6results about How to "Improve demodulation accuracy" patented technology

This invention discloses a multi-channel programmable miniaturized high-speed FBG demodulation system and method based on an AWG (Optical Fiber Optic Generator), belonging to the field of fiber optic sensing technology. The AWG-based multi-channel programmable miniaturized high-speed FBG demodulation system includes a high-stability broadband light source module, a low-loss isolation module, a miniaturized programmable fiber optic amplifier, a circulator, a two-stage miniaturized high-speed optical switch, a high-crosstalk AWG module, a photoelectric conversion module, a programmable A / D conversion module, and a core control module. The AWG-based multi-channel programmable miniaturized high-speed FBG demodulation method involves the optical signal entering an FBG sensor array, the FBG sensor reflecting the optical signal, the reflected optical signal entering the AWG module, and the output light undergoing photoelectric conversion to calculate the center wavelength of the FBG sensor. This invention, based on an AWG, improves demodulation accuracy while ensuring the demodulation range, achieving continuous wavelength demodulation within the AWG wavelength range.

According to the EFPI acoustic sensor demodulation system and method, three lasers provide three beams of lasers with different wavelengths, an optical fiber coupler is connected with the three lasers so as to combine the three beams of lasers with different wavelengths into one beam of light, a scanning laser carries out wavelength scanning, lasers with variable wavelengths are provided for the initial cavity length of an EFPI acoustic sensor, and the optical fiber coupler is connected with the three lasers. The optical switch is connected with the optical fiber coupler and the scanning laser, the wavelength division multiplexer receives reflected light of the EFPI acoustic sensor probe and divides the reflected light into light with three different wavelengths, the three photoelectric detectors are connected with the wavelength division multiplexer and collect light intensity signals of the light with the three different wavelengths, the computer carries out operation processing on the collected light intensity signals, and the EFPI acoustic sensor is obtained. Phase information of the interference light beams is obtained, and the real-time cavity length of the EFPI acoustic sensor is obtained through demodulation.

The application provides a kind of optical fiber pressure sensor demodulation method and device for sensing ship-bridge impact force, and relates to the field of optical fiber sensing technology.The method comprises: constructing an optical fiber pressure sensor demodulation system, an initial multi-modal model based on a double-branch radial basis function neural network, and using a hybrid optimization algorithm including an improved adaptive particle swarm global exploration and an enhanced sparrow search local optimization.In the global stage, a nonlinear adaptive PSO is used to obtain the global optimal solution, and in the local stage, the solution is fine-tuned by SSA and dynamic refocusing is achieved using multi-modal monitoring to obtain the optimal solution of the model.The characteristic vector is input into the model, the analytic signal is obtained by Hilbert transform, the envelope is extracted by extracting the modulus, and the real-time pressure prediction value is output by the weighted fusion layer.The application can significantly improve the convergence speed and accuracy of nonlinear spectral inversion, and meet the demand for real-time and high robustness monitoring of local high pressure in ship-bridge impact scenarios.

This application provides an IQ imbalance calibration method, apparatus, signal transmitter, and zero-IF transceiver. The method includes: acquiring a reference baseband signal and a radio frequency (RF) signal output by the IQ modulation channel based on the reference baseband signal, and converting the RF signal into a modulation baseband signal; reconstructing the modulation baseband signal to generate a baseband feedback signal characterizing the distortion of the IQ modulation channel; obtaining pre-distortion parameters for compensating for IQ imbalance based on the reference baseband signal and the baseband feedback signal; performing pre-distortion processing on the reference baseband signal using the pre-distortion parameters to generate a baseband pre-distortion signal; and performing imbalance calibration on the IQ modulation channel based on the baseband pre-distortion signal. Because the IQ modulation channel is calibrated, the image rejection ratio and error vector amplitude performance of the output signal can be improved, thus increasing the calibration accuracy of the IQ modulation channel.

The invention belongs to the technical field of optical fiber temperature measurement, and particularly relates to an overhead line composite optical fiber temperature measurement method, device and equipment and a medium. The method comprises the following steps: firstly, acquiring Brillouin gain spectrum data along the axial direction of an optical fiber; then, the Brillouin frequency shift is directly calculated by adopting a gravity center method, iterative fitting is not needed, and the processing speed is remarkably improved; further, an error estimation formula is obtained through theoretical derivation, and the measurement error is rapidly evaluated according to the sweep frequency center frequency, the frequency shift value and the line width; and finally, temperature distribution is demodulated based on the linear relationship between the frequency shift and the temperature, and a temperature measurement error is calculated in combination with a frequency shift error. The method solves the problem that the traditional method is difficult to balance among speed, precision and efficiency, realizes rapid and reliable temperature measurement with an evaluable result, and is suitable for occasions needing real-time monitoring, such as overhead lines.

The application discloses a kind of enhanced deep residual neural network receiving methods for non-orthogonal superimposed pilot transmission, belong to wireless communication technical field.For the coupling interference problem caused by pilot and data high overlap in non-orthogonal superimposed pilot system, a receiver architecture based on physical feature reconstruction and residual network optimization is proposed.The method comprises: extracting the amplitude and phase characteristics of the received signal and the pilot by amplitude-phase conversion operator, respectively, and splicing to construct a multi-dimensional input feature map;Nonlinear mapping is carried out using a cascaded 6-layer enhanced residual convolutional network, wherein the frequency coherence between subcarriers is captured by expanding the time-frequency domain receptive field using dilated convolution, and the key features are adaptively weighted using squeezing and excitation modules;Finally, the bit-level log-likelihood ratio estimate is output, and the original bits are recovered by decoding.The application is suitable for high-speed dynamic scenarios, has less parameters and low complexity, can efficiently demodulate under complex interference multi-stream transmission, and meets the demand of 6G high spectral efficiency.