231 results about "Band spectrum" patented technology

There is disclosed an encoding device capable of improving similarity between the high frequency band spectrum of the original signal and a new spectrum to be generated while realizing a low bit rate when encoding a wide-band signal spectrum. The encoding device has sub-band amplitude calculation units (122, 128) for calculating the amplitude of the respective sub-bands for the high frequency band spectrum obtained from the wide-band signal. A search unit (124) and a gain codebook (125) select some sub-bands from a plurality of sub-bands and only the gain of the selected sub-bands is subjected to encoding. An interpolation unit (126) expresses the gain of the sub-band not selected, by mutually interpolating the selected gains.

A dual band spectrum allocation system and method for wireless data communications uses discrete bands for upstream and downstream data communications. A preferred embodiment uses unlicensed UNII bands for license-free data transmissions from a subscriber to a hub, and uses relatively interference free licensed bands for data transmissions from a hub to subscribers, thereby allowing use of greater bandwidth, simplifying system licensing and reducing filtering requirements for subscribers.

The embodiment of the invention discloses band spreading method and apparatus, relating to the field of communications and can obtain wideband signals with better quality aiming at different signals of languages or types of languages. The band spreading method of the embodiment comprises the steps of: obtaining types of the wideband signals; obtaining a low band linear prediction coefficients of low band signals and low band pumping signals according to the type of the wideband signals and the low band signals; spreading the low band linear prediction coefficients according to the relation between the pitch pairs of the low band spectrum frequency parameters to obtain wideband linear predication coefficients, and spreading the low band pumping signals to obtain the wideband pumping signals; and synthesizing the wideband linear prediction coefficients and the wideband pumping signals to obtain the wideband signals. The embodiment of the invention is mainly applied to spreading the band.

The invention discloses a crop pest monitoring method based on a multispectral remote sensing image of deep learning, and belongs to the technical field of satellite remote sensing image processing and application. The objective of the invention is to solve the problems of poor timeliness of crop pest monitoring, unstable single-index spectral information, difficulty in acquiring hyperspectral unmanned aerial vehicle data and the like in the existing method. According to the invention, combination of ten groups of characteristic band spectrums is adopted. An LSTM long short-term memory network is constructed. Crop insect pest disasters can be automatically and efficiently identified from the multispectral satellite remote sensing image, and certain technical support is provided for the fields of agricultural production disaster prediction and prevention, agricultural insurance claim settlement and the like. The method has the advantages that the crop insect pest disasters can be automatically and efficiently identified from the multispectral satellite remote sensing image;

The present invention relates to a BDPD-based method for improving efficiency of RF power amplifier, comprising: first, choose key neural network architecture and scale and input initial values of modeling data and network parameters necessary for establishing the neural network model for RF power amplifier; second, correct network parameters with back propagation method and output the neural network model for RF power amplifier when the error meets the criterion; next, solve the pre-distortion algorithm of the RF power amplifier with said model and then carry out pre-distortion processing for the input with the pre-distortion algorithm and feed the input to the RF power amplifier. The present invention can be used to establish a neural network model with adequate accuracy and easy to solve corresponding pre-distortion algorithm for RF power amplifier, in order to improve RF power amplifier efficiency, reduce costs, and suppress out-of-band spectrum leakage effectively through base-band digital pre-distortion technology.

The invention discloses an optimal training sample selection method for a broad band spectrum imaging system. The method includes the steps that an actual broad band spectrum imaging system is built, and parameters of the spectrum imaging system are calibrated; a spectrum imaging commonly used sample set is prepared, and spectrum reflectivity of the spectrum imaging commonly used sample set is measured; by means of the actual spectrum imaging system, the sample set is shot, and a digital response value of the sample set is corrected according to the calibration information of the system; the sample set is reconstructed through a pseudo-inverse spectrum reconstruction method, and training samples are selected from the sample set to from a training sample set according to the spectrum error minimization principle; when each training sample is selected to add into the training sample set, all samples in the sample set are traversed once until a spectrum reconstruction error of the training sample set to a main sample set begins to converge to a certain minimum value Jmin, the optimal training sample set is locked, and selection of a board band spectrum imaging optimal training sample is achieved. The method has the technical advantages of remarkably reducing spectrum imaging complexity, improving spectrum construction precision and the like.

