CN109581377B - Resolution evaluation method and device for point echo imaging quality and storage medium - Google Patents
Resolution evaluation method and device for point echo imaging quality and storage medium Download PDFInfo
- Publication number
- CN109581377B CN109581377B CN201811629062.3A CN201811629062A CN109581377B CN 109581377 B CN109581377 B CN 109581377B CN 201811629062 A CN201811629062 A CN 201811629062A CN 109581377 B CN109581377 B CN 109581377B
- Authority
- CN
- China
- Prior art keywords
- resolution
- imaging
- distance
- azimuth
- point
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
- G01S13/90—Radar or analogous systems specially adapted for specific applications for mapping or imaging using synthetic aperture techniques, e.g. synthetic aperture radar [SAR] techniques
- G01S13/9004—SAR image acquisition techniques
- G01S13/9011—SAR image acquisition techniques with frequency domain processing of the SAR signals in azimuth
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
- G01S13/90—Radar or analogous systems specially adapted for specific applications for mapping or imaging using synthetic aperture techniques, e.g. synthetic aperture radar [SAR] techniques
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
Landscapes
- Engineering & Computer Science (AREA)
- Remote Sensing (AREA)
- Radar, Positioning & Navigation (AREA)
- Physics & Mathematics (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Signal Processing (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
The invention discloses a resolution evaluation method, a device and a storage medium for point echo imaging quality, which are used for carrying out Fourier transform on a point echo image obtained by an SAR, selecting a coordinate point to be evaluated, marking out an imaging area by taking the coordinate point to be evaluated as a circle center, and carrying out resolution calculation in the azimuth direction and the distance direction according to a place with a peak value reduced by 3dB in the imaging area, thereby providing an evaluation basis for experimenters.
Description
Technical Field
The invention relates to the technical field of Synthetic Aperture Radar (SAR) imaging, in particular to a resolution evaluation method and device for point echo imaging quality and a storage medium.
Background
The most widely applied aspect of Radar imaging technology is Synthetic Aperture Radar (SAR for short). At present, airborne and spaceborne SAR are widely applied, sub-meter resolution can be obtained, and the quality of a scene image can be comparable with that of an optical image with the same purpose. By utilizing the high resolution capability of the SAR and combining other radar technologies, the SAR can also complete the elevation measurement of a scene and display a ground moving target in the scene.
The SAR has high resolution, a radial distance depends on broadband signals, and a frequency band of hundreds of megahertz can reduce a distance resolution unit to a sub-meter level; the direction depends on the motion of the radar platform, a long linear array is equivalently formed in the space, and each echo is stored for synthetic array processing, which is the source of the name of the synthetic aperture radar. The synthetic aperture can be several hundred meters or more, and thus high azimuthal resolution can be achieved.
The CS (cs scaling) algorithm is a nearly perfect frequency domain processing method for SAR imaging, and a phase factor is used to change the spatial shift characteristic of distance migration, so that distance migration correction avoids interpolation operation, not only does not need complex operation, but also well maintains the phase precision of an image, and has a good imaging effect.
Disclosure of Invention
In order to solve the above problems, an object of the present invention is to provide a method, an apparatus, and a storage medium for evaluating the resolution of the dot echo imaging quality, which are suitable for evaluating the resolution of the dot echo imaging.
The technical scheme adopted by the invention for solving the problems is as follows:
a resolution evaluation method for point echo imaging quality comprises the following steps:
performing Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) on the point echo data to obtain an SAR imaging image;
acquiring a coordinate point to be evaluated, wherein the coordinate point to be evaluated is positioned on the SAR imaging image;
acquiring the radius radii of an imaging area of the coordinate point to be evaluated and a signal interpolation multiple insert;
interpolating an insert multiple within the imaging region radius radii;
selecting a peak position and positions of-3 dB at the left side and the right side of the peak value in the radius radii of the imaging area after interpolation, and obtaining the resolution of the azimuth direction and the distance direction as follows:
wherein resaDenotes azimuth resolution, prf denotes repetition frequency, range _ far denotes the position of 3dB drop to the right of the peak, range _ near denotes the position of 3dB drop to the left of the peak, resrRepresenting the range resolution, fsDenotes the sampling frequency, siti denotes the squint angle, v denotes the velocity.
