86 results about "Channel reciprocity" patented technology

In a communication network that comprises a reciprocal channel between a transmitter and a receiver, the receiver produce a measurement of the reciprocal channel and exploits channel reciprocity to agree with the transmitter on a random code derived from the measurement. The transmitter employs the random code to produce linearly coded data, which is transmitted to the receiver. The receiver uses the random code to decode the linearly coded data by solving a system of linear equations.

The invention provides a lattice public key encryption method and device based on super-large-scale MIMO. The method is composed of a physical layer public key encryption part and a private key decryption part. And the base station completes encryption and SVD precoding operation by combining the channel matrix and the public key. And the legal user side completes key generation and decryption operation. The legal user side generates a private key based on the orthogonal basis of the lattice; and based on the private key and the orthogonal basis, carrying out nearest plane algorithm operation on the noisy encrypted information, and finally realizing decryption. When the number of antennas of an eavesdropper is infinite and far larger than the number of legal antennas, and the distance between the eavesdropper and a legal end is smaller than one half of the wavelength, or when the eavesdropper and the legal end directly break through the channel estimation process to obtain legal channel information, the method is safe. The method can be simultaneously suitable for time division duplex and frequency division duplex channels, does not need to depend on channel reciprocity, is based on lattice cryptography, can resist currently known quantum attacks, and meets the requirement of future 6G for communication security.

Techniques are provided for implementing time reversed reference signals for radio frequency (RF) sensing operations in a communication system. An example method for generating channel reciprocity information for radio frequency sensing operations includes receiving radio frequency sensing information from a sensing node, generating a channel reciprocity prediction based at least in part on the radio frequency sensing information and a channel reciprocity prediction model, and providing an indication for time reversal precoding to the sensing node based on the channel reciprocity prediction.

The present disclosure relates to apparatus, methods, computer-readable storage medium and computer program product for CSI-RS enhancement for Port Selection Codebook with Channel Reciprocity. A cellular base station, comprising: at least one antenna; at least one radio coupled to the at least one antenna; and a processor coupled to the at least one radio; wherein the cellular base station is configured to: provide a Radio Resource Control (RRC) message to a wireless device; and provide a Channel State Information-Reference Signal (CSI-RS) to the wireless device via one or more ports based on the RRC message, wherein, the RRC message at least indicates one or more of: information on a density of the CSI-RS, information on time domain locations of the CSI-RS, information on a subset of ports for the wireless device to measure the CSI-RS, and information on a subset of Code Division Multiplexing (CDM) groups for the wireless device to measure the CSI-RS.

The present application discloses a communication method, apparatus, system and storage medium, which belongs to the field of communication. The method includes: a first wireless unit RU receives the device identifications of m network devices sent by a first network device, the m network devices include the first network device, the m network devices are connected to each other, and m is an integer greater than 0; the first RU receives the device identifications of n network devices sent by a second RU, the second RU and the n network devices are connected, and n is an integer greater than 0; the first RU determines that the same device exists between the m network devices and the n network devices based on the m device identifications and the n device identifications; the first RU performs collaborative communication processing, and the collaborative communication processing is used to realize collaborative communication between the first RU and the second RU. The present application can make the channel reciprocity between the first RU and the second RU.

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.

The invention provides a communication method and a related device. In the method, a terminal determines a time coherence degree of one or more sub-band groups based on N CSI reports, determines first information based on the time coherence degree of one or more sub-band groups and a first duration, and sends the first information to a network device, the first information being used for indicating a confidence coefficient of each sub-band group or a confidence coefficient of a broadband corresponding to each sub-band group, the confidence coefficient of the sub-band group is the confidence coefficient of the channel reciprocity between the uplink and downlink channels of the sub-band group, and the confidence coefficient of the broadband is the confidence coefficient of the channel reciprocity between the uplink and downlink channels of the broadband corresponding to the sub-band group. Under the condition that the network equipment determines the downlink channel characteristics according to the first information, the uplink channel estimation result and the downlink channel estimation result from the terminal, the accuracy of the downlink channel characteristics obtained based on channel reciprocity can be improved.

The invention discloses a low-overhead uplink and downlink channel reciprocity air interface calibration method based on terminal assistance, which comprises the following steps of: sending a frequency division orthogonal downlink reference signal sequence by a far-end wireless unit, estimating a downlink channel after a terminal receives a downlink reference signal, and calibrating the downlink channel according to a frequency domain pattern of the downlink reference signal, and mapping the uplink reference signal sequence to different frequency domain positions. A terminal weighs an uplink reference signal sequence according to downlink channels at different frequency domain positions and then sends the uplink reference signal sequence, and a base station side carries out channel estimation and frequency domain fitting interpolation on the uplink reference signal to obtain a full-band calibration coefficient of each antenna. According to the method, service transmission does not need to be interrupted, the self-calibration defect of the base station is overcome, the terminal does not need to report channel information, the continuity of communication between the base station and the terminal is guaranteed, reporting overhead does not exist, it is guaranteed that the orthogonality of the reference signals is not damaged by preprocessing, the calibration coefficient of the full frequency band can be obtained, the calibration coefficient can be filtered, and the accuracy of calibration is improved. And the calibration precision is improved.

