CN113938204A - Signal transmission method and device and network equipment - Google Patents
Signal transmission method and device and network equipment Download PDFInfo
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- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
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- H—ELECTRICITY
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- H04B10/516—Details of coding or modulation
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Abstract
The embodiment of the invention relates to the technical field of communication, and discloses a signal transmission method, a signal transmission device and network equipment. A method of signal transmission, comprising: acquiring a first electrical signal and a second electrical signal; carrying out polarization separation on an optical signal emitted by a laser to obtain signal light and local oscillator light; modulating the first electric signal onto a first sideband of the signal light, and modulating the second electric signal onto a second sideband of the signal light to obtain modulated signal light; and combining the modulated signal light and the local oscillator light into emitted light for sending. According to the signal transmission method provided by the invention, a digital signal processing circuit is not required in hardware design, and the size, weight and power consumption of the hardware design can be reduced.
Description
Technical Field
The embodiment of the invention relates to the technical field of communication, in particular to a signal transmission method, a signal transmission device and network equipment.
Background
With the commercial start-up of 5G, the base station density of the network will be higher. Therefore, for the base station, the light weight, the small size and the low power consumption are the first considerations for designing the communication system, and the radio over optical technology can solve the above problems well.
The coherent light-carried radio frequency technology is a key technology of next-generation optical communication, compared with a traditional direct detection scheme, the coherent light-carried transmission technology has higher sensitivity which can be generally improved by 10-20dB, and the self-homodyne coherent technology can be theoretically improved by 3dB compared with a heterodyne coherent technology. The principle of coherent communication is that a local oscillator light with the same frequency, phase and polarization direction as the signal light is added into the received signal light, and the two beams of light are subjected to interference mixing. The application of the high-order modulation format enables coherent optical communication to have higher single-wavelength-channel spectrum utilization rate compared with the existing system. The transmitting end light source (including local oscillator light and Signal light) of the existing self-homodyne coherent light-carried microwave transmission method comes from the same laser, but needs to be transmitted through two paths respectively, the coherence of the two paths of light is deteriorated in the transmission process, and the receiving end needs to use a DSP (Digital Signal Processing) circuit to perform related Signal compensation on the received Signal so as to reconstruct the Signal.
However, in implementing the embodiments of the present invention, the inventors found that: since the conventional coherent receiving end needs to perform related signal compensation on the received signal by means of a high-speed digital signal processing technology to reconstruct the signal and implement distortion compensation, a DSP circuit for implementing the high-speed signal processing technology needs to include circuits such as digital processing, a mixer, and a clock, and has large volume, weight, and power consumption, which increases the volume, weight, and power consumption of the design of hardware (AAU (Active Antenna Unit)/RRU (Radio Remote Unit)).
Disclosure of Invention
An object of embodiments of the present invention is to provide a signal transmission method, an apparatus, and a network device, which do not require a digital signal processing circuit in hardware design, and can reduce the size, weight, and power consumption of the hardware design.
In order to solve the above technical problem, an embodiment of the present invention provides a signal transmission method, including: acquiring a first electrical signal and a second electrical signal; carrying out polarization separation on an optical signal emitted by a laser to obtain signal light and local oscillator light; modulating the first electric signal onto a first sideband of the signal light, and modulating the second electric signal onto a second sideband of the signal light to obtain modulated signal light; and combining the modulated signal light and the local oscillator light into emitted light for sending.
The embodiment of the invention also provides a signal transmission method, which comprises the following steps: receiving emitted light, wherein the emitted light comprises signal light and local oscillator light; performing optical filtering processing on the emitted light to acquire first sideband light and second sideband light, wherein the first sideband light comprises a first sideband of the signal light and the local oscillator light, and the second sideband light comprises a second sideband of the signal light and the local oscillator light; and demodulating the first sideband light and the second sideband light respectively to obtain a first electric signal and a second electric signal.
