A microwave photonic wideband blind source signal separation device and method

Abstract

A microwave photonic wide-bandwidth blind source signal separation device and method includes: a receiving antenna, a laser source, an electro-optic conversion unit, an optical domain weighting unit, an opto-receiving unit, an electrical splitter, and a signal acquisition and processing unit. The mixed blind source signal received by the receiving antenna is modulated onto an optical carrier emitted by the laser source through the electro-optic conversion unit. The optical carrier microwave signal enters the opto-receiving unit through the optical domain weighting unit. The output of the opto-receiving unit, after being split by the electrical splitter, enters the signal acquisition and processing unit. The signal acquisition and processing unit performs principal component analysis and independent component analysis using the received statistical information as the objective function of a feedback algorithm. It outputs a control signal to the optical domain weighting unit for weighted modulation. The separation of multiple blind source signals is achieved through iterative feedback algorithm iteration. This microwave photonic wide-bandwidth blind source signal separation device and method has the advantages of a wide operating frequency range, large bandwidth, and low power consumption, enabling effective separation of blind source signals.

Description

Technical Field

[0001] This invention belongs to the field of information processing technology and relates to a microwave photonic wideband blind source signal separation device and method. Background Technology

[0002] Blind source separation technology refers to processing observed signals to separate the source signals without any prior knowledge of the source signals or the transmission process. This technology has important applications in fields such as speech processing, image processing, radar detection, and wireless communication. In particular, with the rapid development of next-generation wireless communication technologies, such as multiple-input multiple-output (MIMO) wireless communication systems, blind source separation technology can achieve efficient communication among multiple users while eliminating multipath effects and power attenuation, thereby improving the signal-to-noise ratio.

[0003] However, with the increase in communication frequency bands and bandwidth, traditional electrical blind source separation technology is difficult to directly achieve wide-band, large-bandwidth blind source signal separation due to the inherent bandwidth limitations of radio frequency devices. It is necessary to divide the wide-band signal into multiple narrow-band sub-bands, and each sub-band requires the same number of analog-to-digital converters as the number of receiving antennas. As a result, the power consumption of the blind source separation device will increase sharply with the product of the number of sub-bands and the number of antennas, which greatly limits the scalability of the blind source separation device. Summary of the Invention

[0004] This invention provides a microwave photonic wide-bandwidth blind source signal separation device and method, which effectively solves the limitations of narrow working bandwidth and high power consumption in blind source separation applications in the prior art, and completes the effective separation of multiple source signals within a wide bandwidth range.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A microwave photonic high-bandwidth blind source signal separation device includes: an antenna, a laser source, an electro-optical conversion unit, an optical domain weighting unit, an optoelectronic receiving unit, an electrical splitter, and a signal acquisition and processing unit.

[0007] The first receiving antenna and the first electro-optical conversion unit are connected in sequence via a cable or microstrip line; the second receiving antenna and the second electro-optical conversion unit are connected in sequence via a cable or microstrip line; ...; the Nth receiving antenna and the Nth electro-optical conversion unit are connected in sequence via a cable or microstrip line.

[0008] The first laser source, the first electro-optic conversion unit, the optical domain weighting unit, and the photoelectric receiving unit are connected in sequence via optical fibers or integrated optical waveguides; the second laser source, the second electro-optic conversion unit, the optical domain weighting unit, and the photoelectric receiving unit are connected in sequence via optical fibers or integrated optical waveguides; ...; the Nth laser source, the Nth electro-optic conversion unit, the optical domain weighting unit, and the photoelectric receiving unit are connected in sequence via optical fibers or integrated optical waveguides.

[0009] The optical domain weighting unit consists of N dual-output Mach-Zehnder interferometer structures; the intensity changes at the two output ports of each dual-output Mach-Zehnder interferometer structure satisfy the laws of sine and cosine functions, respectively.

[0010] The photoelectric receiving unit consists of a first wavelength division multiplexing combiner, a second wavelength division multiplexing combiner, a first photodetector, and a second photodetector. The first wavelength division multiplexing combiner and the first photodetector are connected through an optical fiber or an integrated optical waveguide, and the second wavelength division multiplexing combiner and the second photodetector are connected through an optical fiber or an integrated optical waveguide. The combining mode of the outputs of the first photodetector and the second photodetector is differential combining.