An apparatus for determining signal strength data within at least one allocated GNSS frequency band is provided. The apparatus includes a GNSS antenna. The GNSS antenna receives signals within the allocated GNSS frequency band. The apparatus further includes receiving circuitry. The receiving circuitry is for demodulating the received signals. The apparatus further includes a processor and memory for storing instructions, executable by the processor. The instructions include instructions for generating signal strength data for the received signals within the GNSS allocated frequency based on the demodulated signals, and for determining a position for a point of interest based upon the demodulated signals. Included in the apparatus is a display screen for displaying a graphical representation of the signal strength data of at least a portion of the at least one GNSS allocated frequency band. The graphical representation identifies interference within at least the portion of the at least one GNSS allocated frequency band.

The invention discloses a method for applying a combined algorithm to a combined learning structure digital predistortion system. Through combination of a classic crest factor restriction (CFR) technology and a digital predistoriton (DPD) technology, a combined learning structure design digital predistoriton system combining an indirect learning structure and a direct learning structure is provided according to advantages and disadvantages of the direction learning structure and the indirect learning structure; then according to advantages of an LMS algorithm, an RLS algorithm and a variable step size LMS, namely, NLMS algorithm, a combined algorithm combining RLS and NLMS is provided for estimating and updating parameters of a digital predistorter. The combined algorithm has the characteristic of rapid convergence of the RLS algorithm and also simplifies computation amount. CFR and DPD are sequentially performed on an input peak average ratio signal, then the processed signal is sent to a power amplifier, so that ideal linear output is obtained, and in-band distortion and out-band spectrum expansion caused by power amplifier non-linear are effectively relieved. Through adoption of the method, performance degradation of a broadband power amplifier caused by memory effect is relieved, furthermore, the linearity and efficiency of the broadband power amplifier are improved.

A kind of fluorescent powder is based on metal sulfoxide, Eu2+ and Cu2+ are co-activators, and other ions are sensitizers. aA, bB, cC, dD, eE. Among them: A is one or two of Y3+, La3+, Ce3+, Pr3+, Nd3+, Sm3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+, Lu3+; B is Bi3+, Sb3+, Mn2+, Pb2+ One or two; C is one or two of F-, Cl-, Br-, I-; D is one or two of Se2-, Te2-. E is one or more of Li+, Na+, K+, Rb+, Cs+, Ag+ and H3BO3. The phosphor has a broadband dual excitation spectrum and a broadband dual emission spectrum, the dual excitation band spectrum is located in the 200-425nm and 425-610nm area, and the dual emission band spectrum is located in the 400-550nm and 600-750nm area. Phosphors can be used in agricultural films, solar photovoltaic cells and LED devices.

An apparatus for determining signal strength data within allocated GNSS frequency band(s) is provided. The apparatus includes a GNSS antenna. The GNSS antenna receives signals within the allocated GNSS frequency band. The apparatus further includes receiving circuitry. The receiving circuitry is for demodulating the received signals. The apparatus further includes a processor and memory for storing instructions, executable by the processor. The instructions include instructions for generating signal strength data for the received signals within the GNSS allocated frequency based on the demodulated signals, and for determining a position for a point of interest based upon the demodulated signals. Included in the apparatus is a display screen for displaying a graphical representation of the signal strength data of at least a portion of the at least one GNSS allocated frequency band. The graphical representation identifies interference within at least the portion of the at least one GNSS allocated frequency band.

The invention discloses a method of near-infrared rapid detection of physicochemical indexes in wine, which is characterized in that representative wine samples are utilized to form a wine sample group; near-infrared band spectrum information of each wine sample in the wine sample group is obtained respectively in a setting modeling condition, and chemical measured values of the physicochemical indexes are obtained by utilizing a standard chemical measuring method; the near-infrared band spectrum information and the chemical measured values of the physicochemical indexes are corresponded one-to-one, and a calibration model of the required physicochemical indexes is built by utilizing a stoichiometry software; the to-be-detected wine samples are subjected to near-infrared spectrum scanning, and the physicochemical indexes of the to-be-detected wine are obtained through a predicted manner by utilizing the calibration model. The method has fast analysis speed, high efficiency, and low cost, has no pollution for environment, can provide reliable reference for analysis and quality-control of wine.

The embodiment of the invention discloses a frequency band expansion method and a frequency band expansion device, relates to the field of communication, realizes signals for different languages or language systems, and can acquire high-quality broadband signals. The method of the embodiment comprises: acquiring the type of a broadband signal; predicting the fine structure and envelope of a high-band spectrum according to the type of the broadband signal and a low band spectrum; weighting the fine structure and envelope of the high-band spectrum to obtain a high-band spectrum; combining a low-band spectrum and the high-band spectrum to into a broadband spectrum; and performing the frequency-time conversion of the broadband spectrum and obtaining a broadband signal.

