59 results about "Single-sideband modulation" patented technology

The invention discloses a photon device and method for simultaneously measuring Doppler frequency shift and an angle of arrival, and belongs to the technical field of microwave photon-assisted radars. The device is configured to enable a transmitting signal and a reference signal to enter a first dual-parallel Mach-Zehnder modulator working in a carrier suppression single sideband modulation mode after being combined so as to generate two positive first-order sideband signals, and then the two positive first-order sideband signals enter a second dual-parallel Mach-Zehnder modulator and are modulated by an echo signal; and a modulation signal output from the second dual-parallel Mach-Zehnder modulator enters a photoelectric detector for photoelectric conversion to generate a down-conversion signal. Comparing the frequency of the down-conversion signal with the frequency of the reference signal by using an electric spectrum analyzer to obtain the magnitude and direction of Doppler frequency shift; the arrival angle of the target can be obtained by monitoring the power of the frequency conversion signal. Measurement of Doppler frequency shift and the angle of arrival can be completed only by using the photoelectric detector with the bandwidth lower than the frequency of the transmitted signal, and the requirement for the bandwidth of the photoelectric detector is lowered.

The invention discloses an automatic locking method of a double-loop laser, which is constructed by using an FPGA (Field Programmable Gate Array) on the basis of a Pound-Drever-Hall principle. Comprising the steps that a high-carrier-suppression single-side-band modulator is added to a classical Pound-Drever-Hall system, a second control loop jointly composed of a voltage-controlled crystal oscillator, a frequency divider, a frequency mixer and a low-pass filter is newly added, error signals of laser resonant frequency and resonant cavity resonant frequency in an FPGA are divided into a high frequency part and a low frequency part, and the high-carrier-suppression single-side-band modulator is added to the high-carrier-suppression single-side-band modulator. The low-frequency signal controls a PZT of a laser resonant cavity through a control loop constructed by the FPGA, and the high-frequency signal controls a single-sideband modulator through a high-frequency control loop constructed by the FPGA; and meanwhile, an automatic relocking mechanism is added in the system, an automatic relocking algorithm is constructed by utilizing an FPGA (Field Programmable Gate Array), the signal is output only when the signal is in a controllable linear interval, and otherwise, the locking mode is quitted and scanning is restarted until the linear interval is entered. According to the invention, the problem of low frequency locking precision caused by simple locking of the laser PZT in a traditional PDH scheme is solved by constructing a dual-control loop.

This invention discloses a simple, multifunctional, integrated 5G analog fronthaul in-band full-duplex communication method for remote units (RUs). This method primarily relates to the fields of optical communication technology and microwave technology. The system structure of the method, as shown in Figure 1 of the specification, includes a laser, downlink vector signal, electrical local oscillator signal, downlink interference signal, target signal, reference signal, 90° electrical coupler, dual-polarization quadrature phase-shift keying modulator, phase modulator, single-mode fiber, optical coupler, polarization beamsplitter, polarization beam combiner, polarization controller, polarizer, and photodetector. The remote unit (RU) uses a single phase (PM) modulator to achieve self-interference cancellation (SIC) combined with anti-fiber dispersion transmission and down-conversion, eliminating the need for bias control and additional local oscillator (LO) branches, resulting in a simple structure. At the central office (CO), the carried downlink signal and local oscillator signal are single-sideband modulated to achieve anti-fiber dispersion transmission. The RU uses wavelength reuse technology to perform PM cascaded down-conversion on the signal received from the uplink, and the SIC is moved from the RU to the CO to simplify the RU. The entire link has no optical filter and is reconfigurable.

