33 results about "Intercarrier interference" patented technology

The invention belongs to the technical field of signal processing, and particularly relates to a coherent light high-speed transmission signal processing method based on deep joint compensation, which comprises the following steps of: performing fine frequency offset and inter-carrier interference joint preprocessing on a coherent light receiving sampling sequence; obtaining a pre-processing output sequence and at least one estimation parameter derived from fine frequency offset and inter-carrier interference combined pre-processing; inputting the preprocessing output sequence into a diffusion type score guide joint compensation network module to obtain a deep joint compensation sequence; performing online judgment and decoding on the deep joint compensation sequence, and adaptively updating internal parameters of the diffusion type score guide joint compensation network module when a preset adaptive updating condition is met; according to the invention, the symbol residual error can be obviously reduced, the forward error correction gain can be improved, and the stability and robustness of the system under high-order modulation, high symbol rate and long-distance link scenes can be enhanced.

The invention discloses a multi-band modulation signal generation method based on OQAM, and a frequency spectrum wireless transmission method and system. The method comprises the following steps: a transmitting end performs OQAM preprocessing and modulation on original data flow to realize subcarrier multiplexing; and the receiving end is used for sampling the received signal, and down-conversion, demodulation and original data recovery of the signal are completed through a DSP (Digital Signal Processor) processing module. The multi-subcarrier staggered orthogonal amplitude modulation technology is combined, the spectrum efficiency is effectively improved, interference among subcarriers is avoided, and efficient spectrum utilization, low-cost transmission and multi-user access are achieved.

The present invention relates to the field of wireless communications, and in particular to a method for adaptively configuring subcarriers and subsymbols in underwater acoustic generalized frequency division multiplexing communications. The purpose of the present invention is to solve the problem that the inter-carrier interference and inter-symbol interference of the GFDM system in underwater acoustic communications are too high due to the multipath effect, resulting in low accuracy of channel estimation and low communication quality. After selecting the optimal configuration, the method of the present invention can significantly improve the performance of the GFDM communication system in the underwater acoustic channel. By accurately analyzing and calculating the energy of inter-subcarrier interference and inter-subsymbol interference, the optimal configuration scheme based on minimizing interference energy is selected. This scheme not only makes full use of the flexible data block structure of GFDM, but also combines interference elimination technology to enable the system to perform better in the underwater acoustic multipath channel, thereby improving the accuracy of channel estimation and communication quality.

The invention discloses an interference equalization method, device and equipment for multi-carrier modulation in a high-dynamic scene and a storage medium, and relates to the technical field of mobile communication, and the method comprises the steps: obtaining a time domain channel matrix of a time-frequency double-color dispersion channel, and determining an inversion core matrix in a minimum mean square error equalization matrix based on the time domain channel matrix; based on the sparsity structure of the inversion core matrix, decomposing the inversion core matrix to obtain a decomposition matrix; based on the time domain channel matrix, the inversion core matrix and the decomposition matrix, determining a multilayer linear equation set with minimum mean square error equalization; and solving the multi-layer linear equation set to obtain an equalization result. By means of the mode, the calculation complexity of the equalization process in the process of resisting inter-symbol interference and inter-carrier interference existing in multi-carrier modulation in a high dynamic scene is remarkably reduced, excellent performance is still kept under the extreme condition that no cyclic prefix exists or the length of the cyclic prefix is zero, and high scene adaptability and system practicability are embodied.

The invention provides a bee colony unmanned aerial vehicle communication system based on an enhanced OTFS frame and a hybrid topology, and relates to the technical field of unmanned aerial vehicle cluster wireless communication, and the system comprises autonomous wireless communication modules which are deployed in all unmanned aerial vehicles and are used for generating and processing orthogonal time-frequency space OTFS modulation signals; a star-mesh-linear IP hybrid topology network dynamically constructed by unmanned aerial vehicle nodes supports autonomous optimization of a communication path according to channel quality; embedding an enhanced OTFS frame structure of reduced-order cyclic prefix (RCP) and reduced-order zero filling (RZP) pilot frequency; a ground control station GSC integrating an OTFS module and a remote controller RC establish a low-delay link through UDP multicast; the invention relates to a RadCom joint module with integrated radar sensing and communication functions. According to the invention, a single-point fault risk is eliminated through decentration topology, inter-symbol and inter-carrier interference caused by multipath interference is effectively suppressed by an enhanced OTFS frame, the anti-interference capability of a complex environment is improved by a dual-band frequency hopping spread spectrum technology, and target detection and data transmission millisecond-level synchronization are realized by a RadCom module.

