36 results about "Path gain" patented technology

The invention discloses an urban canyon-oriented unmanned aerial vehicle multipath reflection communication enhancement method and system, and the method comprises the steps: collecting a direct signal and a multipath reflection signal received by an unmanned aerial vehicle in an urban canyon environment, synchronously scanning a surrounding three-dimensional environment through an airborne laser radar, and generating a multipath signal feature set with an environment feature tag; path gain modeling is carried out on the multipath signal feature set, a mapping relation of path importance-reflection gain is constructed, a particle swarm optimization algorithm is adopted to solve a reflection plane phase combination enabling the signal-to-noise ratio of a receiving end to be maximum, and a phase control sequence of an IRS unit is generated; and the phase of each reflection unit of the intelligent reflection surface is dynamically adjusted according to the phase control sequence, interference signals of a weak reflection path are suppressed at the same time, the superposed signal intensity and bit error rate are collected in real time, and a communication signal after cooperative enhancement is generated. According to the embodiment of the invention, the signal-to-noise ratio and stability of the communication link of the unmanned aerial vehicle can be improved, and low-power-consumption and high-reliability communication enhancement of urban canyons is realized.

This invention discloses a deep learning-based channel estimation method for asymmetric all-digital communication systems, comprising: designing an uplink receiving array based on a nested sparse array topology to recover the received signal of the sparse array into a virtual array signal of full dimension; decomposing the obtained virtual signal into a grid part and an off-grid part based on Taylor formula, and designing a two-step-angle estimation net (Ts-AEnet) to estimate the signal angle of arrival; solving a least-squares problem to estimate the signal path gain and reconstructing the downlink channel. This invention proposes an uplink receiving array based on a nested sparse array topology in asymmetric all-digital communication systems, minimizing information loss caused by missing antennas, and proposes a deep learning-based Ts-AEnet angle estimation network, which reduces the complexity of channel estimation while ensuring the system's estimation accuracy.

The invention discloses a three-dimensional millimeter wave time-varying channel estimation method and device, and belongs to the field of wireless communication, and the method comprises the steps: building a millimeter wave communication system containing array motion; a three-dimensional time-varying channel model considering the Doppler effect is established, composite signals, caused by array motion, in a three-dimensional time-varying channel are analyzed, each column of a direction matrix after synthesis is consistent with the array manifold of a planar array, and it is indicated that a moving linear array can form a virtual planar array; sparse representation of a three-dimensional time-varying channel is realized through linear array motion; a three-dimensional time-varying channel is recovered based on an iterative meshless weighting algorithm of array motion; comprising AoAs estimation and path gain estimation. According to the method, the negative influence of Doppler frequency shift in the time-varying channel on channel estimation is overcome, the virtual array element is constructed, channel estimation of the three-dimensional millimeter wave time-varying channel is realized through linear array motion, the channel estimation precision is improved, and the pilot frequency overhead and the algorithm complexity are greatly reduced.

A receiver includes an analog to digital converter circuit, a phase detector circuit, a digital loop filter circuit, a phase interpolator circuit, and a bias adaption circuit. The analog to digital converter circuit is configured to convert a first signal into a second signal according to a clock signal. The phase detector circuit is configured to detect a phase of the second signal to generate a phase detection signal. The digital loop filter circuit is configured to scale the phase detection signal with a proportional path gain coefficient and a bias value to generate a third signal. The phase interpolator circuit is configured to generate the clock signal according to the third signal. The bias adaptation circuit is configured to accumulate the phase detection signal to generate the bias value.

The invention relates to an unmanned aerial vehicle physical layer secret key secret communication method based on an orthogonal time-frequency space. Comprising the following steps: establishing an unmanned aerial vehicle air-ground communication system consisting of a multi-antenna unmanned aerial vehicle base station, ground single-antenna legal users and ground passive eavesdropping illegal users; obtaining channel estimation vectors of all dominant paths by adopting a three-dimensional structured orthogonal matching pursuit algorithm; the method comprises the steps of obtaining a channel characteristic value of a communication channel through a path gain self-adaptive weighted moving average coding method, carrying out double-bit uniform quantization, carrying out Winnow key negotiation based on dynamic grouping and carrying out SHA-2 hash function confidentiality enhancement, and thus obtaining a physical layer key. According to the method, the channel dimension is converted through the orthogonal time-frequency space technology, the influence of Doppler frequency shift is effectively resisted, the channel reciprocity is improved, the key inconsistency rate is reduced, and the safety and stability of a communication system can be remarkably improved.