An embodiment of the present invention further provides a signal transmission apparatus, including: the system comprises a laser, a polarization beam splitter, an IQM modulator, a phase delayer and a beam combiner; wherein the laser is used for emitting optical signals; the polarization beam splitter is used for carrying out polarization separation on the optical signal to obtain signal light and local oscillation light; the IQM modulator is configured to modulate a received first electrical signal onto a first sideband of the signal light, modulate a received second electrical signal onto a second sideband of the signal light, and obtain modulated signal light; the phase delayer is used for carrying out phase correction on the local oscillator light to obtain corrected local oscillator light; and the beam combiner is used for combining the corrected local oscillation light and the modulated signal light to generate and transmit emitted light.
An embodiment of the present invention further provides a signal transmission apparatus, including: a first optical filter, a second optical filter, a first photodetector and a second photodetector; the first optical filter is configured to perform filtering processing on the received emitted light to obtain first sideband light, where the first sideband light includes a first sideband of the signal light and the local oscillator light; the second optical filter is configured to perform filtering processing on the received emitted light to obtain second sideband light, where the second sideband light includes a second sideband of the signal light and the local oscillator light; the first photoelectric detector is used for demodulating the first sideband light to obtain a first electric signal; and the second photodetector is used for demodulating the second sideband light to obtain a second electric signal.
An embodiment of the present invention further provides a network device, including:
at least one processor; and a memory communicatively coupled to the at least one processor; wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the signal transmission method described above.
Compared with the prior art, the embodiment of the invention modulates the first electric signal onto the first sideband of the signal light, modulates the second electric signal onto the second sideband of the signal light, and acquires the modulated signal light; the modulated signal light and the local oscillator are combined into emitted light to be sent, the first electric signal and the second electric signal can be modulated onto two side bands of the signal light through single-side-band processing, the two electric signals are not interfered, the phase correlation of the two signal lights is guaranteed to be strong through combined sending, and the two electric signals are not interfered and have strong correlation, so that a receiving end does not need to compensate the two electric signals, a DSP circuit which needs to be used for compensation is omitted, and the size, the weight and the power consumption of hardware design can be reduced.
Drawings
One or more embodiments are illustrated by the corresponding figures in the drawings, which are not meant to be limiting.
Fig. 1 is a flowchart of a signal transmission method according to a first embodiment of the present invention;
fig. 2 is a flowchart of a signal transmission method according to a second embodiment of the present invention;
fig. 3 is a flowchart of a signal transmission method according to a third embodiment of the present invention;
fig. 4 is a flowchart of a signal transmission method according to a fourth embodiment of the present invention;
fig. 5 is a schematic diagram of a signal transmission device provided in a fifth embodiment of the present invention;
FIG. 6 is a schematic diagram of the spectrum of the corresponding node in FIG. 5;
FIG. 7 is a schematic diagram of dual single sideband signal generation in the prior art;
fig. 8 is a schematic view of a signal transmission device provided in a sixth embodiment of the present invention;
FIG. 9 is a schematic diagram of the spectrum of the corresponding node in FIG. 7;
fig. 10 is a schematic diagram of a network device according to a seventh embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that numerous technical details are set forth in order to provide a better understanding of the present application in various embodiments of the present invention. However, the technical solution claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments. The following embodiments are divided for convenience of description, and should not constitute any limitation to the specific implementation manner of the present invention, and the embodiments may be mutually incorporated and referred to without contradiction.
A first embodiment of the present invention relates to a signal transmission method, see fig. 1, comprising the steps of:
step S101, a first electrical signal and a second electrical signal are acquired.
Specifically, the first electrical signal and the second electrical signal are baseband signals, and after frequency conversion and hilbert transform, according to the addition characteristic of fourier transform, the real part and the imaginary part of the complex signal are separated and used as I/Q signals to drive the IQ modulator, respectively, which will be described in detail later and is only briefly described here.
And S102, carrying out polarization separation on the optical signal emitted by the laser to obtain signal light and local oscillator light.
Specifically, an optical signal emitted by the laser is separated into X-polarized light and Y-polarized light by a Polarization Beam Splitter (PBS), where the X-polarized light is modulated as the signal light and the Y-polarized light is local oscillation light required for coherent reception.
Step S103, modulating the first electrical signal onto a first sideband of the signal light, and modulating the second electrical signal onto a second sideband of the signal light, to obtain the modulated signal light.
In particular, the first electrical signal and the second electrical signal are modulated onto two side bands of the signal light, in particular onto an upper side band and a lower side band of the X polarization state by means of an IQM modulator, so that no interference between the two electrical signals can be achieved.
