11 results about "Spreading factor" patented technology

This invention discloses a LoRa chip adaptive spreading factor selection terminal device and method. The terminal device includes a main control microprocessor, an RF transceiver, and a mechanical state sensor connected to the main control microprocessor. The main control microprocessor extracts the first-order differential values ​​of RF parameters and simultaneously acquires vibration acceleration magnitude values, mapping them to a two-dimensional discrete state set. An environment mask is generated based on the comparison between the instantaneous rate of change of the vibration acceleration magnitude and a set threshold. In response to the environment mask being in a first logic state, the spreading factor is updated and issued according to an action value lookup table. In response to the environment mask being in a second logic state, the update operation is blocked, and a spreading factor locking command is issued. This application can achieve cross-domain feedforward intervention by fusing physical states, blocking the invalid spreading factor rise caused by instantaneous broadband noise, and reducing node ineffective power consumption.

This invention belongs to the field of non-cooperative signal processing technology, specifically relating to a method for estimating LoRa communication signal parameters based on fractional Fourier transform. The invention constructs a fractional Fourier transform model of the LoRa signal and determines the search range and accuracy of the fractional order. It then performs a fractional Fourier transform on the LoRa signal and obtains the matching order of the LoRa signal's fractional Fourier transform by searching for the peak values. Subsequently, under the matching order, the fractional-domain frequencies of the two peak values ​​of the LoRa fractional Fourier transform are searched. Finally, the bandwidth and spreading factor parameters of the LoRa signal are calculated based on the relationship between bandwidth, spreading factor, matching order, and peak frequencies. The performance of this method under different signal-to-noise ratio conditions is evaluated using Monte Carlo simulation. This method can achieve relatively good parameter estimation of LoRa signal bandwidth and spreading factor.

A system and a method thereof for performing modulation and demodulation based on a chirp spread band technique are disclosed. A system for performing modulation and demodulation based on a chirp spread band technique according to one embodiment of the present disclosure includes: a transmitter that transmits a chirp signal; and a receiver that receives and demodulates the chirp signal. The transmitter determines the number of data bits (M) modulated in a unit symbol based on a first residual carrier frequency offset and a spreading factor (SF), and transmits a first chirp signal obtained by modulating the first data bits in at least one symbol according to the determined number of data bits modulated in the unit symbol to the receiver. The receiver may transmit information indicating a second residual carrier frequency offset detected based on the received first chirp signal to the transmitter.

The present invention discloses a multi-user spatial IoT transmission method based on LFM, configuring corresponding slopes for LFM-modulated time-frequency waveforms for different users in order to determine the modulated signal of any user, wherein the slope configured for said user satisfies a fractional multiplicative slope without changing the frequency spreading factor; determining, on the basis of the phase-frequency relationship, a time-domain signal for the LFM-modulated signal of any user, in order to perform a transmission on the basis of the determined time-domain signal; determining a time-domain signal of the unmodulated and down-chirped LFM signal corresponding to any user;the processing of the time-domain signal from any of said users based on the time-domain signal of said unmodulated and down-chirped LFM signal; the signal obtained after signal processing is subjected to a discrete Fourier transform, which is used to demodulate the signal received from any of the users. To reduce the transmission power demand, obtain low energy consumption, propose a simultaneous multi-user scheme and achieve simultaneous multi-user access and transmission with the same time-frequency resources. [Fig.1];

This invention discloses a low-power, high-throughput 5G LDPC decoder implementation method, specifically comprising: Step 1, calculating the parameters required for decoding from the input parameters; Step 2, based on the spreading factor Z... c The values ​​are stored in different blocks according to different storage methods; Step 3: Based on the expansion factor Z c The value of determines whether to perform layer splitting transformation on the base matrix and update the required posterior probability information of the variable nodes; Step 4: Update the information of the check nodes and the posterior probability information of the variable nodes within the layer; Step 5: Implement layered iterative decoding; Step 6: After updating the information of all check nodes in each layer and reaching the set number of iterations, the decoding iteration is completed, and the output processing of the decoding result begins. This method significantly reduces the required resources; and by utilizing the orthogonality of adjacent layers of the split matrix, the intra-layer pipelining operation improves the decoder throughput after reducing the decoding parallelism. A low-consumption, high-throughput 5G LDPC decoder implementation device is also disclosed.