Further, the generation of the SAR imaging image comprises the steps of:
carrying out azimuth FFT processing on the point echo data to obtain a Doppler frequency spectrum of the echo data;
multiplying the frequency spectrum processed by the azimuth FFT by a Chirp Scaling factor;
performing distance-direction FFT processing on the frequency spectrum multiplied by the Chirp Scaling factor;
multiplying the distance to the FFT-processed spectrum by a distance factor;
performing distance-oriented IFFT processing on the frequency spectrum multiplied by the distance factor;
multiplying the spectrum processed by the distance to IFFT by a azimuth factor;
the frequency spectrum multiplied by the azimuth factor is subjected to azimuth IFFT processing.
Further, before multiplying the Doppler frequency spectrum by a Chirp Scaling factor, the center of the Doppler frequency spectrum is moved to the position of the origin of coordinates of the calculation window through coordinate transformation.
Further, the interpolation of insert multiples within the imaging region radius radii comprises the steps of:
intercepting an imaging area, wherein the imaging area takes the coordinate point to be evaluated as a circle center, and radii as a radius;
performing fast Fourier transform on the imaging region to a frequency domain;
carrying out frequency domain zero padding;
and performing inverse fast Fourier transform on the frequency domain subjected to zero padding.
A resolution assessment device for point echo imaging quality comprising at least one control processor and a memory for communicative connection with the at least one control processor; the memory stores instructions executable by the at least one control processor to enable the at least one control processor to perform a method of resolution assessment of spot echo imaging quality as described in any one of the above.
A computer-readable storage medium characterized by: the computer-readable storage medium stores computer-executable instructions for causing a computer to perform a method of resolution assessment of point echo imaging quality as described in any one of the above.
The invention has the beneficial effects that: after Fourier transformation is carried out on a point echo image obtained by the SAR, a coordinate point to be evaluated is selected, an imaging area is marked by taking the coordinate point to be evaluated as a circle center, and the resolution of the azimuth direction and the distance direction is calculated according to the position where the peak value in the imaging area is reduced by 3dB, so that an evaluation basis is provided for experimenters.
Drawings
The invention is further illustrated by the following figures and examples.
FIG. 1 is an overall flow diagram of an embodiment of the present invention;
FIG. 2 is a schematic flow chart of interpolation according to an embodiment of the present invention;
FIG. 3 is a flow chart illustrating resolution evaluation according to an embodiment of the present invention.
Detailed Description
Referring to fig. 1-3, one embodiment of the present invention provides a resolution evaluation method of point echo imaging quality, comprising the steps of:
performing Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) on the point echo data to obtain an SAR imaging image;
acquiring a coordinate point to be evaluated, wherein the coordinate point to be evaluated is positioned on the SAR imaging image;
acquiring the radius radii of an imaging area of the coordinate point to be evaluated and a signal interpolation multiple insert;
interpolating an insert multiple within the imaging region radius radii;
selecting a peak position and positions of-3 dB at the left side and the right side of the peak value in the radius radii of the imaging area after interpolation, and obtaining the resolution of the azimuth direction and the distance direction as follows:
wherein resaDenotes azimuth resolution, prf denotes repetition frequency, range _ far denotes the position of 3dB drop to the right of the peak, range _ near denotes the position of 3dB drop to the left of the peak, resrRepresenting the range resolution, fsDenotes the sampling frequency, siti denotes the squint angle, v denotes the velocity.
The embodiment provides a formula for calculating the resolution of a point echo image after interpolation, is suitable for calculating two sides of a peak value reduced by 3dB, has the characteristics of being capable of well matching the valley-peak distribution of SAR point echo imaging, and has more specificity compared with a general analysis method of general mathematical tool software.
Preferably, an embodiment of the present invention provides a resolution evaluation method for a point echo imaging quality, and the generation of the SAR imaging image includes the following steps:
carrying out azimuth FFT processing on the point echo data to obtain a Doppler frequency spectrum of the echo data;
multiplying the frequency spectrum processed by the azimuth FFT by a Chirp Scaling factor;
performing distance-direction FFT processing on the frequency spectrum multiplied by the Chirp Scaling factor;
multiplying the distance to the FFT-processed spectrum by a distance factor;
performing distance-oriented IFFT processing on the frequency spectrum multiplied by the distance factor;
multiplying the spectrum processed by the distance to IFFT by a azimuth factor;
the frequency spectrum multiplied by the azimuth factor is subjected to azimuth IFFT processing.
