62 results about "Code division multiple access" patented technology

The invention relates to the technical field of wireless communication, in particular to a multimode chip core architecture system realized based on a software radio technology, which comprises an anti-interference module used for executing real-time optimization on a multi-system compatible baseband data stream and calling a dynamic compensation mechanism based on dynamic frequency shift characteristics in an environment characteristic data set, adjusting a local frequency source and a channel equalization parameter through multi-stage compensation operation to obtain an anti-interference enhanced data stream; and the packaging module is used for packaging the anti-interference enhanced data stream and the positioning data into a time-hopping pulse-direct sequence code division multiple access fusion frame structure and sending the fusion frame structure through a radio frequency unit. Through an ASIC and SDR hybrid architecture and a four-level hierarchical design, a multi-system communication function is integrated, and the hardware efficiency is improved and the power consumption is reduced.

The invention discloses a low-slow small target detection and data fusion method based on 5G signals, and relates to a low-slow small target detection and data fusion method. The invention aims to solve the problems of low detection precision and difficulty in effective identification and tracking of the low-slow small target in the prior art. According to the invention, a 5G signal retroreflection detection system with separated transmitting end and receiving end is constructed, direct wave and multipath interference are eliminated by using 5G signal code division multiple access characteristics, and target position and speed information are obtained through two-dimensional matched filtering and two-dimensional sliding correlation processing; a 5G base station forward scattering detection system is established, and target detection is realized by analyzing target forward scattering signal characteristic parameters according to the Babinet principle; a specific data fusion algorithm is adopted to carry out fusion processing on heterogeneous data obtained by backward reflection and forward scattering, and accurate information such as target position, speed, attribute and the like is output. The invention belongs to the technical field of low-slow small target detection.

The invention provides a signal detection method for a multi-antenna orthogonal time-frequency-space sparse code division multiple access system, which is characterized in that dimensionality reduction is carried out on time domain and time delay Doppler domain signals by utilizing sparsity of a sparse code division multiple access codebook, and prior distribution of the time domain signals is approximated by using Gaussian distribution. Preliminary detection is realized by acquiring cavity distribution of a signal in a time domain, and the posterior probability of the signal is calculated by using a sparse code division multiple access codebook in a time delay Doppler domain. Based on a transformation relation in a multi-antenna orthogonal time-frequency-space sparse code division multiple access system, information exchange between a time domain and a time delay Doppler domain is realized. The sparse structure of the time domain matrix in the multi-antenna orthogonal time-frequency-space sparse code division multiple access system is utilized, and the complexity of matrix inversion in the algorithm is reduced. By using the method, the complexity of algorithm implementation can be reduced while the signal detection performance is ensured by utilizing the dual sparsity of the multi-antenna orthogonal time-frequency-space system and the sparse code division multiple access codebook.

The invention discloses a multi-source information fusion method based on wide-narrow band communication, and relates to the field of information fusion, and the method comprises the steps: carrying out the preprocessing of obtained multi-source heterogeneous data; extracting a text feature vector # imgabs0 # by using a pre-trained BERT network, and extracting an image feature vector # imgabs1 # by using a pre-trained convolutional neural network ResNET; the method comprises the following steps: respectively acquiring priorities # imgabs2 # and # imgabs3 # by utilizing a pre-trained bidirectional gating loop network BiGRU; a text priority threshold value # imgabs4 # and an image priority threshold value # imgabs5 # are set in a self-adaptive mode; transmitting the text data or image data of which the priority # imgabs6 # is greater than the priority # imgabs7 # or the priority # imgabs8 # is greater than the priority # imgabs9 # through orthogonal frequency division multiple access (OFDMA) by adopting a broadband channel; on the contrary, a narrow-band channel is adopted for transmission through code division multiple access (CDMA); performing sparse representation on the decoded text data and image data by using Bayes estimation, and performing data reconstruction through L1 norm minimization; and carrying out association fusion on the recovered data by utilizing an attention mechanism. Aiming at low multi-source information fusion precision in the prior art, the multi-source information fusion precision is improved.