The application discloses a kind of bandwidth saving coherent transmission method and PON system, it is related to optical access network technical field, including: in downlink transmission direction, OLT sending end generates M digital subcarriers, after digital-analog conversion, it is carried out double polarization modulation, as downlink signal is sent to ONU receiving end;Each subarea ONU receiving end carries out heterodyne coherent detection to the partial spectrum of downlink signal, and downlink signal occupies the single sideband spectrum of ONU end light source;In the direction of uplink transmission, the data of corresponding digital subcarrier is generated by ONU sending end, and single sideband modulation is carried out based on ONU end light source, as uplink signal is sent to the OLT receiving end of corresponding subarea, and uplink signal occupies another single sideband spectrum of ONU end light source;OLT receiving end carries out analog-digital conversion and digital signal processing after heterodyne coherent detection.The application selects subcarrier by configuring light source of different wavelength at ONU end to reduce device bandwidth, so that PON system reduces cost while maintaining transmission capacity, sensitivity and flexibility.

A broadband microwave photon instantaneous frequency measuring device in a high-power range comprises an LD, a CS-SSB module, an MZI structure, a BPD and a post-processing module. The invention also provides a broadband microwave photon instantaneous frequency measurement method in a high-power range. The method comprises the following steps: the LD generates continuous optical carriers and outputs the continuous optical carriers to the CS-SSB module; the CS-SSB module carries out carrier suppression single side band modulation on the optical carrier; the CS-SSB signal is transmitted to the MZI structure; output signals of the 2 * 290-degree coupler are respectively subjected to photoelectric detection in the BPD to realize photoelectric conversion; the post-processing module performs ratio processing on output signals of different BPDs, and constructs a power-independent monotonic amplitude comparison function ACF curve. The ACF curve is constructed through the ratio of two signal amplitudes, multiple delays are introduced through link extension, and large-bandwidth, unambiguous and high-precision measurement is achieved; the method is not influenced by the tested signal power and is wide in application range; the device is simple in structure, does not contain a polarization device, and has wide application prospects in the fields of reconnaissance confrontation and weak signal detection.

This invention proposes a method for generating broadband signals that is resistant to dispersion fading based on an electro-optical modulator. By rationally changing the phase of the driving signal, a chirp signal with opposite chirp signs can be generated during the beat frequency, thereby switching between single chirp and double chirp. Furthermore, this scheme proposes carrier-suppressed single-sideband modulation of the chirp signal, which effectively avoids amplitude fading caused by dispersion in optical fiber transmission while eliminating interference signals that fall within the chirp signal band after the beat frequency. The proposed scheme based on the DP-DPMZM integrated device is easy to integrate, has a simple structure, and is low-cost. The generated dual-band chirp signal can be flexibly switched between up-chirp, down-chirp, and double chirp, greatly improving the flexibility of the system. Furthermore, it effectively eliminates amplitude fading caused by dispersion in optical fiber transmission, significantly increasing the transmission distance of traditional systems. This scheme is expected to provide technical support for the development of future high-performance radar technology.

The present invention discloses a photon device and method for simultaneously measuring Doppler frequency shift and angle of arrival, belonging to the technical field of microwave photon-assisted radar. The device is configured such that after the transmitted signal and the reference signal are combined, they enter a first dual-parallel Mach-Zehnder modulator operating in the carrier-suppressed single-sideband modulation mode to generate two positive first-order sideband signals. The two positive first-order sideband signals then enter a second dual-parallel Mach-Zehnder modulator and are modulated by the echo signal. The modulated signal output from the second dual-parallel Mach-Zehnder modulator enters a photodetector for photoelectric conversion to generate a down-converted signal. An electrical spectrum analyzer is used to compare the frequency of the down-converted signal and the reference signal to obtain the magnitude and direction of the Doppler frequency shift; monitoring the power of the frequency-converted signal can obtain the angle of arrival of the target. In the present invention, only a photodetector with a bandwidth lower than the transmitted signal frequency is used to complete the measurement of the Doppler frequency shift and the angle of arrival, reducing the requirements for the bandwidth of the photodetector.

The invention belongs to the technical field of optics, and particularly relates to an unequal-interval frequency comb generation and detection device and method based on a single side band modulator. In order to improve phase coherence between comb teeth, an arbitrary waveform generator generates a modulation signal, the modulation signal is amplified by a power amplifier and then input into a single-side-band phase modulator, a laser is connected with an optical signal input end of the single-side-band phase modulator, and an output end of the single-side-band phase modulator is connected with an optical beam splitter. The light beam splitter divides light into two paths, one path serves as reference light to enter the first detector, the first detector converts the reference light into an electric signal and then carries out FFT observation, the other path serves as detection light, is absorbed by the gas chamber and then is input into the second detector, and the second detector converts the detection light into an electric signal and then carries out FFT observation.