And step S104, combining the modulated signal light and the local oscillator light into emitted light for sending.
Specifically, the modulated signal light and the local oscillator light are combined by an Optical Combiner (OC) and transmitted through an Optical fiber, so that the strong correlation between the two signal light phases can be ensured.
Compared with the prior art, the embodiment of the invention modulates the first electric signal onto the first sideband of the signal light, modulates the second electric signal onto the second sideband of the signal light, and acquires the modulated signal light; the modulated signal light and the local oscillator are combined into emitted light to be sent, the first electric signal and the second electric signal can be modulated onto two side bands of the signal light through single-side-band processing, the two electric signals are not interfered, the phase correlation of the two signal lights is guaranteed to be strong through combined sending, and the two electric signals are not interfered and have strong correlation, so that a receiving end does not need to compensate the two electric signals, a DSP circuit which needs to be used for compensation is omitted, and the size, the weight and the power consumption of hardware design can be reduced.
A second embodiment of the present invention relates to a signal transmission method, and is substantially the same as the first embodiment except that:
referring to fig. 2, in the second embodiment, step S104, the combining the modulated signal light and the local oscillator light into transmission light for transmission includes:
step S1041, performing phase correction on the local oscillation light, and acquiring corrected local oscillation light.
Specifically, the phase correction of the local oscillator light (Y polarized light) is specifically performed by a phase delay device (TOD).
Step S1042, performing beam combining processing on the corrected local oscillation light and the modulated signal light, generating emission light, and sending the emission light.
Specifically, the phase-corrected X-polarized signal light and the Y-polarized local oscillator light are combined by a Polarization Beam Combiner (PBC) and then transmitted through an optical fiber.
In addition, in the second embodiment, after the step S1041 of performing phase correction on the local oscillator light and acquiring corrected local oscillator light, and before the step S1042 of performing beam combining processing on the corrected local oscillator light and the modulated signal light to generate emitted light and sending the emitted light, the method further includes:
and step S1043, performing polarization rotation on the corrected local oscillator light, and acquiring rotated local oscillator light, where the polarization state of the rotated local oscillator light is consistent with that of the modulated signal light.
Specifically, the local oscillator light (Y polarized light) is polarization-rotated by a Faraday Rotator Mirror (FRM), so that the polarization states of the rotated local oscillator light and the modulated signal light are consistent.
Step S1042, the combining process is performed on the corrected local oscillator light and the modulated signal light, and the generated emitted light is sent specifically as:
and combining the rotated local oscillation light and the modulated signal light to generate emission light and send the emission light.
Specifically, the local oscillation light and the signal light after the phase correction and the polarization rotation have no polarization state and phase difference, and are combined to generate the emission light which is transmitted through the optical fiber.
In this embodiment, the local oscillator light is subjected to phase correction and polarization rotation, so that there is no difference between the polarization state and the phase between the local oscillator light and the signal light, and thus, the demodulated signal can be directly connected to the wave control board, thereby greatly reducing the complexity of hardware design, weight, size and power consumption.
A third embodiment of the present invention relates to a signal transmission method, see fig. 3, including the steps of:
step S201, receiving emitted light, where the emitted light includes signal light and local oscillator light.
Specifically, the emitted light is received after being transmitted through the optical fiber, and includes signal light and local oscillator light, the signal light is modulated signal light, and a first electrical signal and a second electrical signal are respectively modulated on upper and lower side bands of the signal light.
Step S202, performing optical filtering processing on the emitted light, and acquiring first sideband light and second sideband light, where the first sideband light includes a first sideband of the signal light and the local oscillator light, and the second sideband light includes a second sideband of the signal light and the local oscillator light.
Specifically, the emitted light is optically filtered by an Optical Filter (OBPF), so as to obtain a first sideband (corresponding to the first electrical signal) and a local oscillator light of the signal light, and a second sideband (corresponding to the first electrical signal) and the local oscillator light, respectively.
Step S203, respectively demodulating the first sideband light and the second sideband light, and acquiring a first electrical signal and a second electrical signal.