A method for implementing uplink and downlink channel reciprocity, a communication node, and a storage medium are provided. The method for implementing uplink and downlink channel reciprocity includes: performing channel estimation in real time according to a received reference signal to obtain a channel estimation result; inputting the channel estimation result into a pre-trained neural network model, to output a channel adaptive matrix; and performing channel adaptation processing on a transmission signal by applying the channel adaptive matrix to the transmission signal.

A method of downlink channel state information (DL CSI) measurement and reporting is proposed in FR1 frequency division duplex (FDD) systems. CSI reference signal (CSI-RS) is directed towards dominant spatial domain (SD, beam) and frequency domain (FD, delay) components in the propagation environment. By partial channel reciprocity, angles and delays in the DL channel can be obtained by UL channel measurement. UE only needs to measure and feedback the DL CSI corresponding to the dominant angles and delays. BS obtains the precoder in the antenna-frequency domain using the CSI feedback in the beam-delay domain. BS uses the precoder for transmission over Physical downlink shared channel (PDSCH). In one embodiment, UE reconstructs the DL channel on a multitude of delays using the DL channel estimated on a few beamformed CSI-RS and delay tap indices signaled from the network.

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 application discloses a channel state information compensation method, a communication device and a computer program product. It relates to the technical field of network communication, and the method comprises the following steps: acquiring a target moving speed of relative motion between a first device and a second device, and a plurality of channel estimation results of a channel between the first device and the second device; determining a target nonlinear interpolation coefficient corresponding to the target moving speed based on a corresponding relationship between the moving speed and the nonlinear interpolation coefficient; and compensating channel state information of the channel based on the plurality of channel estimation results and the target nonlinear interpolation coefficient to obtain a channel state information compensation result. The application solves the technical problem that in the related art, the channel considered when performing channel compensation is mostly a channel in a static or slow moving environment, and in the case that the terminal moving speed is relatively high, the channel has strong time variation, the channel reciprocity is poor, and the channel compensation accuracy is low.

The application discloses a kind of based on affine frequency division multiplexing covert communication method and system.The method includes: transmitting end and receiving end respectively carry out channel estimation, obtain channel state information, and construct frequency domain channel matrix;Using channel reciprocity, both sides independently generate the same Chirp parameter codebook, avoid eavesdropper reconstruction;Transmitting end generates corresponding modulation symbol according to the input modulation bit;According to the amplitude of the diagonal element of frequency domain channel matrix, index bit is selected to the starting position of the Chirp parameter codebook;Transmitting end carries out affine frequency division multiplexing modulation according to the Chirp parameter codebook selected by index bit to constellation symbol and transmits;Receiving end reconstructs Chirp parameter codebook using its own CSI and completes matching decoding and modulation decryption.The application realizes shared password book without the need of privacy information exchange, makes full use of waveform parameter degree of freedom, improves the spectral efficiency and communication security of system, and is suitable for high-speed mobile communication data covert transmission.

Techniques are provided for implementing time-inverted reference signals for radio frequency (RF) sensing operations in a communication system. An example method for generating channel reciprocity information for a radio frequency sensing operation includes receiving radio frequency sensing information from a sensing node; generating a channel reciprocity prediction based at least in part on the radio frequency sensing information and a channel reciprocity prediction model; and providing an indication for time reversal precoding to the sensing node based on the channel reciprocity prediction.

The invention belongs to the technical field of wireless communication, and discloses a cellular-removed large-scale MIMO distributed dual-time-scale hybrid precoding method, which comprises the following steps of: constructing a user average channel covariance matrix at each access point (AP); carrying out eigenvalue decomposition on the user average covariance matrix and extracting a main eigenvector to construct an initial simulation precoding matrix; performing constant modulus constraint processing on the initial analog precoding matrix to obtain an analog precoding matrix; a user sends an orthogonal pilot frequency, each AP carries out instantaneous channel state information estimation by adopting a minimum mean square error criterion, and a downlink channel is obtained based on the reciprocity of uplink and downlink channels; each AP designs a digital precoding vector according to a downlink channel; the AP allocates power to the user according to the power constraint; system spectral efficiency is calculated to assess method performance. According to the method, the expandability of the system is effectively improved while the channel estimation overhead and the operation complexity are reduced, and the method is suitable for efficient implementation of the honeycomb-removed large-scale MIMO system.