The application discloses a kind of based on dual three-dimensional memory hyperchaos SCMA-OFDM transmission system, the system includes sending end and receiving end, the user of sending end possesses respective codebook, J user shares K subcarrier, initial bit information and after the calculation of hyperchaos model of memristor triangle mapping chaotic codebook enter SCMA encoder and carry out codebook mapping processing, obtain encrypted SCMA-OFDM signal, for carrier synchronization, it is inserted pilot, after pilot, obtain frequency domain signal and information data using fast inverse fourier transform after the calculation of hyperchaos model of memristor triangle mapping, frequency domain signal is changed into time domain signal;Then to time domain signal is increased cyclic prefix CP and cyclic suffix CS to eliminate intercarrier interference, then parallel-serial conversion parallel signal is changed into serial signal, finally through up-conversion DUC complex signal mixing becomes real signal into transmission channel.The transmission system of regular hexagon chaotic codebook, its performance is improved by 2.5dB than traditional codebook.

A method for reducing inter symbol interference (ISI) and inter carrier interference (ICI) in transmissions between a sender and a recipient within a wireless communication network. For at least one multicarrier symbol comprising a first subcarrier modulated with an original reference signal and multiplexed with a second subcarrier modulated with an original payload signal. The method includes applying a multiple symbol shift configuration on at least a second multicarrier symbol adjacent to the first multicarrier symbol by repeating the original reference signal and the original payload signal in the second multicarrier symbol on respective subcarriers and applying a linear phase shift to each repeated reference signal and payload signal. The same linear phase shift is used for both the repeated reference signal and the repeated payload signal.

The application discloses an asynchronous distributed large-scale MIMO general filter multicarrier active user detection method, which is suitable for communication field use. A signal model of a frequency domain receiving signal of an asynchronous large-scale MIMO general filter multicarrier system is given first, and even components of the frequency domain receiving signal not influenced by inter-subband interference and inter-carrier interference are obtained; the asynchronous active user detection problem is expressed as a maximum likelihood estimation problem, then in order to solve the discontinuous and non-convex l0 norm constraint caused by asynchronous transmission, an equivalent penalty reconstruction form is introduced; further, a detection algorithm is provided, which can meet the highly non-convex constraint in a gentle way with the increase of iteration times, converges to a stable point of the original asynchronous active detection problem, and achieves good detection performance.

The present invention discloses an underwater acoustic orthogonal frequency division multiplexing secure communication method. The multiple transmit time reversal pre-filtering at the transmitter focuses the energy of the legitimate channel on the main path, shortening the channel of the cooperating party, while the eavesdropper still exhibits severe multipath characteristics. An orthogonal frequency division multiplexing signal with a short cyclic prefix smaller than the channel delay spread is transmitted, causing severe inter-symbol interference and inter-carrier interference to the eavesdropper. At the legitimate receiver, an interference cancellation-decision feedback equalizer is used to eliminate the residual interference of the cooperating party, improving the quality of the communication link of the cooperating party. Moreover, the secrecy capacity expression of the proposed method is given to evaluate the security performance of the system. The present invention is suitable for the underwater acoustic environment and has good performance in the long-delay frequency-selective underwater acoustic channel. When the location and channel information of the eavesdropper are both unknown, a considerable secrecy rate is obtained without the assistance of artificial noise.

According to some embodiments, a method performed by a wireless device comprises receiving a wireless signal Rk over all subcarriers allocated to the wireless device. The signal Rk comprises a phase tracking reference signal (PT-RS) on a subset of subcarriers allocated to the wireless device and the subset comprises at least one non-contiguous subcarrier. The method further comprises computing a de-inter-carrier interference (ICI) filter based on the PT-RS and a channel estimate using a convolutional matrix CR of the received signal Rk and applying the de-ICI filter to the received signal Rk to generate a de-ICI filtered signal.