[0011] The optical microwave signal output by the first electro-optical conversion unit is output to the first dual-output Mach-Zehnder interferometer structure of the optical domain weighting unit; the optical microwave signal output by the second electro-optical conversion unit is output to the second dual-output Mach-Zehnder interferometer structure of the optical domain weighting unit; ...; the optical microwave signal output by the Nth electro-optical conversion unit is output to the Nth dual-output Mach-Zehnder interferometer structure of the optical domain weighting unit;

[0012] The two optical microwave signals output from the first dual-output Mach-Zehnder interferometer structure in the optical domain weighting unit are respectively transmitted to the first input port of the first wavelength division multiplexing combiner and the first input port of the second wavelength division multiplexing combiner in the optoelectronic receiving unit; the two optical microwave signals output from the second dual-output Mach-Zehnder interferometer structure in the optical domain weighting unit are respectively transmitted to the second input port of the first wavelength division multiplexing combiner and the second input port of the second wavelength division multiplexing combiner in the optoelectronic receiving unit; ...; the two optical microwave signals output from the Nth dual-output Mach-Zehnder interferometer structure in the optical domain weighting unit are respectively transmitted to the Nth input port of the first wavelength division multiplexing combiner and the Nth input port of the second wavelength division multiplexing combiner in the optoelectronic receiving unit;

[0013] The first laser source, the second laser source, ..., the Nth laser source each have a different wavelength of output light. The wavelength of the first laser source is consistent with the center wavelength of the first input port of the first wavelength division multiplexing combiner and the first input port of the second wavelength division multiplexing combiner in the optoelectronic receiving unit; the wavelength of the second laser source is consistent with the center wavelength of the second input port of the first wavelength division multiplexing combiner and the second input port of the second wavelength division multiplexing combiner in the optoelectronic receiving unit; ...; the wavelength of the Nth laser source is consistent with the center wavelength of the Nth input port of the first wavelength division multiplexing combiner and the Nth input port of the second wavelength division multiplexing combiner in the optoelectronic receiving unit.

[0014] The electrical splitter includes one input port and two output ports; the input port is connected to the output of the photoelectric receiving unit; one of the two output ports outputs the demixed source signal, and the other port is connected to the signal sampling and data processing unit.

[0015] The signal acquisition and data processing unit has the function of sampling the output signal of the photoelectric receiving unit and running a feedback algorithm, and outputting a control signal to the optical domain weighting unit.

[0016] The microwave photonic wideband blind source signal separation method of the present invention includes the following steps:

[0017] In the first step, the first receiving antenna receives the signal emitted by each signal source and mixed together after spatial transmission. The mixed signal is modulated onto the light wave emitted by the first laser source by the first electro-optic conversion unit. The second receiving antenna receives the signal emitted by each signal source and mixed together after spatial transmission. The mixed signal is modulated onto the light wave emitted by the second laser source by the second electro-optic conversion unit. ... The Nth receiving antenna receives the signal emitted by each signal source and mixed together after spatial transmission. The mixed signal is modulated onto the light wave emitted by the Nth laser source by the Nth electro-optic conversion unit.

[0018] In the second step, the optical microwave signal output from the first electro-optical conversion unit is output to the first dual-output Mach-Zehnder interferometer structure of the optical domain weighting unit; the optical microwave signal output from the second electro-optical conversion unit is output to the second dual-output Mach-Zehnder interferometer structure of the optical domain weighting unit; ...; the optical microwave signal output from the Nth electro-optical conversion unit is output to the Nth dual-output Mach-Zehnder interferometer structure of the optical domain weighting unit; the dual-output Mach-Zehnder interferometer structure in the optical domain weighting unit performs weighting processing on the optical microwave signal and outputs it through the first output port and the second output port, so that the optical microwave signal obtains a weight value from 0 to 1.

[0019] In the third step, the weighted optical microwave signals output from the first and second output ports of each dual-output Mach-Zehnder interferometer structure in the optical domain weighting unit are respectively fed into the first and second wavelength division multiplexing combiners. The multiple optical microwave signals output from the first wavelength division multiplexing combiner are fed into the first photodetector for photoelectric conversion, and the multiple optical microwave signals output from the second wavelength division multiplexing combiner are fed into the second photodetector for photoelectric conversion. The electrical signals output from the first and second photodetectors are differentially combined to expand the weighting range of the optical microwave signals to -1 to 1. The weighted signals output from the electrical splitter are fed into the signal acquisition and data processing unit to obtain the statistical information of the output signal. Principal component analysis and independent component analysis are performed using the statistical information as the objective function of the feedback algorithm to solve the source signal. The weighting value of the mixed signal is controlled by changing the phase difference between the two arms of each Mach-Zehnder interferometer structure in the optical domain weighting unit.