A circuit may include a two-stage feedforward compensated operational transconductance integrated amplifier, and the two-stage feedforward compensated operational transconductance integrated amplifier may include an input terminal, an output terminal, a signal path between the input terminal and the output terminal, the signal path comprising a first signal path gain stage and a second signal path gain stage, and ripple rejection circuitry coupled between the input terminal and an intermediate node of the signal path located between the first signal path gain stage and the second signal path gain stage. The ripple rejection circuitry may include a first ripple rejection circuitry gain stage coupled at its input to the input terminal and coupled at its output to an input terminal of a chopper circuit, a notch filter coupled at its input to an output terminal of the chopper circuit, and a second ripple rejection circuitry gain stage coupled at its input to an output terminal of the notch filter and coupled at its output to the intermediate node.

A method for positioning a set of reconfigurable intelligent surfaces associated with an access point of a telecommunications network. The set includes at least one reconfigurable intelligent surface, called an “intermediate surface” and at least one other reconfigurable intelligent surface, called a “main surface”. The method particularly includes determining positioning data of the intermediate and main surfaces such that signals emitted by the access point are reflected by the intermediate surface toward the main surface to exchange data with at least one user terminal situated in the geographical area served by the main surface, but also such that a path gain of a path taken by said signals between the access point and this user terminal is greater than a predetermined threshold or maximized.

The invention discloses a near-field CSI distributed estimation method for broadband XL-MIMO, and the method comprises the steps: firstly, enabling a center LPU to estimate a path time delay parameter of a center sub-array channel, enabling other LPUs to rapidly extrapolate the path time delay parameters of other sub-array channels, and transmitting an estimation result to a CPU; then, based on near-field wave beam squint and parameter symmetry characteristics brought by a large array and a large bandwidth, the CPU fuses time delay parameters estimated by different sub-arrays, and decouples and independently estimates near-field channel parameters including angle, distance and range parameters; then, the CPU transmits the estimated near-field channel parameters back to the LPUs, and each LPU independently estimates the path gain of the sub-array channel; and finally, transmitting the estimated path gain to a CPU (Central Processing Unit) by the LPUs, and further reconstructing a full-dimensional broadband near-field channel. The problems that the CSI acquisition calculation complexity is too high and the reconstruction precision is low in a large-array and large-bandwidth scene are solved.

The invention provides a downlink channel recovery method for an asymmetric large-scale MIMO system under UPA. The method comprises the following steps: S1, according to the distribution of an asymmetric array, carrying out zero padding on a received signal, defining a mixed angle and constructing a virtual array; s2, designing an antenna selection algorithm on the premise of ensuring the UPA first row array aperture, and constructing a maximum aperture virtual array with as few antennas as possible; s3, respectively executing improved Newton orthogonal matching pursuit on receiving signals of the virtual array and the first row of arrays, and obtaining all possible path gains, azimuth angles and elevation angles until the gains, azimuth angles and elevation angles respectively meet threshold values; s4, combining and pairing the estimated path gain, elevation angle and azimuth angle according to related criteria; and S5, recovering a downlink channel by using the obtained path gain and angle parameter pair and the downlink steering vector. According to the method, part of channel information contained in the virtual array is fully utilized, and the downlink channel recovery performance is effectively improved while the number of received uplink radio frequency chains and the calculation complexity are remarkably reduced.

The invention discloses a 4D tensor-based RIS-assisted millimeter wave MIMO-NOMA Internet of Vehicles system channel estimation method, and aims to reduce the influence of serious Doppler frequency shift and sight line path blockage on communication performance, first, a 5G subframe division scheme without changing a standard 5G frame structure is proposed by introducing concepts of aggregation time slot and half time slot, and a 5G subframe division scheme without changing a standard 5G frame structure is provided; modeling of the received signal is facilitated; then, modeling the received signal into a four-order tensor so as to separate channel parameters into four factor matrixes, thereby avoiding parameter coupling; then, the tensor is decomposed in a closed-form solution form; then, carrying out one-dimensional search on a factor matrix obtained by decomposition to extract channel parameters; after channel parameters are obtained, a least square problem is constructed to obtain channel path gains, and solving of a scaling matrix is avoided; finally, experiments verify that the method can accurately estimate the parameters of the channel, and excellent demodulation performance can be realized based on the parameters of the channel.