Common phase error and / or inter-carrier interference. A technique comprising: transmitting data and / or control information; and transmitting a common phase error and / or inter-carrier interference correction reference signal, wherein the common phase error and / or inter-carrier interference correction reference signal occupies variable radio resources.

The invention relates to the field of wireless communication, and provides an iterative channel estimation and signal decoding method of a windowing OFDM (Orthogonal Frequency Division Multiplexing) system in a time-varying frequency selective fading channel. The windowing OFDM system comprises a transmitting end and a receiving end, wherein the transmitting end is used for generating and converting an OFDM symbol into a transmitting signal; performing windowing processing on the transmitted signal by using a time domain window function, and adding a cyclic prefix to obtain a final transmitted signal; transmitting the final transmitting signal to a receiving end through a time-varying frequency selective fading channel; the receiving end is used for removing the cyclic prefix of the transmitting signal transmitted by the transmitting end and demodulating to obtain a frequency domain receiving signal; converting a frequency domain receiving signal into a simplified form based on windowing operation of a time domain window function; obtaining an input and output relation of pilot frequency subcarriers based on the simplified form of the frequency domain receiving signal; and performing channel estimation and signal decoding based on the input and output relationship of the pilot frequency subcarriers. By adopting the method, the inter-carrier interference generated by improving the spectrum efficiency can be effectively inhibited.

A method for intelligent coding and mapping of underwater acoustic physical layer network coding is proposed, relating to the field of underwater acoustic communications. Combining the BP algorithm with deep learning, a superposition signal intelligent coding and mapping method (FBENet) with low coupling to channel information is proposed. The feature extraction module effectively extracts abstract features of the input information through a convolutional neural network (CNN). The bidirectional equalization module utilizes Bi-LSTM network neurons to equalize inter-carrier interference (ICI) in a time-frequency dual-extended channel, correcting the posterior probability distribution of subcarriers by simulating the sum-product message passing process of the BP algorithm. The probability output module outputs the probability distribution of the transmitting codeword combination for each subcarrier through a fully connected network for subsequent network coding. The network model's loss function uses a multi-classification cross-entropy loss function. During the training phase, as the model calculates parameter updates, the difference between the sample and the output decreases until it reaches a threshold, indicating successful training.

This invention discloses a time-frequency cooperative Doppler frequency offset suppression method and system for underwater acoustic OFDM communication, belonging to the field of underwater acoustic communication. The method includes: designing a novel channel adaptive tracking resampling factor estimation method, which performs cross-correlation processing only between two specific synchronization signal segments of the received signal, enabling it to adaptively track the time-varying channel and significantly improving the robustness of the communication system in underwater acoustic environments; based on the estimated resampling factor, performing time-domain resampling operations to transform non-uniform frequency offset into uniform frequency offset, thereby eliminating the impact of time-domain scale transformation on the underwater acoustic signal; and designing a residual uniform frequency offset suppression method based on subspace decomposition, using frequency domain eigenvalue decomposition to finely suppress the residual uniform frequency offset of the underwater acoustic signal. Combining the advantages of time-domain resampling and frequency-domain eigenvalue decomposition, it performs excellently in suppressing inter-carrier interference of underwater acoustic signals in highly mobile scenarios, significantly improving signal detection accuracy.

A method, system and apparatus are disclosed for enabling inter carrier interference compensation for interleaved mapping from virtual to physical resource blocks. In one embodiment, a network node is configured to determine to configure the first signal to be located at a subcarrier except at an edge sub-carrier of a resource block, RB; transmit the configuration of the first signal to the WD; and receive a physical uplink shared channel, PUSCH, signaling and the first signal from the WD based at least in part on the determined configuration. In one embodiment, a WD is configured to perform a de-inter-carrier-interference (de-ICI) filter estimation on a first received signal and a second received signal; apply a de-ICI filter to a third received signal, the de-ICI filter being based on the de-ICI filter estimation; and after the application of the de-ICI filter, de-interleaved map and demodulate the third received signal.