[0020] The fourth step involves randomly initializing the weight values ​​applied to the mixed signal by the optical domain weighting unit, comparing the signal statistics obtained by the signal acquisition and data processing unit with the convergence conditions of the feedback algorithm, adjusting the weight values ​​applied to the mixed signal by the optical domain weighting unit, and performing iterative optimization to achieve the separation and output of each blind source signal in sequence.

[0021] The beneficial effects of this invention are:

[0022] (1) The weight values ​​of the mixed signal are adjusted by using the optical domain weighted modulation method. The outputs of the two ports of the dual-output Mach-Zehnder interferometer structure satisfy the law of sine and cosine function changes. The bandwidth of the weight assignment range is not limited. Furthermore, the dual-output Mach-Zehnder interferometer structure has strong scalability and can separate multiple blind source signals.

[0023] (2) The signal acquisition and processing unit that performs weighted adjustment of large bandwidth mixed signals in the optical domain and executes feedback algorithm can use an analog-to-digital converter with a sampling rate lower than Nyquist to sample the signal output by the photoelectric receiving unit, which greatly reduces the requirements of analog-to-digital converter and the power consumption of blind source separation device. Attached image description:

[0024] Figure 1 This is a structural diagram of the microwave photonic high-bandwidth blind source signal separation device of the present invention.

[0025] Figure 2 This is a structural diagram of the microwave photonic blind source signal separation device in an embodiment of the present invention.

[0026] Figure 3 This is a waveform diagram of a mixed 1GHz square wave and 4GHz sine wave signal received by the first receiving antenna in an embodiment of the present invention.

[0027] Figure 4 This is a waveform diagram of a mixed 1GHz square wave and 4GHz sine wave signal received by the second receiving antenna in this embodiment of the invention.

[0028] Figure 5 This is a waveform diagram of a 1GHz square wave output by the microwave photonic blind source signal separation device according to an embodiment of the present invention.

[0029] Figure 6 This is a waveform diagram of the 4GHz sine wave output by the microwave photonic blind source signal separation device in an embodiment of the present invention. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] The embodiment of the microwave photonic high-bandwidth blind source signal separation device includes: a receiving antenna, a laser source, an electro-optical conversion unit, an optical domain weighting unit, an optoelectronic receiving unit, an electrical splitter, and a signal acquisition and processing unit.

[0032] The optical weighting unit consists of two dual-output Mach-Zehnder interferometer structures;

[0033] The photoelectric receiving unit consists of a first wavelength division multiplexing combiner, a second wavelength division multiplexing combiner, a first photodetector, and a second photodetector; the combining mode of the outputs of the first photodetector and the second photodetector is differential combining.

[0034] The wavelengths of each laser source correspond one-to-one with the center wavelengths of each input port of the wavelength division multiplexing combiner in the optoelectronic receiving unit;

[0035] Example

[0036] Take the separation of two mixed blind source signals as an example. Figure 2 As shown, the first signal source generates a 4 GHz sine wave signal; the second signal source generates a 1 GHz square wave signal. After the source signals are mixed through spatial transmission, the mixed signal is received by the receiving antenna.

[0037] The waveform of the mixed signal received by the first receiving antenna is as follows: Figure 3 As shown, the mixed signal is modulated onto the optical carrier by the first electro-optical conversion unit; the waveform of the mixed signal received by the second receiving antenna is as follows. Figure 4 As shown, the mixed signal is modulated onto the optical carrier by the second electro-optical conversion unit.

[0038] The optically carried microwave signal output from the first electro-optical conversion unit is output to the first dual-output Mach-Zehnder interference structure of the optical domain weighting unit; the optically carried microwave signal output from the second electro-optical conversion unit is output to the second dual-output Mach-Zehnder interference structure of the optical domain weighting unit.

[0039] The optical microwave signals output from the first and second output ports of the first Mach-Zehnder interferometer structure in the optical domain weighting unit are respectively input to the first input port of the first wavelength division multiplexing combiner and the first input port of the second wavelength division multiplexing combiner; the optical microwave signals output from the first and second output ports of the second Mach-Zehnder interferometer structure are respectively input to the second input port of the first wavelength division multiplexing combiner and the second input port of the second wavelength division multiplexing combiner.