A miniaturized distributed optical fiber sensing system based on an integrated optoelectronic chip includes a light source, a first erbium-doped fiber amplifier (EDFA), an integrated optoelectronic chip with electro-optical modulation and beat frequency detection functions, a second erbium-doped fiber amplifier (EDFA), a circulator, and a sensing optical fiber. The integrated optoelectronic chip includes: a first end coupler, a directional coupler, a single-stage tunable optical attenuator (VOA), an IQ single-sideband modulator, a cascaded tunable optical attenuator (VOA), a second end coupler, a third end coupler, a 2×2 multimode interferometer (MMI), and an on-chip balanced detector (BPD). The on-chip IQ modulator and the cascaded VOA are combined to realize frequency shift and pulse modulation. The IQ modulator realizes single-sideband modulation, and the cascaded VOA converts continuous light into pulse light and couples it into the optical fiber through the second end coupler for detection. The scattered signal light is coupled to the chip through the third end coupler to beat with the local oscillator reference light, and is detected by the on-chip BPD. The new system is more integrated, miniaturized, highly stable, and has low energy consumption.

The application provides a wireless signal generation device and method based on integrated optical comb synchronization. The device comprises: an integrated optical comb repetition frequency signal generation unit: generating an optical comb signal, filtering the optical comb signal to obtain first and second optical signals adjacent to the beam, and third and fourth optical signals with different frequencies, and obtaining a high-frequency clock signal with the same frequency as the optical comb signal by combining, amplifying and frequency mixing the first and second optical signals; a standard microwave clock signal generation unit: after amplification and filtering of the high-frequency clock signal, the microwave clock signal with a standard frequency and synchronized with the high-frequency clock signal is obtained by integer frequency division and decimal frequency division in turn; a wireless signal generation unit: converting the microwave clock signal into a low-frequency baseband signal, generating an optical carrier microwave signal by single sideband modulation of the fourth optical signal through the low-frequency baseband signal, and obtaining a high-frequency coherent wireless signal by combining and frequency mixing the optical carrier microwave signal and the third optical signal.

The invention discloses a long-distance distributed disturbance sensing system and method based on single-sideband modulation OFDR. The system comprises a narrow-linewidth fiber laser, a single-sideband modulator, an erbium-doped fiber amplifier, a 1: 99 polarization-maintaining beam splitter, an acquisition card, a computer, a trigger line, an additional interferometer and a main interferometer. According to the invention, an ultra-narrow linewidth fiber laser is used as a system light source, SSB-SC is used to suppress carrier waves and other sidebands, frequency tuning is realized in an external modulation mode, the system is applied to OFDR long-distance distributed disturbance sensing, and the light source is used as a tunable laser of an optical frequency domain reflection system to carry out distributed disturbance sensing. Rayleigh scattering spectrums are measured under the undisturbed condition and the disturbed condition respectively, the non-similarity of the undisturbed Rayleigh scattering spectrums and the disturbed Rayleigh scattering spectrums is solved after the light source tuning nonlinear effect is compensated through a dechirping filtering method, and the position where the non-similarity is increased is the disturbing position; the system can realize 50m spatial resolution disturbance positioning at the tail end of the 97.8 km optical fiber.

The invention provides a signal generation system. The signal generation system comprises an external modulation laser, an optical splitter, a Mach-Zehnder modulator, a phase shifter, an attenuator, a coupler and a photoelectric conversion unit. According to the invention, Mach-Zehnder modulation is carried out on optical carriers through asymmetric double single side band signals, and millimeter wave / terahertz signals in the form of optical signals are obtained through destructive interference between output signals of a phase shifter and an attenuator and optical signals subjected to Mach-Zehnder modulation. And finally, millimeter wave / terahertz signals in an electric signal form are obtained through the photoelectric conversion unit. Millimeter wave / terahertz signals are generated by adopting a single push-pull Mach-Zehnder modulator and attenuator optical double-single-side-band modulation, transmitter precoding and a complex and expensive I / Q modulator are avoided, the complexity and cost of the system can be effectively reduced, meanwhile, the frequency interval can be flexibly adjusted, and the system performance is improved. And the tunable range of the system is increased.

