33 results about "Asynchronous interference" patented technology

This invention discloses improved single antenna interference cancellation (SAIC) receivers utilizing joint channel estimation for suppression of interference of co-channel signals. This invention describes the technique to perform joint channel estimation for either synchronous or asynchronous co-channel signals without a prior knowledge of the interfering training sequence or its timing position. The invented joint channel estimation can require initial detection of the desired signal and can be implemented as a multistage equalization structure.

This invention discloses improved single antenna interference cancellation (SAIC) receivers utilizing joint channel estimation for suppression of interference of co-channel signals. This invention describes the technique to perform joint channel estimation for either synchronous or asynchronous co-channel signals without a prior knowledge of the interfering training sequence or its timing position. The invented joint channel estimation can require initial detection of the desired signal and can be implemented as a multistage equalization structure.

The invention discloses a method for synchronously inhibiting radar clutter and multiple interferences based on power distinction, and is suitable for a signal processing system of sky-wave over-the-horizon radar. The method realizes the separation of strong clutter, interferences and target signal using the power difference among the clutter, interferences and target signal, and can effectively inhibit clutter and multiple interferences including transient interference and shared-frequency asynchronous interference. The specific steps are showed in the figure 1. Compared with the prior method, the method does not need to detect and analyze the clutter and multiple interferences complicatedly, has obvious effect on the randomly varied interferences of all parameters and clutter, and has strong applicability. The invention uses the separated strong clutter as a standard signal to correct phase pollution, can realize phase correction and inhibit the clutter and interferences synchronously, and simplify the signal processing process of the sky-wave over-the-horizon radar. The invention is not limited to the sky-wave over-the-horizon radar system, can be widely applied to multiple large-scale phased array radars, and has wide application value.

The invention relates to an anti-interference treatment method based on a navigation management secondary radar test system, which comprises the following steps: S1, initializing original data: initializing the system data of the navigation management secondary radar test system; S2, detecting a dynamic threshold sliding window: extracting an effective pulse signal sequence from the pulse signals received from a navigation management secondary radar function test analyzer; S3, removing asynchronous interference pulse signals: removing the asynchronous interference pulse signals in the effective pulse signal sequence extracted in the step S2 to obtain the effective pulse signal sequence of a target navigation management secondary radar; S4, grouping pulses: grouping the pulses of the effective pulse signal sequence of the target navigation management secondary radar obtained in the step S3 to obtain the integral information data of target navigation management secondary radar; and S5, outputting a result. The invention has the advantage of improving the anti-interference capacity of the navigation management secondary radar test system.

The invention relates to a method for resisting asynchronous interference in the field of radar signal processing, in particular to the method for resisting asynchronous interference based on frequency domain. The method is widely applicable to radar signal processing systems and is used to solve the problem of inappropriate setting of constant false alarm threshold due to approximate time domain amplitude of radar target echo and interference signals in existing method for resisting asynchronous interference of the radar. By transforming the frequency domain, time domain echo of target signals and the interference signals are transformed to the frequency domain, frequency domain amplitude of the radar target echo and the interference signals are increased, setting of the constant false alarm threshold is facilitated, and false alarm rate of the radar is lowered.

The present invention belongs to the field of underwater acoustic communications, and particularly relates to an asynchronous multi-user access method for underwater acoustic OFDM (Orthogonal Frequency Division Multiplexing). The method comprises the following steps: overlap truncation; interference cancellation; frequency domain oversampling; multi-user channel estimation and decoding; and interference reconstruction. According to the present invention, an asynchronous interference model is established by using an overlap truncation method based on a sliding iteration structure, and then a received signal after interference cancellation is equivalent to a quasi-synchronous MIMO (multiple-input multiple-output) system to realize the multi-user data decoding, so that the asynchronous multi-user access method can be better to take the processing delay and the decoding performance into account, and has practical application value.

