CN109450520A - Satellite communication method and corresponding satellite communication terminal - Google Patents
Satellite communication method and corresponding satellite communication terminal Download PDFInfo
- Publication number
- CN109450520A CN109450520A CN201811471966.8A CN201811471966A CN109450520A CN 109450520 A CN109450520 A CN 109450520A CN 201811471966 A CN201811471966 A CN 201811471966A CN 109450520 A CN109450520 A CN 109450520A
- Authority
- CN
- China
- Prior art keywords
- signal
- satellite
- satellite communication
- communication terminal
- software
- 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.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/1851—Systems using a satellite or space-based relay
- H04B7/18517—Transmission equipment in earth stations
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/005—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/1851—Systems using a satellite or space-based relay
- H04B7/18519—Operations control, administration or maintenance
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L7/00—Arrangements for synchronising receiver with transmitter
- H04L7/0016—Arrangements for synchronising receiver with transmitter correction of synchronization errors
- H04L7/0033—Correction by delay
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Astronomy & Astrophysics (AREA)
- Aviation & Aerospace Engineering (AREA)
- General Physics & Mathematics (AREA)
- Mobile Radio Communication Systems (AREA)
- Radio Relay Systems (AREA)
Abstract
The invention discloses satellite communication method and corresponding satellite communication terminals.The satellite communication terminal includes Hardware Subdivision and software portion, the Hardware Subdivision includes multiple satellite antennas and software radio, and the software portion includes base band signal process program, wherein the base band signal process program includes multiple modules for being handled baseband signal.According to the technique and scheme of the present invention, hardware module generalization may be implemented, software and hardware can configure and can reduce, be compatible with the Utility Satellite transmitting-receiving process terminal of Different Modulations.
Description
Technical field
This invention relates generally to satellite communication fields.More particularly it relates to be based on software radio (" SDR ")
The ICBM SHF satellite terminal of platform designs.
Background technique
For a long time, the reasons such as difference of many and diverse and working frequency of satellite system cause to be difficult to realize interconnect.With
Extensive use of the radio communication service in civil fields such as personal mobile communications, weather monitorings, wireless communication technique it is quick
Develop and the lasting change of bring communication equipment, causes the serious wasting of resources.The design of ICBM SHF satellite terminal is all towards list
One satellite, function and purposes, different satellite communication systems use different hardware platform and architecture.It is duplicate hard in this way
Part design results in that the ICBM SHF satellite terminal development cycle is long and cost is big, program inheritance is difficult, so that present high bandwidth is not adapted to, it is more
The fast-developing of the satellite communication of function requires.
Summary of the invention
Based on various deficiencies of above-mentioned existing satellite communication terminal, the present invention proposes that one kind is adapted to multiband, more
Modulation demodulation system, the satellite communication terminal that development cost is small, the development cycle is short and hardware is reconfigurable.For this purpose, this hair
It is bright to use software radio (" Software Defined Radio ", SDR) design philosophy, it is based on software communications architecture
(" SCA "), devises satellite communication terminal.
According to an aspect of the present invention, a kind of satellite communication terminal based on software radio, including Hardware Subdivision are provided
With software portion, the Hardware Subdivision includes: multiple satellite antennas, is configured to support multiple frequency ranges and multiple modes, and be used for
Send and receive satellite-signal；Software radio comprising Radio Frequency Subsystem, analog/digital and D A switch module, processing
Module, the software radio are configured to Analog Baseband intermediate-freuqncy signal being modulated to radiofrequency signal in order to export, or
The radiofrequency signal received is down-converted to digital baseband signal, so as to subsequent processing；The software portion includes at baseband signal
Program is managed, wherein the base band signal process program includes multiple modules for being handled baseband signal.
In one embodiment, base band signal process program includes satellite signal acquisition module, synchronization module, upper down-sampling
Module, modulation /demodulation module and coding/decoding module.
