltage amplitude, V pp Is the MZM half-wave voltage. As can be seen from the output signal expression, the frequency of the resulting millimeter wave signal is 4 times the clock frequency, and quadrature phase modulation is realized.
The working flow of the receiving end is that after 1m wireless transmission, the receiving end receives the signals through an antenna, firstly down-converts the received signals, then collects the signals through an analog-digital converter such as an oscilloscope, and finally recovers the modulated signals through offline DSP processing.
So far, the system has completed vector M 2 -functions of QAM quad millimeter wave signal generation and communication.
Compared with the prior art, the millimeter wave signal generation mode provided by the invention has a simple structure, only comprises two MZMs, one ODL and one PD, and has no DAC and optical filter, thereby reducing the cost of the system and the complexity of the structure. Limiting factors such as bandwidth limitation caused by using a DAC are effectively avoided, and a feasible scheme is provided for future high-speed optical communication.
Drawings
FIG. 1 shows an ODL-based M generation according to the present invention 2 -QAM millimeter wave signals and communication system architecture schematic, where the solid line part is the optical path and the dashed line part is the circuit.
FIG. 2 is a graph of a Bessel function of the first type, showing only even orders (J 0 、J 2 、J 4 、J 6 ) A variation curve according to the modulation index k, J when k is 2.4048 2 Is significantly greater than J 0 、J 4 、J 6 。
Reference numerals in the drawings: 1 is a distributed feedback semiconductor laser DFB-LD;2 is the optical modulator MZM1; 3. 6, 17, 23 are first-fourth electronic amplifiers EA1, EA2, EA3, EA4, respectively; 4 is a signal source; 5 is a first radio frequency source RF1;7 is the optical modulator MZM2;8 is an optocoupler PM-OC; 9. 10, 15 are first-third attenuators ATT1, ATT2, ATT3;11 is an optical delay line ODL;12 is a polarization beam combiner PBC;13 is a dispersion shifted fiber DSF;14 is an Erbium Doped Fiber Amplifier (EDFA), 16 is a photodiode PD;18 is the transmitting antenna HA1;19 is a lens; 20 is a receiving antenna HA2;21 is a mixer; 22 is a second radio frequency source RF2;24 is oscillograph OSC; and 25 is an off-line digital signal processing terminal.
Detailed Description
The invention is further described with reference to fig. 1.
At the signal transmitting end, the DFB-LD (1) generates continuous light waves as light sources to be input into the MZM1 (2). MZM1 (2) consists of:
and driving a signal source (4) amplified by the EA1 (3) to obtain an optical baseband signal by modulation. Then MZM2 (7) is input, the first radio frequency source (5) of the MZM2 is driven, and the amplitude of the input clock signal is modulated by EA2 to realize odd-order carrier suppression and ensure that + -2-order carriers have larger power. Then the optical signal is divided into an upper path and a lower path by an optical splitter PM-OC (8), and the two paths are made by using attenuators AAT1 (9) and ATT2 (10)The signal amplitudes are matched. The upper branch circuit adjusts the phase by using the ODL (11) as a phase shifter so that the phases of the two signals are in quadrature. Subsequently, the add/drop optical signals are combined by the PBC (12) and transmitted through the 1km dispersion shift optical fiber DSF (13). The power of the signal after optical fiber transmission is adjusted by using EDFA (14) and ATT3 (15) of erbium-doped optical fiber amplifier, and then M is obtained by detection of photodiode PD (16) 2 -QAM millimeter wave signals. Amplified by EA3 (17), and transmitted by antenna HA1 (18). In the wireless transmission process, a lens (19) is used for focusing the wireless signal power between the transmitting and receiving antennas, so that the signal transmission effect is improved.
At the signal receiving end, the signal is received by the antenna HA2 (20). Subsequently, the radio frequency source (22) is used as a local oscillation source and is used for carrying out signal down-conversion with the received signal through the mixer (21), so that an intermediate frequency signal is obtained. The intermediate frequency signal is power-adjusted by EA4 (23), and the amplified signal is captured by oscillograph OSC (24). Finally, the received M is recovered by an off-line DSP (25) 2 -QAM millimeter wave signals.
It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples of implementing the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
[1]P.S.Mundra,T.L.Singal,R.Kapur.“The choice of a digital modulation scheme in amobile radio system,”in Proc.IEEE 43rd Vehicular Technology Conference,1993,pp.1-4.
