CN110943773B - Satellite broadcast demodulating equipment suitable for fixed wing aircraft platform - Google Patents
Satellite broadcast demodulating equipment suitable for fixed wing aircraft platform Download PDFInfo
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- CN110943773B CN110943773B CN201911170310.7A CN201911170310A CN110943773B CN 110943773 B CN110943773 B CN 110943773B CN 201911170310 A CN201911170310 A CN 201911170310A CN 110943773 B CN110943773 B CN 110943773B
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- 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
- H04B7/18523—Satellite systems for providing broadcast service to terrestrial stations, i.e. broadcast satellite service
- H04B7/18526—Arrangements for data linking, networking or transporting, or for controlling an end to end session
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- 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
- H04B7/18502—Airborne stations
- H04B7/18506—Communications with or from aircraft, i.e. aeronautical mobile service
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
- H04L2027/0024—Carrier regulation at the receiver end
- H04L2027/0026—Correction of carrier offset
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Abstract
The invention discloses a satellite broadcast demodulation device suitable for a fixed-wing aircraft platform, and belongs to the technical field of satellite broadcast. The satellite broadcast demodulation device comprises a frequency offset correction module, an A-TDM demodulation module and a monitoring module. The technology realizes the correct demodulation of large frequency offset self-adaptive time division multiplexing A-TDM broadcast signals (variable modulation mode, variable channel coding rate and variable spread spectrum ratio) so as to realize the reliable reception of small stations with different receiving capacities of different platforms in the coverage area of satellite data broadcast services. The invention can realize the correct receiving function of the large frequency offset A-TDM signal which is not possessed by the common modem, and is particularly suitable for the fixed wing aircraft platform airborne multi-mode satellite communication modem.
Description
Technical Field
The invention relates to the technical field of satellite broadcasting, in particular to a satellite broadcasting demodulation device suitable for a fixed-wing aircraft platform.
Background
In recent years, based on the demand of a digital satellite transmission market and the development of technology, the performance of a high-power direct broadcast satellite is greatly improved, after a first-generation satellite digital video broadcasting standard (DVB-S), a second-generation standard DVB-S2 with higher performance and efficiency is widely applied to digital television broadcasting, and satellite digital televisions are popularized to users and are popularized to the field of satellite communication. However, in the digital satellite broadcast service transmission, the satellite needs to consider the reliable reception of the small stations with different satellite antenna apertures and different receiving capabilities in the coverage area to ensure the minimum broadcast information transmission for the broadcast service of the receiving station in the coverage area. Meanwhile, the great maneuvering such as roll and hover of the fixed-wing aircraft platform can cause the reduction of the tracking precision of the airborne antenna, the reduction of the receiving capability of the broadcast signal and the influence on the correct demodulation of the superframe signal due to the large frequency offset caused by Doppler.
Disclosure of Invention
In view of the above, the technical problem to be solved by the present invention is to provide a satellite broadcast demodulation apparatus suitable for a fixed-wing aircraft platform, which has a feature of performing adaptive demodulation on a-TDM signal of satellite broadcast in a state where receiving capability of a receiving station is unstable due to an onboard high maneuvering condition, and receives broadcast services using a low-order modulation and low-rate mode in a low signal-to-noise ratio, and receives broadcast services using a high-order modulation and high-rate mode in a high signal-to-noise ratio.
The dynamic range of the transmission rate of the broadcast information is 198kbps to 67 Mbps.
The compensation range of the high dynamic Doppler frequency shift is +/-40 kHz, and the dynamic change rate is 3.0 kHz/s.
Based on the above purpose, the technical scheme provided by the invention is as follows:
a satellite broadcast demodulation device suitable for a fixed-wing aircraft platform comprises a frequency offset correction module, an A-TDM demodulation module, a clock processing module and a monitoring module;
the frequency offset correction module calculates a real-time Doppler frequency offset absolute value according to the satellite beacon frequency used in the high dynamic environment of the fixed wing aircraft;
the A-TDM demodulation module performs real-time frequency offset correction on the input broadcast signals according to the real-time Doppler frequency offset absolute value calculated by the frequency offset correction module, performs adaptive demodulation combined by 12 modulation coding modes, and then performs UDP data encapsulation on the demodulated and decoded data according to different code rates;
the monitoring module sets parameters of the frequency offset correction module and the A-TDM demodulation module, monitors and displays the real-time states of the parameters;
the clock processing module provides a variable rate sampling clock for the frequency offset correction module and the A-TDM demodulation module.