In one embodiment, wherein the satellite signal acquisition module is configured to for multi-satellite code phase and carrier wave
Frequency is scanned for and is captured, to reach satellite-signal fast search and capturing function, wherein the synchronization module is configured to root
According to signal offset estimation and skew estimation compensate, and the delay of signal is determined, to reach the synchronous function of signal.
In one embodiment, wherein the sampling module up and down is configured to through interpolation and pumping value operation, to reach pair
Satellite-signal increases or decreases the function of sample rate.
In one embodiment, wherein the modulation /demodulation module is configured to support a variety of based on software and radio technique
Modulation and demodulation mode, so that the satellite communication terminal has versatility.
In one embodiment, wherein the coding/decoding module is configured to for different satellite communication systems using different
Encoding and decoding technique, and its parameter is adjustable at any time under interface environments, to realize the versatility of codec code.
In one embodiment, wherein the software portion further includes hardware device driver comprising upper layer application journey
Sequence is simultaneously configured to driving Hardware Subdivision.
In one embodiment, wherein the hardware device driver includes modifiable hardware parameter and associated
Application Programming Interface, to increase the inheritance of driver.
In one embodiment, wherein the satellite communication terminal includes computer, the computer is by means of software wireless
Drawing or parameter calculation procedure is added, so as to the waveform correlation and parameter of real-time display satellite communications data in the software of electricity.
According to another aspect of the present invention, a kind of method of satellite communication based on software radio is provided, comprising: make
Satellite-signal is sent and received with multiple satellite antennas；Analog Baseband intermediate-freuqncy signal is modulated using software radio
To radiofrequency signal in order to export, or the radiofrequency signal received is down-converted to digital baseband signal, so as to subsequent processing；
Baseband signal is handled using base band signal process program；And driven using hardware device driver antenna and
Software radio.
According to the technique and scheme of the present invention, hardware module generalization may be implemented, software and hardware can configure and can cut out
Subtract, be compatible with the Utility Satellite transmitting-receiving process terminal of Different Modulations.
Specifically, using technical solution of the present invention, the satellite communication terminal based on SDR platform can be obtained, is met more
The communication requirement of the satellite communication system of frequency range.Specifically, satellite communication terminal of the invention is divided into Hardware Subdivision and software portion two
A part, Hardware Subdivision is based on SDR platform, can be reconfigured, so that the versatility of terminal hardware is increased, and software portion realizes
The a variety of demodulation modulation systems and code encoding/decoding mode of satellite-signal reduce development cycle and the exploitation of subsequent satellites communication terminal
Cost.
Detailed description of the invention
Fig. 1 is the structure chart for showing the satellite communication terminal totality based on SDR platform of embodiment according to the present invention；With
And
Fig. 2 is the module map for showing the base band signal process program of embodiment according to the present invention.
Specific embodiment
The embodiment of the present invention is specifically described below in conjunction with attached drawing.
Fig. 1 is the structure chart for showing the satellite communication terminal totality based on SDR platform of embodiment according to the present invention.
As shown in fig. 1, satellite communication terminal of the invention is mainly by antenna 101, SDR platform 102 and PC machine 106
Program three parts composition.Wherein, the main parameter request of antenna 101 is multiband, multi-mode, the satellite communication day of adjustable gain
Line is attached with the hardware device of SDR platform 102 by SMA interface.The hardware device of SDR platform includes radio-frequency module
103, bandwidth and frequency will match with antenna, the analog/digital (" A/D ") and D/A (" D/A ") module 104 of high speed, high performance
Field programmable gate array (" FPGA ") module 105 (such as xilinx kintex-7 Series FPGA), processing speed is sufficiently fast simultaneously
And including multiple logic units.SDR platform 102 can be connect by network interface with PC machine 106.In one embodiment, network interface can
To be gigabit grade or 10,000,000,000 grades of network interfaces.