The invention discloses a method for restraining PAPR of optical OFDM system based on FHT and improved Mu law companding transform to firstly improve the traditional Hadamard transform and Mu law companding transform and then perform the cascade connection. The computation complexity of fast Hadamard transform is much lower than Hadamard transform and the improved Mu law companding transform may undertake joint optimization for peak-to-average ratio performance and error rate performance, control the single BER performance while reducing single PAPR and eliminate the band spectrum regeneration resulting from signal distortion in the course of repetition. After the fast Hadamard transform for single is completed, the PAPR of single reduces a little. While the companding transform is performed for the single, the predistortion of single will not be too serious. Thus, when undertaking the inverse transformation in the receiving end, the single will be recovered better. The PAPR performance after using the provided method is better than the performance after separately adopting one of methods and the comprehensive performance is superior to traditional SLM and PTS.

The invention provides an obliquely-tangential gallium arsenide single crystal photo-thermal detector which is composed of obliquely-tangential gallium arsenide single crystal wafers, a metal copper heat sink and a metal support sequentially, wherein the obliquely-tangential gallium arsenide single crystal wafers are bonded through heat conducting glue. Two symmetrical metal electrodes are arranged on the upper surfaces of the obliquely-tangential gallium arsenide single crystal wafers and serve as voltage signal output ends, and the voltage signal output ends of the obliquely-tangential gallium arsenide single crystal wafers are connected with the input ends of a voltmeter through electrode leads. The obliquely-tangential gallium arsenide single crystal photo-thermal detector has the advantages of being easy to prepare, low in cost, high in response sensitivity and capable of achieving full-wave band spectrum detection and all kinds of thermal radiation detection.

By the present invention, the number of encoding bits allocated to encoding of extended-band spectrum is reduced while degradation of sound quality in the extended band is suppressed. A band compression unit creates combinations of sub-band spectra in pairs of two samples each in order from a low-range side in a band compression target sub-band, selects a spectrum having a large absolute-value amplitude among the combinations, and arranges the selected spectrum close to the low-range side on a frequency axis. A number-of-units recalculation unit redistributes bits saved in the sub-band for which band compression was performed to a low range outside the extended band, and redistributes the number of units on the basis of the redistributed bits.

A method of generating a wideband signal may include estimating a high-band spectrum parameter from a reconstructed narrowband signal based on a combination of at least two mapping schemes; estimating a high-band excitation signal based on the reconstructed narrowband signal; generating a high-band signal based on the estimated high-band spectrum parameter and the estimated high-band excitation signal; and generating a wideband signal by synthesizing the reconstructed narrowband signal with the high-band signal.

The invention relates to a voice signal dereverberation processing method and device based on machine learning, computer equipment and a storage medium. The method comprises the steps: acquiring an original voice signal, and extracting amplitude spectrum characteristics and phase spectrum characteristics of a current frame in the original voice signal; extracting a sub-band amplitude spectrum of the amplitude spectrum characteristics, inputting the sub-band amplitude spectrum into a first reverberation predictor, and outputting a reverberation intensity index corresponding to the current frame; determining a pure voice sub-band spectrum of the current frame by using a second reverberation predictor according to the sub-band amplitude spectrum and the reverberation intensity index; and carrying out signal conversion on the pure voice sub-band spectrum and the phase spectrum characteristics to obtain a pure voice signal after reverberation removal. By adopting the method, the reverberation elimination accuracy of the voice signal can be effectively improved.

The invention provides an on-line measurement method for water content of mechanically-parched Longjing tea leaves, which is implemented based on spectral characteristic parameters. The method comprises the following steps: firstly determining a sampling plan by the uniform design method, obtaining the all-band spectrum of the mechanically-parched Longjing tea leaves by use of a hyperspectral device, and performing spectral pretreatment and analysis; and determining sensitive spectral bands and calculating spectral characteristic parameters according to the relevance analysis on water content of mechanically-parched Longjing tea leaves, and establishing an inverse model based on the small-sample non-statistical theory and ant colony algorithm to predict the water content of the mechanically-parched Longjing tea leaves. The technical scheme provided by the invention can achieve the purpose of on-line real-time detection of the water content of mechanically-parched Longjing tea leaves, and can be used in a full-automatic tea leaf processing equipment system to increase the production efficiency.