69results about How to "Improve signal to interference ratio" patented technology

The invention discloses a velocity-deception-jamming-resistant phase encoding method for a cognitive radar, belongs to the technical field of radar jamming resistance, and particularly relates to a radar jamming-resistant waveform design technology. According to the method, relevant parameters of a target and jamming are extracted from prior information acquired by the cognitive radar, a stop band is arranged close to each real target Doppler according to a real target Doppler estimated value, a stop band is arranged at the same position as a constant-mode encoding sequence configured in advanced, and an optimal pulse-to-pulse phase encoding transmission waveform is designed according to the criterion that the spectrum energy of a coded signal in the stop band, thereby effectively inhibiting velocity deception jamming in a multi-target and multi-jamming scene, increasing the signal-to-jamming ratio of each real target, and realizing the effect of correct detection of a plurality of real targets.

The present invention provides a pulse Doppler radar polarization anti-jamming method under a complicated interference environment. By utilizing the method of the present invention, the inhibition capability aiming at various interference, such as chaffs, active suppression, cheat, etc., can be improved substantially, and the targets can be detected effectively. The method is realized by the following technical scheme of inputting a radar dual polarization echo signal, determining whether the active suppression-type interference exists, when the suppression-type interference exists, carrying out the polarization cancellation; then calculating the target signal walking time between the front and back pulses, and carrying out the range walking correction on a pulse sequence; and then carrying out the phase-coherent accumulation on a dual polarization channel, shifting the zero to a frequency spectrum center in a frequency shift manner, identifying the channel number of a target in a Doppler-range two-dimensional matrix, setting a two dimensional tracking gate of the target, and carrying out the two dimensional constant false alarm detection in the tracking gate; finally, carrying out the target polarization ratio detection determination, and outputting a signal passing the detection determination as a target signal after the interference inhibition, thereby improving the correct detection probability of the target.

The invention discloses a reducing method, base station and system of adjacent area interference of honeycomb system, which comprises the following steps: 1) obtaining the distance of mobile table base station; 2) dividing multiple mobile tables to different layers of area according to the distance of base station; 3) setting different power gain factor for the mobile table at different area layers; 4) utilizing power gain factor to modulate the gain of business channel; transmitting data to corresponding mobile table. The invention satisfies SIR need of data transmission, which reduces ACI.

The invention relates to civil aviaton groud air communication self-adapting interference suppression method and its system based on the lasting model array, including the following steps: translate the bi-aerial wire array received two path high frequency amplitude modulation signals into the medium frequency signal; and carries on data capture and analog-to-digital convert; carries on the digital down-conversion filtering drawoff; sends the drawoffed signal into the monitoring model to judge, if no interference into the demodulation, has the interference to enter the interference signal drawoff; sends the interference signal into the self-adapting lasting model interference suppression module to drawoff the interference signal and self-adapting cancellation; demodulates the state no interference signal and filters the high frequency noise to carry on D / A conversion output. Under no reference signal premise, the invention separates out the groud air communication useful signal of using the lasting model blind signal processing technogy and the self-adapting interference cancellation technogy, removes the flight safety hidden danger, outputs the high quality pronunciation signal, enhances the flight safety coefficient, achieves the goal of taking stopgap measure and effect a permanent cure.

The invention relates to wireless network security, particularly to a multi-user reinforcement learning-based cognitive wireless network anti-hostile interference method. Cognitive source nodes adopt a multi-user reinforcement learning strategy to automatically select transmitted power by observation of status information of a master user working condition, self-adaptive jammer transmitted power and the like. Learning of multiple cognitive source nodes is performed at the same time, and each time transmission of a data packet is finished, according to obtained immediate returned report and a state of the next moment, an update state, a behavior and a mapping relation, and according to feedback information, the learning rate of the multi-user reinforcement learning algorithm is replaced, thereby improving the signal to interference ratio of a receiving end, and finally obtaining the optimal transmitted power. Each cognitive source node can assist forwarding of the data packet or transmit data by itself. The method utilizes a multi-user reinforcement learning mechanism, and through a method of attempting and comparison, improves communication efficiency of a cognitive wireless network in a scene of an intelligent hostile jammer.