Apparatuses, methods, and systems are disclosed for configurations corresponding to inter-carrier interference. One method includes receiving, at a user equipment (UE), first configuration information for reference signals for performing inter-carrier interference (ICI) estimation including time-frequency resources, a multiplexing pattern, a time-domain behavior, or some combination thereof. The method includes receiving second configuration information for reporting ICI. The second configuration information includes instances of the reference signals for ICI estimation, the time-frequency resources for reporting, the time-domain behavior for reporting, or some combination thereof. The method includes measuring the ICI due to phase noise. The method includes transmitting the ICI report. The method includes receiving third configuration information for performing ICI pre-distortion and phase-tracking reference-signal (PT-RS) adaptation.

The application discloses a signal processing method of power carrier communication based on OFDM modulation, relates to the technical field of power carrier communication, and comprises the following steps: S1, cyclic prefix and guard interval design and insertion; S2, improved synchronization algorithm for frequency offset processing; S3, noise suppression optimization of a front-end signal processing module; S4, parallel processing architecture design and task allocation; S5, channel estimation at a receiving end; S6, frequency domain equalization processing; S7, OFDM demodulation processing; and S8, symbol synchronization and data recovery. Through the steps S1 and S2, the effects of effectively resisting power line channel multipath delay, reducing inter-symbol interference and inter-carrier interference are achieved. Through the steps S3, S5 and S6, the effects of accurately identifying power line impulse noise and Gaussian noise characteristics and dynamically suppressing noise are achieved. Through the steps S4 and S8, the effects of improving signal processing efficiency by using a parallel processing architecture and avoiding processor overload are achieved, and meanwhile, the data error correction capability is enhanced by convolution coding or Turbo coding, so that the real-time performance and reliability of high-speed data transmission are ensured.

The present invention provides a CP-free PS-OFDM communication system based on an autoencoder, comprising a transmitter, a channel and a receiver; the transmitter comprises a modulation module, a serial-to-parallel conversion module, an inverse Fourier transform module and a transmitter pulse shaping module connected in sequence, the transmitter pulse shaping module comprising a transmitting DNN, the transmitting DNN comprising a transmitting input layer connected to the output end of the inverse Fourier transform module, and a transmitting output layer; the channel is a multipath fading channel; the receiver comprises a receiving pulse shaping module, a coarse equalization module and a demodulation mapping module connected in sequence, the receiving pulse shaping module comprising a receiving DNN, the receiving DNN comprising a receiving input layer for inputting a received signal, and a receiving output layer, the receiving output layer being a receiving PS filter. The present invention can reduce the influence of inter-symbol interference and inter-carrier interference on signal detection, control the time and frequency characteristics of the OFDM signal, and realize flexible configuration of pulse shaping to flexibly support different communication scenarios.

The invention discloses an inter-carrier interference suppression method based on an OFDM radar communication integrated system, and belongs to the technical field of radar communication integration. The method comprises the following steps: firstly, constructing an OFDM radar communication integrated transmitting signal; a target is preset in the space, and an OFDM radar communication integrated signal is transmitted to the target; after target reflection, a target echo signal is obtained, and down-conversion, sampling and cyclic prefix removal processing are sequentially carried out on the target echo signal; carrying out 2D-DFT processing to obtain an original distance-speed image of the target; non-fuzzy velocity estimation based on multi-hypothesis velocity compensation; estimating a target scattering coefficient; reconstructing an ICI-free target signal by using the estimated target scattering coefficient; and carrying out 2D-DFT processing on the target signal without ICI to obtain a target distance-speed image without ICI. According to the method, the problem of inter-carrier interference generated by high dynamic is solved without sacrificing the communication rate and the fuzzy distance.

The embodiment of the invention discloses a signal preprocessing method and device, communication equipment and a storage medium. The method comprises: a network device receiving first information and a first reference signal sent by a terminal, the first information being used for instructing or notifying the network device to perform inter-carrier interference (ICI) preprocessing; the network device predicts ICI based on the first information and the first reference signal to obtain an ICI prediction result; and the network device preprocesses the signal based on the ICI prediction result.