The hardware device of SDR platform of the invention is mainly the thought for considering software radio.Software radio
(" Software Defined Radio ") uses Digital Signal Processing, in the FPGA common hardware based on PLC technology
On chip and radio-frequency module 103, A/D and D/A module 104 and high-speed communication network interface module form one can complete signal from
Hardware platform of the analog intermediate frequency to digital baseband signal.The functions for realizing communication, including signal are defined using software
Capture receive, modulation /demodulation, coding and decoding etc..That is, entire satellite communication process can be with the part of software realization all by soft
Part programs to complete.SDR platform is the hardcore support of entire satellite communication terminal of the invention, utilizes the programmability of FPGA
Flexibility with software design increases the versatility of terminal hardware, to reduce development cost and the period of terminal hardware.
In one embodiment, the program of computer PC106 includes SDR hardware drive program 107 and application software or journey
108 two parts of sequence.SDR hardware drive program 107 mainly completes driving hardware device and reserves Application Programming Interface
(" API ") gives application call, so SDR driver can mainly include driver (it is related to hardware equipment information)
109 and interface routine (its be related to using calling interface) 110 two parts.In one embodiment, application software or program 106
Dividing may include networking synchronization program 111, signal handler 112 and the figure ginseng of the program for base band signal process
Digital display shows program 113, is used to carry out real-time display.
According to Fig. 1, it will be appreciated by those skilled in the art that the software portion of satellite communication terminal of the invention can be with
It mainly include (application program) signal handler and hardware device driver.
In one embodiment, as shown in Fig. 2, signal handler 112 includes signal capture module 201, synchronization module
202, upper down sample module 203, modulation /demodulation module 204 and coding/decoding module 205.
In one embodiment, signal capture module 201 is configured to carry out for multi-satellite code phase and carrier frequency
Search and capture obtain the obvious relevant peaks of signal in order to subsequent judgement, and receiving end uses square root raised cosine matched filter
To realize signal capture.
In one embodiment, the satellite-signal that synchronization module 202 configures that paired terminal is related to synchronizes, main root
According to signal offset estimation and skew estimation compensate, the delay of signal is calculated by operation, sync section includes
The position that sliding correlation finds time delay and the starting of corresponding data is carried out to data, then carries out estimating for frequency deviation and skew
Meter/compensation, to realize the synchronous function of signal.
In one embodiment, upper down sample module 203 is configured to mainly to complete by interpolation and the operation of pumping value to defending
Star signal increases or decreases sample rate function.
In one embodiment, communication system of the modulation /demodulation module 204 based on SDR technology, for satellite communication terminal
With versatility, it is configured to support more modulation and demodulation mode, including QPSK (quadrature phase shift keying), DPSK (difference phase shift
Keying), the methods of MPSK (phase-modulation).
In one embodiment, coding/decoding module 205 is used primarily directed to different satellite communication systems, which can be with
Support encoding and decoding technique different such as LDPC code, convolutional code and turbo code.In one embodiment, the parameter of encoding and decoding
Can be adjustable at any time under interface environments, complete the versatility of codec code.
In one embodiment, SDR equipment mainly completes the hardware Up/Down Conversion of signal, the mistake of all satellite-signal processing
Journey and driving are all realized in PC machine side.The workflow of entire satellite communication terminal is as follows:
(1) antenna sends and receivees satellite-signal.In one embodiment, which may include S band satellite antenna,
It supports multiband (frequency ranges such as S, L, Ka), a variety of polarization modes (linear polarization and elliptic polarization etc.)；
(2) SDR equipment completes the Up/Down Conversion of signal, converts between frequency and digital baseband signal in simulations, with PC machine
It is communicated by network interface；
(3) SDR driver is the linker of hardware and application software, and driver converts SDR hardware device to
By calling the corresponding api interface of hardware device, using hardware device, equipment center frequency is such as arranged in api interface, application software
Rate and sample rate etc.；
(4) the signal synchronization program in application software completes the correlation operation of signal, calculates frequency deviation, skew and time delay,
And compensate, it is synchronized with completing to network；
(5) signal processing is then carried out, which may include upper down-sampling, modulation /demodulation, encoding and decoding, the CRC of signal
The operation such as verification, thus output satellite data-signal backward；
(6) PC machine displays in real time the waveform and parameter of the satellite information signal received by man-machine interface.
