CN115296721A - High-speed demodulation method, device and equipment suitable for low-earth-orbit satellite - Google Patents
High-speed demodulation method, device and equipment suitable for low-earth-orbit satellite Download PDFInfo
- Publication number
- CN115296721A CN115296721A CN202210920090.0A CN202210920090A CN115296721A CN 115296721 A CN115296721 A CN 115296721A CN 202210920090 A CN202210920090 A CN 202210920090A CN 115296721 A CN115296721 A CN 115296721A
- Authority
- CN
- China
- Prior art keywords
- module
- speed
- signal
- low
- frequency
- 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
- 238000000034 method Methods 0.000 title claims abstract description 27
- 238000001914 filtration Methods 0.000 claims abstract description 19
- 230000001360 synchronised effect Effects 0.000 claims abstract description 13
- 238000005070 sampling Methods 0.000 claims abstract description 7
- 238000006243 chemical reaction Methods 0.000 claims description 25
- 238000007781 pre-processing Methods 0.000 claims description 12
- 238000000605 extraction Methods 0.000 claims description 8
- 230000006870 function Effects 0.000 claims description 6
- 238000013507 mapping Methods 0.000 claims description 6
- 238000009825 accumulation Methods 0.000 claims description 3
- 238000005516 engineering process Methods 0.000 abstract description 13
- 238000004891 communication Methods 0.000 abstract description 11
- 230000010365 information processing Effects 0.000 abstract description 4
- 238000012545 processing Methods 0.000 abstract description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000008054 signal transmission Effects 0.000 description 2
- 108091092878 Microsatellite Proteins 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 238000010606 normalization Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 230000001502 supplementing effect Effects 0.000 description 1
Images
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
- H04B7/18513—Transmission in a satellite or space-based system
-
- 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
- H04B7/18578—Satellite systems for providing broadband data service to individual earth stations
- H04B7/18582—Arrangements for data linking, i.e. for data framing, for error recovery, for multiple access
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0056—Systems characterized by the type of code used
- H04L1/0057—Block codes
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0008—Modulated-carrier systems arrangements for allowing a transmitter or receiver to use more than one type of modulation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Abstract
The invention discloses a high-speed demodulation method, a high-speed demodulation device and high-speed demodulation equipment suitable for a low-orbit satellite. The demodulation method comprises the steps of down-converting an intermediate frequency signal into a baseband signal, then performing decimation down-sampling and low-pass filtering on the baseband signal, then searching a frame header through an FFT-based capture method, determining a pilot frequency position, then performing power estimation and channel gain control, then performing rapid timing synchronization and carrier synchronization, and finally performing LDPC decoding on the synchronized data. The invention adopts high-speed parallel processing technology and high-order modulation and demodulation technology, and the information processing capacity can reach more than 1 Gbps; and a high dynamic acquisition and synchronization technology is adopted, so that the method can adapt to the characteristic of high-speed motion of a low-earth-orbit satellite. The center frequency point and the channel gain of the invention are flexible and configurable, can support various rates and modulation modes, and are particularly suitable for high-speed signal communication of a low-orbit satellite communication system.
Description
Technical Field
The invention relates to the field of satellite communication, which can be used for high-speed signal communication of a low-orbit satellite communication system.
Background
With the research and development of the microsatellite technology, the economic cost and the realization difficulty of satellite communication are obviously reduced, and the application of low-orbit satellite communication is more and more extensive. At present, low-speed signal communication is mainly used for low-orbit satellite communication, and the low-speed signals are difficult to meet the requirements of high-performance image transmission, large-capacity signal acquisition and the like, so that research on high-speed signal transmission of low-orbit satellites is necessary.
Disclosure of Invention
In view of this, the present invention provides a high-speed demodulation method, apparatus and device suitable for a low-earth orbit satellite, which solves the problem of high-speed signal transmission of the low-earth orbit satellite. The method adopts a high-speed parallel processing technology and a high-order modulation and demodulation technology, and the information processing capacity can reach more than 1 Gbps; and a high dynamic acquisition and synchronization technology is adopted, so that the method can adapt to the characteristic of high-speed motion of a low-orbit satellite. The method can also support various rates and modulation modes, and has the advantages of high transmission performance, good real-time performance and the like.