Specifically, the required first electrical signal and second electrical signal may be obtained by performing homodyne beat frequency on the local oscillator light and the first sideband and the second sideband, respectively.
In this embodiment, the emitted light is optically filtered to obtain a first sideband light and a second sideband light, where the first sideband light includes the first sideband of the signal light and the local oscillator light, and the second sideband light includes the second sideband of the signal light and the local oscillator light, and the first sideband light and the second sideband light are demodulated respectively to obtain a first electrical signal and a second electrical signal.
A fourth embodiment of the present invention relates to a signal transmission method, and is substantially the same as the third embodiment except that:
referring to fig. 4, after receiving the emitted light in step S201, before performing optical filtering processing on the emitted light to obtain the first sideband light and the second sideband light in step S202, the method further includes:
step S204, performing a splitting process on the emitted light, and acquiring the signal light and the local oscillator light.
Specifically, the emitted light may be split by a Wavelength Division Module (WDM) to obtain a signal light and a local oscillator light, where the signal light is modulated, and the upper and lower bands of the signal light are respectively modulated with a first electrical signal and a second electrical signal.
Step S205, performing polarization rotation on the local oscillation light, and obtaining the rotated local oscillation light.
Specifically, the polarization rotation is performed on the local oscillator light through the faraday rotator FRM, so that the local oscillator light is consistent with the polarization of the sideband optical signal.
Step S206, reflecting the signal light to obtain a reflected signal light, where the phase of the rotated local oscillator light is consistent with that of the reflected signal light.
Specifically, signal light is reflected by a faraday reflector (FM), and phase coincidence with local oscillator light of Y polarization is ensured.
And step S207, combining the reflected signal light and the rotated local oscillator light to generate the emitted light to be processed.
Specifically, the emitted light to be processed includes reflected signal light and rotated local oscillator light with the same phase and polarization state, and optical filtering processing and demodulation processing are performed subsequently after combining processing.
In addition, in the fourth embodiment, in step S202, the emitted light is subjected to optical filtering processing to obtain first sideband light and second sideband light, specifically:
and carrying out optical filtering processing on the emitted light to be processed to obtain first sideband light and second sideband light.
Specifically, the emitted light to be processed is passed through an optical filter OBPF to obtain a first sideband light and a second sideband light.
In this embodiment, the local oscillator light is adjusted in phase and rotated in polarization, so that there is no polarization state and phase difference between the local oscillator light and the signal light, and thus, the demodulated signal can be directly connected to the wave control board, thereby greatly reducing the complexity of hardware design, weight, size and power consumption.
A fifth embodiment of the present invention relates to a signal transmission apparatus, including a transmitting end and a receiving end, wherein the transmitting end includes: the system comprises a laser, a polarization beam splitter, an IQM modulator, a phase delayer and a beam combiner;
wherein the laser is used for emitting optical signals;
the polarization beam splitter is used for carrying out polarization separation on the optical signal to obtain signal light and local oscillation light;
the IQM modulator is configured to modulate a received first electrical signal onto a first sideband of the signal light, modulate a received second electrical signal onto a second sideband of the signal light, and obtain modulated signal light;
the phase delayer is used for carrying out phase correction on the local oscillator light to obtain corrected local oscillator light;
and the beam combiner is used for combining the corrected local oscillation light and the modulated signal light to generate and transmit emitted light.
The receiving end includes: a first optical filter, a second optical filter, a first photodetector and a second photodetector; wherein,
the first optical filter is configured to perform filtering processing on the received emitted light to obtain first sideband light, where the first sideband light includes a first sideband of the signal light and the local oscillator light;
the second optical filter is configured to perform filtering processing on the received emitted light to obtain second sideband light, where the second sideband light includes a second sideband of the signal light and the local oscillator light;
the first photoelectric detector is used for demodulating the first sideband light to obtain a first electric signal;
and the second photodetector is used for demodulating the second sideband light to obtain a second electric signal.