In addition, can be adjusted to waveform parameter by man-machine interface.
According to the technical solution of the present invention, can solve when satellite communication terminal alternates leads to asking for terminal cost waste
Topic, while also solving the problems, such as that long satellite communication terminal development cycle, portability of program and terminal versatility are poor.
Although the mode that the present invention is implemented is as above, the content is implementation that is of the invention for ease of understanding and using
Example, the range and application scenarios being not intended to limit the invention.Technical staff in any technical field of the present invention, not
Be detached from disclosed herein spirit and scope under the premise of, can make in the formal and details of implementation any modification with
Variation, but scope of patent protection of the invention, still should be subject to the scope of the claims as defined in the appended claims.
Claims (10)
1. a kind of satellite communication terminal based on software radio, including Hardware Subdivision and software portion,
The Hardware Subdivision includes:
Multiple satellite antennas are configured to support multiple frequency ranges and multiple modes, and for sending and receiving satellite-signal；
Software radio comprising Radio Frequency Subsystem, analog/digital and D A switch module, processing module, the software without
Line electric equipment is configured to Analog Baseband intermediate-freuqncy signal being modulated to radiofrequency signal in order to export, or the radio frequency received is believed
Number it is down-converted to digital baseband signal, so as to subsequent processing；
The software portion includes base band signal process program, wherein the base band signal process program includes for baseband signal
The multiple modules handled.
2. satellite communication terminal according to claim 1, wherein the base band signal process program includes that satellite-signal is caught
Obtain module, synchronization module, upper down sample module, modulation /demodulation module and coding/decoding module.
3. satellite communication terminal according to claim 2, wherein the satellite signal acquisition module is configured to for more
Satellite code phases and carrier frequency are scanned for and are captured, to reach satellite-signal fast search and capturing function, wherein described
Synchronization module is configured to be compensated according to offset estimation and the skew estimation to signal, and determines the delay of signal, to reach
The synchronous function of signal.
4. satellite communication terminal according to claim 3, wherein the sampling module up and down is configured to through interpolation and pumping
It is worth operation, to reach the function of increasing or decreasing sample rate to satellite-signal.
5. satellite communication terminal according to claim 4, wherein the modulation /demodulation module is configured to based on software wireless
Power technology and support more modulation and demodulation mode so that the satellite communication terminal have versatility.
6. satellite communication terminal according to claim 5, wherein the coding/decoding module is configured to lead to for different satellites
Letter system uses different encoding and decoding techniques, and its parameter is adjustable at any time under interface environments, to realize codec code
Versatility.
7. satellite communication terminal according to claim 1, wherein the software portion further includes hardware device driver,
Including upper level applications and it is configured to driving Hardware Subdivision.
8. satellite communication terminal according to claim 7, wherein the hardware device driver includes modifiable hard
Part parameter and associated Application Programming Interface, to increase the inheritance of driver.
9. satellite communication terminal according to claim 1, wherein the satellite communication terminal includes computer, the computer
By means of the software of software radio, drawing or parameter calculation procedure is added, so as to the phase of real-time display satellite communications data
Close waveform and parameter.