The frequency deviation correction module comprises a second AD conversion module, a matched filter, a power control unit and a frequency estimation module;
the second AD conversion module carries out digital sampling on the received satellite beacon;
the matched filter adopts a narrow-band filter to filter the satellite beacon which is digitally sampled by the second AD conversion module;
the power control unit calculates and adjusts the power of the satellite beacon filtered by the matched filter;
and the frequency estimation module calculates the real-time Doppler frequency offset absolute value of the satellite beacon processed by the power control unit.
The A-TDM demodulation module comprises a first AD conversion module, a preprocessing module, a superframe capturing and tracking module, a channel equalization signal-to-noise ratio estimation module, a subframe extraction module, a subframe carrier recovery module, a subframe soft information extraction module, an LDPC decoding module, a synchronous data UDP conversion module and a decryption module;
the first AD conversion module carries out digital sampling on the received broadcast signals;
the preprocessing module performs matched filtering, power detection and adjustment on the digitally sampled broadcast signals transmitted by the first AD conversion module, and performs frequency difference compensation on the broadcast signals by using a real-time Doppler frequency offset absolute value transmitted by the frequency offset correction module and a variable-rate sampling clock provided by the clock processing module;
the superframe acquisition and tracking module carries out superframe head acquisition, superframe control information analysis and timing tracking on the broadcast signals transmitted by the preprocessing module after frequency difference compensation;
the channel equalization signal-to-noise ratio estimation module adopts a maximum value comparison method to estimate the signal-to-noise ratio of the signal transmitted by the superframe acquisition and tracking module to obtain the signal-to-noise ratio of the current signal, and transmits the signal to the monitoring module; generating a corresponding digital filter to eliminate the influence of phase ambiguity according to the channel parameters set by the monitoring module to obtain a superframe signal;
the subframe extraction module receives a superframe signal which is transmitted by the channel equalization signal-to-noise ratio estimation module and consists of a plurality of subframes, and extracts a superframe body which consists of a timing synchronization carrier synchronization leader sequence, a superframe mode field and a sub data frame in the superframe signal to obtain the required sub data frame and the modulation coding information of the superframe;
the sub-frame carrier recovery module receives the sub-data frame and the super-frame modulation coding information transmitted by the sub-frame extraction module, generates a coherent carrier by using the super-frame modulation coding information, and recovers the original carrier by using the coherent carrier in a mode of making phase difference from the peer-to-peer interval code words in the sub-data frame;
the sub-frame soft information extraction module receives the original carrier transmitted by the sub-frame carrier recovery module, and strips the pilot head and the data block part of the sub-data frame in the original carrier to obtain an original coding data block;
the LDPC decoding module receives the original coding data block transmitted by the sub-frame soft information extraction module and performs LDPC + BCH decoding on the original coding data block to obtain an encrypted fixed-length cell bit stream;
the decryption module receives the fixed-length cell bit stream transmitted by the LDPC decoding module and restores the encrypted fixed-length cell bit stream into an original data bit stream according to a decryption rule;
the synchronous data UDP conversion module carries out UDP encapsulation on the original data bit stream transmitted by the decryption module and transmits the original data bit stream to an external interface;
the monitoring module is respectively connected with the preprocessing module, the channel equalization signal-to-noise ratio estimation module, the superframe capturing and tracking module and the synchronous data UDP conversion module, transmits a setting command of channel parameters and a real-time channel state query command, and displays the received parameters.