The receiving end further includes: the device comprises a wavelength division module, a Faraday rotation mirror and a Faraday reflector; wherein,
the wavelength division module is used for carrying out shunt processing on the emitted light to obtain the signal light and the local oscillator light;
the Faraday rotator is used for carrying out polarization rotation on the local oscillator light to obtain the rotated local oscillator light;
the Faraday reflector is used for reflecting the signal light to obtain reflected signal light, wherein the phase of the rotated local oscillator light is consistent with that of the reflected signal light;
the first optical filter is further configured to perform filtering processing on the to-be-processed emitted light to obtain first sideband light, where the first sideband light includes a first sideband of the signal light and the local oscillator light, and the to-be-processed emitted light is generated by combining the reflected signal light and the rotated local oscillator light;
the second optical filter is further configured to perform filtering processing on the to-be-processed emitted light to obtain second sideband light, where the second sideband light includes a second sideband of the signal light and the local oscillator light, and the to-be-processed emitted light is generated by combining the reflected signal light and the rotated local oscillator light.
Referring to fig. 5 and 6, the signal transmission apparatus is specifically described below by taking fig. 5 and 6 as an example, and with reference to fig. 5 and 6, the signal transmission apparatus includes a transmitting end and a receiving end, and the transmitting end includes: laser 1, polarization beam splitter PBS2, IQM modulator 3, phase retarder TOD4, polarization beam combiner PBC 5; the receiving end includes: circulator C1, wavelength division module WDM6, Faraday rotator mirror FRM7, Faraday reflector FM8, optical filter OBPF9, 10 and photo detector PD11, 12.
In fig. 5, light emitted from the laser 1 is polarization-separated by the polarization beam splitter PBS2, and the X-polarized light is modulated as signal light and the Y-polarized light is local oscillation light required for coherent reception. The electrical signal is passed through an IQM modulator 3 to perform single sideband modulation (corresponding to the a signal) on the signal light in such a way that the signals S1, S2 are respectively on both sidebands of the X-polarized light. The light of Y polarization is subjected to phase correction (corresponding to a signal b) through a phase delayer TOD4, then the signal light of X polarization and the local oscillator light of Y polarization are combined (corresponding to a signal C) through a polarization beam combiner PBC5, then the signal light and the local oscillator light of Y polarization are transmitted through an optical fiber, then the signal light enters from a port 1 and exits from a port 2 of a circulator C1, a wavelength division module WDM6 splits a sideband optical signal and the local oscillator light of Y polarization, the local oscillator light of Y polarization is subjected to polarization rotation through a Faraday rotator FRM7 to be consistent with the polarization of the sideband optical signal, the sideband light passes through a Faraday reflector FM8 to ensure the phase consistency with the local oscillator light of Y polarization, and finally the sideband optical signal and the local oscillator light are recombined to enter a port 2 of the circulator and then exit from a port 3 (corresponding to a signal d). Two side band lights (corresponding to e and f signals) containing local oscillation lights are respectively filtered out through optical filters OBPF9 and OBPF 10, signals S1 and S2 are demodulated through photoelectric detectors PD11 and PD 12, and then signal transmission can be carried out by connecting a wave control board. The spectrum diagram corresponding to the signals a, b, c, d, e and f is shown in FIG. 6.
Fig. 7 illustrates the principle of dual sideband optical signal generation. Here a single polarization state enables 2-dimensional signal transmission. Suppose that the 2 independent signals to be transmitted are denoted S respectively1(t) and S2(t) of (d). Both signals are baseband signals, the frequency spectra of which are shown in fig. 7. At a passing frequency fsThe frequency source realizes up-conversion and then becomes a radio frequency signal. The real radio frequency signal after up-conversion is converted into a complex single sideband signal through single sideband filtering processing. The single sideband filter is shown in FIG. 7 and includes a Hilbert transform and a complex scaleNumber j. The single sideband signal of the upper sideband or the lower sideband can be obtained by adjusting the positive and negative of j. The frequency spectra of the generated single sideband signals a (t) and b (t) are shown in the figure. a (t) and b (t) can be expressed as:
a(t)＝S1(t)·cos(2π·fst)+j·HT(S1(t)·cos(2π·fst))
b(t)＝S2(t)·cos(2π·fst)-j·HT(S2(t)·cos(2π·fst))
where HT (-) represents the Hilbert transform. Finally, according to the additive characteristic of fourier transform, i.e., F (a) (t) + b (t)) + F (a (t)) + F (b (t)), the real part and the imaginary part of the complex signal after a (t)) + b (t) are separated and used as I/Q signals to drive the IQ modulator. It is noted here that the bias point of the I/Q modulator is at the NULL point. The signal S can be clearly seen1(t) and S2(t) are allocated to the left and right sides of the optical carrier fc, respectively. When receiving, the optical filter filters out a sideband signal and carrier wave to be detected, so as to realize the detection without crosstalk between signals. The modulation mode of single sideband can avoid the phase noise introduced by IQM and IQ mismatch problem of traditional coherent reception Hybrid.