10. a kind of method of the satellite communication based on software radio, comprising:
Satellite-signal is sent and received using multiple satellite antennas；
Analog Baseband intermediate-freuqncy signal is modulated to radiofrequency signal using software radio in order to export, or will be received
To radiofrequency signal be down-converted to digital baseband signal, so as to subsequent processing；
Baseband signal is handled using base band signal process program；And
Antenna and software radio are driven using hardware device driver.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811471966.8A CN109450520A (en) | 2018-12-04 | 2018-12-04 | Satellite communication method and corresponding satellite communication terminal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811471966.8A CN109450520A (en) | 2018-12-04 | 2018-12-04 | Satellite communication method and corresponding satellite communication terminal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109450520A true CN109450520A (en) | 2019-03-08 |
Family
ID=65556199
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811471966.8A Pending CN109450520A (en) | 2018-12-04 | 2018-12-04 | Satellite communication method and corresponding satellite communication terminal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109450520A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110224745A (en) * | 2019-06-25 | 2019-09-10 | 哈尔滨工业大学 | Injection system and method on a kind of satellite Wide Band Data |
| CN110233809A (en) * | 2019-06-27 | 2019-09-13 | 上海金卓网络科技有限公司 | A kind of method for processing baseband signal, device, equipment and storage medium |
| CN110266325A (en) * | 2019-05-30 | 2019-09-20 | 中国人民解放军63921部队 | A kind of device carrying out satellite communication using software radio |
| CN110311724A (en) * | 2019-06-27 | 2019-10-08 | 上海金卓网络科技有限公司 | A kind of digital front-end based on software definition, physical layer architecture and terminal |
| CN113794506A (en) * | 2021-09-07 | 2021-12-14 | 曙光星云信息技术（北京）有限公司 | Automatic tracking satellite communication equipment and working method thereof |
| CN116208238A (en) * | 2023-05-06 | 2023-06-02 | 北京安天网络安全技术有限公司 | Satellite signal receiving switching circuit |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050143005A1 (en) * | 2003-12-29 | 2005-06-30 | Peersat Llc. | Inter-satellite crosslink communications system, apparatus, method and computer program product |
| CN1858616A (en) * | 2006-05-24 | 2006-11-08 | 北京东方联星科技有限公司 | Platform system for researching and developing satellite navigation receiver |
| CN101833100A (en) * | 2010-03-29 | 2010-09-15 | 北京航空航天大学 | Method for constructing fully-digital GNSS compatible navigation receiver |
| CN101945490A (en) * | 2010-09-03 | 2011-01-12 | 电子科技大学 | Software radio-based wireless communication system terminal equipment |
| US20120295537A1 (en) * | 2011-05-20 | 2012-11-22 | Honeywell International Inc. | Reconfigurable satcom avionics radio |
| CN105278404A (en) * | 2015-09-18 | 2016-01-27 | 广州北航新兴产业技术研究院 | Base-band device based on software radio |
| CN108347278A (en) * | 2017-12-23 | 2018-07-31 | 航天恒星科技有限公司 | Adapt to the high speed bandwidth modulator approach and system of variable bit rate |
-
2018
- 2018-12-04 CN CN201811471966.8A patent/CN109450520A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050143005A1 (en) * | 2003-12-29 | 2005-06-30 | Peersat Llc. | Inter-satellite crosslink communications system, apparatus, method and computer program product |
| CN1858616A (en) * | 2006-05-24 | 2006-11-08 | 北京东方联星科技有限公司 | Platform system for researching and developing satellite navigation receiver |
| CN101833100A (en) * | 2010-03-29 | 2010-09-15 | 北京航空航天大学 | Method for constructing fully-digital GNSS compatible navigation receiver |
| CN101945490A (en) * | 2010-09-03 | 2011-01-12 | 电子科技大学 | Software radio-based wireless communication system terminal equipment |
| US20120295537A1 (en) * | 2011-05-20 | 2012-11-22 | Honeywell International Inc. | Reconfigurable satcom avionics radio |
| CN105278404A (en) * | 2015-09-18 | 2016-01-27 | 广州北航新兴产业技术研究院 | Base-band device based on software radio |