The technical scheme of the invention has the beneficial effects that:
1. in digital satellite broadcast service transmission, a satellite broadcasts service to receiving stations within its coverage area. The broadcasting signal demodulation technology of the variable modulation mode and the variable channel coding code rate is comprehensively used to realize the self-adaptive receiving of different issuing rates, and the reliable receiving of the small stations with different receiving capacities in the beam coverage range is realized by the broadcasting service.
2. The method adopts two parallel signals (broadcast signals and satellite beacons) for operation, wherein one satellite beacon signal is used for calculating and correcting the real-time frequency difference of the other broadcast link, and the satellite beacons of different broadcast satellites can be directly used for completing the correction of the transmission link Doppler frequency offset, so that a special pilot signal link for a fixed-wing aircraft platform by a satellite broadcast master station is omitted, the design complexity of a satellite broadcast system is reduced, and the reliability and the flexibility are improved.
Drawings
Fig. 1 is an electrical schematic diagram of a satellite broadcast demodulation apparatus according to an embodiment of the present invention.
Fig. 2 is an electrical schematic diagram of an a-TDM demodulation module in an embodiment of the present invention.
Fig. 3 is an electrical schematic diagram of a frequency offset correction module in an embodiment of the present invention.
Detailed Description
In order to facilitate understanding of the technical solutions of the present invention by those skilled in the art, and to make the technical objects, technical solutions and advantages of the present invention clearer and to fully support the scope of the claims, the technical solutions of the present invention are further described in detail below in the form of specific examples with reference to the accompanying drawings.
As shown in fig. 1, the satellite broadcast demodulation apparatus of the present invention includes a frequency offset correction module, an a-TDM demodulation module, a clock processing module, and a monitoring module;
under the high dynamic environment of the fixed-wing aircraft, the frequency offset correction module calculates the absolute value of real-time Doppler frequency offset caused in the flight process according to the beacon frequency of the used broadcast satellite, and provides real-time frequency offset correction for the A-TDM demodulation module. The A-TDM demodulation module performs real-time frequency offset correction on the input broadcast signals according to the real-time Doppler frequency offset absolute value calculated by the frequency offset correction module, performs adaptive demodulation combined by 12 modulation coding modes, and then performs UDP data encapsulation on the demodulated and decoded data according to different code rates; the monitoring module sets the parameters of the frequency deviation correction module and the A-TDM demodulation module and monitors the real-time state. The clock processing module completes the configuration of modules such as VCO (voltage controlled oscillator), DDS (direct digital frequency synthesizer), NCO (digital controlled oscillator) and the like to complete the digital frequency multiplication and frequency division of a clock source to generate the required frequency, thereby realizing the generation of the variable-rate sampling clock and providing the variable-rate sampling clock for the frequency deviation correction module and the A-TDM demodulation module.
As shown in fig. 3, the frequency offset correction module includes a second AD conversion module, a matched filter, a power control unit, and a frequency estimation module;
the second AD conversion module carries out digital sampling on the received satellite beacon;
the matched filter adopts a narrow-band filter to filter the satellite beacon which is digitally sampled by the second AD conversion module;
the power control unit calculates and adjusts the power of the satellite beacon filtered by the matched filter;
and the frequency estimation module calculates the real-time Doppler frequency offset absolute value of the satellite beacon processed by the power control unit.
The monitoring module and the clock processing module are matched to complete the whole process of the frequency offset calculation.