The invention discloses an asynchronous interference suppression method based on notch filtering processing. The method comprises the following steps of determining an airborne radar, wherein there isa target in an airborne radar detection range, and an echo signal which is reflected by the target and is received by the airborne radar which emits the signal to the detection range is recorded as aradar original echo data matrix; according to the radar original echo data matrix, acquiring a distance-Doppler domain data matrix; then, determining a main-lobe clutter; calculating the Doppler frequency of the main-lobe clutter and obtaining a column vector g with a R length, wherein the R is a positive integer which is greater than 1;dertermining a reference threshold, successively acquiring amodified and processed result gpro, normalized power and a vector G, and then acquiring a notch filtering weight coefficient vector F; and using the notch filtering weight coefficient vector F to carry out sliding window processing on the radar original echo data matrix, and acquiring a result after the sliding window processing, wherein the result of the sliding window processing is an asynchronous interference suppression result based on limited wave filtering processing.

The invention discloses a transmitting-interference-resistant wireless communication link adaptive method. The method includes the steps: when a sending node transmits frames to a receiving node by means of A-MPDU (aggregated MAC protocol data unit) frame aggregation, capturing transmission state information of PHY (physical layer) terminals and MPDU subframes in real time, and calculating synchronous interference occurrence probability and asynchronous interference occurrence probability; once loss of the PHY terminals or the MPDU subframes happens, estimating interference factors in communication links according to relation between a each of the synchronous interference occurrence probability and asynchronous interference occurrence probability and a corresponding threshold, immediately executing corresponding measures for transmitting interference resistance to guarantee reliability in frame transmission. By means of estimation of interferences in the links from a sending end, on the one hand, protocol expenditure is saved while frame length is reduced; on the other hand, frame transmissions states are acquired and counted in real time by means of B-ACK frames so as to reason out synchronous interferences and asynchronous interferences in the links to assist the sending end in execution of optimal measures for transmitting interference resistance, proper frame transmission speed is selected, and the problem of inaccuracy in estimation of the synchronous interferences and the asynchronous interferences is avoided.

Interference management may involve the transmission of interference management messages by wireless nodes that are experiencing interference and appropriate responses by potential interferers that receive the interference management messages. Upon detection of interfering signals, a wireless node may determine whether the signals are from a synchronous interferer or an asynchronous interferer. Based on this determination, the wireless node may use different types of signals to manage the different types of interference. In some aspects, asynchronous interference management may involve backing-off in frequency and / or in time in response to interference signals. Asynchronous interference management may involve transmitting back-off beacons to clear potential interferers from a given carrier. Here, the transmission of beacons by a wireless node may be metered to facilitate fair sharing of communication resources.

Interference management may involve the transmission of interference management messages by wireless nodes that are experiencing interference and appropriate responses by potential interferers that receive the interference management messages. Upon detection of interfering signals, a wireless node may determine whether the signals are from a synchronous interferer or an asynchronous interferer. Based on this determination, the wireless node may use different types of signals to manage the different types of interference. In some aspects, asynchronous interference management may involve backing-off in frequency and / or in time in response to interference signals. Asynchronous interference management may involve transmitting back-off beacons to clear potential interferers from a given carrier. Here, the transmission of beacons by a wireless node may be metered to facilitate fair sharing of communication resources.

The invention provides a navigation radar dense same-frequency asynchronous interference medium-frequency signal layer suppression method. The method includes: through envelope signals generated through zero medium-frequency signals, finding a position where same-frequency asynchronous interference appears in video azimuth echo; according to recorded same-frequency asynchronous interference position, respectively performing interference suppression in real signals of branches I and Q of zero medium frequency to retain zero medium frequency phase information so as to lay a foundation for coherent processing of subsequent radar signals. In the process of interference suppression, weight coefficient and protection factor are introduced, and the protection factor is utilized to protect original azimuth echo amplitude, so that same-frequency asynchronous interference signals are eliminated while original data are protected to greatest extent from being modified.