Circuit and method for electro-optic modulation of an RF signal to produce a single-sideband reduced-carrier phase-shifted (SSB-RC-PS) modulated signal includes: receiving an optical carrier signal; receiving the RF signal; modulating the RF signal with a first portion of the optical carrier to produce a single sideband (SSB) modulated signal; amplitude and phase modulating a second portion of the optical carrier signal and combining with the modulated signal to produce a first combined signal, the amplitude modulation and phase modulation of the second portion of the optical carrier signal are dynamically controlled to directly match the amplitude and inversely match the phase of the modulated signal; and amplitude modulating and phase modulating a third portion of the optical carrier signal and combining third portion with the first combined signal to produce the second combined signal, the product of which is a single sideband reduced carrier phase shifted (SSB-RC-PS) modulated signal.

This invention discloses a coherent transmission method and PON system based on digital subcarrier multiplexing, relating to the field of optical access network technology. The method includes: in the downlink transmission direction, the OLT transmitter generates an Alamouti-coded signal of M digital subcarriers, performs digital-to-analog conversion and dual polarization modulation, and transmits it as a downlink signal to the ONU receiver; the ONU receiver performs heterodyne coherent detection, analog-to-digital conversion, and digital signal processing, with the downlink signal occupying a single-sideband spectrum of the ONU's light source; in the uplink transmission direction, the ONU transmitter generates data of M digital subcarriers, performs digital-to-analog conversion, and then performs single-sideband modulation based on the ONU's light source, transmitting it as an uplink signal to the OLT receiver, with the uplink signal occupying another single-sideband spectrum; the OLT receiver performs analog-to-digital conversion and digital signal processing after coherent reception. This application enables bidirectional high-speed transmission, and uses the same light source for both transmission and reception at the ONU, which increases the capacity of the PON system, simplifies the ONU's structure and algorithm, and reduces system costs.

The present application discloses a method for automatically locking a dual-loop laser based on the Pound-Drever-Hall principle using an FPGA. It includes adding a high-carrier-suppression single-sideband modulator to a classical Pound-Drever-Hall system, and adding a second control loop composed of a voltage-controlled crystal oscillator, a frequency divider, a mixer, and a low-pass filter. In the FPGA, the error signal between the laser resonance frequency and the resonator resonance frequency is divided into high-frequency and low-frequency parts. The low-frequency signal controls the PZT of the laser resonator through the control loop constructed by the FPGA, and the high-frequency signal controls the single-sideband modulator through the high-frequency control loop constructed by the FPGA. At the same time, an automatic relocking mechanism is added to the system, and an automatic relocking algorithm is constructed using the FPGA. Only when the signal is in a controllable linear range is the signal output; otherwise, the locking mode is exited and scanning starts again until the linear range is entered. The present invention solves the problem of low frequency-locking accuracy caused by simply locking the PZT of the laser in the traditional PDH scheme by constructing a dual control loop.

The invention discloses a single-channel direction finding system based on optical single side band modulation and an implementation method thereof, belongs to the technical field of radio frequency signal processing, and solves the problem that the direction finding efficiency is low under the conditions of frequency hopping, short duration, uncertain arrival and end time and the like of received radio frequency signals. The existing single-channel direction finding technology is difficult to realize broadband, high probability and real-time direction finding in electronic reconnaissance equipment. Comprising N antennas used for receiving N radio frequency signals respectively, a multi-channel electro-optical conversion unit connected with the N antennas, a reference signal generation unit and a photoelectric synthesis conversion unit which are connected with the multi-channel electro-optical conversion unit, and a signal processing unit connected with the photoelectric synthesis conversion unit. According to the method, high-probability interception and accurate direction finding of radio frequency signals can be realized in a large instantaneous frequency range, and the method has obvious advantages in the aspects of performance level, implementation architecture and the like.