The embodiment provides a method for processing SAR point echo imaging images based on a CS algorithm, the SAR point echo imaging images are obtained by forward FFT, multiplication with a Chirp Scaling factor and a distance factor, and then reverse IFFT, multiplication with the distance factor and a direction factor. The purpose of multiplying by the distance factor is to perform distance compression and distance migration correction, and the purpose of multiplying by the orientation factor is to perform orientation compression and remaining distance migration correction.
Preferably, an embodiment of the present invention provides a resolution evaluation method for point echo imaging quality, before multiplying the doppler spectrum by a Chirp Scaling factor, the center of the doppler spectrum is moved to the position of the origin of coordinates of the calculation window through coordinate transformation. The movement through the center in this embodiment facilitates mathematical calculations.
Preferably, an embodiment of the present invention provides a resolution evaluation method for point echo imaging quality, wherein the interpolation of insert times within the radius radii of the imaging region comprises the following steps:
intercepting an imaging area, wherein the imaging area takes the coordinate point to be evaluated as a circle center, and radii as a radius;
performing fast Fourier transform on the imaging region to a frequency domain;
carrying out frequency domain zero padding;
and performing inverse fast Fourier transform on the frequency domain subjected to zero padding.
The embodiment provides an interpolation method, wherein the frequency domain zero padding method has various methods, different zero padding modes can be selected according to the characteristics of the SAR imaging image, and the signal interpolation is completed by performing frequency domain zero padding and then performing IFFT (inverse fast Fourier transform), which are not detailed herein.
A resolution assessment device for point echo imaging quality comprising at least one control processor and a memory for communicative connection with the at least one control processor; the memory stores instructions executable by the at least one control processor to enable the at least one control processor to perform a method of resolution assessment of spot echo imaging quality as described in any one of the above.
A computer-readable storage medium characterized by: the computer-readable storage medium stores computer-executable instructions for causing a computer to perform a method of resolution assessment of point echo imaging quality as described in any one of the above.
Referring to fig. 1-3, one embodiment of the present invention provides a resolution evaluation method of point echo imaging quality, comprising the steps of:
carrying out azimuth FFT processing on the point echo data to obtain a Doppler frequency spectrum of the echo data;
moving the center of the Doppler frequency spectrum to the position of the origin of coordinates of a calculation window through coordinate transformation;
multiplying the transformed frequency spectrum by a Chirp Scaling factor which is
Wherein phi1(τ，fη；rref) Is a frequency modulation scaling function, rrefDenotes the reference slope distance, fηIndicating the azimuth frequency, KsDenotes the modulation frequency,. tau.denotes the pulse width, CsRepresenting a Chirp Scaling factor;
performing distance-direction FFT processing on the frequency spectrum multiplied by the Chirp Scaling factor;
multiplying the distance-wise FFT-processed spectrum by a distance factor of
Wherein phi2(fτ；fη；rref) Representing a distance-wise processing function, fτRepresents a range frequency;
performing distance-oriented IFFT processing on the frequency spectrum multiplied by the distance factor;
multiplying the frequency spectrum processed by the distance to IFFT by an orientation factor of
Wherein phi3(τ；fη(ii) a r) represents an azimuth processing function, λ represents a wavelength, and v represents a velocity;
performing azimuth IFFT processing on the frequency spectrum multiplied by the azimuth factor;
by this time, the imaging operation is finished, and an interested coordinate point is selected from the image result, so that the imaging quality evaluation can be performed, in this embodiment, the resolution evaluation method is as follows:
acquiring a coordinate point to be evaluated, wherein the coordinate point to be evaluated is positioned on the SAR imaging image;
acquiring the radius radii of an imaging area of the coordinate point to be evaluated and a signal interpolation multiple insert;
interpolating an insert multiple within the imaging region radius radii;
selecting a peak position and positions of-3 dB at the left side and the right side of the peak value in the radius radii of the imaging area after interpolation, and obtaining the resolution of the azimuth direction and the distance direction as follows:
wherein resaDenotes azimuth resolution, prf denotes repetition frequency, range _ far denotes the position of 3dB drop to the right of the peak, range _ near denotes the position of 3dB drop to the left of the peak, resrRepresenting the range resolution, fsIndicating the frequency used and siti the squint angle.