The terminal includes: a control unit that applies a spectral spread factor and further applies a constellation rotation associated with the spectral spread factor to generate a signal; and a transmission unit that transmits the signal to a base station.

Disclosed are a long-range radio communication method and device based on a spreading factor index, the method including: within one symbol period, dividing a plurality of information bits into index bits and modulated bits; mapping the index bits into a spreading factor sequence, and generating first chirp signals corresponding to various spreading factors (SFs); and converting the modulated bits to decimal numbers associated with the various SFs, modulating the decimal numbers into carrying signals, multiplying the carrying signals by the first chirp signals associated with the SFs to obtain second chirp signals associated with the various SFs, and superposing the second chirp signals to obtain a transmitted signal. According to the disclosure, by combining different SFs, an additional dimension is created to carry more information bits, so as to achieve the effect of increasing a data rate.

This invention discloses a method and system for optimizing the energy efficiency of LoRa networks considering coding rate, belonging to the field of network optimization technology. The method mainly includes: constructing a LoRa performance model considering coding rate based on LoRa network parameters and the non-slotted ALOHA protocol; performing energy-aware sorting configuration initialization to obtain a priority list; performing asymptotic probability constraint allocation to obtain an initial spread factor and coding rate combination for each node; and performing neighborhood refinement search to obtain a refined spread factor and coding rate combination. Implementing the LoRa network energy efficiency optimization method and system considering coding rate provided by this invention can enhance the scalability of LoRa networks and further improve energy efficiency.

The invention discloses an unmanned aerial vehicle self-adaptive anti-interference device and method based on deep reinforcement learning, and belongs to the technical field of unmanned aerial vehicle wireless communication anti-interference, and the device comprises a node transmitter and a node receiver which form a closed loop through a special feedback channel. A node transmitter acquires spectrum information through a spectrum sensor, and constructs an enhanced state vector by fusing the spectrum information with link quality feedback from a receiver; the intelligent decision-making module outputs an action index based on a deep reinforcement learning model; and the parameter mapping and execution control module analyzes the signal into a spreading factor and a frequency hopping pattern parameter, and drives the code modulation, direct expansion and frequency hopping module to carry out adaptive signal processing. According to the method, autonomous joint optimization and real-time switching of anti-interference parameters in a dynamic interference environment are realized, and the reliability, the anti-interference capability and the response speed of unmanned aerial vehicle communication are remarkably improved.

A system comprises: a power electronics converter with controllable electronic switches; and a control device configured to: determine a range of carrier frequencies based on a principal carrier frequency and a spreading factor, wherein the spreading factor is a non-one value; generate a control signal with a variable switching frequency, wherein the variable switching frequency has a first switching frequency value within a range of carrier frequencies and, after a predetermined number of cycles with the first switching frequency value, has a second switching frequency value within the range of carrier frequencies; and supply the control signal to the power electronics converter such that the controllable electronic switches change their state at the variable switching frequency.

The application relates to a LoRa relay adaptive transmission device and method based on multi-dimensional channel sensing, wherein the device comprises a physical layer sensing module, which is used for detecting channel information to obtain a channel detection result; a calculation decision module, which is used for adaptively calculating a terminal spreading factor and a data buffer queue length threshold value according to the channel detection result; a data convergence and forwarding module, which is used for uploading relevant data according to a data fluctuation rate in a data buffer queue module; a bidirectional transmission module, which is used for receiving data collected by a terminal and uploading the data to a gateway, and issuing an instruction containing the spreading factor confirmation information to the terminal; and a data buffer queue module, which is used for storing the data collected by the terminal. The application solves the communication reliability and efficiency problem in a high-density pension scene.