This invention relates to an optical frequency domain reflection system and method based on a voltage-controlled oscillator (VCO). The system mainly includes an arbitrary function generator, a laser, a VCO, a single-sideband modulator, an auxiliary interferometer, a main interferometer, and a polarization beam splitter. The arbitrary function generator, laser, VCO, and VSB modulator work together to generate the sweeping light required for measurement. This sweeping light is split into two paths: one path enters the main interferometer as probe light, and the other path enters the auxiliary interferometer to obtain the instantaneous frequency of the probe light. Based on the instantaneous frequency, the signal from the main interferometer is resampled using a one-dimensional interpolation method. This invention uses a low-cost, small-sized VCO as the radio frequency signal generator to generate a sweeping signal with fast frequency modulation performance, and compensates for phase noise caused by the nonlinearity of the sweeping signal by designing the optical path of the auxiliary interferometer and using a linear interpolation algorithm.

This invention discloses a method for generating broadband microwave signals based on microwave photonics technology. A reference microwave signal and an excitation microwave signal are simultaneously passed through a 90° microwave bridge to obtain two orthogonal microwave signals. These two orthogonal microwave signals are then used to perform carrier-suppressed single-sideband modulation on an optical carrier using a dual parallel intensity modulator. The generated modulated optical signal is then optically amplified and filtered before photoelectric conversion to generate a frequency-converted microwave signal. This frequency-converted microwave signal is split into two paths: one is used as the system output, and the other is electrically amplified and filtered before being fed back to the 90° microwave bridge, thus forming a closed frequency conversion loop. After multiple frequency conversions, the system outputs an ultra-wide bandwidth microwave signal. This invention also discloses a broadband microwave signal generation device based on microwave photonics technology. Compared with existing technologies, this invention can generate ultra-wide bandwidth microwave signals in different frequency bands and multiple formats.

The invention discloses a microwave photon channelized receiving method based on a double-vernier effect. The method comprises the following steps: S1, generating two paths of coherent optical frequency comb signals of which the initial frequency and the free spectral range are slightly different; s2, performing single side band modulation on the two paths of optical frequency comb signals by using the original radio frequency signal; s3, respectively carrying out wavelength division multiplexing on the two paths of modulated optical signals, separating out each comb tooth and radio-over-fiber signal components at the same frequency with each comb tooth in the other path of modulated optical signals, and then forming a local oscillator / signal pair by the comb teeth at the same frequency and the radio-over-fiber signal components; and S4, performing dual-output image frequency suppression mixing on each group of local oscillator / signal pairs. The invention further discloses a microwave photon channelization receiving device based on the double-vernier effect. Compared with the prior art, the channelization efficiency and the image frequency suppression effect can be greatly improved.

The invention relates to the technical field of distributed optical fiber sensing, in particular to an optical fiber Rayleigh scattering signal enhancement device based on a chaotic Brillouin dynamic grating, which comprises a chaotic laser, chaotic laser from the first output end of the first coupler is subjected to sideband modulation through a single sideband modulator, passes through a first polarization controller and a first polarizer, and enters a sensing optical fiber as first pump light; a chaotic laser signal output from the second output end of the first coupler passes through a second polarization controller, a second polarizer and a polarization beam splitter and then enters the sensing optical fiber from the other end of the sensing optical fiber as second pump light; the two paths of pump light meet in the sensing optical fiber and generate a stimulated Brillouin effect to form a chaotic Brillouin dynamic grating; according to the invention, the chaotic laser is adopted to form the chaotic Brillouin dynamic grating, so that the Rayleigh scattering response bandwidth of a detection signal is obviously widened, and the bandwidth of a Rayleigh scattering enhanced signal is improved.