[2]M.Barnela,D.S.Kumar.“Digital modulation schemes employed in wireless communication:A literature review,”International Journal of Wired and WirelessCommunications,2014,vol.2,no.2,pp.15-21
[3]S.Kharbech,I.Dayoub,M.Zwingelstein-Colin,et al.“Blind digital modulation identification for MIMO systems in railway environments with high-speed channels and impulsive noise,”IEEE Transactions on Vehicular Technology,2018,vol.67,no.8,pp.7370-7379
[4]C.U.Ndujiuba,O.Oni,A.E.Ibhaze.“Comparative analysis of digital modulation techniques in LTE 4G systems,”Journal of Wireless Networking and Communications,2015,vol.5,no.2,pp.60-66
[5]Q.Zhang,J.Yu,X.Li,et al.“Adaptive photonic-assisted M 2-QAM millimeter-wavesynthesis in multi-antenna radio-over-fiber system using M-ASK modulation,”Opt.Lett.,2014,,vol.39,no.21,pp.6106-6109。
Claims (3)
1. ODL-based M 2 -QAM four-frequency millimeter wave signal generation and transmission system characterized by a structure divided into a signal transmitting end and a signal receiving end, wherein:
the signal transmitting terminal comprises:
a distributed feedback semiconductor laser DFB-LD for outputting continuous light wave as light source and modulating thereafter;
a pseudo random code PRBS generator for generating a binary signal;
a radio frequency source RF1 for generating a clock signal;
two electronic amplifiers EA, wherein a first electronic amplifier EA1 is used for amplifying the binary signal and a second electronic amplifier EA2 is used for amplifying the clock signal;
the two cascaded optical modulators MZM, wherein the first optical modulator MZM1 is used for modulating the amplified binary signal onto an optical carrier, the second optical modulator MZM2 uses the amplified clock signal as a driving voltage to modulate the output signal of the first optical modulator MZM1, and the modulation index is controlled to ensure that the optical carrier has larger optical power in + -2 order subcarriers;
an optical coupler PM-OC for dividing the cascade modulated signal into the same upper and lower paths;
the first attenuator ATT1 and the second attenuator ATT2 are respectively used for matching the amplitude gains of the upper optical signal and the lower optical signal;
an optical extension line ODL for changing the phase of one optical signal of the upper and lower optical signals so that the upper and lower optical signals are orthogonal;
a polarization beam combiner PBC for combining the optical signals of the two branches;
a dispersion shifted fiber DSF for transmitting the optical signal outputted from the polarization beam combiner PBC to the next part of the system;
an erbium-doped fiber amplifier EDFA for enhancing the signal transmitted by the optical fiber;
an attenuator ATT3 for adjusting the power of the optical signal to avoid saturation effects of the photodiode;
a photodiode PD for generating M by square rate detection 2 -QAM millimeter wave signals;
an electronic amplifier EA for boosting M 2 -power of QAM millimeter wave signals;
a transmitting antenna for obtaining M 2 -transmitting out QAM millimeter wave signals;
a lens for focusing the optical signal power between the antennas;
and (II) the signal receiving terminal comprises:
a receiving antenna for receiving M 2 -QAM millimeter wave signals;
a radio frequency source RF2 providing a local oscillation source;
a Mixer for down-converting the signal received by the antenna;
an oscilloscope OSC captures the amplified signal and observes the time and frequency domain patterns of the signal.
2. The ODL-based M of claim 1 2 -a QAM four-frequency millimeter wave signal generation and transmission system, characterized in that the workflow of the transmitting end is:
first, the laser source generates a center frequency f c Through two cascaded intensity modulators MZM1 and MZM2; the MZMl is driven by a digital signal data amplified by EA, and an optical baseband signal is obtained after modulation and is input into MZM2; the DC bias point of MZM2 is set at zero bias point and is controlled by clock signal f s Driving; meanwhile, the output voltage of a clock source input to the MZM2 is regulated through EA, so that the modulated + -2-order subcarrier has larger optical power;
dividing an optical signal obtained by MZM2 modulation into an upper branch and a lower branch through an optical coupler, and adjusting the amplitude of the optical signal through attenuators ATTl and ATT2 of the upper branch and the lower branch respectively to realize amplitude matching; meanwhile, the optical signal phase information of the upper branch is changed by the ODL, so that the phase orthogonality of the two paths of signals is realized;
then, combining two paths of signals by using a polarization beam combiner, transmitting optical signals through a dispersion shift optical fiber, and adjusting signal power by using an erbium-doped optical fiber amplifier and an attenuator;
finally, the optical signal transmitted by the optical fiber is passed through PD to generate vector M 2 -QAM quad millimeter wave signals; after the power is regulated by the amplifier, millimeter wave signals are transmitted through the antenna; here, the millimeter wave signal after passing through the PD is:
κ＝πV drive /V pp (2)
wherein R is the sensitivity of the photodiode; kappa is the modulation index; g 0 The power gain of the upper optical signal and the lower optical signal is obtained; phi is the phase delay; j (J) -2 (κ)，J 2 (kappa) is a second order Bessel function, data upper 、data lower The signals to be modulated are respectively an upper branch and a lower branch; v (V) drive Is the MZM driving voltage amplitude, V pp Is the half-wave voltage of the MZM; the frequency of the resulting millimeter wave signal is 4 times the clock frequency, and quadrature phase modulation is achieved.