As shown in fig. 2, the a-TDM demodulation module includes a first AD conversion module, a preprocessing module, a superframe capture and tracking module, a channel equalization snr estimation module, a subframe extraction module, a subframe carrier recovery module, a subframe soft information extraction module, an LDPC decoding module, a synchronous data UDP conversion module, and a decryption module;
the first AD conversion module carries out digital sampling on the received broadcast signals; the broadcast signals after digital sampling are transmitted to a preprocessing module;
the preprocessing module performs matched filtering, power detection and adjustment on the broadcast signals transmitted by the first AD conversion module, and performs frequency difference compensation on the broadcast signals by using a real-time Doppler frequency offset absolute value transmitted by the frequency offset correction module and a variable-rate sampling clock provided by the clock processing module;
the monitoring module is respectively connected with the preprocessing module, the channel equalization signal-to-noise ratio estimation module, the superframe capturing and tracking module and the synchronous data UDP conversion module, transmits a setting command of broadcast channel parameters and a real-time channel state query command, and displays the received parameters of beacon frequency, channel bandwidth frequency, signal-to-noise ratio and received power;
the superframe acquisition and tracking module carries out superframe head acquisition, superframe control information analysis and timing tracking on the signals transmitted by the preprocessing module;
the channel equalization signal-to-noise ratio estimation module adopts a maximum value comparison method to estimate the signal-to-noise ratio of the signal transmitted by the superframe acquisition and tracking module to obtain the signal-to-noise ratio of the current signal, and transmits the signal to the monitoring module; generating a corresponding digital filter to eliminate the influence of phase ambiguity according to the channel parameters set by the monitoring module to obtain a superframe signal;
the subframe extraction module receives a superframe signal which is transmitted by the channel equalization signal-to-noise ratio estimation module and consists of a plurality of subframes, and extracts a superframe body which consists of a timing synchronization carrier synchronization leader sequence, a superframe mode field and a sub data frame in the superframe signal to obtain the required sub data frame and the modulation coding information of the superframe;
the sub-frame carrier recovery module receives the sub-data frame and the super-frame modulation coding information transmitted by the sub-frame extraction module, generates a coherent carrier by using the super-frame modulation coding information, and recovers the original carrier by using the coherent carrier in a mode of making phase difference from the peer-to-peer interval code words in the sub-data frame;
the sub-frame soft information extraction module receives the original carrier transmitted by the sub-frame carrier recovery module, and strips the pilot head and the data block part of the sub-data frame in the original carrier to obtain an original coding data block;
the LDPC decoding module receives the original coding data block transmitted by the sub-frame soft information extraction module and performs LDPC + BCH decoding on the original coding data block to obtain an encrypted fixed-length cell bit stream;
the decryption module receives the fixed-length cell bit stream transmitted by the LDPC decoding module, and restores the encrypted fixed-length cell bit stream into an original data bit stream (the fixed-length cell bit stream obtained by compression encoding of service types such as videos, files, short messages and the like) according to a decryption rule;
and the synchronous data UDP conversion module carries out UDP encapsulation on the original data bit stream transmitted by the decryption module and transmits the original data bit stream to an external interface.
This completes a specific implementation of the present invention.
Claims (3)
1. The utility model provides a satellite broadcast demodulating equipment suitable for fixed wing aircraft platform which characterized in that: the satellite broadcast demodulation device comprises a frequency offset correction module, an A-TDM demodulation module, a clock processing module and a monitoring module;
the frequency offset correction module calculates a real-time Doppler frequency offset absolute value according to the satellite beacon frequency used in the high dynamic environment of the fixed wing aircraft;
the A-TDM demodulation module performs real-time frequency offset correction on the input broadcast signals according to the real-time Doppler frequency offset absolute value calculated by the frequency offset correction module, performs adaptive demodulation combined by 12 modulation coding modes, and then performs UDP data encapsulation on the demodulated and decoded data according to different code rates; the self-adaptive demodulation mode is as follows: the method comprises the steps that a broadcasting signal is demodulated by using a variable modulation mode and a variable channel coding code rate broadcasting signal demodulation technology, namely, a low-order modulation mode and a low-code rate mode are used for receiving broadcasting services when the signal-to-noise ratio is low, and a high-order modulation mode and a high-code rate mode are used for receiving the broadcasting services when the signal-to-noise ratio is high;
the monitoring module sets parameters of the frequency offset correction module and the A-TDM demodulation module, monitors and displays the real-time states of the parameters;
the clock processing module provides a variable rate sampling clock for the frequency offset correction module and the A-TDM demodulation module.
2. The satellite broadcast demodulation apparatus for a fixed-wing aircraft platform as claimed in claim 1, wherein:
the frequency deviation correction module comprises a second AD conversion module, a matched filter, a power control unit and a frequency estimation module;
the second AD conversion module carries out digital sampling on the received satellite beacon;
the matched filter adopts a narrow-band filter to filter the satellite beacon which is digitally sampled by the second AD conversion module;
the power control unit calculates and adjusts the power of the satellite beacon filtered by the matched filter;
and the frequency estimation module calculates the real-time Doppler frequency offset absolute value of the satellite beacon processed by the power control unit.