The present invention discloses a single-channel direction-finding system based on optical single-sideband modulation and an implementation method, belonging to the field of radio frequency signal processing technology. The system solves the problem that existing single-channel direction-finding technology cannot achieve broadband, high-probability, and real-time direction-finding in electronic reconnaissance equipment when the received radio frequency signal has frequency hopping, short duration, and uncertain arrival and end times. The system includes N antennas for receiving N radio frequency signals, a multi-channel electro-optical conversion unit connected to the N antennas, a reference signal generating unit and an optoelectronic synthesis conversion unit connected to the multi-channel electro-optical conversion unit, and a signal processing unit connected to the optoelectronic synthesis conversion unit. The present invention can achieve high-probability interception and accurate direction-finding of radio frequency signals in a large instantaneous frequency range, and has obvious advantages in terms of performance level and implementation architecture.

The invention discloses an optical carrier suppression single side band modulation device and method based on a variable optical coupler. The device comprises a laser, a first adjustable optical coupler, an optical single side band modulation module, a second optical phase shifter and a fourth adjustable optical coupler. And the first adjustable optical coupler divides the optical carrier into two paths according to a preset proportion, and the two paths are respectively input into the optical single side band modulation module and the second branch, so that the power matching of the two paths of carriers is ensured. The optical single side band modulation module comprises a second adjustable optical coupler, a first optical phase shifter and a third adjustable optical coupler, and accurate splitting ratio control and phase adjustment are achieved. And the second optical phase shifter performs phase adjustment on the second branch optical carrier to enable the second branch optical carrier to be opposite to the carrier phase in the modulation signal, and a high-purity optical carrier suppression single side band signal is output through combination of a fourth adjustable optical coupler. According to the invention, through cooperative configuration of the multi-stage adjustable device, process errors are effectively overcome, the carrier-to-sideband suppression ratio and the system power efficiency are improved, and the method can be applied to the fields of radio over fiber communication and the like.

The application relates to the field of distributed optical fiber sensing, and discloses a high-speed chaotic Brillouin sensing device and method based on a correlation method multi-address positioning method, wherein strong periodic broadband chaotic laser is divided into two beams through a first beam splitter, one beam is used as probe light and sequentially enters a sensing optical fiber after passing through a single sideband modulator and an erbium-doped fiber amplifier; the other beam sequentially passes through an optical delay line, an erbium-doped fiber amplifier, and a second beam splitter to be divided into pump light and reference light, the pump light passes through an optical circulator and occurs stimulated Brillouin amplification with the probe light at different positions in the sensing optical fiber; the signal in the sensing optical fiber is output after passing through the optical circulator, Stokes light is filtered out by a tunable optical filter and is detected by a first photodetector, the reference light is detected by a second photodetector, a data acquisition unit collects two-way signals and sends the two-way signals to a computer for data processing; the application improves the signal-to-noise ratio of the system, widens the sensing distance, and realizes high-speed and accurate positioning of multiple sensing points.

The invention discloses an information processing method, and the method comprises the steps: detecting a single side band modulation SSB signal after the SSB signal is received, and obtaining a first peak value of a main synchronization signal and a second peak value of an auxiliary synchronization signal which are included in the SSB signal; determining the position of a time slot head of the SSB signal based on the first peak value and the second peak value; and performing downlink beam synchronization based on the position of the time slot head. The invention further discloses an information processing device and equipment, a computer readable storage medium and a computer program product.

The present invention discloses a microwave frequency shifting method based on optical injection locking. A continuous single-frequency optical carrier is divided into three channels; the first channel of continuous single-frequency optical carrier is subjected to carrier suppression single-sideband modulation with the microwave signal to be frequency-shifted to obtain signal light; the second channel of continuous single-frequency optical carrier is used as the injection optical signal, injected into the slave laser and makes the slave laser work in the injection locking mode of a single-cycle oscillation state, the phase and power of the third channel of continuous single-frequency optical carrier are adjusted so that it is equal to the injection locking optical signal output from the slave laser but opposite in phase, and then the two signals are coupled into one channel to obtain a local oscillator optical signal containing only the red-shifted resonant component of the slave laser; finally, the local oscillator optical signal is beat with the signal light to obtain a frequency-shifted microwave signal. The present invention also discloses a microwave frequency shifting device based on optical injection locking. Compared with the prior art, the present invention can tune the frequency shift amount over a large range and improve the spurious suppression effect.