The purpose of the invention is realized as follows:
a high-speed demodulation method suitable for low-orbit satellites comprises the following steps:
(1) Receiving a radio frequency signal, and converting the radio frequency signal into an intermediate frequency signal through analog down conversion;
(2) Sampling the intermediate frequency signal by using a high-speed AD (analog-to-digital) to obtain a plurality of paths of parallel digital signals;
(3) A configurable digital down-conversion is adopted to move the digital signal to zero frequency and change the digital signal into a baseband signal;
(4) Extracting and filtering the baseband signal, wherein the extraction multiple sets different values according to different symbol rates; the filtering adopts a matched filtering mode to carry out low-pass filtering, reduces the crosstalk between symbols and filters out-of-band noise;
(5) Capturing the filtered signal with a fixed length through a sliding window, and determining a pilot frequency position through a capture synchronization head;
(6) Performing power estimation by using pilot frequency, and performing channel gain control by using power information as a state parameter;
(7) Carrying out rapid timing synchronization and carrier synchronization by using pilot frequency;
(8) And performing demapping and LDPC decoding on the synchronized data.
Further, the analog down-conversion in the step (1) is realized by a module with configurable frequency points, and by configuring different frequency points, an intermediate frequency signal with a variable center frequency point is obtained.
Further, the digital down-conversion in the step (3) is realized by a module with configurable frequency points.
Further, the specific mode of the step (5) is as follows:
1) Only taking sign bits of the filtered signals as signal amplitudes; namely only taking +1 or-1 to obtain the normalized signal amplitude irrelevant to the signal amplitude;
2) Taking the length of the synchronous head as the length of a sliding window, carrying out sliding XOR operation on the normalized signal and the content of the synchronous head, and then carrying out partial length accumulation, namely partial correlation operation, to obtain a plurality of correlation values;
3) Zero padding is carried out on the plurality of correlation values, and then FFT operation is carried out;
4) Searching the maximum amplitude after FFT operation, judging whether the maximum amplitude is greater than a threshold, and if the maximum amplitude is greater than the threshold, considering that the acquisition is successful; if not, sliding capture is continued.
Further, the sync header in step (5) is a piece of continuous data, and the length and content of the sync header are determined when the frame structure is designed.
Further, the timing synchronization and the carrier synchronization in step (7) are both synchronized by using a pilot, wherein the pilot of the timing synchronization is 1, 0 code, and the pilot of the carrier synchronization is a single carrier signal.
A high-speed demodulation device suitable for a low-orbit satellite comprises a frequency conversion module a, a high-speed ADb, a preprocessing module c, a capturing module d, a synchronization module e, a high-speed demodulation decoding module f, a power estimation module g, a parameter configuration module h, a channel gain control module i and a control center j;
the parameter configuration module h receives the control signal sent by the control center j, analyzes the instruction, and sends the analyzed frequency point to the frequency conversion module a so as to control the frequency conversion center frequency point; the analyzed parameters such as the modulation coding mode and the like are sent to a preprocessing module c, a capturing module d, a synchronizing module e and a high-speed demodulation decoding module f to control the modulation mode and the symbol rate of the modules, and in addition, a parameter configuration module h also receives state information sent by the modules and reports the state information to a control center j; the parameter configuration module h also receives power information of the power estimation module g and sends level control parameters to the channel gain control module i;
the preprocessing module c comprises a parallel digital down-conversion module, a parallel extraction module, a parallel matched filtering module and a power estimation and adjustment module; the preprocessing module c receives the sampling data of the high-speed ADb, completes the functions of down-conversion, extraction, filtering and the like according to the parameters such as frequency points, speed and the like sent by the parameter configuration module h, and then sends the data to the capturing module d; the power estimation module g sends the power information to the parameter configuration module h; the acquisition module d completes the positioning function, determines the pilot frequency position and sends the pilot frequency position to the synchronization module e;
the synchronization module e comprises a timing synchronization module and a carrier synchronization module and is used for completing the accurate synchronization of a clock and a carrier;
the high-speed demodulation decoding module f comprises a parallel de-mapping and multi-path decoding module and is used for completing de-mapping and LDPC decoding of signals in different modulation modes;
and the channel gain control module i receives the power parameter sent by the parameter configuration module h and controls the level gain of the analog channel.