After Fourier transformation is carried out on a point echo image obtained by the SAR, a coordinate point to be evaluated is selected, an imaging area is marked by taking the coordinate point to be evaluated as a circle center, and the resolution of the azimuth direction and the distance direction is calculated according to the position where the peak value in the imaging area is reduced by 3dB, so that an evaluation basis is provided for experimenters.
The above description is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiment, and the present invention shall fall within the protection scope of the present invention as long as the technical effects of the present invention are achieved by the same means.
Claims (5)
1. A resolution evaluation method of point echo imaging quality is characterized in that: the method comprises the following steps:
performing Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) on the point echo data to obtain an SAR imaging image;
acquiring a coordinate point to be evaluated, wherein the coordinate point to be evaluated is positioned on the SAR imaging image;
acquiring the radius radii of an imaging area of the coordinate point to be evaluated and a signal interpolation multiple insert;
interpolating an insert multiple within the imaging region radius radii;
selecting a peak position and positions of-3 dB at the left side and the right side of the peak value in the radius radii of the imaging area after interpolation, and obtaining the resolution of the azimuth direction and the distance direction as follows:
wherein resaDenotes azimuth resolution, prf denotes repetition frequency, range _ far denotes the position of 3dB drop to the right of the peak, range _ near denotes the position of 3dB drop to the left of the peak, resrRepresenting the range resolution, fsRepresenting the adopted frequency, siti represents the squint angle, and v represents the velocity;
wherein, the generation of SAR imaging image includes the following steps:
carrying out azimuth FFT processing on the point echo data to obtain a Doppler frequency spectrum of the echo data;
multiplying the frequency spectrum processed by the azimuth FFT by a Chirp Scaling factor;
performing distance-direction FFT processing on the frequency spectrum multiplied by the Chirp Scaling factor;
multiplying the distance to the FFT-processed spectrum by a distance factor;
performing distance-oriented IFFT processing on the frequency spectrum multiplied by the distance factor;
multiplying the spectrum processed by the distance to IFFT by a azimuth factor;
the frequency spectrum multiplied by the azimuth factor is subjected to azimuth IFFT processing.
2. The method for evaluating the resolution of the quality of point echo imaging according to claim 1, wherein: before the Doppler frequency spectrum is multiplied by a Chirp Scaling factor, the center of the Doppler frequency spectrum is moved to the position of the origin of coordinates of a calculation window through coordinate transformation.
3. The method for evaluating the resolution of the quality of point echo imaging according to claim 1, wherein: the interpolation of insert multiples within the imaging region radius radii comprises the following steps:
intercepting an imaging area, wherein the imaging area takes the coordinate point to be evaluated as a circle center, and radii as a radius;
performing fast Fourier transform on the imaging region to a frequency domain;
carrying out frequency domain zero padding;
and performing inverse fast Fourier transform on the frequency domain subjected to zero padding.
4. A resolution evaluation apparatus of a point echo imaging quality, characterized by: comprises at least one control processor and a memory for communicative connection with the at least one control processor; the memory stores instructions executable by the at least one control processor to enable the at least one control processor to perform a method of resolution assessment of spot echo imaging quality as claimed in any one of claims 1 to 3.