The invention discloses a cognitive radar waveform designing method based on interference and side-lobe equilibrium suppression. The method comprises: on the basis of a self-adaptive framework, in a noise suppressing interference model, and through the MMSE criteria, introducing and structuring a cognitive radar waveform optimization model of interference and side-lobe equilibrium suppression; converting the model into a minimized multivariable and multi-constrained objective function model; then according to Lagrange multiplier method, developing the Lagrange function of the objective function, and according to the principle of duality, converting the model into the optimized dual function again, solved with the introduction of auxiliary variables and the KKT optimality; and finally, designing the alternating iterative method to combine with the optimized emission shape and the filter sequence; and estimating the evaluation of performance brought about by the comprehensive processing algorithm. The simulation results show that the proposed algorithm can realize the balance of the interfering signal suppression and the self-processing side-lobe, which improves the detection performance of the target.

The invention relates to a robust twin-channel restraining method and a system for civil aviation ground-air radio CM interference. The invention comprises the steps as follows: two-way VHF signals received by a double antenna array are transformed into intermediate frequency digital signals; two-way intermediate frequency digital signals respectively act filtering extraction and orthogonal transformation; two-way complex signals after the orthogonal transformation is transmitted to a monitoring module for judging, if no interference exists, one undisturbed signal in the two-way complex signals is output, and if the interference exists, the two-way complex signals are transmitted to an adaptive interference suppression module based on a CM array for the interference suppression, thus the signal attribute output by the CM array is judged and corresponding action is adopted, the signal is directly output if the array outputs an amplitude-modulated signal, otherwise the signal is output after adaptive interference cancellation; the undisturbed signal output from the steps of the invention is demodulated, and then the high-frequency noise is filtered, the undisturbed signal then is transmitted into a D / A converter to output an aural signal. By adopting the method that the invention judges the signal attribute output by the CM array and then executes corresponding operation, the false lock of the CM array is avoided, and the robustness of an adaptive interference suppression system is effectively enhanced.

The invention discloses an interference coordination method and device. The method comprises the steps: obtaining the information transmitted by an interference cell on a pair of or all resources through a service cell and / or a third cell; and transmitting an interference offset signal formed by the obtained information according to a preset weight and / or transmission power through the service cell and / or the third cell.

The invention discloses a radar moving target detection method based on a cognitive framework. The radar moving target detection method mainly solves the problem that in the strong clutter background, an existing method is poor in detection performance for a low-speed target. The achieving process comprises the following steps of separating ground clutter components from backward waves; obtaining a clutter image of a current frame according to the ground clutter components; sensing the environment according to the clutter image and separating the current frame into a noise region and a clutter region; calculating coefficients of associations according to the ground clutter components, utilizing the coefficients of associations to correct antenna pointing errors, and storing backward wave data after corrected to an environment dynamic data bank (EDDB); and utilizing the backward wave data of the EDDB to estimate an interference covariance matrix according to division of the current frame; obtaining a self-adaption filter coefficient according to the estimated interference covariance matrix, and conducting self-adaption filtering processing on input data; and conducting constant false alarm detection on output of a filter. The radar moving target detection method has the advantage of greatly improving detection performance under the condition that an existing device is not greatly changed, and can be used for conducting detection on the low-speed target in the strong clutter background.

The invention relates to the signal reception of an uplink in a multi-user MIMO system. The invention provides an uplink system and a signal reception method thereof in a multi-user MIMO system. The signal reception method comprises the following steps of: generating a user signal to be transmitted to a base station by a user processing module; transmitting the signal transmitted by the user processing module to a wireless channel by an omnidirectional transmitting antenna module; receiving all the signals within the range of the arrival direction of the specific signal by a receiving antenna unit module; carrying out airspace filtering on the receiving signal of each array element of each antenna unit by a multi-user antenna space response control module; and carrying out channel estimation, multi-user detection, demodulation and decoding aiming at the airspace filtering results of users by a processing module of the base station and realizing multi-user data separation. The invention can enhance the signal interference ratio of the input end of a receiver of the base station and lower the complexity of the post-treatment of channel estimation, multi-user detection and the like at the position of the base station.