A sixth embodiment of the present invention relates to a signal transmission apparatus, including a transmitting end and a receiving end,
the transmitting end includes: the system comprises a laser, a polarization beam splitter, an IQM modulator, a phase delayer and a beam combiner;
wherein the laser is used for emitting optical signals;
the polarization beam splitter is used for carrying out polarization separation on the optical signal to obtain signal light and local oscillation light;
the IQM modulator is configured to modulate a received first electrical signal onto a first sideband of the signal light, modulate a received second electrical signal onto a second sideband of the signal light, and obtain modulated signal light;
the phase delayer is used for carrying out phase correction on the local oscillator light to obtain corrected local oscillator light;
and the beam combiner is used for combining the corrected local oscillation light and the modulated signal light to generate and transmit emitted light.
The transmitting end further comprises: a Faraday rotator mirror; wherein,
the Faraday rotator is used for performing polarization rotation on the corrected local oscillator light to obtain rotated local oscillator light, wherein the polarization state of the rotated local oscillator light is consistent with that of the modulated signal light;
and the beam combiner is further configured to combine the rotated local oscillator light and the modulated signal light to generate emitted light and send the emitted light.
The receiving end includes: a first optical filter, a second optical filter, a first photodetector and a second photodetector; wherein,
the first optical filter is configured to perform filtering processing on the received emitted light to obtain first sideband light, where the first sideband light includes a first sideband of the signal light and the local oscillator light;
the second optical filter is configured to perform filtering processing on the received emitted light to obtain second sideband light, where the second sideband light includes a second sideband of the signal light and the local oscillator light;
the first photoelectric detector is used for demodulating the first sideband light to obtain a first electric signal;
and the second photodetector is used for demodulating the second sideband light to obtain a second electric signal.
In the following, the signal transmission apparatus is specifically described by taking fig. 8 and fig. 9 as an example, and specifically, referring to fig. 8 and fig. 9, the transmitting end includes: a laser 1, a polarization beam splitter PBS2, an IQM modulator 3, a beam combiner OC4, a circulator C1, a phase retarder TOD5 and a Faraday rotator mirror FRM 6; the receiving end includes: optical filters OBPF 7, 8, photodetectors PD 9, 10.
In fig. 8, light emitted from the laser 1 on the left side is polarization-separated by the polarization beam splitter PBS2, and the X-polarized light is modulated as signal light and the Y-polarized light is local oscillation light required for coherent reception. The signal light is subjected to single-sideband modulation (corresponding to a signal) by an IQM modulator 3, the modulation mode causes signals S1 and S2 to be respectively positioned on two sidebands of X polarized light, the local oscillator light (corresponding to b signal) of polarization Y enters through a port 1 of a circulator C1, a port 2 exits, phase correction is carried out through a phase delayer TOD5, polarization rotation is carried out through a Faraday rotator FRM6, the polarization state of the local oscillator light of Y polarization is consistent with the signal light of the polarization state of the X polarized light, the signal light enters from the port 2 of the circulator C1 after reflection, a port 3 exits (corresponding to C signal), the signal light and the local oscillator light are combined (corresponding to d signal) through a combiner OC4, then the signal light is transmitted through an optical fiber, then the two sidebands light (corresponding to e and f signals) containing the local oscillator light are respectively filtered through optical filters OBPF 7 and 8, and then the two sidebands light (corresponding to e and f signals) containing the local oscillator light are respectively filtered through a photoelectric detector PD 9 and PD 9, 10 demodulate the signals S1 and S2, and then transmit the signals to a prior art wave control board. The spectrum diagrams corresponding to a, b, c, d, e and f are shown in FIG. 9.