| CN108347278A (en) * | 2017-12-23 | 2018-07-31 | 航天恒星科技有限公司 | Adapt to the high speed bandwidth modulator approach and system of variable bit rate |
Non-Patent Citations (2)
| Title |
|---|
| 李兴国 等: "高动态软件接收机自适应门限快速捕获算法", 《电子设计工程》 * |
| 王晓海: "软件无线电技术在卫星系统中的应用", 《现代电信科技》 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110266325A (en) * | 2019-05-30 | 2019-09-20 | 中国人民解放军63921部队 | A kind of device carrying out satellite communication using software radio |
| CN110224745A (en) * | 2019-06-25 | 2019-09-10 | 哈尔滨工业大学 | Injection system and method on a kind of satellite Wide Band Data |
| CN110233809A (en) * | 2019-06-27 | 2019-09-13 | 上海金卓网络科技有限公司 | A kind of method for processing baseband signal, device, equipment and storage medium |
| CN110311724A (en) * | 2019-06-27 | 2019-10-08 | 上海金卓网络科技有限公司 | A kind of digital front-end based on software definition, physical layer architecture and terminal |
| CN110233809B (en) * | 2019-06-27 | 2022-06-17 | 上海金卓科技有限公司 | Baseband signal processing method, device, equipment and storage medium |
| CN113794506A (en) * | 2021-09-07 | 2021-12-14 | 曙光星云信息技术（北京）有限公司 | Automatic tracking satellite communication equipment and working method thereof |
| CN116208238A (en) * | 2023-05-06 | 2023-06-02 | 北京安天网络安全技术有限公司 | Satellite signal receiving switching circuit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109450520A (en) | Satellite communication method and corresponding satellite communication terminal | |
| CN106788476B (en) | Mobile forward pass device and method based on Walsh code channel aggregation | |
| CN105049076B (en) | software radio communication method and system | |
| CN101902420B (en) | Continuous phase differential phase-shift keying modulation and demodulation method in signs | |
| CN107888276B (en) | Multi-frequency band multi-mode modulation and demodulation device | |
| CN105099496A (en) | Methods and apparatus for frequency offset estimation and correction prior to preamble detection of direct sequence spread spectrum (DSSS) signals | |
| CN102843178B (en) | Spread spectrum relay measurement and control system compatible with standard unified S-band measurement and control system | |
| CN105388500A (en) | Method for improving continuous phrase frequency shift key (CPFSK) signal carrier tracking precision | |
| CN113872909B (en) | Short-time burst carrier capturing method and system for low-orbit satellite Internet of things | |
| CN102025669A (en) | Short-wave data transmission method based on dual multisystem quasi-orthogonal spread-spectrum composite phase modulation | |
| CN103338175A (en) | Non-coherent demodulation device and demodulation method of CPM (continuous phase modulation) signal | |
| CN103685133A (en) | High-order continuous polarization modulation method of improving spectral efficiency | |
| CN113194052B (en) | Reconfigurable radio frequency direct digital modulation communication system | |
| CN105099977A (en) | Communicating method and communicating system based on EBPSK | |
| CN105227511A (en) | A kind of microwave and millimeter wave signal of communication method for generation based on frequency multiplication mode | |
| CN103107970B (en) | A kind of communication system based on compressed sensing | |
| CN104393911B (en) | A kind of air-ground narrow-band communication system and its method for unmanned plane | |
| CN103684570A (en) | Method and device for searching carrier frequency point of GSM base station, and repeater | |
| CN103888198B (en) | The method of estimation of the signal quality of MSK and O-QPSK signal | |
| CN106710182A (en) | Data collector having timing function | |
| CN102333389A (en) | Three-mode digital optical fiber remote system | |
| CN102685055B (en) | Device and method for interpolating, extracting and multiplexing multiple data streams | |
| CN104333391A (en) | Air-ground narrow-band communication method for unmanned aerial vehicle | |
| CN202393914U (en) | Base-band module and big dipper signal receiving system | |
| Li | Analysis and design of software defined radio |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20190308 |