318 results about "Artificial noise" patented technology

An active control of an unwanted noise signal at a listening site radiated by a noise source uses a reference signal that has an amplitude and/or frequency such that it is masked for a human listener at the listening site by the unwanted noise signal and/or a wanted signal present at the listening site in order to adapt for the time-varying secondary path in a real time manner such that a user doesn't fell disturbed by an additional artificial noise source.

In the present invention, an image processing method includes a dividing process, a performing process, and a superimposing process. In the dividing process, an image is divided into plural local portions. In the performing process, the blurring processing is performed on at least one of the plural local portions. In the superimposing process, the artificial noise is superimposed on the at least one local portion.

The invention discloses a physical layer safety method based on artificial noise power distribution, and relates to a physical layer safety method. The objective of the invention is to solve the problems of high confidentiality interruption probability and poor confidentiality in an existing broadcasting system. The method comprises the following steps: 1, transmitting a signal by a transmitting end; 2, calculating a received signal reaching the kth legal receiver end and a received signal reaching the eavesdropper end; 3, calculating the signal to interference plus noise ratio of the kth legal receiver and the signal to interference plus noise ratio of the eavesdropper; 4, calculating the instantaneous confidentiality capacity of the kth legal receiver; 5, calculating an optimal artificial noise power distribution factor; and 6, calculating the confidentiality interruption probability according to different artificial noise power factors, and drawing a change curve of the confidentiality interruption probability along with the artificial noise power distribution factor to obtain the artificial noise power distribution factor meeting the requirements. The invention is applied to the field of physical layer security of a wireless broadcast communication system.

The invention discloses two robust beam forming methods for an MISO wiretap channel based on interruption probability constraints. Two robust beam forming schemes for the MISO wiretap channel are provided, a method of bisection, semidefinite relaxation and a Bernstein-type inequality are utilized to transform a nonconvex problem with the interruption probability constraints into a series of semidefinite programming problems in the absence of artificial noise assistance, so that the optimal robust beam forming design is obtained; the total transmitting power is divided into two parts of a useful signal and artificial noise in the presence of artificial noise assistance, through transforming the nonconvex problem with the interruption probability constraints into the semidefinite programming problems, the optimal design of robust beam forming of the useful signal and a covariance matrix of the artificial noise is obtained; the secrecy rate of a communication system is effectively improved, the wiretapping capability of a user is reduced and the security of the communication system is improved.

The invention belongs to the technical field of physical layer security, and provides a secret transmission method of a wireless energy-carrying cooperative system, and the transmission method comprises the steps: realizing system secret rate maximization on the basis of comprehensively considering energy collection constraint and cooperative interference performance; A relay node of the system isprovided with a plurality of antennas and works in a full duplex mode, a power switching mode is adopted for energy collection and data receiving and transmitting, artificial noise is sent for collaborative interference while information signals are forwarded, and the signal-to-noise ratio of a destination node is increased by adjusting an antenna array matrix by adopting a beam forming technology; According to the method, the energy collection constraint and the cooperative interference performance are comprehensively considered, the maximum confidentiality rate is taken as an objective function, and the optimal values of an energy collection factor and a cooperative interference power distribution factor are solved; Simulation results show that the proposed confidential transmission scheme can effectively improve the confidentiality rate of the system.

The invention discloses a safe transmission method in an MIMO Y eavesdropping network based on real interference alignment. According to the method, through utilization of a real interference alignment technology and an artificial noise technology, through construction of useful signal precoding matrixes and interference suppression matrixes, inter-user interference signals at legal user positions are located in null spaces of receiving suppression matrixes; and noise signals are completely eliminated through linear combination. Moreover, through construction of a noise signal coding matrix at a relay position, the noise signals are completely aligned to receiving signal spaces of eavesdropping users, so the eavesdropping users cannot eavesdrop the signals and the whole multi-user eavesdropping network can obtain multiple safe communication channels.

The invention provides an accurate wireless security transmission technology based on a random frequency diversity array (RFDA) and directional modulation (DM). According to the invention, artificial noise (AN) is projected to the desired position-oriented vector zero space to interfere with surrounding potential eavesdroppers, which enhances the security of signal transmission. Compared with a traditional directional modulation technology based on a phased array (PA), the technology provided by the invention uses the random frequency diversity array to elevate security transmission from one dimension (angle) to two dimensions (distance and angle) to realize accurate point-to-point signal transmission. According to the invention, a closed expression of the lower bound of the traversal security rate is acquired; the influence of power allocation and frequency allocation on the performance of the technology provided by the invention is investigated; and compared with the original directional modulation technology, the technology can effectively improve the security transmission rate.