A power-imbalanced multi-level decoding method for sparse code multiple access includes: encoded bits of all users are mapped to multi-dimensional sparse codewords through predetermined codebooks; a factor graph matrix is constructed using the predetermined codebooks, all users are classified according to the factor graph matrix under predetermined constraints to determine Z levels; based on a predetermined total transmission power, a progressive multi-level power optimization algorithm is employed to perform power-imbalanced allocation for all users according to the Z levels, thereby determining a locally optimal power vector; transmission signals corresponding to the multi-dimensional sparse codewords are transmitted according to the locally optimal power vector; SCMA detection and power-oriented decoding are sequentially performed for users each level, and outputs decoded bit sequences for the L levels.

The invention provides a capacity evaluation method for a code division multiple access spread spectrum communication system, which comprises the following steps of: selecting a reference user according to user configuration information of the code division multiple access spread spectrum communication system, calculating a cross correlation coefficient between spread spectrum codes of the reference user and other users, and analyzing random characteristics of the cross correlation coefficient; obtaining a signal intensity ratio relation of system users according to the system user distribution and the beam directional diagram; based on the signal strength ratio relation, the random characteristic, the system communication requirement and the non-ideal power control, the failure probability of the reference user is deduced and calculated; and calculating a curve that the failure probability of the reference user changes along with the number of the system users through a conditional probability mode, and selecting a target failure probability according to a system communication requirement to obtain a system user capacity estimation value corresponding to the target failure probability. In this way, the capacity of the multi-beam code division multiple access system can be evaluated more accurately.

Touch driving apparatus, touch control apparatus and touch driving method are provided. The touch driving apparatus is used for driving a mutual capacitance type touch panel. The touch driving apparatus includes at least one output module and a controller. Each output module includes at least two output stage circuits, and an output end of each output stage circuit is used for outputting a driving signal to a connected driving electrode. The touch driving method includes: for each output module, determining, according to a code division multiple access (CDM) code matrix, a first group of output stage circuits and a second group of output stage circuits in a current driving period, wherein a first group of driving signals of the output ends of the first group of output stage circuits are expected to discharge a first group of driving electrodes, and a second group of driving signals of the output ends of the second group of output stage circuits are expected to charge a second group of driving electrodes; and in response to the determination, controlling charging of the second group of driving electrodes with power from the first group of driving electrodes.

The invention relates to the technical field of multi-node ranging, and particularly discloses a multi-node ranging method and system based on code division multiple access, and the method comprises the steps: S1, calculating the network complexity, obtaining the bandwidth when the network complexity exceeds a certain range, and calculating the channel capacity; s2, calculating transmission time, calculating a transmission time ratio, correcting the bandwidth based on the transmission time ratio to obtain a corrected bandwidth, and obtaining corrected time; and S3, setting the bandwidth as a modified bandwidth, sending bytes with the same number to the test nodes, obtaining actual transmission time, screening qualified nodes, presetting a byte number gradient, obtaining a ladder coefficient when the requirement is met, sorting the test nodes, retaining efficient nodes and adjusting the corresponding bandwidth as the modified bandwidth. According to the invention, the byte data transmission frequency in the multi-node ranging process can be reduced, the positioning delay is reduced, and the response speed is improved.

The invention relates to the technical field of wireless communication network distribution, and discloses a high-density small local area network multiple access cooperation rapid network distribution method and system, a transmitting end generates a network identifier containing a code division multiple access password and a frequency division multiple access table according to a preset mode, the preset mode comprises an address preset mode and an address distribution mode, and the address distribution mode comprises a code division multiple access password and a frequency division multiple access table; in the address distribution mode, the transmitting end and the receiving end dynamically enter a network distribution mode according to environmental interference, dynamically generate a unique network identifier, and finish broadcasting and receiving of the network identifier in a preset frequency band; the transmitting end sequentially initiates network distribution requests according to the dynamic interval time, after receiving the network distribution requests, the receiving end performs dual verification on code division multiple access passwords, frequency division multiple access table integrity and secret keys in the requests, network distribution is completed if verification is passed, and a communication link is established; according to the invention, simultaneous and stable coexistence of multiple networks in a high-density small local area network is realized, low-delay network distribution and communication are achieved, the anti-interference capability and the network expansion capability of the distribution network are improved, and the exclusive demand of a multi-transmitting-end coexistence scene is adapted.