The present disclosure relates to a device and a communication method with which it is possible to perform appropriate filtering / image suppression when single side band modulation is used for D2R transmission of an A-IoT device. A device that has a lower complexity than an NB-IoT device comprises: a transmission unit that transmits to a wireless base station by using single side band modulation; and a control unit that selects either an upper side band or a lower side band in the single side band modulation, and uses the selected side band to perform transmission control of a transmission signal to the wireless base station.

The application discloses an encryption communication method and system based on probability shaping and double single sideband modulation, and the method comprises the following steps: receiving an original bit stream and an initial key, generating a chaotic sequence according to the initial key by using a hyperchaotic model; calculating a mask factor according to the chaotic sequence; performing constellation mapping processing on the original bit stream to obtain a constellation diagram; performing rotation encryption on the constellation diagram according to the mask factor to obtain an encrypted signal; performing QPSK modulation on the encrypted signal to obtain a left sideband carrier signal; performing constellation mapping on the initial key after repeating and superimposing to obtain a key signal; performing probability shaping and QPSK modulation on the key signal to obtain a right sideband carrier signal; superimposing the left sideband carrier signal and the right sideband carrier signal to obtain a mixed signal, and transmitting the mixed signal to a receiver through a transmitter; and the safety and reliability of key transmission are improved while the signal transmission efficiency is ensured.

The present invention relates to an optical fiber communication system and method, and particularly to a microwave photon frequency conversion method and system based on injection-locked OEO, which solves the problems of poor tunability and low conversion efficiency existing in the existing all-optical mixing technology based on ultrafast optical nonlinear effects, and the technical problem that although the electro-optic modulation mixing technology based on the electro-optic effect has a simple structure, the frequency conversion effect is limited by the characteristics of the local oscillator signal and the modulator, making it difficult to flexibly frequency-convert broadband microwave signals. The microwave photon frequency conversion system based on injection-locked OEO includes a first laser, a first optical coupler, an upper branch module, a lower branch module, a band-stop filtering module, and a second photodetector; the upper branch module is used for optically suppressing the carrier double-sideband modulation of the signal to be frequency-converted; the lower branch module is used for realizing the optically suppressing the carrier single-sideband modulation of the tunable local oscillator signal and the oscillation signal; the present invention can achieve the flexible frequency conversion characteristics of broadband microwave signals.

To provide a device and a communication method that can perform appropriate filtering / image suppression when single sideband modulation is used for D2R transmission of an A-IoT device.SOLUTION: A device with lower complexity than an NB-IoT (Narrow Band Internet of Things) device includes a transmitter that transmits to a wireless base station using single sideband amplitude modulation, and a controller that selects either an upper sideband or a lower sideband in the single sideband modulation and controls transmission of a transmission signal to the wireless base station using the selected sideband.SELECTED DRAWING: Figure 11

A microwave photon frequency-hopping transmission and reception system comprises a dual-band, dual-frequency cascaded optical frequency comb module, a transmission carrier generation and signal modulation module, a radio frequency transmission module, an orthogonal optical sampling clock generation module, an electro-optical sampling and orthogonal demultiplexing module, a radio frequency reception module, an optoelectronic conversion and digital processing module, and a synchronization and control module. In the frequency-hopping transmission portion, the communication signal is loaded onto the optical carrier via carrier-suppressed single-sideband modulation. The beat frequency of the optical carrier and the optical comb teeth selected by the optical switch generates an RF transmission signal carrying the communication signal. Rapid switching of the optical switch enables rapid, flexible, and wide-range switching of the transmission carrier frequency. In the frequency-hopping reception portion, the optical comb teeth are selected by the optical switch to generate an orthogonal optical sampling clock. Rapid switching of the optical switch enables rapid, flexible, and wide-range switching of the center frequency of the receiving passband. Flexible configuration of the frequency-hopping reception passband bandwidth is achieved by varying the filter bandwidth.