A high speed demodulation apparatus suitable for use with low earth orbit satellites, comprising a housing, a processor and a memory, the memory storing program code which, when executed, implements the method as claimed in any one of the preceding claims.
Compared with the background art, the invention has the following advantages:
1. the invention adopts high-speed parallel processing technology and high-order modulation and demodulation technology, and the information processing capacity can reach more than 1 Gbps.
2. The invention adopts high dynamic capture and synchronization technology, and can adapt to the characteristic of high-speed motion of low-orbit satellites.
3. The invention can support various rates and modulation modes.
4. The center frequency point and the channel gain of the invention are flexible and configurable.
5. The invention has the advantages of high transmission performance, good real-time performance and the like.
Drawings
FIG. 1 is a flow chart of the method of the present invention.
FIG. 2 is a schematic diagram of the connection relationship of the device of the present invention.
Fig. 3 is a flowchart of the FFT-based acquisition method of step (5).
Fig. 4 is a block diagram of the apparatus of the present invention.
Detailed Description
The present invention is described in further detail below.
As shown in fig. 1, a high-speed demodulation method suitable for low-earth orbit satellites includes the following steps:
(1) Receiving a radio frequency signal, and converting the radio frequency signal into an intermediate frequency signal through analog down conversion;
(2) Sampling the intermediate frequency signal by using a high-speed AD to obtain a plurality of paths of parallel digital signals;
(3) Shifting the digital signal to zero frequency by adopting configurable digital down-conversion to become a baseband signal;
(4) Decimating and filtering the baseband signal. The decimation multiple sets different values according to different symbol rates; the filtering adopts a matched filtering mode to carry out low-pass filtering, reduces the crosstalk between symbols and filters out-of-band noise;
(5) Capturing the filtered signal with a fixed length through a sliding window, and determining a pilot frequency position through a capture synchronization head;
(6) Performing power estimation by using pilot frequency, and performing channel gain control by using power information as a state parameter;
(7) Carrying out rapid timing synchronization and carrier synchronization by using pilot frequency;
(8) And performing demapping and LDPC decoding on the synchronized data.
Further, the analog down-conversion in the step (1) is a module with configurable frequency points, and different frequency points are configured in a certain range, so that an intermediate frequency signal with a variable center frequency point can be obtained;
further, the digital down-conversion in the step (3) is similar to the analog down-conversion in the step (2), and is still a module with configurable frequency points.
Furthermore, the capturing method in step (5) adopts an FFT-based amplitude normalization partial coherent capturing method, which normalizes the signal amplitude, so that the calculation result is not affected by the signal amplitude, and can adapt to the high dynamic characteristics of low-orbit satellites. Wherein, the length of the sliding window is the length of the synchronous head. As shown in fig. 3, the specific method is:
1) Only taking sign bits of the matched and filtered signals as signal amplitudes; namely only taking +1 or-1 to obtain the normalized signal amplitude irrelevant to the signal amplitude;
2) Carrying out sliding XOR operation on the normalized signal and the content of the synchronous head, and then carrying out partial length accumulation, namely partial correlation operation, so as to obtain a plurality of correlation values;
3) Supplementing zero with a certain length to the plurality of correlation values, and then performing FFT operation;
4) Searching the maximum amplitude after FFT operation, judging whether the maximum amplitude is greater than a threshold, and if the maximum amplitude is greater than the threshold, considering that the acquisition is successful; if not, continuing the sliding capture.
Further, the sync header in step (5) is a segment of continuous data, and the length and content of the sync header are determined when the frame structure is designed. A pseudo-random sequence is typically chosen as the synchronization header.