Methods, systems, and devices for wireless communications are described. A test apparatus may determine a set of channel path gains and a set of beamforming gains between transmit probes and a device-under-test based on a beam direction of a set of beam directions for testing. The channel path gains may be based on angles of departure from a transmit probe and angles of arrival to the device-under-test. The beamforming gains may be based on an antenna panel configuration and the beam direction. The test apparatus may apply a time varying function input transmit powers for transmit probes based on a beam sweeping across the set of beam directions. The test apparatus may transmit, by the set of transmit probes, signals to the device-under-test based on applying the time varying function to the input transmit powers.

The application relates to a full-polarization-maintaining fiber femtosecond laser based on a mode-locking starting promotion structure. The laser comprises a nonlinear amplification ring mirror with a double-path gain fiber, can realize continuous adjustment of a phase difference, introduces a nonlinear phase shift related to laser pulse intensity, reduces a mode-locking threshold of the nonlinear amplification ring mirror laser, improves self-starting mode-locking capability of the laser, and outputs high-power and high-stability ultrashort pulses; a non-reciprocal phase shift element introduces a linear phase shift bias for clockwise and counterclockwise propagation pulses; a linear arm introduces an optical element with a dispersion compensation function, ensures compactness of the oscillator, is used for outputting pulses, simultaneously provides seed pulse pre-chirp management for subsequent higher-power amplification, and realizes flat wide spectrum. The laser adopts a full-polarization-maintaining fiber structure, has good self-starting mode-locking characteristics, is beneficial to pulse filtering and shaping, and simultaneously has the advantages of compact structure, good stability, high damage threshold, high output power and low noise.

A three-dimensional millimeter wave time-varying channel estimation method and device belong to the field of wireless communication, comprising: establishing a millimeter wave communication system containing array motion; establishing a three-dimensional time-varying channel model considering Doppler effect, analyzing the synthesized signal in the three-dimensional time-varying channel caused by array motion, each column of the synthesized direction matrix being consistent with the array manifold of the planar array, indicating that the linear array in motion can form a virtual planar array; realizing sparse representation of the three-dimensional time-varying channel through linear array motion; recovering the three-dimensional time-varying channel based on the iterative meshless weighted algorithm of array motion; comprising AoAs estimation and path gain estimation. The application overcomes the negative influence of Doppler frequency shift in the time-varying channel on channel estimation, constructs virtual array elements, realizes channel estimation on the three-dimensional millimeter wave time-varying channel through linear array motion, improves channel estimation accuracy, and greatly reduces pilot overhead and algorithm complexity.

This invention relates to a method for secure physical layer communication for unmanned aerial vehicles (UAVs) based on orthogonal time-frequency space. The method includes the following steps: establishing an UAV air-to-ground communication system consisting of a multi-antenna UAV base station, a legitimate ground-based user with a single antenna, and an unauthorized ground-based user passively eavesdropping; obtaining channel estimation vectors for all dominant paths using a three-dimensional structured orthogonal matching pursuit algorithm; obtaining channel eigenvalues ​​of the communication channel using a path gain adaptive weighted moving average coding method; performing double-bit uniform quantization; and enhancing security through Winnow key negotiation based on dynamic grouping and SHA-2 hash function, thereby obtaining the physical layer key. This invention effectively combats the effects of Doppler shift by transforming the channel dimension using orthogonal time-frequency space technology, improving channel reciprocity, reducing key inconsistency rate, and significantly improving the security and stability of the communication system.

The invention discloses a U6G FDD (Frequency Division Duplexing) super-large-scale MIMO (Multiple Input Multiple Output)-oriented downlink channel reconstruction and user positioning method, which comprises the following steps that: firstly, a user sends an uplink pilot signal to a base station, designs a Cartesian domain codebook-based channel image generation method, and visualizes an uplink received signal into a channel image; secondly, detecting the positions of a user and a scatterer in a channel image by using a target detection network, finely adjusting the detected coordinates, performing uplink path gain estimation by using a least square algorithm, and positioning the user according to the maximum uplink path gain; then designing a downlink beam forming matrix based on a base vector, adjusting the direction of a downlink pilot beam by using the matrix, and estimating a downlink path gain according to a downlink receiving signal; and finally, completing reconstruction of a downlink channel according to the coordinates of the user and the scatterer and the estimated downlink path gain. According to the method, rapid and high-precision multi-cluster multi-path downlink channel reconstruction and user positioning can be realized with relatively low calculation complexity and pilot frequency overhead.