The invention discloses a high mobility scene channel estimation and prediction method based on a channel map, and relates to the field of wireless communication system research, and the method comprises the steps: building channel key parameter prior distribution based on a power spectrum density function provided by the channel map; constructing and converting a pilot frequency training model considering inter-carrier interference into a parameterized linear estimation problem; and iteratively solving the problem by using a maximization-minimization algorithm, and obtaining a current channel estimation value and a subsequent channel prediction value based on a channel multipath structure. Compared with an existing method, the method has the advantages that the channel estimation precision can be improved by 10 times, high-precision time domain channel prediction can be realized, and a high-precision channel estimation and prediction solution is provided for high-mobility scenes such as high-speed railways and unmanned aerial vehicles. Instantaneous channel state information estimation of a double-selective channel can be realized, and time domain channel prediction in a quasi-static time interval can be realized.

Methods, systems, and apparatus for wireless communication are described, wherein random access preambles are designed to provide relatively low inter-carrier interference (ICI) of adjacent available frequency resources in a non-terrestrial network (NTN). The random access preamble for an NTN random access request may be selected from a first set of random access preambles, which differs from a second set of random access preambles used for terrestrial random access requests. The first set of random access preambles may be a subset of the second set. The first set of random access preambles may be provided for contention-based random access (CBRA), and contention-free random access (CFRA) preambles may be configured by the base station from random access preambles that correspond to or differ from the second set.

The application discloses a radar communication integrated signal optimization method and belongs to the technical field of radar communication integration. The application constructs a multi-pulse OFDM integrated signal model, designs an ICI self-cancellation precoding matrix based on frequency offset and Doppler effect, and suppresses inter-subcarrier interference; meanwhile, an inter-pulse coherent communication sequence is designed by combining Gold sequences and coherent accumulation constraints, so that the multi-pulse phase coherence is ensured. The transmitting end loads the precoded communication information to OFDM subcarriers to generate an integrated signal; the receiving end first performs ICI compensation and coherent accumulation, and then completes detection and demodulation. The application can significantly reduce waveform sidelobes, improve ranging and speed measurement accuracy and weak target detection performance, is compatible with a traditional OFDM structure, and is suitable for high-speed motion scenes such as vehicle-mounted radars and airborne detection.

Systems, methods, and apparatuses disclosed herein may mitigate interference in a wireless network. The systems, methods, and apparatus may determine a mode of operation of a base station (BS) within the wireless network. The systems, methods, and devices may select a first time advance (TA) when the BS is operating in a static time division duplex (TDD) mode of operation, or a second TA when the BS is operating in a subband full duplex (SBFD) mode of operation or a dynamic TDD mode of operation. The systems, methods, and apparatus may advance a signal on an uplink (UL) by the first TA such that the signal on the UL is time aligned with other signals on the UL from other UEs at the BS to mitigate inter-carrier interference (ICI) at the BS. Otherwise, the systems, methods, and apparatus may advance the signal on the UL by the second TA such that the signal on the UL is time aligned with a signal from the BS on the DL at a victim UE within the wireless network to mitigate cross-link interference (CLI) at the victim UE.

Disclosed in embodiments of the present disclosure are a signal preprocessing method and apparatus, a communication device, and a storage medium. The method comprises: a network device receives first information and a first reference signal which are sent by a terminal, the first information being used for instructing or notifying the network device to perform inter carrier interference (ICI) preprocessing; the network device predicts ICI on the basis of the first information and the first reference signal to obtain an ICI prediction result; and the network device preprocesses a signal on the basis of the ICI prediction result.

The invention discloses a signal processing method for power line carrier communication based on OFDM (Orthogonal Frequency Division Multiplexing) modulation, which relates to the technical field of power line carrier communication, and comprises the steps of S1, designing and inserting a cyclic prefix and a guard interval, S2, improving a synchronization algorithm to realize frequency offset processing, S3, performing noise suppression optimization on a front-end signal processing module, and S4, designing a parallel processing architecture and allocating tasks. S5, receiving end channel estimation, S6, frequency domain equalization processing, S7, OFDM demodulation processing, and S8, symbol synchronization and data recovery. According to the invention, through the steps S1 and S2, multipath time delay of a power line channel is effectively resisted, and inter-symbol interference and inter-carrier interference are reduced; through the steps S3, S5 and S6, the effects of accurately identifying the pulse noise and Gaussian noise characteristics of the power line and dynamically suppressing the noise are achieved; through the steps S4 and S8, the parallel processing architecture is utilized to improve the signal processing efficiency and avoid the overload effect of the processor, and meanwhile, the data error correction capability is enhanced through convolutional coding or Turbo coding, so that the real-time performance and reliability of high-speed data transmission are ensured.