The present application relates to the technical field of communications, and provides a method and apparatus for determining a channel calibration coefficient. The method comprises: on a first channel, sending a first reference signal to a second apparatus, wherein the first reference signal is used for determining a first parameter, and the first parameter is used for indicating a response matrix of the first channel; on a second channel, receiving a second reference signal from the second apparatus, wherein the second reference signal is used for determining a second parameter, and the second parameter is used for indicating a response matrix of the second channel; on the second channel, receiving a third reference signal from the second apparatus, wherein the third reference signal is precoded on the basis of the first parameter, and the third reference signal is used for determining the first parameter; and on the basis of the first parameter and the second parameter, determining a third parameter, wherein the third parameter is used for calibrating the reciprocity between the second channel and the first channel. In the solution, a channel reciprocity calibration coefficient is determined with low complexity by means of simple air interface interaction.

The invention belongs to but is not limited to the technical field of optical key distribution, and discloses a communication and encryption integrated key distribution system and method based on channel reciprocity and coherent optical communication, which utilizes a scrambler to enable the tap coefficient of a time-varying depolarization algorithm to change quickly, thereby improving the key generation rate and improving the key transmission efficiency. And the method is combined with a channel reciprocity characteristic and is applied to secure key distribution. According to the invention, key distribution and secure coherent light communication can be carried out simultaneously. And during digital signal processing of the signal receiving module, on one hand, key generation is carried out, and on the other hand, secure optical communication is carried out. It is guaranteed that two legal parties obtain consistent secret keys through dynamic reciprocity of channels, and safety is guaranteed through mutual disturbance of the channel reciprocity and a time-varying cross-polarization state. The system does not need additional devices and is highly compatible with the current coherent communication system, so that the deployment cost of the key distribution module can be reduced.

Aspects of the disclosure relate to communication using a multi-panel base station. In an aspect, a base station may determine a plurality of indicators identifying a plurality of antenna panels on the base station, wherein each indicator of the plurality of indicators identifies a respective antenna panel of the plurality of antenna panels. Further, the base station may transmit the plurality of indicators to a user equipment (UE) to respectively identify the plurality of antenna panels.

Systems and methods are described for radio frequency (RF) calibration in a multiple antenna system (MAS) with multi-user (MU) transmissions (“MU-MAS”) exploiting uplink / downlink channel reciprocity. The RF calibration is used to compute open-loop downlink precoder based on uplink channel estimates, thereby avoiding feedback overhead for channel state information as in closed-loop schemes. For example, a MU-MAS of one embodiment comprises a wireless cellular network with one or multiple beacon stations, multiple client devices and multiple distributed antennas operating cooperatively via precoding methods to eliminate inter-client interference and increase network capacity.

Systems and methods are described for radio frequency (RF) calibration in a multiple antenna system (MAS) with multi-user (MU) transmissions (“MU-MAS”) exploiting uplink / downlink channel reciprocity. The RF calibration is used to compute open-loop downlink precoder based on uplink channel estimates, thereby avoiding feedback overhead for channel state information as in closed-loop schemes. For example, a MU-MAS of one embodiment comprises a wireless cellular network with one or multiple beacon stations, multiple client devices and multiple distributed antennas operating cooperatively via precoding methods to eliminate inter-client interference and increase network capacity.

The invention provides a channel calibration coefficient determination method and device, and relates to the technical field of communication. The method comprises: on a first channel, sending a first reference signal to a second device, the first reference signal being used to determine a first parameter, the first parameter being used to indicate a response matrix of the first channel; on a second channel, receiving a second reference signal from the second device, the second reference signal being used to determine a second parameter, the second parameter being used to indicate a response matrix of the second channel; on the second channel, receiving a third reference signal from the second device, the third reference signal being subjected to precoding processing based on the first parameter, the third reference signal being used for determining the first parameter; and determining a third parameter according to the first parameter and the second parameter, the third parameter being used for calibrating the reciprocity of the second channel and the first channel. According to the scheme, the channel reciprocity calibration coefficient is determined with relatively low complexity through simple air interface interaction.

The application discloses a channel information compression feedback method using frequency division duplex channel implicit reciprocity. For the frequency division duplex channel information data with implicit reciprocity, the application firstly converts the spatial frequency domain channel matrix to the angle delay domain and performs clipping, and then splits and splices the real part and the imaginary part of the channel matrix into two real number matrices; three encoder networks are used for decoupling characterization learning of the downlink channel, and the downlink channel unique information, the uplink and downlink channel common information and the virtual uplink and downlink channel common information are extracted respectively; the decoder network recovers the original channel information by using the downlink channel unique information and the uplink and downlink channel common information during training, and recovers the original channel information by using the downlink channel unique information and the virtual uplink and downlink channel common information during testing; in the application, the user only needs to feed back the downlink channel unique information, the channel feedback load is effectively reduced, the channel information recovery performance is improved, and the application has a significant performance advantage.