The invention relates to a pilot allocation method based on user clustering. In view of random distribution of users in a system cell, the users are divided into user clusters based on large-scale decline information of the users. Then, a same pilot cluster is allocated to the user clusters choosing the same cooperation base station, and the principle on which the user clusters in the same cell allocate orthogonal pilots is that users allocate pilots and then interference brought about by pilot contamination is weakened by use of a pilot contamination pre-coding technology. Therefore, the signal-to-interference ratio of users' reception is improved, and the purpose of system performance improving is achieved.

The invention discloses a method and a device of enhancing calibration performance of an intelligent antenna of a test driven development (TDD) system. Basic training sequence power sent by a launch channel of a self-adaptive adjustment intelligent antenna system enables power of basic training sequence signals to be proper when the basic training sequence signals arrive at an antenna mouth outside an outdoor antenna in order to improve signal to interference ratio between the training sequence and external disturbance, so that the purpose of reducing the influence of calibration training signals on other stations is achieved, meanwhile, the launch position of basic training sequence in a guard gap, and combining a plurality of continuous basic training sequences of a receiving channel to conduct an amplitude phase estimation, and therefore the influence of the external disturbance on calibration of the receiving channel of the intelligent antenna, and accuracy and precision of the amplitude phase estimation is improved.

The invention provides a strong correlation self-interference cancellation method based on a deep neural network, which introduces a DNN neural network into a strong correlation self-interference cancellation system of a receiving and transmitting system. The method adopts the DNN neural network to fit a self-adaptive cancellation system model, which replaces a traditional self-adaptive filtering algorithm, and puts forward the strong correlation self-interference cancellation method based on the DNN. According to the method, instead of a traditional adaptive algorithm, the system model can effectively eliminate the strong correlation self-interference signals through the trained DNN network model, so that target signals can be recovered from the strong correlation self-interference signals more accurately.

The invention discloses a satellite positioning method and apparatus. The method comprises the following steps: a receiver receiving satellite signals sent by multiple navigation satellites through an antenna array, and generating a satellite signal matrix; according to the satellite signal matrix, obtaining a first output signal sequence, performing synthesis operation on the first output signal sequence to obtain a first synthesis satellite signal sequence, and according to the first synthesis satellite signal sequence, carrying out positioning; in case that the positioning fails, according to the satellite signal matrix, obtaining a second output signal sequence through a self-adaptive zeroing algorithm, and according to the first output signal sequence and the second output signal sequence, carrying out synthesis operation on the received satellite signals sent by the multiple navigation satellites to obtain a second synthesis satellite signal sequence; and according to the second synthesis satellite signal sequence, carrying out the positioning. According to the invention, the technical problem of poor anti-interference capability in satellite positioning is solved.

The invention discloses an independent components analysis (ICA) blind signal separation method and an ICA blind signal separation system based on a smoothing function and Parzen window estimation. A new ICA blind signal separation method is provided on the basis of Parzen window estimation technology assisted by a newly constructed smoothing function, so that a probability density function and a hybrid matrix of a source signal are estimated, and an unknown blind source signal is effectively separated out. A corresponding separation system comprises a signal receiving module, a single preprocessing module, a NewICA reconstruction source signal module and a subsequent processing module which are connected in turn. An effective ICA blind signal separation method and an effective ICA blind signal separation system with small error and high signal to interference ratio are provided.

The invention discloses an inter-pulse initial phase third-power modulation and FRFT (fractional Fourier transform)-based DRFM (digital radio frequency memory) interference detection and resisting method. According to the method, a multi-channel matched filter and MTD (moving target detection) are utilized to detect whether interference exists, and if interference exists, the priori information of the interference and a target are utilized to design the initial phase of the transmission pulses of a radar, the transmission pulses of the radar are transmitted; matched filtering processing of corresponding channels is carried out on echoes; and FRFT (fractional Fourier transform) is utilized to suppress the interference. With the method of the invention adopted, the detection of the target can be realized under a low signal-to-interference ratio; the signal-to-interference ratio can be improved greatly under the premise that a signal-to-noise ratio is not affected, so that the subsequent processing of signals can be facilitated; and with the decrease of the signal-to-interference ratio, the interference suppression performance of the method is stable.