[0040] The two optical microwave signals output from the first wavelength division multiplexing combiner in the photoelectric conversion unit enter the first photodetector to complete the photoelectric conversion, and the two optical microwave signals output from the second wavelength division multiplexing combiner enter the second photodetector to complete the photoelectric conversion; the electrical signals output from the first photodetector and the electrical signals output from the second photodetector are differentially combined.

[0041] The electrical splitter outputs one electrical signal into the signal acquisition and data processing unit to obtain the statistical information of the output signal. The statistical information is used as the objective function of the feedback algorithm to perform principal component analysis and independent component analysis to solve the source signal. The weighting value of the mixed signal is controlled by changing the phase difference between the two arms of each Mach-Zehnder interference structure in the optical domain weighting unit.

[0042] The weight values ​​applied to the mixed signal by the optical domain weighting unit are randomly initialized. The signal statistical information obtained by the signal acquisition and data processing unit is compared with the convergence condition of the feedback algorithm. The weight values ​​applied to the mixed signal by the optical domain weighting unit are adjusted, and iterative optimization is performed to sequentially separate the 1GHz square wave signal and the 4GHz sine wave signal. The waveform of the separated 1GHz square wave signal is shown in the figure. Figure 5 As shown, the waveform of the separated 4GHz sine wave signal is as follows. Figure 6 As shown. From Figure 5 and Figure 6 It can be seen that, Figure 2 The microwave photonic blind source signal separation device of the present invention shown achieves effective separation of two blind source signals with a wide frequency band and a large bandwidth.

[0043] The above-described embodiments are merely illustrative of the implementation methods of the present invention, but should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A microwave photonic wideband blind source signal separation device, characterized in that, The microwave photonic high-bandwidth blind source signal separation device includes: an antenna, a laser source, an electro-optical conversion unit, an optical domain weighting unit, an optoelectronic receiving unit, an electrical splitter, and a signal acquisition and processing unit; The first receiving antenna and the first electro-optical conversion unit are connected in sequence via a cable or microstrip line; the second receiving antenna and the second electro-optical conversion unit are connected in sequence via a cable or microstrip line; ...; the Nth receiving antenna and the Nth electro-optical conversion unit are connected in sequence via a cable or microstrip line. The first laser source, the first electro-optic conversion unit, the optical domain weighting unit, and the photoelectric receiving unit are connected in sequence via optical fiber or integrated optical waveguide; the second laser source, the second electro-optic conversion unit, the optical domain weighting unit, and the photoelectric receiving unit are connected in sequence via optical fiber or integrated optical waveguide; ...; the Nth laser source, the Nth electro-optic conversion unit, the optical domain weighting unit, and the photoelectric receiving unit are connected in sequence via optical fiber or integrated optical waveguide. The optical domain weighting unit consists of N dual-output Mach-Zehnder interferometer structures; the intensity changes at the two output ports of each dual-output Mach-Zehnder interferometer structure satisfy the laws of sine and cosine functions, respectively. The photoelectric receiving unit consists of a first wavelength division multiplexing combiner, a second wavelength division multiplexing combiner, a first photodetector, and a second photodetector. The first wavelength division multiplexing combiner and the first photodetector are connected through an optical fiber or an integrated optical waveguide, and the second wavelength division multiplexing combiner and the second photodetector are connected through an optical fiber or an integrated optical waveguide. The combining mode of the outputs of the first photodetector and the second photodetector is differential combining. The optical microwave signal output by the first electro-optical conversion unit is output to the first dual-output Mach-Zehnder interferometer structure of the optical domain weighting unit; the optical microwave signal output by the second electro-optical conversion unit is output to the second dual-output Mach-Zehnder interferometer structure of the optical domain weighting unit; ...; the optical microwave signal output by the Nth electro-optical conversion unit is output to the Nth dual-output Mach-Zehnder interferometer structure of the optical domain weighting unit; The two optical microwave signals output from the first dual-output Mach-Zehnder interferometer structure in the optical domain weighting unit are respectively transmitted to the first input port of the first wavelength division multiplexing combiner and the first input port of the second wavelength division multiplexing combiner in the optoelectronic receiving unit; the two optical microwave signals output from the second dual-output Mach-Zehnder interferometer structure in the optical domain weighting unit are respectively transmitted to the second input port of the first wavelength division multiplexing combiner and the second input port of the second wavelength division multiplexing combiner in the optoelectronic receiving unit; ...; the two optical microwave signals output from the Nth dual-output Mach-Zehnder interferometer structure in the optical domain weighting unit are respectively transmitted to the Nth input port of the first wavelength division multiplexing combiner and the Nth input port of the second wavelength division multiplexing combiner in the optoelectronic receiving unit; The first laser source, the second laser source, ..., the Nth laser source each have a different output wavelength. The wavelength of the first laser source is consistent with the center wavelength of the first input port of the first wavelength division multiplexing combiner and the first input port of the second wavelength division multiplexing combiner in the optoelectronic receiving unit; the wavelength of the second laser source is consistent with the center wavelength of the second input port of the first wavelength division multiplexing combiner and the second input port of the second wavelength division multiplexing combiner in the optoelectronic receiving unit; ...; the wavelength of the Nth laser source is consistent with the center wavelength of the Nth input port of the first wavelength division multiplexing combiner and the Nth input port of the second wavelength division multiplexing combiner in the optoelectronic receiving unit. The electrical splitter includes one input port and two output ports; the input port is connected to the output of the photoelectric receiving unit; one of the two output ports outputs the demixed source signal, and the other port is connected to the signal sampling and data processing unit. The signal acquisition and data processing unit has the function of sampling the output signal of the photoelectric receiving unit and running a feedback algorithm, and outputting a control signal to the optical domain weighting unit.

