31results about How to "Low signal to noise" patented technology

A relay-based distributed cooperative spectrum sensing method belongs to the field of wireless spectrum allocation and utilization. The existing distributed spectrum sensing method has the problems of low spectrum utilization, and the sudden appearance of authorized users interfering with the transmission of authorized user information and the separation of authorized user information and cognitive user information. A relay-based distributed cooperative spectrum sensing method, including: authorized users obtain and send signals, and the one with higher signal power is recorded as cognitive user U1, and the other is recorded as cognitive user U2; The cognitive user with high received signal power acts as a relay, and uses the Amplify and Forward (AF) protocol to assist another cognitive user in spectrum sensing and signal transmission. In the case of ideal channel estimation and signal separation, the present invention can improve the detection probability of the cognitive user end, and at the same time can improve the spectrum efficiency of the system.

The invention discloses a pre-stack seismic texture analysis method based on a gradient co-occurrence matrix, comprising the following steps: S1, obtaining 4-dimensional data V to be analyzed from pre-stack seismic data D; S2, defining the gradient calculation direction and defining the 4-dimensional sub Data set S∈V; S3, centered on the line (:, i, j, k) composed of T sample points in V, the size is T×N I ×N C ×N o The 4-dimensional sub-dataset S of S, calculates the gradient of each point in S sequentially, and obtains the gradient matrix M; S4, constructs the gradient co-occurrence matrix G based on the gradient matrix, and calculates the texture feature attribute based on the gradient co-occurrence matrix G. The present invention adds gradient information on the basis of the gray level co-occurrence matrix, and extracts some statistics from the gradient co-occurrence matrix to reflect texture features. This texture analysis method reduces noise influence while improving signal resolution.

The invention provides a method for judging the source of a colored soluble organic matter based on a fluorescence-spectrum integral specific value. After a three-dimensional fluorescence spectrum of the colored soluble organic matter in a lake is measured, the source of the colored soluble organic matter is distinguished by utilizing the specific value IC to IT between a peak-C spectrum integral value of humic acid and a peak-T spectrum integral value of similar tryptophan; when the IC to IT is less than 5, the source of the colored soluble organic matter is an endogenous dominant; when the IC to IT is not less than 5 but not more than 20, the source of the colored soluble organic matter is an exogenous dominant; when the IC to IT is more than 20, the source of the colored soluble organic matter is an intensive exogenous effect. By using the method provided by the invention, the addition of a chemical reagent is not needed; the carrying out of fussy complicated calculations of the measurement of a conventional chemical index, the parallel factor analysis of a three-dimensional fluorescent component, and the like, is also not needed; the measurement of the fluorescence intensity, in several common waveband ranges, of the colored soluble organic matter is only needed; thus, the quick evaluation and division of the source of the colored soluble organic matter in an inland water body can be realized; the operability is high; the method is easy to popularize and is compared with peer research results at home and abroad; meanwhile, the fluorescence spectrum is easily modified to form an on-line or in-situ monitoring fluorescent probe; therefore, the method has important and high application value.

The invention discloses an orthogonal reflection index modulation method for an intelligent reflective surface assisted wireless communication system, comprising the following steps: S1, grouping element units of the intelligent reflective surface to perform orthogonal reflection modulation on information; S2, establishing to receive the serial number of the antenna Index modulation for index resources; S3. Determine the optimal reflection phase shift of each group of elements on the smart reflective surface; S4. Select the orthogonal scheme of the two signals after orthogonal reflection index modulation; S5. Demodulate the transmission at the receiving end Information. The operation of grouping the intelligent reflective surface element units proposed by the present invention can additionally transmit a certain bit of information; establish an index modulation with the receiving antenna serial number as the index resource and select the orthogonal scheme of the modulated two-way signal, which can be used at a lower In the case of the signal-to-noise ratio, the bit error rate of the system is reduced, and the spectral efficiency of the communication system is improved.

The invention provides a restoring-type near infrared fluorescence probe with pH response. The chemical structural formula is shown as a formula (I) in the specification, wherein X refers to C(CH3)2, O, S or Se, Y refers to halogen, Z refers to NH, O or S, R1 and R2 are respectively independently selected from H, C1-18 alkyl or SO3R5, R5 refers to C1-18 alkyl or benzyl, and R3 and R4 are respectively independently selected from C1-18 alkyl or benzyl. When the restoring-type near infrared fluorescence probe with pH response is between pH 5.0 and pH 7.5, the fluorescence intensity is gradually enhanced along with reduction of the pH value, and an excellent linear relation is formed between the fluorescence intensity and the pH value. The stocks displacement is large, the signal to noise ratio is low, the toxicity is low, the damage to cells and living bodies is small, the pKa is 6.4, the probe is very suitable for tumor detection, and the defects of fluorescence probes in the prior art are overcome. The invention also provides a method for preparing the probe. The preparation method is simple.

The invention provides a nanochannel with a nanocage structure. The nanochannel comprises a top SiN film layer, a middle SiO2 interlayer and a bottom SiN film layer which form a sandwich structure, wherein a small nanopore with area slightly larger than the maximum sectional area of antigen to be detected and smaller than the minimum sectional area of antibody to be detected is machined on the top SiN film layer, a large nanopore with diameter larger than that of the small nanopore is machined on the bottom SiN film layer and located at a position aligned with the small nanopore in the axial direction, and SiO2 between the small nanopore and the large nanopore is corroded into a hollow nanocage structure; two liquid bath units filled with ionic solution are connected to the two ends of the nanochannel with a nanocage structure, and the antigen and the antibody are added into the same liquid bath next to the small nanohole. When ionic current change is detected under both forward and reverse voltage, it is concluded that specific binding of the antigen and the antibody is not achieved. When ionic current change is detected under forward voltage only, it is concluded that specific binding of the antigen and the antibody is achieved, and then identifying detection of antigen or antibody molecules can be achieved.

The present application relates to a separation method, device, electronic equipment and readable medium of a mixed sound signal. The method includes: extracting mixed sound feature data from the mixed sound signal; inputting the mixed sound feature data into a mixed sound coding model to obtain a first latent variable and a second latent variable, the first latent variable characterizes vocal features, and the second The two hidden variables represent the sound characteristics of the accompaniment; the first hidden variable and the second hidden variable are respectively input into the human voice decoding model and the accompaniment decoding model to obtain the human voice characteristic data and the accompaniment sound characteristic data; and based on the human voice characteristic data and the accompaniment sound Characteristic data get vocals and accompaniment. The signal-to-noise ratio of human voice and accompaniment sound obtained by this method is low.