The invention relates to a method for designing a signal, specifically to a method for designing a continuous phase-modulation signal of a non-continuous spectrum, and aims to solve the problem in an existing waveform design method that details of each frequency point of each pass band and stop band are not considered, so sufficient matching with changeable interference environment cannot be realized in signal design and the problem that balance design of a proportion of a signal to interference ratio to a sidelobe index is not flexible enough in a design process. The method firstly directs at a signal design general objective function P<Total>=[lambda]x<H>kx+(1-lambda)(2N-x<H>b-b<H>x), then utilizes a gradient iteration method to obtain a waveform optimal solution; then weight lambda is traversed from 1 to 0, a series of values of the signal to interference ratio and the sidelobe are obtained, one of the indexes are used as a horizontal axis, the other index is used as a longitudinal axis, and a curve that is obtained is a Pareto optimal curve; and the Pareto optimal curve is used as a tool for assisting selection an optimal balance between objective functions in multi-objective optimization to design the continuous phase-modulation signal of the non-continuous spectrum. The method provided by the invention is suitable for design of the continuous phase-modulation signal of the non-continuous spectrum.

The invention discloses a control channel information sending method and a device based on common cell networking. The method comprising: obtaining uplink signal intensity information corresponding to each sector according to uplink signals sent by user equipment, wherein the sectors share the same cell identification, and the uplink signal intensity information represents the intensity of corresponding uplink signals; selecting the working sectors from all the sectors according to the uplink signal intensity information corresponding to each sector; and sending control channel information to the user equipment through the working sectors, and ordering the other sectors of all the sectors except the working sectors not to send the control channel information to the user equipment, so that in the common cell networking technology, when the sector in a cell sends signals, signal interference on a cell nonadjacent to the sector sending signals is prevented.

The invention relates to a method and a device for eliminating the narrow-band interference in an under-sampling rate pulse UWB (Ultra Wide Band) communication system. The method comprises the following steps of: S1, sampling the received signal in which out-of-band noise in an information packet which does not contain a UWB signal is filtered to obtain a sampling vector y1 and calculating an orthogonal projection matrix of a narrow-band interference signal; and S2, sampling a subsequently received signal in which out-of-band noise in an information packet which contains a UWB signal is filtered to obtain a sampling vector yi and obtaining the UWB signal in which the narrow-band interference signal is eliminated based on the orthogonal projection matrix of an NBI (Narrow Band Imaging) signal. According to the method and the device disclosed by the invention, the NBI signal can be effectively eliminated, the signal-noise ratio is increased and the system sampling rate is far lower than the Nyquist sampling rate; and in addition, the estimation and elimination of the NBI are completely carried out in a digital domain without a parallel system structure or generation of a simulation projection signal, and thus the complexity and the realization difficulty of the system are greatly reduced.

The invention relates to SAR interference suppression method and device based on De-Chirp technology. The method comprises the steps of: 1, performing interference signal detection and judgment on SARsingle echo data; 2, when it is judged that the interference signal exists, performing De-chirp on the linear frequency modulation interference signal through De-Chirp operation, and the fixed frequency and bandwidth of the linear frequency modulation interference signal are obtained; 3, carrying out variational mode decomposition on the echo data with the interference signals, and k intrinsic mode functions including interference and non-interference are obtained; step 4, constructing a wave trap by using fixed frequency and bandwidth, and then operating the intrinsic mode function containing interference to obtain an intrinsic mode function after interference suppression; and step 5, carrying out reconstruction and inverse De-Chirp operation on the intrinsic mode function without interference and without interference to obtain SAR single echo data after interference suppression. SAR linear frequency modulation interference can be suppressed, and SAR imaging quality can be improved.

The invention discloses a consumer terminal access method and system in a high level long-term evolutionary progression system which comprises: a relay node determines whether itself at an overloading or underloading state, if at the overloading state, the transmission power of sent broadcasting messages are reduced according to the predetermined requirement; if at the underloading state, the transmission power of the sent broadcasting messages is accreted according to the predetermined requirement; a user terminal receives the broadcasting messages from a base station and the relay node, determines a signal to interference ratio corresponding to different broadcasting messages, the sending terminal of the broadcasting messages corresponding to the signal to interference ratio with the maximal value is acted as an access point, and the access in finished. The invention also discloses a delay node which is applied to the method, system and device of the invention, and can improve the average throughput of the system and improve the service performance of the system.