In a network comprising a plurality of macro base stations, a plurality of micro base stations and a plurality of user devices (UEs), a method of establishing a wireless communication network includes: assigning the micro base stations into a plurality of clusters and selecting a micro base station from each of the clusters as a cluster head; receiving, from cluster heads of the clusters by the network device, information about candidate sub-clusters determined by UEs, each of the candidate sub-clusters comprises micro base stations whose signal power received at a UE exceeds a pre-defined threshold; identifying at least two schemes of grouping the micro base stations into non-overlapping sub-clusters based on the candidate sub-clusters; for a scheme of the at least two schemes, making each of the UEs select to access a macro base station or to be associated with one of the non-overlapping sub-clusters of the scheme base on respective measurements of signals received from at least one of a macro base station and a sub-cluster of the non-overlapping sub-clusters of the scheme; suppressing, by a UE, inter-symbol interference by subtracting a tail of a first symbol from a second symbol before recovering the second symbol; suppressing, by the UE, inter-carrier interference by adding a tail estimated of the second symbol to the second symbol before recovering the second symbol; acquiring information about power consumption of each of the macro base stations and power consumption of each of the micro base stations in communications with the UEs which performs inter-symbol interference suppression and inter-carrier interference suppression at the UEs; and making the micro base stations perform joint transmissions in sub-clusters as specified in a scheme selected from the at least two schemes according to the information about power consumption.

Embodiments of the present application provide a signal processing method, comprising: receiving, by a first device, a second signal from a second device, the second signal being generated based on time clipping and amplitude clipping of a first signal, the first signal being generated based on quadrature amplitude modulation mapping of a first bit sequence; performing, by the first device, quadrature amplitude demodulation mapping processing on the second signal to obtain a third signal, the third signal comprising time clipping noise and amplitude clipping noise; and performing, by the first device, time clipping noise and amplitude clipping noise processing on the third signal according to a successive interference cancellation algorithm to recover the first bit sequence. The method uses the successive interference cancellation algorithm, including decision-directed successive interference cancellation and coded-aided successive interference cancellation algorithm, to eliminate interference noise to recover the signal, which can reduce inter-carrier interference and amplitude clipping noise, and further improve system performance.

The invention provides a frequency offset residual error and phase noise joint compensation method for a lightning stroke scene, and relates to the technical field of signal processing, and the method comprises the steps: obtaining two-dimensional time domain data corresponding to an output balance baseband I / Q of a coherent optical receiver, and sequentially carrying out the phase observation construction and frequency preprocessing of the two-dimensional time domain data, so as to obtain an observation vector sequence; based on the observation vector sequence, the weight information of each observation sample and a preset subcarrier set, constructing a weighted sample covariance matrix, performing characteristic decomposition on the weighted sample covariance matrix, obtaining information subspace, noise subspace and phase jump characteristics caused by lightning stroke, constructing a joint cost function, and calculating the phase jump characteristics of the information subspace, the noise subspace and the lightning stroke. Obtaining residual frequency offset and random phase noise at each sampling frequency point according to the optimal solution of the joint cost function; and performing frequency and phase joint compensation on the received coherent optical baseband signal according to the residual frequency offset and the random phase noise. According to the invention, suppression of inter-carrier interference caused by frequency offset and phase noise is facilitated.

Apparatuses, methods, and systems are disclosed for indicating a subcarrier spacing value. One method includes receiving a configuration from a network device for a report including an indication of at least one subcarrier spacing value for transmitting a physical channel, receiving the physical channel, or a combination thereof. The method includes, in response to receiving the configuration, estimating the at least one subcarrier spacing value by calculating a Doppler spread, an average delay, a delay spread, a phase noise power, an inter carrier interference level, or some combination thereof. The method includes transmitting the report including the indication of the at least one subcarrier spacing value.