The circulators in the fifth embodiment and the sixth embodiment may be implemented by other circuit structures, such as a multiplexer, as long as the circulators can realize the entry and exit of signals.
In the fifth and sixth embodiments of the present invention, the mode, frequency, and bandwidth of the signal to be modulated can be changed according to the user's requirement, and the coherent optical carrier transmission capable of implementing multi-mode and multi-frequency high and low frequency fusion can be realized. In addition, IQ mismatch of Hybrid adopted by traditional coherent reception can be effectively avoided, and phase noise introduced by the mismatch is eliminated.
The present invention is not limited to the application to transmissions in base stations, but can also be applied to data centers and other fields that use coherent transmissions.
A seventh embodiment of the present invention relates to a network device, as shown in fig. 10, including:
at least one processor 1001; and the number of the first and second groups,
a memory 1002 communicatively coupled to the at least one processor 1001; wherein,
the memory 1002 stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor 1001 to enable the at least one processor 1001 to perform the signal transmission method provided by the above embodiments of the present invention.
Where the memory and processor are connected by a bus, the bus may comprise any number of interconnected buses and bridges, the buses connecting together one or more of the various circuits of the processor and the memory. The bus may also connect various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. A bus interface provides an interface between the bus and the transceiver. The transceiver may be one element or a plurality of elements, such as a plurality of receivers and transmitters, providing a means for communicating with various other apparatus over a transmission medium. The data processed by the processor is transmitted over a wireless medium via an antenna, which further receives the data and transmits the data to the processor.
The processor is responsible for managing the bus and general processing and may also provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. And the memory may be used to store data used by the processor in performing operations.
It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples for carrying out the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.
Claims (10)
1. A signal transmission method, comprising:
acquiring a first electrical signal and a second electrical signal;
carrying out polarization separation on an optical signal emitted by a laser to obtain signal light and local oscillator light;
modulating the first electric signal onto a first sideband of the signal light, and modulating the second electric signal onto a second sideband of the signal light to obtain modulated signal light;
and combining the modulated signal light and the local oscillator light into emitted light for sending.
2. The method of claim 1, wherein the combining the modulated signal light and the local oscillator light into the emitted light for transmission comprises:
performing phase correction on the local oscillator light to obtain corrected local oscillator light;
and carrying out beam combination processing on the corrected local oscillation light and the modulated signal light to generate and send emitted light.
3. The method according to claim 2, wherein before the phase correcting the local oscillator light, acquiring the corrected local oscillator light, and combining the corrected local oscillator light and the modulated signal light to generate the emitted light, the method further comprises:
carrying out polarization rotation on the corrected local oscillator light to obtain the rotated local oscillator light, wherein the polarization state of the rotated local oscillator light is consistent with that of the modulated signal light;
the combining processing is performed on the corrected local oscillation light and the modulated signal light, and emitted light is generated and sent specifically as follows:
and combining the rotated local oscillation light and the modulated signal light to generate emission light and send the emission light.
4. A signal transmission method, comprising:
receiving emitted light, wherein the emitted light comprises signal light and local oscillator light;
performing optical filtering processing on the emitted light to acquire first sideband light and second sideband light, wherein the first sideband light comprises a first sideband of the signal light and the local oscillator light, and the second sideband light comprises a second sideband of the signal light and the local oscillator light;
and demodulating the first sideband light and the second sideband light respectively to obtain a first electric signal and a second electric signal.
5. The method of claim 4, wherein after receiving the emitted light, the optical filtering of the emitted light before obtaining the first sideband light and the second sideband light further comprises:
carrying out shunt processing on the emitted light to obtain the signal light and the local oscillator light;
carrying out polarization rotation on the local oscillator light to obtain the rotated local oscillator light;
reflecting the signal light to obtain reflected signal light, wherein the phase of the rotated local oscillator light is consistent with that of the reflected signal light;
combining the reflected signal light and the rotated local oscillator light to generate emitted light to be processed;
the optical filtering processing is performed on the emitted light, and the obtaining of the first sideband light and the second sideband light specifically includes:
and carrying out optical filtering processing on the emitted light to be processed to obtain first sideband light and second sideband light.