The invention discloses a random access method and device of a terminal, equipment, a medium and a program product, the terminal receives an inventory instruction sent by read-write equipment, responds to the inventory instruction, and sends an air interface temporary identifier in the same time slot by using a code division multiple access mode or a frequency division multiple access mode to preempt random access resources; and under the condition that the random access resource is successfully preempted, performing time domain serial transmission on uplink data by using a time division multiple access mode. By adopting the invention, the hybrid random access of the terminal can be realized by combining different schedulable resources in the competition access and data transmission stage in the passive Internet of Things communication process, and the access efficiency of the terminal is improved.

The application discloses a decoding method and device, electronic equipment and a non-transitory computer readable storage medium, and belongs to the technical field of communication. The method comprises the following steps: determining the activation probability of each user based on at least one sparse code division multiple access signal received in a current time period and the codebook of each user in a communication network; the activation probability represents the probability of a user sending a non-all-zero code word in the current time period; determining each activated user from each user in the communication network according to the activation probability of each user; constructing an initial factor graph based on the activated user and the subcarriers occupied by the non-zero elements in the corresponding codebook; and performing decoding processing on each sparse code division multiple access signal based on a message passing algorithm, the initial factor graph and the codebook of each user, to obtain the sending code word of each activated user, so that data detection can be performed only on the activated user; when the activation probability of a user is low, the user is directly considered as a non-activated user sending an all-zero code word, and the calculation complexity of data detection can be reduced.

The invention discloses a regional navigation communication method and system based on multi-user frequency hopping. The system comprises air users divided into a plurality of sub-networks; and a plurality of ground base stations. According to the system, time-frequency domain resources are divided into a plurality of non-interfering network layers according to different frequency hopping patterns, and different members are divided in each sub-network by using a code division multiple access technology, so that hybrid multiple access is realized, while the signal measurement precision is guaranteed, certain concealment is realized, and the measurement accuracy is improved. And a regional navigation signal waveform system supporting anti-interference and low interception is formed.

The invention discloses an access network construction method based on rail transit infrastructure service state detection in the technical field of rail transit detection. The access network construction method comprises the following steps: step 1, network architecture design: constructing a self-adaptive access network architecture comprising a data acquisition layer, a data transmission layer, a data processing layer and an application layer; step 2, a self-adaptive access mechanism: dynamically adjusting the positions and the number of access points according to the distribution condition and the service requirements of the rail transit infrastructure; and step 3, establishing a wireless communication mode: in a data transmission layer, based on a mobile communication technology, establishing an evolution process from analog to digital and from frequency division multiple access to code division multiple access (CDMA) by adopting the wireless communication mode. The rail transit service information is collected through the non-contact sensing equipment, the rail transit service state is detected by means of sound waves, lasers and the like, and the flatness of the rail and the integrity of materials are evaluated.

The present invention provides a method, device and electronic equipment for generating a scrambling code of a wideband code division multiple access system, and relates to the field of communication technology. The method comprises: determining a real part index value according to a maximum scrambling code number and a frame length of a downlink scrambling code, wherein the downlink scrambling code is a downlink scrambling code in a wideband code division multiple access (WCDMA) system; determining an imaginary part index value according to the maximum scrambling code number, the frame length and an M value of the downlink scrambling code, wherein the M value is a constant value in the WCDMA system protocol; generating a real part of the scrambling code according to the scrambling code number and the real part index value; generating an imaginary part of the scrambling code according to the scrambling code number and the imaginary part index value; and obtaining a target scrambling code according to the real part and the imaginary part of the scrambling code. The method achieves rapid generation of a downlink scrambling code sequence, reduces cyclic calculations and unnecessary storage, and saves storage resources.

This invention provides a method, system, and storage medium for vector signal analysis and processing at the uplink signal receiver of a wideband code division multiple access (WCDMA) wireless communication system. It is used to perform frequency domain and modulation domain index measurements, channel decoding, and other processing on the uplink signal of a WCDMA wireless communication system. The beneficial effects of this invention are: by using an R&S cellular test instrument to sample WCDMA uplink signals, the various processes of this invention were debugged. Under conditions of AWGN, DC bias of -39dB, random delay, and random frequency offset, the uplink signal waveform of WCDMA FDD was generated. Simulation processing of various processes, including synchronization, carrier frequency offset estimation and compensation, descrambling, equalization, and despreading, was performed. The DC bias and error vector amplitude (EVM) of the uplink signal were measured, and the downlink physical control channel (DPCCH) and downlink physical dedicated channel (DPDCH) were demodulated and decoded. The CRC check of the DPDCH channel passed, verifying the correctness of each process.