The embodiment of the invention discloses a multi-base station cooperative communication system asynchronous interference rejection method comprising the following steps: building a base station and user same codebook set; using the minimum mean squared error estimation method to estimate a channel matrix Hj corresponding to users j (j=1,..K); quantifying the user j channel matrix, and returning a quantified channel index value obtained by quantification to the base station; allowing the base station to restore the user j channel matrix from the cookbook according to the index value, and using a BD algorithm to calculate a user j precoding matrix according to the restored channel matrix; allowing the base station to transmit signals according to the obtained precoding matrix. The method uses the feedback bit number corresponding to the signal to noise ratio to solve the quantification codebook, uses the codebook to quantify the user channel state information, and uses the BD algorithm to resolve and obtain the precoding matrix according to the quantified channel state information for transmission, thus improving the precoding matrix algorithm, reducing the system rate loss, and well rejecting the asynchronous interferences.

The present invention belongs to the field of underwater acoustic communications, and particularly relates to an asynchronous multi-user access method for underwater acoustic OFDM (Orthogonal Frequency Division Multiplexing). The method comprises the following steps: overlap truncation; interference cancellation; frequency domain oversampling; multi-user channel estimation and decoding; and interference reconstruction. According to the present invention, an asynchronous interference model is established by using an overlap truncation method based on a sliding iteration structure, and then a received signal after interference cancellation is equivalent to a quasi-synchronous MIMO (multiple-input multiple-output) system to realize the multi-user data decoding, so that the asynchronous multi-user access method can be better to take the processing delay and the decoding performance into account, and has practical application value.

The invention provides an interference elimination method and a device under asynchronous interference data, wherein the interference elimination method under the asynchronous interference data comprises the following steps: (1) confirming an interference tipping point j of first time slot data and dividing the first time slot data into first part time slot data and second part time slot data, (2) respectively carrying out interference elimination to the first part time slot data and the second part time slot data, (3) combining the first part time slot data and the second part time slot data which are processed in an interference eliminated mode and obtaining the first time slot data after interference is eliminated. According to the interference elimination method and the device under the asynchronous interference data, the time slot data are divided into two parts, namely an interference part and a non-interference part, and interference elimination to the interference part and the non-interference part is respectively carried out, and thus the interference of the time slot data can be eliminated more effectively.

An apparatus (302) for wireless communication, comprising: means for determining whether an interferer is a synchronous interferer or an asynchronous interferer; and means for managing interference associated with the interferer based on the determination, wherein the means for managing interference is configured to manage asynchronous interference by performing adjusting coding associated with processing of received signals..

The embodiment of the invention discloses a multi-base station cooperative communication system asynchronous interference rejection method comprising the following steps: building a base station and user same codebook set; using the minimum mean squared error estimation method to estimate a channel matrix Hj corresponding to users j (j=1,..K); quantifying the user j channel matrix, and returning a quantified channel index value obtained by quantification to the base station; allowing the base station to restore the user j channel matrix from the cookbook according to the index value, and using a BD algorithm to calculate a user j precoding matrix according to the restored channel matrix; allowing the base station to transmit signals according to the obtained precoding matrix. The method uses the feedback bit number corresponding to the signal to noise ratio to solve the quantification codebook, uses the codebook to quantify the user channel state information, and uses the BD algorithm to resolve and obtain the precoding matrix according to the quantified channel state information for transmission, thus improving the precoding matrix algorithm, reducing the system rate loss, and well rejecting the asynchronous interferences.

The invention provides a channel estimation method suitable for single-antenna interference elimination technology. The method comprises steps of: pre-equalizing a signal so as to obtain a signal sequence estimation value; reducing the sequence estimation value into a burst sequence form and determining direction determination through signal energy; and executing adaptive sequence estimation on a half sequence including a training sequence according to the reference value of the obtained burst sequence and the direction determination. The method comprises three steps of: pre-processing, sequence reduction and direction determination and adaptive channel estimation. The invention also provides a channel estimation device suitable for the single-antenna interference elimination technology of decoupling linear filtering nonlinear balancing method. Thus, asynchronous interference elimination performance is improved.