The invention discloses a multi-target aircraft networking measurement and control method based on TDD time-frequency multiple access. The method comprises the following steps: firstly, establishing amulti-target aircraft networking measurement and control system based on TDD time-frequency multiple access, secondly, designing a working mechanism of the multi-target aircraft networking measurement and control system: planning time-frequency resources of uplink and downlink bidirectional links, and sending remote control frame information to a plurality of aircrafts by a ground station in a ground-air uplink by using an omnidirectional antenna; the airborne station receiving the remote control frame information and obtains the start time information and the end time information of the remote control frame TU, so that simple measurement and control network time synchronization is realized by taking the ground station as a reference; and each aircraft extracting time information from thereceived remote control frame information, and sending self remote measurement frame information to a ground station in an air-ground downlink by using an omnidirectional antenna. The method can effectively simplify the time synchronization requirement of the networking node, and achieves the high-efficiency time-frequency resource scheduling of the auxiliary link for the measurement and controlof the networking aircraft.

The invention discloses a method for improving a signal-to-interference ratio of a phase coded signal, and belongs to the field of signal processing. The method comprises: in a first step, carrying out speed separation and compensation to solve pulse pressure primary-to-secondary ratio loss caused by target speeds, wherein the target speeds can correspond to Doppler frequency shifts, i.e., acquiring and storing data of units at the same distance in N adjacent transmission periods and carrying out N-point FFT calculation to obtain N pieces of channel data so as to separate different speed targets into different channels, and carrying out Doppler compensation on each channel, wherein a compensation value of an nth path is n*fr / N+m*fr, fr represents a transmission pulse repetition frequency and m represents folding times by which a target Doppler frequency corresponds to fr; in a second step, carrying out channel noise reduction to solve signal-to-interference ratio loss caused by noise,i.e., designing a high-stopband suppression filter so as to filter out out-of-band noise in an effective signal of each channel; and in a third step, mismatching a pulse pressure and selecting large outputs so as to further improve the signal-to-interference ratio, i.e., designing a phase coded mismatched filter by utilizing a least square method, and selecting the large outputs for multiple pathsof data after mismatching the pulse pressure to obtain final output values.

The invention discloses an information modulation method based on data packets. This method divides the binary digital information to be transmitted into a data group with multiple bits as the unit, and divides the data group into two parts, the first part is the waveform selection state bit, and the second part is the time slot position state bit; the code The meta-time is divided into multiple time slots of the same size. The signal transmission waveform lasts for one time slot, and other time slots do not transmit signals. The transmission waveform mapping rule and the time slot position mapping rule are formulated; according to the mapping rule, the The state of the divided waveform selects the state bit to select the shape of the transmission waveform, and determines the time slot position of the transmission waveform in the symbol time according to the state of the divided time slot position state bit in the data group to form a transmission signal. The invention improves the power efficiency of the modulated signal and improves the anti-interference ability of the signal.

A receiver resistant to transient ultra-wideband electromagnetic interference comprises an antenna which is connected with a power divider through a low-noise amplifier. The power divider is connected with the transient pulse detection circuit; the transient pulse detection circuit is connected with the time domain gating decision circuit; the time domain gating decision circuit is connected with the AGC module of the rear-end receiver; the power divider is connected with the delay circuit; the delay circuit is connected with the single-pole double-throw switch; the single-pole double-throw switch is respectively connected with the rear-end receiver and the load; interference signals are effectively filtered out from the time domain, and the anti-interference purpose is achieved.

The invention belongs to the technical field of underwater acoustic communication, and particularly relates to a multi-user underwater acoustic communication method based on cyclic shift keying spreadspectrum modulation. The method comprises the following steps: step 1, enabling a transmitting end to interleave cm by utilizing a bit interleaver pi m of an mth user, then carrying out CSK modulation to improve the communication rate, and then carrying out interleaving to distinguish the users; step 2, transmitting the data after carrier modulation by using an underwater acoustic communication transmitter; and step 3, enabling a receiving end to perform passive time reversal processing on the multiple paths of preprocessed receiving signals so as to compress the channel and improve the signal to interference ratio. Then, a CSK soft demodulation mode is adopted so that CSK modulation and a traditional IDMA iterative demodulation system are perfectly combined. The detection performance ofthe system can be effectively improved. The communication rate of each user can be effectively improved, and meanwhile, the number of users can be increased.