A system comprises one or more sensor devices for subcutaneous electroencephalography where each sensor device includes a flexible biocompatible polymer sensor strip adapted to be inserted into a cranial subdermal space and including a plurality of electrodes. The strip includes a microchip responsive to each of the electrodes and comprising a multi-channel integrated circuit system-on-chip with a wireless transceiver, a low-noise neural amplifier, a unique network address, and RF energy harvesting microcircuits. In one embodiment, the sensor strip is no more than about 1 mm wide, at least about 5 cm long, and no more than about 300 μm thick. An external transceiver is disposed on the exterior of the subject's skin near one or more sensor devices in secure wireless communication with the respective wireless transceivers comprised in the sensor devices microchips. The system is configured to communicate using a network communication protocol, such as time division multiple access or code division multiple access.

The invention provides a method and device for generating a scrambling code of a wideband code division multiple access (WCDMA) system and electronic equipment, and relates to the technical field of communication, and the method comprises the following steps: determining a real part index value according to the maximum scrambling code number of a downlink scrambling code and the frame length of the downlink scrambling code, the downlink scrambling code being the downlink scrambling code in the wideband code division multiple access (WCDMA) system, and the frame length of the downlink scrambling code being the maximum scrambling code number of the downlink scrambling code; an imaginary part index value is determined according to the maximum scrambling code number of the downlink scrambling code, the frame length of the downlink scrambling code and an M value, the M value is a constant value in a WCDMA system protocol, a scrambling code real part is generated according to the scrambling code number and the real part index value, a scrambling code imaginary part is generated according to the scrambling code number and the imaginary part index value, and a target scrambling code is obtained according to the scrambling code real part and the scrambling code imaginary part; according to the invention, the downlink scrambling code sequence is quickly generated, cyclic calculation and unnecessary storage are reduced, and storage resources are saved.

The invention discloses an MMSE-FED (Molecular Code Division Multiple Access) and decision feedback interference removing method and device, and the method comprises the steps: carrying out the fast Fourier transform of an original observation value, obtaining a frequency domain observation matrix, carrying out the sorting according to the receiving power or distance of a nanometer transmitter at a fusion center, and obtaining a frequency domain observation matrix; the method comprises the following steps: taking a first nanometer transmitter as the current most reliable, taking an initial frequency domain observation matrix as a basis, obtaining a judgment variable through MMSE-FED, IFFT and de-spreading operation, then obtaining a hard judgment result through a judgment function as a bit sequence of a first nanometer transmitter, reconstructing signal contribution according to the bit sequence, obtaining an updated frequency domain receiving signal, and obtaining a second nanometer transmitter; for the kth nanometer transmitter after sorting, based on the updated frequency domain receiving signal, repeating the operation to detect the bit sequence, and reconstructing the signal again for interference elimination; and finally, detecting the bit sequence of the Kth transmitter based on the signal updated for the (K-1) th time through loop iteration.

The application discloses a kind of near-field coherent heart radio frequency sensing method and system based on code division multiple access, comprising: 4-way frequency f synchronous baseband signal is configured, 4-way synchronous chip is configured, synchronous baseband signal is multiplied with corresponding synchronous chip to modulate, and 4-way digital baseband signal is obtained;4-way digital baseband signal is handled to obtain 4-way heart measurement signal;4-way heart measurement signal is respectively transmitted to corresponding antenna by radio frequency transceiver and is emitted;The antenna is respectively arranged in left ventricle, left atrium, right ventricle, right atrium;Antenna receives reflected signal, and is recorded as heart sensing signal;Heart sensing signal is transmitted to radio frequency transceiver, and after processing, the baseband signal containing heart chamber beat information is obtained;The baseband signal containing heart chamber beat information is multiplied with corresponding synchronous chip to demodulate, band-pass filter, and the demodulation signal corresponding to heart chamber beat information is obtained respectively.

The invention discloses a decoding method and device, electronic equipment and a non-transient computer readable storage medium, and belongs to the technical field of communication. The method comprises the following steps: determining an activation probability of each user based on at least one sparse code division multiple access signal received in a current time period and a codebook of each user in a communication network; the activation probability represents the probability that the user sends non-all-zero code words in the current time period; according to the activation probability of each user, determining each activated user from each user of the communication network; constructing an initial factor graph based on the activated users and subcarriers occupied by non-zero elements in the corresponding codebook; on the basis of a message passing algorithm, the initial factor graph and the codebook of each user, each sparse code division multiple access signal is decoded to obtain a sending codeword of each activated user, data detection can be only performed on the activated user, and when the activation probability of one user is relatively low, the user is directly considered to be a non-activated user sending all-zero codewords, so that the efficiency of sending all-zero codewords is improved. The calculation complexity of data detection can be reduced.

An optical transmitter includes lasers configured to generate a wave division multiplex (WDM) on a light guide, and a Code Division Multiple Access (CDMA) symbol generator coupled to modulate CDMA symbols on the light guide across the channels of the WDM. The transmitter utilizes of laser locking controls configured to correlate the CDMA symbols to frequency adjustments applied to the lasers.

Communication system, comprising: a first data bus configured to transport a first data signal according to a first transmission direction; a second data bus configured to transport a second data signal according to a second transmission direction different from the first transmission direction; a synchronization bus; and a plurality of local resources generating a respective local signal to be transmitted on the first and second data bus. All transceivers are modulated with CDMA encoding and take place following a synchronism signal. The unidirectionality of transmission on the data buses guarantees the absence of interference. The communication system is fully scalable.

The application relates to the field of space laser communication, in particular to a face array APD multi-spot overlapping state simultaneous identification method and system based on code division multiple access, which comprises the following steps: three slave optical terminals respectively emit three beacon light beams to a master optical terminal; the three beacon light beams pass through a converging lens and converge to a 5*5 face array APD detector photosensitive surface to generate 25 APD pixel photoelectric current signals; the 25 APD pixel photoelectric current signals are input to a signal conditioning circuit, and a digital signal corresponding to each APD pixel photoelectric current signal is output; the digital signals are all input to a preprocessing unit to obtain a summary signal; the preprocessing unit inputs the summary signal to a code tracking loop to obtain an output signal; integrated processing is conducted on the output signal output by the code tracking loop and the digital signal output by the signal conditioning circuit to obtain an integrated processing result; and a centroid algorithm is used to solve the spot center position of the integrated processing result. The number of code tracking loops, the complexity and the scale of the circuit system are reduced.

The invention relates to the technical field of power line carrier communication optimization. The invention relates to a power line carrier communication optimization method based on synchronous code division multiple access. The method comprises the following steps: S1, acquiring a communication coverage area, performing area division according to the communication coverage area into a branch area, a branch area and a tail end area, setting a data gateway in each area at the same time, and configuring power line carrier and millimeter wave double-link communication in the data gateways; according to the method, three levels of transmission areas are divided in combination with link characteristics, so that the coverage boundary accuracy is improved by more than 40%, the problems of unreasonable area division and poor coverage and link adaptability in the prior art are solved, a foundation is laid for double-link linkage transmission, unique binding of fragments and terminals is realized by adopting 128-bit SCDMA composite coding, a self-adaptive fragmentation strategy is combined, and the transmission efficiency is improved. The interference-free transmission of multiple users and multiple fragments is guaranteed, the flexibility of data transmission is improved, and the transmission requirements of different service types are met.

An indoor positioning system includes a camera, a position detection sensor, a first communication module, memory storing at least one instruction, and at least one processor. The at least one processor is configured to, by executing the at least one instruction, generate positional information by recognizing a position of a vehicle moving on a road based on a position detection signal of the position detection sensor, and recognize vehicle license plate information and the position of the vehicle moving on the road based on an input image captured by the camera. The at least one processor is further configured to encode the positional information in a code-division multiple access (CDMA) method using a spreading code generated from the vehicle license plate information, and output the encoded positional information as a wireless signal through the first communication module.