The invention provides a navigation radar dense same-frequency asynchronous interference medium-frequency signal layer suppression method. The method includes: through envelope signals generated through zero medium-frequency signals, finding a position where same-frequency asynchronous interference appears in video azimuth echo; according to recorded same-frequency asynchronous interference position, respectively performing interference suppression in real signals of branches I and Q of zero medium frequency to retain zero medium frequency phase information so as to lay a foundation for coherent processing of subsequent radar signals. In the process of interference suppression, weight coefficient and protection factor are introduced, and the protection factor is utilized to protect original azimuth echo amplitude, so that same-frequency asynchronous interference signals are eliminated while original data are protected to greatest extent from being modified.

Interference management may involve the transmission of interference management messages by wireless nodes that are experiencing interference and appropriate responses by potential interferers that receive the interference management messages. Upon detection of interfering signals, a wireless node may determine whether the signals are from a synchronous interferer or an asynchronous interferer. Based on this determination, the wireless node may use different types of signals to manage the different types of interference. In some aspects, asynchronous interference management may involve backing-off in frequency and / or in time in response to interference signals. Asynchronous interference management may involve transmitting back-off beacons to clear potential interferers from a given carrier. Here, the transmission of beacons by a wireless node may be metered to facilitate fair sharing of communication resources. The interferer may well receive interference management messages and determine that it is an asynchronous or synchronous interferer to an interfered node. The interferer then may determine to react consequently.

The present invention relates to a method for common frequency asynchronous interference resistance in the radar signal processing field, especially to a common frequency asynchronous interference resistance method based on the interference spectrum and the MTD filtering amplitude-phase characteristics which can be widely applied in the radar signal processing system. According to the invention, the analysis of spectrum for the asynchronous interference is completed through the MTD filter amplitude-phase characteristics, the time-frequency two-dimensional combination detection is realized through combination of each channel frequency domain information on the basis of each Doppler channel time domain detection in the MTD processing process, and the effective inhibition of the common frequency asynchronous interference is completed while effectively detecting targets so as to basically eliminate the problems of interference or target misjudgement and target false dismissal.

The invention discloses a method for synchronously inhibiting radar clutter and multiple interferences based on power distinction, and is suitable for a signal processing system of sky-wave over-the-horizon radar. The method realizes the separation of strong clutter, interferences and target signal using the power difference among the clutter, interferences and target signal, and can effectively inhibit clutter and multiple interferences including transient interference and shared-frequency asynchronous interference. The specific steps are showed in the figure 1. Compared with the prior method, the method does not need to detect and analyze the clutter and multiple interferences complicatedly, has obvious effect on the randomly varied interferences of all parameters and clutter, and has strong applicability. The invention uses the separated strong clutter as a standard signal to correct phase pollution, can realize phase correction and inhibit the clutter and interferences synchronously, and simplify the signal processing process of the sky-wave over-the-horizon radar. The invention is not limited to the sky-wave over-the-horizon radar system, can be widely applied to multiple large-scale phased array radars, and has wide application value.

The invention provides a processing method of radar co-frequency asynchronous interference video signals. The echo amplitude in each azimuth is endowed with a weight coefficient, namely, different weight coefficients are used to adjust correlations between different pulses and a present pulse, and the problem of a relatively large error of a present sampling point is overcome. The average of every N azimuth echo amplitudes endowed with the weight coefficients is calculated, the calculated average value is endowed with a protection factor, the protection factor is used to protect the echo amplitude in the original azimuth and further to prevent original data from modification to the largest degree while removing the co-frequency asynchronous interference signals, and accurate basis is provided for subsequent data processing of the radar signals. In the processing process, the quantity of pulses can be adjusted properly according to whether adjacent pulses occur in the co-frequency asynchronous interference signals and whether the adjacent pulses include an interfering distance overlap condition, and problems in processing interference signals of different densities can be solved.