The invention discloses an uplink secure transmission method based on downlink auxiliary feedback in a 5G communication system. In the first stage, a multi-antenna base station end sends both artificial interference and artificial noise signals on a downlink by means of a wave beam formation technology; and a single-antenna user end receives an emission signal from the base station end, and scrambles the received signal to a to-be-sent secret signal so that a mixed emission signal is formed. In the second stage, the user terminal broadcasts the mixed emission signal; and the base station end receives the mixed emission signal. Since the base station end already knows an artificial interference signal emitted by the base station itself, an expected secret signal can be separated from the received signal. A single-antenna passive eavesdropping end receives mixed signals during both transmission stages, and cannot know any prior information about the artificial interference and artificial noise signals, so the possibility of stealing secret information is low. Therefore, the transmission security of a 5G uplink single-input and multi-output system is effectively guaranteed.

The invention discloses an artificial noise precoding secure transmission method for a full duplex relay system. The method comprises the following steps: an information source adopts an artificial noise precoding scheme to simultaneously broadcast useful signals and artificial noise signals; a relay receives the signals broadcast by the information source and the self-interference at the relay, and a wiretapper receives the signals broadcast by the information source and recoding signals transmitted by the relay; a relay node reduces the influence caused by the self-interference by adopting a self-interference elimination technique; an information sink receives the transmitted signals that are recoded by the relay by adopting a maximal-ratio combining strategy; the signal to interference and noise ratios of the information source to a relay link and the relay to an information sink link are obtained, and the received signal to interference and noise ratios at the information sink and the wiretapper are also calculated; and the instantaneous safety rate of the system is obtained according to the received signal to interference and noise ratios at the information sink and the wiretapper, and an average safety rate is calculated. According to the method disclosed by the invention, the legal channel transmission rate can be increased, and the capacity of wiretap channels can also be effectively reduced.

A telecommunication system with a modem (MCO) having a controlling module (CCO) coupled to a data transmission module (DTM) comprising a transmitter (TX) adapted to transmit channels via a communication line (LN), the channels transporting user data (UD) by means of signals (STX) with modulation having a bitload that is modifiable. The data transmission module comprises an artificial noise generator (ANG) coupled to the transmitter and controlled by the controlling module to inject an artificial noise (AN) into the transmitter. The artificial noise is used to influence the signals transmitted by the data transmission module to the communication line and may be added to the data signals either in the transmit time domain processing module (TXTDP) or in the transmit frequency domain processing module (TXFDP) of the transmitter. The system is particularly advantageous for DSL applications where the margin is larger than 3 dB. This corresponds to distances lower than 4000 meter for an ADSL cable with 50 users.

The invention discloses an energy harvesting relay safety transmission method adopting artificial noise precoding, which is applied to a system including four nodes that are a source, a relay, a sink and a wiretapper. The system requires two time slots to complete transmission. In the first time slot, the source broadcasts signals, the sink and the wiretapper receive the signals, and the relay adopts the maximal ratio to combine received signals, harvest energy and receives a secrecy signal. In the second time slot, the relay obtains state information of a channel from the relay to the sink, an artificial noise auxiliary precoding strategy is adopted to carry out precoding of secrecy information and artificial noise, then an amplification forwarding protocol is used for forwarding coding signals, the sink and the wiretapper receive the coding signals, and the received signals during the two time slots are combined at the maximal ratio. The relay safety transmission method applies artificial noise auxiliary precoding to an energy harvesting relay adopting power distribution, so that the remote transmission system limited in energy is enabled to have the great safety transmission performance.

The invention discloses a physical layer safe communication method designed by combining signal feedback and artificial noise in a wireless communication network. The method comprises a first stage that a sending end sends information needing to be kept secret to a legal receiving end; a second stage that after the legal receiving end receives the information, a certain amount of artificial noise is mixed in the received information, and the mixed signal is fed back to the sending end; and a third stage that the sending end sends feedback signal to the receiving end. The legal receiving end knows the artificial noise mixed in the second stage, so that the legal receiving end can eliminate the artificial noise; an eavesdropping end cannot eliminate the noise, so that the performance is weakened by the artificial noise; and the safe communication between the sending end and the receiving end is realized. According to the scheme, the safe communication between the legal devices can be realized under the condition that the legal communication devices have no antenna, no external helper and no any channel information of the eavesdropping end. The method has superiority in the communication safety aspect.

The invention discloses a physical layer secure transmission method for resisting information eavesdropping of an eavesdropping node. The physical layer secure transmission method comprises the steps that: 1) a source node and a target node sequentially send a training sequence before the beginning of information transmission, so that the source node and the target node estimate equivalent channel information h<n, k> from the source node to the target node, wherein n is contained in {1, ... , Nr}, k is contained in {1, ... , Nt}, Nt is antenna number set by the source node, and Nr is antenna number set by the target node; 2) the source node encodes to-be-transmitted data, obtains a to-be-transmitted symbol and an antenna serial number for transmitting the to-be-transmitted symbol, then adds artificial noise into the to-be-transmitted symbol, and transmits the to-be-transmitted symbol added with the artificial noise to the target node through a selected antenna; 3) and the target node receives the symbol transmitted by the source node, decodes the symbol transmitted by the source node by means of a maximum likelihood decoder, and completes physical layer secure transmission of information. The physical layer secure transmission method can achieve physical layer secure transmission of the information.