Circuit for maximizing the dynamic range in a digital-to-analog signal path (100; 200; 300; 400), comprising: a. an input for receiving an input signal (110; 201; 301; 401); b. a first gain stage (120; 210; 330; 445) coupled to the input, the first gain stage (120; 210; 330; 445) having a first gain setting; c. a second gain stage (140; 230; 370; 460) coupled to the first gain stage (120; 210; 330; 445), the second gain stage (140; 230; 370; 460) having a second gain setting, the second gain stage (140; 230; 370; 460) having an analog gain stage and the second gain setting having an analog gain setting; d. a controller (150; 250; 320; 420) for dynamically selecting the first gain setting to maximize the first gain setting without clipping the input signal and for selecting the second gain setting to achieve a desired signal path gain; and e. an output coupled to the second gain stage (140; 230; 370; 460) for transmitting an output signal (235) having the desired overall signal path gain.

A method of estimating a channel of a base station in a communication system using an IRS may comprise: receiving a first signal through a direct path between a terminal and the base station from the terminal and a second signal through an indirect path through the IRS from the terminal; estimating a first angle of arrival of the second signal received from the IRS; estimating a second angle of arrival of a signal transmitted to the IRS by the terminal based on the estimated first angle of arrival; estimating a third angle of arrival of the first signal received from the terminal based on the estimated first angle of arrival; and estimating path gains on the direct path and the indirect path based on the estimated first angle of arrival to the estimated third angle of arrival.

The invention relates to a receiver and a clock data recovery method. The receiver includes an analog-to-digital converter circuit, a phase detector circuit, a digital loop filter circuit, a phase interpolator circuit, and a bias adaptation circuit. The analog-to-digital converter circuit is used for converting a first signal into a second signal according to a clock signal. The phase detector circuit is configured to detect a phase of the second signal to generate a phase detection signal. The digital loop filter circuit is configured to scale the phase detection signal using a proportional path gain coefficient and an offset value to generate a third signal. The phase interpolator circuit is configured to generate the clock signal according to the third signal. The bias adaptation circuit is used for accumulating the phase detection signals to generate the bias value.

The application belongs to the technical field of integrated circuits, and particularly relates to a fourth-order delta-sigma modulator design method and system based on passive stacking. The application cascades a quantizer after a third-order active loop filter, and couples capacitors in parallel on the plate of a capacitor array of the quantizer. Sampling and quantization are performed in each cycle. The quantizer quantizes the output of the current loop filter. After quantization, the plate of the capacitor array naturally forms a residual voltage and stores the coupling capacitors. In the noise injection phase of the next cycle, the quantization error stored in the coupling capacitors in the last cycle is injected into the input end of the quantizer through charge redistribution, is weighted and superimposed with the intermediate signal to form the input voltage of the quantizer, and the main path attenuation coefficient and the coupling path gain coefficient are obtained through charge conservation analysis. A gain compensation factor is preset in the front-stage active integrator to offset signal attenuation, and the capacitor ratio is optimized to realize fourth-order noise shaping. The application does not require additional active circuits, has small area and low power consumption, and improves the signal-to-noise ratio.

The invention discloses a wireless channel capacity optimization method for an intelligent network connection meteorological monitoring vehicle, and the method comprises the steps: building a communication system model suitable for the intelligent network connection meteorological monitoring vehicle in consideration of the Doppler effect; an original MIMO channel is equivalent to a plurality of parallel SISO paths through SVD decomposition, and a channel capacity optimization problem is constructed. An original optimization problem is decoupled into two sequentially processed sub-problems: IRS reflection unit phase shift optimization and base station precoding design. According to the coupling characteristic of the two sub-problems, a closed-form solution of an optimal IRS reflection matrix is obtained by indirectly optimizing path gain, and then the optimal precoding of the base station is solved by adopting a water injection algorithm. The algorithm provided by the invention has higher convergence speed and lower calculation complexity, provides an efficient scheme for IRS phase shift optimization, and can effectively adapt to the time-varying characteristic of a meteorological monitoring vehicle channel.