5. A computer-readable storage medium characterized by: the computer-readable storage medium stores computer-executable instructions for causing a computer to perform a method for resolution assessment of point echo imaging quality as claimed in any one of claims 1 to 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811629062.3A CN109581377B (en) | 2018-12-28 | 2018-12-28 | Resolution evaluation method and device for point echo imaging quality and storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811629062.3A CN109581377B (en) | 2018-12-28 | 2018-12-28 | Resolution evaluation method and device for point echo imaging quality and storage medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109581377A CN109581377A (en) | 2019-04-05 |
| CN109581377B true CN109581377B (en) | 2021-02-26 |
Family
ID=65932254
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811629062.3A Active CN109581377B (en) | 2018-12-28 | 2018-12-28 | Resolution evaluation method and device for point echo imaging quality and storage medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109581377B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105759263A (en) * | 2016-02-29 | 2016-07-13 | 西安电子科技大学 | High resolution satellite-borne squint SAR imaging method in large-scale scene |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100507601C (en) * | 2007-01-08 | 2009-07-01 | 清华大学 | Double-threshold constant false alurm motion target detecting method of double base synthetic aperture radar |
| CN102955150B (en) * | 2011-08-25 | 2014-07-23 | 中国科学院电子学研究所 | SAR (synthetic aperture radar) direction ambiguity suppression method based on antenna main lobe dominance intensity constraint |
| CN102608602B (en) * | 2012-03-13 | 2013-08-14 | 北京航空航天大学 | Ultralow sidelobe synthetic aperture radar imaging method based on complete complementary sequence |
| US10551491B2 (en) * | 2017-03-10 | 2020-02-04 | Planet Labs Inc. | Systems and methods for performing synthetic aperture radar imaging using superchirps |
| JP6945309B2 (en) * | 2017-03-22 | 2021-10-06 | 古野電気株式会社 | Signal processing device and signal processing method |
| CN108776342B (en) * | 2018-07-13 | 2022-03-15 | 电子科技大学 | High-speed platform SAR slow moving target detection and speed estimation method |
-
2018
- 2018-12-28 CN CN201811629062.3A patent/CN109581377B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105759263A (en) * | 2016-02-29 | 2016-07-13 | 西安电子科技大学 | High resolution satellite-borne squint SAR imaging method in large-scale scene |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109581377A (en) | 2019-04-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107229048B (en) | High-resolution wide-range SAR moving target speed estimation and imaging method | |
| CN111142105B (en) | ISAR imaging method for complex moving target | |
| CN104007440B (en) | One accelerated decomposition rear orientation projection spot beam SAR formation method | |
| CN104898119B (en) | A kind of moving target parameter estimation method based on correlation function | |
| Torgrimsson et al. | Factorized geometrical autofocus for synthetic aperture radar processing | |
| CN104749570B (en) | It is a kind of to move constant airborne biradical synthetic aperture radar target localization method | |
| CN108490443B (en) | Multi-subarray synthetic aperture sonar omega-k imaging algorithm based on analytic solution and NUFFT | |
| CN111352107B (en) | Single pulse tracking and imaging method based on multi-channel digital sum and difference | |
| CN114545411B (en) | Polar coordinate format multimode high-resolution SAR imaging method based on engineering realization | |
| JP6261839B1 (en) | Synthetic aperture radar signal processor | |
| RU2661941C1 (en) | Method for radar imaging using the radar station with the synthesized aperture | |
| WO2017195297A1 (en) | Radar processing apparatus | |
| CN110879391B (en) | Radar image data set manufacturing method based on electromagnetic simulation and missile-borne echo simulation | |
| Vehmas et al. | Data-driven motion compensation techniques for noncooperative ISAR imaging | |
| CN109799502B (en) | Two-dimensional self-focusing method suitable for filtering back projection algorithm | |
| CN112415512B (en) | SAR moving target focusing method based on advance and retreat method and golden section method | |
| CN112859018B (en) | Video SAR imaging method based on image geometric correction | |
| Ryu et al. | Frame selection method for isar imaging of 3-d rotating target based on time–frequency analysis and radon transform | |
| CN108445458A (en) | A kind of synthetic aperture radar orbit error removing method and device | |
| CN109581377B (en) | Resolution evaluation method and device for point echo imaging quality and storage medium | |
| CN116819466A (en) | Double-base ISAR azimuth calibration and geometric correction method based on minimum entropy of image | |
| CN111880179A (en) | Imaging method of missile-borne arc diving high squint TOPS SAR | |
| CN102495408B (en) | Method for automatically searching point of synthetic aperture radar dot-matrix target image data | |
| CN109541598B (en) | Side lobe ratio evaluation method and device for SAR imaging quality and storage medium | |
| CN107450058B (en) | Radar signal time-frequency parameter estimation method based on FrFT and HT |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP03 | Change of name, title or address | ||
| CP03 | Change of name, title or address |
Address after: 211135 floor 1-3, auxiliary building, building 6, artificial intelligence Industrial Park, Nanjing City, Jiangsu Province Patentee after: Zhongke Nanjing mobile communication and computing Innovation Research Institute Address before: 211135 3rd floor, building 6, no.266 Chuangyan Road, Qilin high tech Zone, Nanjing City, Jiangsu Province Patentee before: INSTITUTE OF COMPUTING TECHNOLOGY, CHINESE ACADEMY OF SCIENCES, NANJING INSTITUTE OF MOBILE COMMUNICATIONS AND COMPUTING INNOVATION |