6. A signal transmission apparatus, comprising: the system comprises a laser, a polarization beam splitter, an IQM modulator, a phase delayer and a beam combiner; wherein,
the laser is used for emitting optical signals;
the polarization beam splitter is used for carrying out polarization separation on the optical signal to obtain signal light and local oscillation light;
the IQM modulator is configured to modulate a received first electrical signal onto a first sideband of the signal light, modulate a received second electrical signal onto a second sideband of the signal light, and obtain modulated signal light;
the phase delayer is used for carrying out phase correction on the local oscillator light to obtain corrected local oscillator light;
and the beam combiner is used for combining the corrected local oscillation light and the modulated signal light to generate and transmit emitted light.
7. The apparatus of claim 6, further comprising: a Faraday rotator mirror; wherein,
the Faraday rotator is used for performing polarization rotation on the corrected local oscillator light to obtain rotated local oscillator light, wherein the polarization state of the rotated local oscillator light is consistent with that of the modulated signal light;
and the beam combiner is further configured to combine the rotated local oscillator light and the modulated signal light to generate emitted light and send the emitted light.
8. A signal transmission apparatus, comprising: a first optical filter, a second optical filter, a first photodetector and a second photodetector; wherein,
the first optical filter is configured to perform filtering processing on the received emitted light to obtain first sideband light, where the first sideband light includes a first sideband of the signal light and the local oscillator light;
the second optical filter is configured to perform filtering processing on the received emitted light to obtain second sideband light, where the second sideband light includes a second sideband of the signal light and the local oscillator light;
the first photoelectric detector is used for demodulating the first sideband light to obtain a first electric signal;
and the second photodetector is used for demodulating the second sideband light to obtain a second electric signal.
9. The apparatus of claim 8, further comprising: the device comprises a wavelength division module, a Faraday rotation mirror and a Faraday reflector; wherein,
the wavelength division module is used for carrying out shunt processing on the emitted light to obtain the signal light and the local oscillator light;
the Faraday rotator is used for carrying out polarization rotation on the local oscillator light to obtain the rotated local oscillator light;
the Faraday reflector is used for reflecting the signal light to obtain reflected signal light, wherein the phase of the rotated local oscillator light is consistent with that of the reflected signal light;
the first optical filter is further configured to perform filtering processing on the to-be-processed emitted light to obtain first sideband light, where the first sideband light includes a first sideband of the signal light and the local oscillator light, and the to-be-processed emitted light is generated by combining the reflected signal light and the rotated local oscillator light;
the second optical filter is further configured to perform filtering processing on the to-be-processed emitted light to obtain second sideband light, where the second sideband light includes a second sideband of the signal light and the local oscillator light, and the to-be-processed emitted light is generated by combining the reflected signal light and the rotated local oscillator light.
10. A network device, comprising:
at least one processor; and the number of the first and second groups,
a memory communicatively coupled to the at least one processor; wherein,
the memory stores instructions executable by the at least one processor to enable the at least one processor to perform a signal transmission method according to any one of claims 1 to 3, or a signal transmission method according to claim 4 or 5.
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| CN202010606768.9A CN113938204A (en) | 2020-06-29 | 2020-06-29 | Signal transmission method and device and network equipment |
| PCT/CN2021/097400 WO2022001546A1 (en) | 2020-06-29 | 2021-05-31 | Signal transmission method and apparatus, and network device |
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| CN202010606768.9A CN113938204A (en) | 2020-06-29 | 2020-06-29 | Signal transmission method and device and network equipment |
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| CN101777953A (en) * | 2010-01-08 | 2010-07-14 | 西安电子科技大学 | Light double-sideband modulation device and method for transmitting two paths of signals |
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| US8582983B2 (en) * | 2011-03-10 | 2013-11-12 | Zte Corporation | Method and system for generation of coherent subcarriers |
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| CN110149154B (en) * | 2019-04-10 | 2020-12-01 | 华中科技大学 | Few-mode preamplification coherent receiving system and method for free space optical signal |
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- 2020-06-29 CN CN202010606768.9A patent/CN113938204A/en not_active Withdrawn
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| CN101777953A (en) * | 2010-01-08 | 2010-07-14 | 西安电子科技大学 | Light double-sideband modulation device and method for transmitting two paths of signals |
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