Further, the timing synchronization and the carrier synchronization in the step (7) are both synchronized by using a pilot, wherein the pilot of the timing synchronization is 1, 0 code, and the pilot of the carrier synchronization is a single carrier signal. The carrier synchronization supports high dynamic frequency tracking, and can adapt to large frequency deviation and large frequency change rate generated by high-speed motion of a low-orbit satellite;
as shown in fig. 2, a high-speed demodulation apparatus suitable for a low-earth orbit satellite includes a frequency conversion module a, a high-speed AD b, a preprocessing module c, a capturing module d, a synchronization module e, a high-speed demodulation decoding module f, a channel gain control module i, a parameter configuration module h, and a control center j;
the parameter configuration module h receives the control signal sent by the control center j, analyzes the instruction, and sends the analyzed frequency point to the frequency conversion module a so as to control the frequency conversion center frequency point; the analyzed parameters such as the modulation coding mode and the like are sent to a preprocessing module c, a capturing module d, a synchronizing module e and a high-speed demodulation decoding module f to control the modulation mode and the symbol rate of the modules, and in addition, state information sent by the modules is received and reported to a control center j; the parameter configuration module h also sends a level control parameter to the channel gain control module i;
the preprocessing module c comprises a parallel digital down-conversion module, a parallel extraction module, a parallel matched filtering module and a power estimation and adjustment module. The preprocessing module c receives the sampling data of the high-speed ADb, completes the functions of down-conversion, extraction, filtering and the like according to the parameters such as frequency points, speed and the like sent by the parameter configuration module h, and then sends the data to the capturing module d; the power estimation and adjustment module sends the power information to a parameter configuration module h; the acquisition module d completes the positioning function, determines the pilot frequency position and sends the pilot frequency position to the synchronization module e;
the synchronization module e comprises a timing synchronization module and a carrier synchronization module and is used for completing the accurate synchronization of a clock and a carrier;
the high-speed demodulation decoding module f comprises a parallel de-mapping and multi-path decoding module and completes de-mapping and LDPC decoding of signals of different modulation modes.
And the channel gain control module i receives the power parameters sent by the parameter configuration module h to control the level gain of the analog channel.
As shown in fig. 4, a high-speed demodulation apparatus suitable for low-earth orbit satellites includes a casing, one or more processors, and a memory, wherein the memory stores program codes and the processors are used for executing the program codes; the program code is operable to implement the above-described method.
In a word, the invention adopts high-speed parallel processing technology and high-order modulation and demodulation technology, and the information processing capacity can reach more than 1 Gbps; and a high dynamic acquisition and synchronization technology is adopted, so that the method can adapt to the characteristic of high-speed motion of a low-earth-orbit satellite. The center frequency point and the channel gain of the invention are flexible and configurable, can support various rates and modulation modes, and are particularly suitable for high-speed signal communication of a low-orbit satellite communication system.
The above description is only one specific embodiment of the present invention, but the scope of the present invention is not limited thereto. Any equivalent replacement or change made by the technical solution of the present invention and the inventive concept thereof by those skilled in the art should be covered within the protection scope of the present invention.
Claims (8)
1. A high-speed demodulation method suitable for a low-earth orbit satellite is characterized by comprising the following steps:
(1) Receiving a radio frequency signal, and converting the radio frequency signal into an intermediate frequency signal through analog down conversion;
(2) Sampling the intermediate frequency signal by using a high-speed AD (analog-to-digital) to obtain a plurality of paths of parallel digital signals;
(3) Moving the digital signal to zero frequency by adopting configurable digital down-conversion to change the digital signal into a baseband signal;
(4) Extracting and filtering the baseband signal, wherein the extraction multiple sets different values according to different symbol rates; the filtering adopts a matched filtering mode to carry out low-pass filtering, reduces the crosstalk between symbols and filters out-of-band noise;
(5) Capturing the filtered signal with a fixed length through a sliding window, and determining a pilot frequency position through a capture synchronization head;
(6) Performing power estimation by using pilot frequency, and performing channel gain control by using power information as a state parameter;
(7) Carrying out rapid timing synchronization and carrier synchronization by using pilot frequency;
(8) And performing demapping and LDPC decoding on the synchronized data.
2. The high-speed demodulation method suitable for the low earth orbit satellite according to claim 1, wherein the analog down-conversion in step (1) is realized by a module with configurable frequency points, and the intermediate frequency signal with a variable center frequency point is obtained by configuring different frequency points.
3. The high-speed demodulation method for low-earth orbit satellites of claim 1 wherein the digital down-conversion in step (3) is realized by a module with configurable frequency points.