2. A method for separating microwave photonic wideband blind source signals, characterized in that, The microwave photonic wideband blind source signal separation device according to claim 1 comprises the following steps: In the first step, the first receiving antenna receives the signal emitted by each signal source and mixed together after spatial transmission. This mixed signal is modulated onto the light wave emitted by the first laser source by the first electro-optic conversion unit. The second receiving antenna receives the signal emitted by each signal source and mixed together after spatial transmission. This mixed signal is modulated onto the light wave emitted by the second laser source by the second electro-optic conversion unit. ... The Nth receiving antenna receives the signal emitted by each signal source and mixed together after spatial transmission. This mixed signal is modulated onto the light wave emitted by the Nth laser source by the Nth electro-optic conversion unit. In the second step, the optical microwave signal output from the first electro-optical conversion unit is output to the first dual-output Mach-Zehnder interferometer structure of the optical domain weighting unit; the optical microwave signal output from the second electro-optical conversion unit is output to the second dual-output Mach-Zehnder interferometer structure of the optical domain weighting unit; ...; the optical microwave signal output from the Nth electro-optical conversion unit is output to the Nth dual-output Mach-Zehnder interferometer structure of the optical domain weighting unit; the dual-output Mach-Zehnder interferometer structure in the optical domain weighting unit performs weighting processing on the optical microwave signal and outputs it through the first output port and the second output port, so that the optical microwave signal obtains a weight value from 0 to 1; In the third step, the weighted optical microwave signals output from the first and second output ports of each dual-output Mach-Zehnder interferometer structure in the optical domain weighting unit are respectively fed into the first wavelength division multiplexing combiner and the second wavelength division multiplexing combiner. The multiple optical microwave signals output from the first wavelength division multiplexing combiner are fed into the first photodetector for photoelectric conversion, and the multiple optical microwave signals output from the second wavelength division multiplexing combiner are fed into the second photodetector for photoelectric conversion. The electrical signals output from the first and second photodetectors are differentially combined to expand the weighting value range of the optical microwave signals to -1 to 1. The weighted signals output from the electrical splitter are fed into the signal acquisition and data processing unit to obtain the statistical information of the output signal. Principal component analysis and independent component analysis are performed using the statistical information as the objective function of the feedback algorithm to solve the source signal. The weighting value of the mixed signal is controlled by changing the phase difference between the two arms of each Mach-Zehnder interferometer structure in the optical domain weighting unit. The fourth step involves randomly initializing the weight values ​​applied to the mixed signal by the optical domain weighting unit, comparing the signal statistics obtained by the signal acquisition and data processing unit with the convergence conditions of the feedback algorithm, adjusting the weight values ​​applied to the mixed signal by the optical domain weighting unit, and performing iterative optimization to achieve the separation and output of each blind source signal in sequence.

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