The present invention relates to an effective method for near-field parameter estimation and positioning in an XL-MIMO system. Considering a more challenging communication scenario where the LoS path is blocked and a system with extremely large-scale antenna arrays deployed at both the transmitter and receiver, the present invention first utilizes the structural relationship between the codebook matrix and near-field parameters to achieve preliminary extraction of the parameters. Subsequently, the steepest descent idea is used to iteratively refine the obtained parameters, thereby achieving super-resolution estimation of parameters such as angles, distances, and path gains. The obtained parameters can also be further applied to the sensing link. With the geometric constraints of the system and the obtained high-precision parameters, the present invention completes the accurate estimation of the location information of the user equipment and scattering points, providing a basis for the development of diverse sensing services. In addition, the proposed method is superior to existing competing methods in terms of both parameter estimation accuracy and positioning accuracy, and can still maintain excellent performance under the conditions of low sampling numbers and low pilot overhead.

The present application relates to the technical field of non-line-of-sight target detection, and particularly relates to a RIS-assisted FMCW radar non-line-of-sight target DOA estimation method, which comprises the following steps: constructing a scene model of RIS-assisted FMCW radar non-line-of-sight target detection; performing DOA estimation on the target to calculate the angle information of the target relative to the radar; and proposing an alternating direction multiplier method based on a path gain maximization criterion to optimize the RIS phase shift matrix parameters, which can significantly enhance the received signal strength and quality by regulating the electromagnetic wave propagation environment, maximize the equivalent channel gain of the target path, effectively suppress the multipath interference and noise, make the real direction information of the target in the received signal more prominent, not only significantly improve the signal-to-noise ratio, but also ensure that the structure of the received signal covariance matrix is highly matched with the model relied on by the high-resolution estimation algorithm of the subspace class, improve the accuracy, resolution and reliability of the angle estimation, and improve the real-time performance.

Method for positioning a set E of reconfigurable intelligent surfaces and associated electronic device The invention relates to a method for positioning a set E of reconfigurable intelligent surfaces associated with an access point (21) of a telecommunications network. The set comprises at least one reconfigurable intelligent surface called "intermediate surface" and at least one other reconfigurable intelligent surface called "main surface".The method comprises in particular a determination (S100) of positioning data of the intermediate and main surfaces so that signals emitted by the access point (21) are reflected by the intermediate surface () towards the main surface (20_i) to exchange data with at least one user terminal (23) located in the geographical area served by the main surface, but also so that a path gain of a path taken by said signals between the access point (21) and this user terminal (23) is greater than a predetermined or maximized threshold. Figure for the abstract: Fig. 3.

A receiver includes an analog to digital converter circuit, a phase detector circuit, a digital loop filter circuit, a phase interpolator circuit, and a bias adaption circuit. The analog to digital converter circuit is configured to convert a first signal into a second signal according to a clock signal. The phase detector circuit is configured to detect a phase of the second signal to generate a phase detection signal. The digital loop filter circuit is configured to scale the phase detection signal with a proportional path gain coefficient and a bias value to generate a third signal. The phase interpolator circuit is configured to generate the clock signal according to the third signal. The bias adaptation circuit is configured to accumulate the phase detection signal to generate the bias value.

The invention relates to the technical field of integrated circuits, in particular to a voltage-controlled oscillator gain calibration method and circuit, and the method comprises the steps: obtaining a first frequency control word and a second frequency control word, generating a first control voltage signal, and outputting a second control voltage signal; an error control signal is generated by comparing the numerical values of the digital signals to adjust the second control voltage signal until voltage locking is achieved; calculating the ratio of the frequency offset corresponding to the second frequency control word to the absolute value of the voltage difference to obtain a gain value of the voltage-controlled oscillator; associatively storing the gain value and the first frequency control word in a lookup table; and querying the lookup table according to the real-time first frequency control word in the phase modulation process to obtain a gain value so as to adjust the gain matching of the modulation path. The influence of frequency, process, voltage and temperature changes on the gain of the voltage-controlled oscillator is compensated through closed-loop calibration, gain matching of a low-pass path and a high-pass path in the phase modulation charge pump phase-locked loop is maintained, phase errors are restrained, and the reliability of a communication link is improved.