3. The ODL-based M of claim 2 2 -a QAM quad millimeter wave signal generation and transmission system, characterized in that the workflow of the receiving end is:
after 1m wireless transmission, the received signal is firstly down-converted after being received by an antenna, then is collected by an analog-to-digital converter such as an oscilloscope, and finally, the modulated signal can be recovered by off-line DSP processing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211618012.1A CN116015467A (en) | 2022-12-15 | 2022-12-15 | ODL-based M 2 QAM quadruple frequency millimeter wave signal generation and transmission system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211618012.1A CN116015467A (en) | 2022-12-15 | 2022-12-15 | ODL-based M 2 QAM quadruple frequency millimeter wave signal generation and transmission system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116015467A true CN116015467A (en) | 2023-04-25 |
Family
ID=86025849
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211618012.1A Pending CN116015467A (en) | 2022-12-15 | 2022-12-15 | ODL-based M 2 QAM quadruple frequency millimeter wave signal generation and transmission system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116015467A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116582182A (en) * | 2023-07-03 | 2023-08-11 | 北京红山信息科技研究院有限公司 | Multi-order multi-quantization digital-to-analog optical fiber radio MDA-RoF method |
-
2022
- 2022-12-15 CN CN202211618012.1A patent/CN116015467A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116582182A (en) * | 2023-07-03 | 2023-08-11 | 北京红山信息科技研究院有限公司 | Multi-order multi-quantization digital-to-analog optical fiber radio MDA-RoF method |
| CN116582182B (en) * | 2023-07-03 | 2023-12-08 | 北京红山信息科技研究院有限公司 | digital-DSM-optical fiber radio DD-RoF method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| McKenna et al. | Experimental demonstration of photonic millimeter-wave system for high capacity point-to-point wireless communications | |
| US10044444B2 (en) | Photonic vector signal generation without precoding | |
| CN110011174B (en) | Optical phase locking method and device based on microwave photon frequency division | |
| CN112087248B (en) | Generation of PDM-m based on polarization multiplexed light modulators2Optical fiber-wireless communication system for QAM radio frequency signals | |
| CN110958053B (en) | Device and method for generating quad-frequency optical millimeter wave BPSK vector signal | |
| CN111464240B (en) | Vector radio frequency signal generation system based on polarization multiplexing intensity modulator | |
| WO2022188241A1 (en) | Polarization multiplexing single sideband signal generation and receiving system and method | |
| CN111416662B (en) | Signal generation and transmission method based on polarization multiplexing double MZM modulator | |
| Termos et al. | All-optical radiofrequency sampling mixer based on a semiconductor optical amplifier Mach–Zehnder interferometer using a standard and a differential configuration | |
| Xu et al. | Demonstration of 60 Gb/s W-band optical mm-wave signal full-duplex transmission over fiber-wireless-fiber network | |
| Li et al. | D-band mm-wave SSB vector signal generation based on cascaded intensity modulators | |
| Kong et al. | Simultaneous generation of wired and wireless signals using a DP-MZM in a RoF system | |
| CN116015467A (en) | ODL-based M 2 QAM quadruple frequency millimeter wave signal generation and transmission system | |
| CN113872700B (en) | High-isolation multichannel microwave photon up-conversion device and method | |
| Tian et al. | Experimental comparison of DSB-SC & OSSB based 60 GHz radio-over-fiber fronthaul links | |
| Kanno et al. | 16-Gbaud QPSK radio transmission using optical frequency comb with recirculating frequency shifter for 300-GHz RoF signal | |
| CN112564813B (en) | Precoding-based terahertz wave signal generation method and device of phase modulator | |
| CN111917475B (en) | System for simultaneously providing wired and single side band wireless services based on single modulator | |
| CN106877934B (en) | Carrier suppression mode radio-on-fiber vector wave system based on phase factor optimization | |
| CN101562482B (en) | Fiber wireless communication system and method for generating downlink multi-service millimeter wave | |
| McKenna et al. | Photonic downconverting receiver using optical phase modulation | |
| Esmail et al. | Demonstration of photonics-based switching of 5G signal over hybrid all-optical network | |
| Xu et al. | Long-reach multicast high split-ratio wired and wireless WDM-PON using SOA for remote upconversion | |
| CN111327364A (en) | System and method for generating vector signal by cascading intensity modulator and IQ modulator | |
| CN111555812B (en) | Device and system for simultaneously generating wired and wireless signals by adopting dual-polarization MZM modulator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |