24 results about "Code division multiple access" patented technology

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.

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 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 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.

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 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.

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 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.

This disclosure describes the operating concept and medium access control protocols of a wireless communication system that uses Code Division Multiple Access with Interference Avoidance (CDMA-IA) as its physical layer. The system can dynamically share a common band with other networks without a central radio resource controller. In one embodiment, the wireless communication system includes several radio nodes forming a wireless mesh network, where pairs of radio nodes use individually optimized time-division duplexing. At least one radio node includes a software-defined radio, memory, and an electronic processor. The electronic processor is configured to control the software-defined radio to transmit a pilot signal and share various status information with the other nodes in the network.The shared information includes local spectrum usage and node connectivity sets. The dominant sharing of spectrum usage among all nodes allows for maximizing the use of the shared band.

The application provides a code word mapping method, which can improve the decoding performance and energy allocation fairness of a communication system designed by combining a multi-ary channel coding technology and an SCMA technology. The method comprises the following steps: obtaining a first mapping relationship of at least one user on at least two resource blocks (S301), determining a second mapping relationship of the at least one user on the at least two resource blocks (S302), and determining a third mapping relationship of the at least one user on the at least two resource blocks according to a peak-to-average power ratio corresponding to the second mapping relationship of the at least one user on the at least two resource blocks (S303). The first mapping relationship of each user on each resource block is composed of at least two corresponding relationships, and each corresponding relationship is a corresponding relationship between a sparse code division multiple access (SCMA) code word and a multi-ary channel coding symbol. The criterion value is used to measure the possibility of the SCMA code word being decoded incorrectly and the multi-ary channel coding symbol being decoded incorrectly. The peak-to-average power ratio is a peak-to-average power ratio of the energy of the SCMA code word after superposition on the at least two resource blocks.

A system and method for time / frequency coding with code-division multiple access (CDMA) for interference reduction of vehicle sensors are presented. This system comprises the generation and transmission of a first chirp signal by a first sensor in a first channel and a second chirp signal by a second sensor in a second channel from a vehicle. Both the first and second channels contain a time channel component, a frequency channel component, and a code dimension. A first sensor receives a first reflection signal, and a second sensor receives a second reflection signal, each from one or more objects.Furthermore, the second channel contains one or more different time channels, different frequency channels, or different code dimensions compared to the first channel, and the code dimensions of the first channel and the code dimensions of the second channel are determined from a set of code dimensions based on an estimate of the minimum noise.

This invention discloses a distributed multiple access system for a symbiotic radio network based on reconfigurable holographic devices, comprising: a background network (BS / UE) and an IoT network consisting of K reconfigurable holographic devices (RHDs) and IoT receivers (IRs); each RHD integrates an antenna, a load modulator, and a reconfigurable holographic surface (RHS), which converts a reference wave carrying IoT information into a target wave and radiates it into free space by activating subwavelength radiating elements, overcoming the size limitations of traditional RIS / phased arrays; the IoT receiver (IR) employs distributed decoding based on random code-based code division multiple access (CDMA), utilizing matched filter (MF) or minimum mean square error (MMSE) receivers combined with asymptotic signal-to-interference-plus-noise ratio (SINNR) theory to eliminate the need for real-time random code feedback; the radiation pattern is optimized based on the weighted minimum mean square error (WMMSE) algorithm to maximize RHD and data rate. The advantages of this invention are: device size supports integration of micro-IoT devices; IoT SINNR is improved by more than 20dB; and it enables massive IoT device access.

The invention discloses an asynchronous code division multiple access underwater wireless optical communication system multi-user access method based on optical wireless access point direction self-adaption, and belongs to the technical field of wireless optical communication. According to the method, user azimuth angle estimation and communication are synchronously realized at an OAP end by utilizing a detector array, and a receiving end direction self-adaptive mechanism is implemented based on multi-user detection and arrival angle information so as to maximize the system capacity. And a multi-user access control strategy is formed by further combining a dynamic code word distribution protocol. According to the method, the difficulty in underwater clock synchronization is overcome, the throughput, the number of users and the fairness are improved by optimizing the OAP space orientation, and an effective solution is provided for practical application of UOWC multi-user communication.

The invention discloses a secure sparse code multiple access transmission method and receiving method based on path superposition shaping, and belongs to the technical field of communication, and the transmission method comprises the steps: carrying out serial-parallel conversion and forward error correction coding according to an original data stream of each user to obtain a parallel coding data stream; performing constellation mapping by querying a preset user codebook to obtain a constellation point sequence corresponding to each user, performing superposition by taking constellation point groups in the user codebook as paths through group operation according to the sparse matrix, and performing probability shaping to obtain superposed constellation point paths to form sparse code division multiple access (SCMA) symbols; performing disturbance encryption according to the four-dimensional hyper-chaos model to obtain an encrypted signal, and performing multicarrier modulation, inverse fast Fourier transform and parallel-serial conversion processing in sequence to obtain a signal to be transmitted; according to the method, the problems that the spectrum efficiency is limited due to non-uniform distribution of constellation points in the traditional sparse code multiple access technology, wireless signals are easy to eavesdrop in the transmission process, and the iterative detection complexity of a receiving end is high are solved.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first device may generate a message, of a code division multiple access (CDMA) based initial access, from a random identifier (ID) associated with the first device based at least in part on a mapping between the random ID and a message code or sequence in CDMA. The first device may transmit, to a second device, the message during the CDMA based initial access. Numerous other aspects are described.

The invention relates to a time-frequency-code sensor coding method and system for interference suppression in a vehicle. A system and method for time-frequency coding with code division multiple access (CDMA) for interference mitigation for vehicle sensors includes generating, by a first sensor, a first chirp signal in a first channel and transmitting, from a vehicle, and generating, by a second sensor, a second chirp signal in a second channel and transmitting. Both the first channel and the second channel include a time channel component, a frequency channel component, and a code dimension. The first sensor receives a first reflected signal and the second sensor receives a second reflected signal, the first and second reflected signals each coming from one or more objects. Further, the second channel includes one or more different time channels, different frequency channels, or different code dimensions relative to the first channel, and the code dimension of the first channel and the code dimension of the second channel are determined from a set of code dimensions based on the lowest interference noise estimate.

The application relates to the technical field of wireless communication, in particular to a multi-mode chip core architecture system based on a software radio technology, which comprises an anti-interference module, a packaging module and a radio frequency unit.The anti-interference module is used for executing real-time optimization on multi-standard compatible baseband data streams based on dynamic frequency shift features in an environment feature data set, calling a dynamic compensation mechanism, adjusting a local frequency source and channel equalization parameters through multi-stage compensation operations, and obtaining anti-interference reinforced data streams.The packaging module is used for packaging the anti-interference reinforced data streams and positioning data into a time-hopping pulse-direct sequence code division multiple access fusion frame structure and sending the time-hopping pulse-direct sequence code division multiple access fusion frame structure through the radio frequency unit.Through an ASIC and SDR hybrid architecture and four-stage hierarchical design, the application integrates multi-standard communication functions, and realizes hardware efficiency improvement and power consumption reduction.

Various aspects of the present disclosure relate to code division multiple access (CDMA) -based communication in an ambient Internet of things (A-IoT) system. In an aspect, a first device (for example, an A-IoT device) receives a first transmission from a second device (for example, a reader). The first transmission comprises an indication indicating code division multiple access (CDMA) is enabled for communication between the first device and the second device. Moreover, the first device performs a second transmission to the second device based on the indication. In this way, it is allowed to improve communication performance in the A-IoT system.

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 terminal of each output stage circuit is used for outputting a driving signal to a connected driving electrode. The touch driving method includes: determining, according to a code division multiple access (CDM) code matrix, a first group of driving electrodes and a second group of driving electrodes in a current driving period, wherein the first group of driving electrodes are driving electrodes in the plurality of driving electrodes expected to be discharged in the current driving period, and the second group of driving electrodes are driving electrodes in the plurality of driving electrodes expected to be charged in the current driving period; 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 discloses a zero-forcing frequency domain equalization-based molecular code division multiple access system detection method and device. The method comprises the following steps of: constructing a molecular code division multiple access system; each nano emitter performs spectrum spreading on data by using a spectrum spreading sequence, and represents a molecular concentration signal of bit information by releasing A-type and B-type molecules; sampling the received molecular concentration signal at the fusion center, and determining a concentration difference observation value of A type molecules and B type molecules; on the basis of the observation value, organizing data in a block transmission mode and inserting a cyclic prefix to eliminate inter-block interference, and forming a time domain observation vector; converting the time domain signal into a frequency domain signal; suppressing inter-symbol, inter-chip and multi-access interference by applying a zero-forcing frequency domain equalization algorithm; performing inverse fast Fourier transform on the equalized signal, converting the equalized signal back to a time domain, and obtaining a judgment variable through de-spreading operation; and comparing the judgment variable with a zero threshold, if the judgment variable is greater than 0, judging as 1, otherwise, judging as-1, and outputting a decoding bit sequence.