The invention provides a wireless communication link high-fidelity simulation method for a high-dynamic Internet of Vehicles, which comprises the following steps of: performing channel modeling by using a channel simulation platform according to an input network layout, a terminal track, a propagation scene and an antenna mode to generate a time-varying channel coefficient; accurate modeling is carried out on key physical phenomena such as multipath propagation, Doppler frequency shift, path gain and propagation time delay in the Internet of Vehicles, and high-fidelity simulation of channel dynamic change characteristics in a high-mobility scene is realized; a transmitter class object, a receiver class object and a channel class object are constructed based on an object-oriented thought, a plurality of processing modules such as QAM modulation, multi-carrier modulation, pilot frequency design, channel estimation and equalization, frequency offset correction and the like are supported, and good transportability and expansibility are achieved. According to the invention, high-fidelity Internet of Vehicles communication system simulation is realized, a communication transceiver signal processing flow is included, and an efficient fidelity verification platform is provided for design and test of an Internet of Vehicles communication protocol and algorithm.

The application relates to a dynamic power supply system and control method for a radio frequency power amplifier, which comprises an envelope detection module, an envelope mapping module, an S-class power amplifier, a mapping establishment module and a feedback demodulation module. The envelope mapping module converts the envelope of a transmitting signal into a control voltage according to a mapping relationship, and the S-class power amplifier efficiently generates a dynamic power supply voltage proportional to the control voltage to supply power to the radio frequency power amplifier, thereby improving the efficiency of the radio frequency power amplifier. The envelope mapping relationship is provided by the mapping establishment module. The mapping establishment module combines and adjusts the transmitting path gain and the maximum power supply voltage, so that the radio frequency power amplifier works in a predetermined compression state, and the envelope mapping relationship is established according to the constant gain criterion. The application can provide dynamic power supply for the radio frequency power amplifier under a large working bandwidth and a complex working environment, effectively improve the efficiency of the radio frequency power amplifier, and has excellent spurious and near-carrier noise suppression capability.

The invention discloses a low-complexity OTFS channel estimation method based on UAMP, which considers an OTFS system under the condition of fractional Doppler frequency shift and provides a low-complexity iterative channel estimation method, and comprises the following steps: expressing an OTFS channel estimation problem as a linear hybrid model; factorization is carried out on the joint posterior probability density function of the to-be-estimated variable of the OTFS system model, and a corresponding factor graph model is obtained; then obtaining an estimated value of an intermediate variable by using a UAMP algorithm; and taking output after UAMP convergence as prior information, and decoupling estimation of path gain and fractional Doppler frequency shift from an intermediate variable by using a VMP algorithm. The reasonable initialization parameter value can provide a good starting point for iteration of the UAMP algorithm, the algorithm is helped to converge to a solution close to a globally optimal solution more quickly, the accuracy of channel estimation is improved, and compared with an existing algorithm, the algorithm has the same normalized mean square error performance, but the calculation complexity is remarkably reduced.

The application discloses a distributed radar-communication integration method based on time delay-Doppler joint modulation, comprising the following steps: acquiring a radar-communication integration signal received by a receiving end, extracting a communication signal echo and a radar signal echo from the radar-communication integration signal; acquiring target time delay, path gain and Doppler information by using a cross-correlation method according to the radar signal echo; demodulating the communication signal echo by using a turbo iterative maximum ratio combining algorithm to obtain communication data in a time delay-Doppler domain grid; and positioning and measuring the speed of the target by using a chan method according to the target time delay and Doppler information, so as to obtain a target positioning and speed measuring result.

The invention discloses an interference signal elimination method and system based on indexes, decomposition and resampling, and the method comprises the following steps: S1, calculating the center frequency and sampling frequency of intermediate frequency sampling according to the frequency band of communication operation; s2, sampling on the sampling frequency band and in the same symbol time interval to obtain a sampling sample; s3, estimating an incident angle of each path of signal by using a Prong-Kung algorithm according to the sampling sample obtained in the step S2; and S4, according to the incident angle estimated in the step S3, interference is removed through a least square method, and the path gain of the required signal is obtained. According to the technical scheme, based on indexes and decomposition, the Prony-Kung algorithm and the resampling technology are used for channel estimation, useful signals and interference signals are separated, and the purpose of interference removal is achieved.