4. The high-speed demodulation method for low-earth orbit satellites according to claim 1, wherein the step (5) is implemented by:
1) Taking only the sign bit of the filtered signal as the signal amplitude; namely only taking +1 or-1 to obtain the normalized signal amplitude irrelevant to the signal amplitude;
2) Taking the length of the synchronous head as the length of a sliding window, carrying out sliding XOR operation on the normalized signal and the content of the synchronous head, and then carrying out partial length accumulation, namely partial correlation operation, to obtain a plurality of correlation values;
3) Zero padding is carried out on the plurality of correlation values, and then FFT operation is carried out;
4) Searching the maximum amplitude after FFT operation, judging whether the maximum amplitude is greater than a threshold, and if so, determining that the acquisition is successful; if not, sliding capture is continued.
5. The high-speed demodulation method for low-earth orbit satellites of claim 4 wherein the sync header in step (5) is a continuous piece of data, and the length and content of the sync header are determined by the frame structure design.
6. The high-speed demodulation method for low-orbit satellites of claim 1, wherein the timing synchronization and the carrier synchronization in step (7) are synchronized by using pilot frequency, wherein the pilot frequency of the timing synchronization is 1, 0 code, and the pilot frequency of the carrier synchronization is single carrier signal.
7. A high-speed demodulation device suitable for a low-orbit satellite is characterized by comprising a frequency conversion module (a), a high-speed AD (b), a preprocessing module (c), an acquisition module (d), a synchronization module (e), a high-speed demodulation decoding module (f), a power estimation module (g), a parameter configuration module (h), a channel gain control module (i) and a control center (j);
the parameter configuration module (h) receives the control signal sent by the control center (j), analyzes the instruction, and sends the analyzed frequency point to the frequency conversion module (a) so as to control the frequency conversion center frequency point; sending the analyzed parameters such as the modulation coding mode and the like to a preprocessing module (c), a capturing module (d), a synchronizing module (e) and a high-speed demodulation decoding module (f) to control the modulation mode and the symbol rate of the modules, and in addition, receiving the state information sent by the modules and reporting the state information to a control center (j); the parameter configuration module (h) also receives power information of the power estimation module (g) and sends a level control parameter to the channel gain control module (i);
the preprocessing module (c) comprises a parallel digital down-conversion module, a parallel extraction module, a parallel matched filtering module and a power estimation and adjustment module; the preprocessing module (c) receives the sampling data of the high-speed AD (b), completes the functions of down-conversion, extraction, filtering and the like according to the parameters such as frequency points, speed and the like sent by the parameter configuration module (h), and then sends the data to the capturing module (d); the power estimation module (g) sends the power information to the parameter configuration module (h); the acquisition module (d) completes the positioning function, determines the pilot frequency position and sends the pilot frequency position to the synchronization module (e);
the synchronization module (e) comprises a timing synchronization module and a carrier synchronization module, and completes the accurate synchronization of the clock and the carrier;
the high-speed demodulation decoding module (f) comprises a parallel de-mapping and multi-path decoding module, and completes de-mapping and LDPC decoding of signals in different modulation modes;
and (c) the channel gain control module (i) receives the power parameter sent by the parameter configuration module (h) and controls the level gain of the analog channel.
