4 results about "Basis expansion" patented technology

The application discloses a kind of spectral modulation radiation temperature measuring device and method, belongs to optical radiation temperature measuring technical field.For the problems, such as limited spectral channel, difficult to realize single-exposure multi-channel synchronous acquisition, temperature measuring stability and insufficient inversion robustness of existing radiation temperature measuring technology under long-distance, high dynamic and complex background conditions, the present application sets up wide-spectrum modulation optical window at the incident end, and combines wide-spectrum modulation multi-modal spectral chip, to synchronously acquire multi-channel wide-spectrum modulation radiation image under single exposure;Pretreatment is carried out using system on chip, and wide-spectrum modulation response model, emissivity spectral basis expansion model and time domain regularization are fused in temperature inversion calculation platform, to realize stable inversion of real temperature field, emissivity distribution and temperature rising sequence, suitable for non-contact temperature measurement in long-distance high-temperature target and other fields.

The invention provides a mixed data regression model-based pm2.5 influence factor analysis method and system, and the method comprises the steps: building a mixed data regression model of which covariables are component data and numerical data and dependent variables are functional data: the mixed data regression model is a pm2.5 concentration curve of a city, is the functional data, is the proportion of first yield, second yield and third yield of the city, and is called the proportion of third yield for short; the data is component data, logarithm of per capita GDP, average temperature and numerical data, is a to-be-estimated component type coefficient changing along with time, is distributed to a component type covariable at any moment, is a to-be-estimated function type coefficient and is a function type residual error; obtaining robust M-estimation based on equidistant logarithmic ratio transformation, functional basis expansion and an iterative reweighted least square method; and according to the estimated values, analyzing the influence of the three-yield ratio, the per capita GDP and the average temperature of each city on the pm 2.5. The method can be used for analyzing the pm 2.5 influence factors.

The application relates to a Bi-LSTM-SA low-complexity OTFS channel estimation method and system based on a basis expansion model and belongs to the technical field of wireless communication and deep learning. In view of the problems of low channel estimation accuracy and high equalization complexity in a high-speed mobile scene, the application converts time-domain channel estimation into low-dimensional basis coefficient estimation through a basis expansion model, extracts basis coefficient time sequence features by using a self-attention enhanced bidirectional long short-term memory network, and realizes high-precision channel estimation. Meanwhile, a two-stage equalizer is adopted, single-tap equalization is carried out in a time-frequency domain, and residual interference is suppressed through iterative interference cancellation in a delay-Doppler domain. The application effectively balances estimation accuracy and calculation complexity, and improves the anti-Doppler spread capability and spectral utilization efficiency of a system.

A near-optimal Karhunen-Loeve basis expansion modeling (KL-BEM) orthogonal time frequency space (OTFS) receiver with superimposed pilots has been proposed for high-mobility communications with Doppler spread channel. First, an initial KL-BEM channel estimation is conducted by superimposed pilots, followed by the removal of superimposed pilots from the received OTFS signal and equalisation by message passing (MP) algorithm. After that, the detected data symbols are utilized as pseudo pilots along with the superimposed pilots to refine both KL-BEM channel estimation and equalisation in an iterative manner. Simulation results confirm the superior performance of the proposed KL-BEM OTFS receiver over the prior art in terms of the mean-square-error (MSE) of channel estimation and bit error rate (BER). It also has a close BER performance to the BER lower bound obtained by assuming perfect channel estimation. It contributes to high spectral efficiency and fast convergence performance.