The present invention provides a pipeline leakage monitoring method and system based on the hierarchical sequential ratio of optical fiber multi-source signals. The method includes: real-time collection of standard optical fiber base sets and detection of central wavelength data of optical fibers transmitted by the optical fiber base sets; and collecting the collected data. Demodulate to obtain environmental data and detection data; analyze the demodulated environmental data, and use the sequential ratio method to perform environmental compensation judgment tests; analyze the compensated detection data, and use the multi-source signal construction influence of the detection basis set The factor-modified sequential ratio method is used to diagnose and inspect pipeline leaks; it determines whether there is leakage and sends an alarm. This invention separates environmental data and detection data by creating two different optical fiber base groups to accurately remove false alarms caused by environmental influences. The base group adopts a spiral structure to facilitate installation and laying and prevent asynchronous interference of optical fibers in the base group. The detection base set improves system operation sensitivity and accuracy through multi-source detection, and provides early warning functions through stretching and vibration changes.

The invention provides an interference elimination method and a device under asynchronous interference data, wherein the interference elimination method under the asynchronous interference data comprises the following steps: (1) confirming an interference tipping point j of first time slot data and dividing the first time slot data into first part time slot data and second part time slot data, (2) respectively carrying out interference elimination to the first part time slot data and the second part time slot data, (3) combining the first part time slot data and the second part time slot data which are processed in an interference eliminated mode and obtaining the first time slot data after interference is eliminated. According to the interference elimination method and the device under the asynchronous interference data, the time slot data are divided into two parts, namely an interference part and a non-interference part, and interference elimination to the interference part and the non-interference part is respectively carried out, and thus the interference of the time slot data can be eliminated more effectively.

The invention discloses a transmitting-interference-resistant wireless communication link adaptive method. The method includes the steps: when a sending node transmits frames to a receiving node by means of A-MPDU (aggregated MAC protocol data unit) frame aggregation, capturing transmission state information of PHY (physical layer) terminals and MPDU subframes in real time, and calculating synchronous interference occurrence probability and asynchronous interference occurrence probability; once loss of the PHY terminals or the MPDU subframes happens, estimating interference factors in communication links according to relation between a each of the synchronous interference occurrence probability and asynchronous interference occurrence probability and a corresponding threshold, immediately executing corresponding measures for transmitting interference resistance to guarantee reliability in frame transmission. By means of estimation of interferences in the links from a sending end, on the one hand, protocol expenditure is saved while frame length is reduced; on the other hand, frame transmissions states are acquired and counted in real time by means of B-ACK frames so as to reason out synchronous interferences and asynchronous interferences in the links to assist the sending end in execution of optimal measures for transmitting interference resistance, proper frame transmission speed is selected, and the problem of inaccuracy in estimation of the synchronous interferences and the asynchronous interferences is avoided.

The invention provides an iterative interference cancellation machine based on data updating, wherein UpSample / 2 double-decreasing sampling of received data, channel impact response estimation of an expectation user, calculation of a linear filter coefficient, a linear filter for performing interference suppression of the received data, a nonlinear equalizer for cancelling inter-symbol interference, self-adaptive LMS channel estimation and the like can be realized. The invention further provides an iterative interference cancellation method based on data updating. On the basis of nonlinear equalization, the whole performance of a link can be greatly improved through filtering operation and LMS channel estimation based on whole burst data; particularly, in an asynchronous interference condition, iteration for many times can be adopted according to a practical condition, so that the ideal performance is achieved; and the iterative interference cancellation machine and the iterative interference cancellation method based on data updating provided by the invention are suitable for expected signals in different modulation modes and interference types.