The invention discloses a collaboration network power distribution method based on artificial noise under a nonideal channel estimation condition of a collaboration channel. The method comprises the steps that S1, a legal receiving end sends pilot sequences to a transmitting end of an transmitting source, and a collaboration jammer; S2, the transmitting end receives the pilot sequence and carries out ideal channel estimation, and the collaboration jammer receives the pilot sequence and carries out nonideal channel estimation; S3, the transmitting end and the collaboration jammer design respective transmitting signals; S4, the transmitting end and the collaboration jammer transmit signals to the legal receiving end and an eavesdropping end at the same time; S5, the optimum transmitting power distribution ratio and the maximum safe transmission rate under the nonideal channel estimation condition of the collaboration channel are calculated; S6, the optimum transmitting power distribution ratio and the maximum safe transmission rate under an ideal channel estimation condition of the collaboration channel are calculated; and S7, the maximum safe transmission rates under the nonideal channel estimation condition and the ideal channel estimation condition are compared. According to the collaboration scheme provided by the method, the condition that an error exists in the channel estimation method of the collaboration channel is taken into full consideration, and the practical power distribution scheme for realizing system safety is proposed.

The invention provides an optimization method for artificial noise direction modulation based on a frequency control array. The method comprises the steps: enabling a transmitting end to obtain the azimuth and distance of a legal receiver, and extracting a normalized beam vector; calculating the maximum confidential rate difference between a maximum legal receiver and an adjacent eavesdropping receiver; calculating a frequency compensation vector with the maximum confidential capability through a non-convex optimization algorithm, and then calculating a legal receiver guide vector; calculatinga normalized artificial noise projection matrix according to the orthogonality of the artificial noise and the legal receiver guide vector, and obtaining an artificial noise baseband signal based onthe frequency control array. The method realizes the dual control of angle and distance, and realizes the maximum confidential rate difference between the legal receiver and the adjacent eavesdroppingreceiver, and ensures higher-precision physical layer wireless security communication.

The invention discloses a collaborative interference physical layer secure transmission method based on optimal relay selection, which mainly solves a problem of low secret rate and high transmissioncost of a wireless transmission system in the prior art. An implementation scheme of the method is as follows: a destination node D acquires state information of each channel from each relay to the destination node D and the state information of each channel from each relay to an eavesdropping node E, and selecting an optimal relay R according to the state information of the channels; the R generates an artificial noise signal V; a sending node A sends an information signal, and simultaneously, the optimal relay R sends the artificial noise signal; the destination node D receives the information signal, and the eavesdropping node is suffered from interference of the artificial noise signal V while receiving the information signal. In the method provided by the invention, the optimal relayis selected for sending the artificial noise signal, the eavesdropping node is interfered, link quality of an eavesdropping channel is weakened, transmission complexity and transmission cost of the system are reduced, and secret rate of the system is improved, and the method can be used for a secret communication system comprising a plurality of relays.

The invention provides a secure communication method in a non-orthogonal multiple access network assisted by an intelligent reflecting surface, and belongs to the field of multi-user non-orthogonal multiple access network security. By superposing a proper amount of artificial noise in transmitted NOMA information and jointly optimizing an IRS reflection phase, a transmitted beam vector and an artificial noise vector, the sum of transmission rates of legal users is maximized. In addition, the artificial noise signal for controlling transmission can be completely eliminated by a serial interference elimination technology at each legal user side, so that eavesdropping is effectively inhibited under the condition of not influencing legal receiving. Compared with an OMA (Orthogonal Multiple Access) scheme without artificial noise and assisted by a traditional reflecting surface, the invention has the advantages that the network security performance can be remarkably improved, and the application value is very high.

The present invention belongs to the technical field of video raindrop removal, and especially relates to a method and a system for removing raindrops in videos. The method comprises: a step a of reading video frames and performing color space conversion for the video frames; a step b of performing raindrop initial detection through photometric characteristics of static raindrops, performing image edge part identification through a guide filter, and subtracting an edge part from an initial detection result, so as to obtain optimized candidate raindrops; and a step c of obtaining final detection raindrops through a denoising algorithm and raindrop area constraint, and removing the raindrops through a defogging equation and photometric characteristics of dynamic raindrops, so as to obtain a final raindrop removing result. The method of the present invention greatly shortens time required for removing the raindrops, improves raindrop removing efficiency, reduces false detection of raindrop pixels, and avoids introducing of artificial noise, in addition, the method combines the defogging equation and the photometric characteristics of dynamic raindrops to perform raindrop removal processing for images, thereby effectively improving image quality and achieving a good raindrop removal effect.