The invention discloses an anti-phase noise codebook optimization method and system based on sparse code division multiple access, and relates to the Internet of Things technology, and the method comprises the steps: creating a one-dimensional basic constellation diagram; according to the created one-dimensional basic constellation diagram, generating an N-dimensional mother constellation through permutation and combination so as to form a plurality of sparse codebooks; and the plurality of sparse codebooks are optimized, so that the plurality of sparse codebooks maximize the minimum phase noise distance, and the performance of the system in the presence of phase noise is improved. According to the anti-phase noise codebook optimization method provided by the embodiment of the invention, the bit error rate performance of the SCMA system in the presence of phase noise can be improved.

A code-division multiple-access (CDMA) based Intra-Aircraft Wireless Sensor Network (IAWSN) configured for structural health monitoring comprises a network of sensor nodes configured as source nodes to transmit sensor data in accordance with a CDMA technique and a wireless data concentrator (WDC) to receive the sensor data simultaneously from at least some of the sensor nodes. Each of the sensor nodes is assigned a synchronous CDMA code for spreading the sensor data and uniquely identifying transmissions from each sensor node. The WDC may use the synchronous CDMA codes to despread the simultaneously received sensor data and identify the particular sensor node from which the sensor data is received. The synchronous CDMA codes serve as a unique identifier of the sensor nodes, as well as provide for improved immunity from interference.

The application discloses a power special network communication system and a signal processing method based on FFH / SCMA. The system combines fast frequency hopping (FFH) and sparse code division multiple access (SCMA), and a sending end maps user symbols onto multiple SCMA subcarriers through fast frequency hopping to form a fast frequency hopping SCMA code word; a receiving end recovers data through frequency hopping, decoding, sub-set combining and maximum likelihood estimation. The signal processing procedure comprises SCMA encoding mapping, frequency hopping, decoding according to frequency hopping pulses, and multi-copy sub-set combining. Compared with the defect that the conventional SCMA fixed subcarrier transmission is vulnerable to electromagnetic interference, the application significantly improves reliability through frequency sub-set combining, and meets the high-reliability communication access requirement of a new power distribution system.

The application provides a kind of multi-antenna orthogonal time-frequency-space sparse code division multiple access system signal detection method, the application utilizes the sparsity of sparse code division multiple access codebook to reduce the dimension of time domain and time delay doppler domain signal, and uses Gaussian distribution to approximate the prior distribution of time domain signal.In the time domain, the preliminary detection is realized by obtaining the cavity distribution of signal, and the posterior probability of signal is calculated in the time delay doppler domain by using the sparse code division multiple access codebook.Based on the transformation relationship in the multi-antenna orthogonal time-frequency-space sparse code division multiple access system, the information exchange between the time domain and the time delay doppler domain is realized.The application utilizes the sparse structure of time domain matrix in the multi-antenna orthogonal time-frequency-space sparse code division multiple access system, and reduces the complexity of matrix inversion in the algorithm.By using the application, the double sparsity of multi-antenna orthogonal time-frequency-space system and sparse code division multiple access codebook can be utilized to reduce the complexity of algorithm implementation while ensuring the signal detection performance.

The invention discloses a space-time-frequency code hybrid multiple access method based on space-based Internet of Things user distribution condition, which relates to the field of satellite communication and comprises the following steps: acquiring a running orbit and a sub-satellite point trajectory of a satellite; predicting the number, the distribution condition and the message service volume of users in a beam coverage area at the satellite top crossing moment; dividing the beam area into a plurality of sub-beam areas, and pre-allocating frequencies and time slots of the sub-beam areas; dividing variable sub-regions in the sub-beam regions, and determining allocated frequencies and time slots; setting a frequency use threshold upper limit and a frequency use threshold lower limit for each sub-beam area; and adjusting the frequency allocated to the sub-beam area according to the frequency use condition of the sub-beam area, providing an access channel for the user in the sub-beam area by using code division multiple access for the sub-beam area of which the frequency use condition exceeds the upper limit, and setting a special spreading code sequence for the user with high priority so as to preferentially de-spread. The frequency resource utilization rate can be improved, and the user access number of the satellite is increased.