The invention provides a communication method and a communication device, and relates to the field of communication. In the method, a terminal device can obtain first channel information and second channel information, the first channel information is channel information of an uplink channel between a network device and the terminal device, and the second channel information is channel information of a downlink channel between the network device and the terminal device; and then the terminal equipment can determine a correction coefficient of an antenna of the terminal equipment according to the first channel information and the second channel information, and the correction coefficient is a channel reciprocity correction coefficient. Based on the scheme, the reciprocity correction of the receiving and transmitting channels of the terminal equipment can be realized.

The application provides a lattice public key encryption method and device based on a super large scale MIMO, which is composed of a physical layer public key encryption and a private key decryption. A base station jointly completes encryption and SVD precoding operation with a channel matrix and a public key. A legal user terminal completes key generation and decryption operation. The legal user terminal generates a private key based on a lattice orthogonal basis; based on the private key and the orthogonal basis, a nearest plane algorithm operation is performed on noisy encrypted information, and finally decryption is realized. When the number of antennas of an eavesdropper is infinite and much larger than the number of antennas of a legal terminal, when the distance between the eavesdropper and the legal terminal is less than one half of the wavelength, or when the channel estimation process is directly attacked to obtain legal channel information, the application is also secure. The application can be simultaneously applied to time division duplex and frequency division duplex channels, does not need to rely on channel reciprocity and is based on lattice cryptography, can resist current known quantum attacks, and meets the requirements of future 6G for communication security.

The invention relates to an electronic device and a beam forming method and device.The electronic device comprises a plurality of antennas, a radio frequency module, a processing module and an adjusting module, and the processing module carries out time inversion on the basis of receiving information of reference signals received by the radio frequency module and the plurality of antennas under the condition that a network device transmits the reference signals so as to adjust the time of the reference signals. Obtaining a phase difference and an amplitude ratio of transmission time reversal signals among the plurality of antennas; and the adjusting module adjusts parameters for transmitting the radio frequency signal on the target radio frequency path based on the phase difference and the amplitude ratio, so that the at least two target antennas perform beam forming according to the phase difference and the amplitude ratio. By introducing the time reversal technology, on one hand, the incoming wave estimation process can be reduced, and on the other hand, the phase difference and the amplitude ratio are obtained based on time reversal, and the at least two target antennas are enabled to carry out beam forming according to the phase difference and the amplitude ratio, so that energy point focusing can be realized, and on the basis of channel reciprocity, beam forming can be realized. And the radio frequency signal can be effectively transmitted between the electronic equipment and the network equipment.

Systems and methods are described for radio frequency (RF) calibration in a multiple antenna system (MAS) with multi-user (MU) transmissions (“MU-MAS”) exploiting uplink / downlink channel reciprocity. The RF calibration is used to compute open-loop downlink precoder based on uplink channel estimates, thereby avoiding feedback overhead for channel state information as in closed-loop schemes. For example, a MU-MAS of one embodiment comprises a wireless cellular network with one or multiple beacon stations, multiple client devices and multiple distributed antennas operating cooperatively via precoding methods to eliminate inter-client interference and increase network capacity.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit an indication of a classification of a link established between the UE and a network node. The classification may indicate whether the link is associated with a reciprocity. The reciprocity may include a beam correspondence and channel reciprocity. The classification of the link may be a binary classification. The classification of the link may be based at least in part on a metric associated with the link. The link may be associated with the reciprocity depending on one or more link characteristics associated with the link. Numerous other aspects are described.

Provided in the present application are a key generation method and apparatus, aiming to generate consistent keys without relying on ideal channel reciprocity. In the method, by exchanging a first signal and first information with a second communication apparatus, a first communication apparatus may acquire a channel between the first communication apparatus and the second communication apparatus and a channel between the second communication apparatus and the first communication apparatus; and during key generation, a key can be generated by means of the channel between the first communication apparatus and the second communication apparatus and the channel between the second communication apparatus and the first communication apparatus. Therefore, it is not necessary to depend on ideal channel reciprocity, that is, consistent keys can be generated when a channel matrix between the first communication apparatus and the second communication apparatus is not necessarily the same as a channel matrix between the second communication apparatus and the first communication apparatus.

The methods (800, 900) and apparatuses (310, 320) enable (834, 934) measurement of downlink reference signals to report (840, 940) values of a subband layer 1 signal-to-interference-and-noise ratio, a subband interference level, and / or a subband layer 1 reference signal received power for each of at least two subbands. These values are used to enhance selection of a modulation and coding scheme and a number of downlink transmission layers. Uplink sounding reference signals are also used to measure and report subband values that lead to this selection, assuming channel reciprocity.