The invention relates to a single-channel radio frequency anti-saturation device, method and system. The device comprises: an electro-optical conversion module for receiving radio frequency input signals, converting the radio frequency input signals into optical signals; an optical branching module, wherein the optical branching module is used for splitting an optical signal into multiple paths ofsynchronous optical signals; an optical fiber delay module used for respectively carrying out multipath transmission on multipath synchronous optical signals to generate multiple paths of time delayoptical signals with different time delays relative to the synchronous optical signals; a photoelectric conversion module used for converting multiple paths of time delay optical signals into multiplepaths of time delay electric signals, and an algorithm processing module used for carrying out iterative computation on the multiple paths of time delay electric signals through an adaptive filteringalgorithm to obtain an optimal weight, weighting the time delay electric signals and outputting the time delay electric signals in a radio frequency mode. By adopting the method, radio frequency single-channel anti-saturation can be realized.

The invention discloses a self-adapting space interference suppression method of a one-dimensional phase scanning three-coordinate radar, which comprises the steps that a radar system distributes detection pulse resources, a signal processing subsystem detects and receives echoes of antenna of all rows, azimuth angles and pitching angles, carries out digital down conversion processing, weights wave beams at equal intervals in directions of the pitching angles to obtain space-distance domain data, then carries out one-dimensional fourier transformation, extracts interference feature information in a frequency domain for interference judgment, and records the azimuth angle and the pitching angle of interference when judging the interference; and at the same time, the signal processing system carries out wave beam weight water-flowing solving for multi-beam weighting to form multiple received wave beams reset in an interference direction by a phase-only method according to an interference angle recorded in the last scanning period and an expected direction of the current target. The method applies self-adapting space interference suppression to a pulse doppler radar according to characteristics of the one-dimensional phase scanning three-coordinate radar, and survivability and target detection capability of the radar in an interference environment are effectively improved.

The invention discloses a radar anti-interference intelligent decision-making method based on reinforcement learning, and belongs to the technical field of radar anti-interference. The invention aims to solve the problem that the design method of the LFM waveform in the existing radar anti-interference method is single and cannot deal with complex interference scenes. The method comprises the following steps: for each adversarial round of a radar and a jammer, transmitting an LFM waveform based on frequency modulation slope disturbance to an electromagnetic interference environment at a radar transmitting end, and receiving an echo signal at a radar receiving end; using a three-step matched filtering interference suppression method for the echo signal, and obtaining a target echo signal; setting a radar anti-interference decision criterion; judging whether the target echo signal meets a decision criterion or not, and if yes, realizing radar anti-interference; otherwise, on the basis of the decision criterion, calculating the LFM waveform parameter of the next adversarial round by adopting a radar online anti-interference intelligent decision algorithm, and generating a new LFM waveform through the radar transmitting end. The method is used for realizing online anti-interference decision.

The invention discloses a broadband receiving array antenna channel amplitude and phase calibration method and system. The method comprises the following steps that a signal generator outputs a specified waveform; after multi-channel acquisition, original signal data is obtained; detecting the original signal data by adopting a matched filter to obtain the position information and complex angle of each signal; according to the position information output by the matched filter, multiple groups of channels are ensured to be coherent; vector superposition is carried out on multiple groups of coherent signals, and the signal-to-interference ratio is improved to the maximum extent; obtaining a correction coefficient of each channel through a multi-channel complex number division method; constructing a diagonal weighting matrix; and transforming the equalization filter to a frequency domain through the frequency factor array, and obtaining a coefficient of the time domain equalization filter by adopting a weighted least square method. According to the method, a least square method with a diagonal weighting matrix is adopted. In the correction process, the environment requirement of an acquisition scene is reduced, the adaptability of an algorithm is improved, and the labor cost of acquisition is reduced.