8. A high speed demodulation apparatus suitable for use with low earth orbit satellites comprising a housing, a processor and a memory, the memory storing program code which, when executed, implements the method of any of claims 1 to 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210920090.0A CN115296721A (en) | 2022-08-01 | 2022-08-01 | High-speed demodulation method, device and equipment suitable for low-earth-orbit satellite |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210920090.0A CN115296721A (en) | 2022-08-01 | 2022-08-01 | High-speed demodulation method, device and equipment suitable for low-earth-orbit satellite |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115296721A true CN115296721A (en) | 2022-11-04 |
Family
ID=83825953
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210920090.0A Pending CN115296721A (en) | 2022-08-01 | 2022-08-01 | High-speed demodulation method, device and equipment suitable for low-earth-orbit satellite |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115296721A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103763062A (en) * | 2014-01-17 | 2014-04-30 | 中国航空无线电电子研究所 | Aviation radio anti-interference broadband transmission method with variable gain and adaptive broadband |
| CN107124193A (en) * | 2017-06-01 | 2017-09-01 | 上海埃威航空电子有限公司 | Marine digital intermediate frequency receiving device |
| CN108512795A (en) * | 2018-03-19 | 2018-09-07 | 东南大学 | A kind of OFDM receiver baseband processing method and system based on low Precision A/D C |
| CN110176977A (en) * | 2019-05-20 | 2019-08-27 | 北京遥测技术研究所 | High-order QAM soft decision method in OFDM data chain based on AGC |
| CN112965089A (en) * | 2021-02-05 | 2021-06-15 | 重庆两江卫星移动通信有限公司 | Method and system for acquiring high-precision signal of communication-conduction integrated low-orbit satellite |
-
2022
- 2022-08-01 CN CN202210920090.0A patent/CN115296721A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103763062A (en) * | 2014-01-17 | 2014-04-30 | 中国航空无线电电子研究所 | Aviation radio anti-interference broadband transmission method with variable gain and adaptive broadband |
| CN107124193A (en) * | 2017-06-01 | 2017-09-01 | 上海埃威航空电子有限公司 | Marine digital intermediate frequency receiving device |
| CN108512795A (en) * | 2018-03-19 | 2018-09-07 | 东南大学 | A kind of OFDM receiver baseband processing method and system based on low Precision A/D C |
| CN110176977A (en) * | 2019-05-20 | 2019-08-27 | 北京遥测技术研究所 | High-order QAM soft decision method in OFDM data chain based on AGC |
| CN112965089A (en) * | 2021-02-05 | 2021-06-15 | 重庆两江卫星移动通信有限公司 | Method and system for acquiring high-precision signal of communication-conduction integrated low-orbit satellite |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112671446B (en) | Demodulation device suitable for high-orbit inter-satellite link | |
| CN109495237B (en) | Multi-rate demodulation device based on sampling point selection | |
| CN105187348B (en) | Arbitrary velocity CPFSK signal timing synchronous method | |
| CN105024962B (en) | The low complex degree coherent demodulation method of GMSK signals | |
| CN105553507A (en) | Full coherence accumulation time-frequency domain parallel capturing method based on FFT | |
| CN113541766B (en) | Method, system and terminal for rapidly capturing frequency of low-earth-orbit satellite communication system | |
| JPS61198848A (en) | Data communication system | |
| CN110300079B (en) | MSK signal coherent demodulation method and system | |
| CN111600823B (en) | Parallel OQPSK offset quadriphase shift keying demodulator | |
| CN108494467B (en) | Physical layer self-adaptive ACM synchronization equipment based on satellite communication | |
| CN108988906A (en) | A kind of incoherent frequency spreading device that data rate is variable | |
| CN112600608B (en) | Multi-frame superimposed satellite signal capturing method and device | |
| CN108123788B (en) | Fast synchronization device based on blind separation iterative reconstruction and suitable for scattering communication | |
| CN115296721A (en) | High-speed demodulation method, device and equipment suitable for low-earth-orbit satellite | |
| CN116073892B (en) | Demodulation method and device for service channel of low-orbit satellite communication system | |
| CN110808772B (en) | Baseband signal processing method and device for receiver of near-moon space communication | |
| CN102316058B (en) | Coherent demodulation device of non-geostationary orbit satellite DQPSK (Differential Quadrature Phase Shift Keying) communication | |
| Liebetreu | Joint carrier phase estimation and data detection algorithms for multi-h CPM data transmission | |
| CN112671445B (en) | Satellite-borne Doppler frequency offset resistant adaptive demodulator | |
| CN113709073B (en) | Demodulation method of quadrature phase shift keying modulation signal | |
| US6975839B2 (en) | Apparatus, and associated method, for estimating frequency offset using filtered, down-sampled likelihood polynomials | |
| CN114900405B (en) | Soc-based Acars signal demodulation method | |
| CN111884700B (en) | Pilot positioning message processing device and method based on low-earth orbit satellite | |
| Fines et al. | Fully digital M-ary PSK and M-ary QAM demodulators for land mobile satellite communications | |
| CN107947810B (en) | Digital domain interference elimination method of full-duplex constant amplitude modulation system |
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 |