3. The satellite broadcast demodulation apparatus for a fixed-wing aircraft platform as claimed in claim 1, wherein:
the A-TDM demodulation module comprises a first AD conversion module, a preprocessing module, a superframe capturing and tracking module, a channel equalization signal-to-noise ratio estimation module, a subframe extraction module, a subframe carrier recovery module, a subframe soft information extraction module, an LDPC decoding module, a synchronous data UDP conversion module and a decryption module;
the first AD conversion module carries out digital sampling on the received broadcast signals;
the preprocessing module performs matched filtering, power detection and adjustment on the digitally sampled broadcast signals transmitted by the first AD conversion module, and performs frequency difference compensation on the broadcast signals by using a real-time Doppler frequency offset absolute value transmitted by the frequency offset correction module and a variable-rate sampling clock provided by the clock processing module;
the superframe acquisition and tracking module carries out superframe head acquisition, superframe control information analysis and timing tracking on the broadcast signals transmitted by the preprocessing module after frequency difference compensation;
the channel equalization signal-to-noise ratio estimation module adopts a maximum value comparison method to estimate the signal-to-noise ratio of the signal transmitted by the superframe acquisition and tracking module to obtain the signal-to-noise ratio of the current signal, and transmits the signal to the monitoring module; generating a corresponding digital filter to eliminate the influence of phase ambiguity according to the channel parameters set by the monitoring module to obtain a superframe signal;
the subframe extraction module receives a superframe signal which is transmitted by the channel equalization signal-to-noise ratio estimation module and consists of a plurality of subframes, and extracts a superframe body which consists of a timing synchronization carrier synchronization leader sequence, a superframe mode field and a sub data frame in the superframe signal to obtain the required sub data frame and the modulation coding information of the superframe;
the sub-frame carrier recovery module receives the sub-data frame and the super-frame modulation coding information transmitted by the sub-frame extraction module, generates a coherent carrier by using the super-frame modulation coding information, and recovers the original carrier by using the coherent carrier in a mode of making phase difference from the peer-to-peer interval code words in the sub-data frame;
the sub-frame soft information extraction module receives the original carrier transmitted by the sub-frame carrier recovery module, and strips the pilot head and the data block part of the sub-data frame in the original carrier to obtain an original coding data block;
the LDPC decoding module receives the original coding data block transmitted by the sub-frame soft information extraction module and performs LDPC + BCH decoding on the original coding data block to obtain an encrypted fixed-length cell bit stream;
the decryption module receives the fixed-length cell bit stream transmitted by the LDPC decoding module and restores the encrypted fixed-length cell bit stream into an original data bit stream according to a decryption rule;
the synchronous data UDP conversion module carries out UDP encapsulation on the original data bit stream transmitted by the decryption module and transmits the original data bit stream to an external interface;
the monitoring module is respectively connected with the preprocessing module, the channel equalization signal-to-noise ratio estimation module, the superframe capturing and tracking module and the synchronous data UDP conversion module, transmits a setting command of channel parameters and a real-time channel state query command, and displays the received parameters.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1949692A (en) * | 2005-10-13 | 2007-04-18 | 北京泰美世纪科技有限公司 | Multi-carrier digital satellite broadcasting system and digital information transmission method thereof |
| CN101137020A (en) * | 2006-09-01 | 2008-03-05 | 夏普株式会社 | Broadcast receiving apparatus |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7738596B2 (en) * | 2002-09-13 | 2010-06-15 | Broadcom Corporation | High speed data service via satellite modem termination system and satellite modems |
| CA2814203C (en) * | 2010-10-29 | 2017-07-04 | Lilee Systems, Ltd | System and method of frequency offset compensation for radio system with fast doppler shift |
| CN105704076A (en) * | 2014-11-24 | 2016-06-22 | 中兴通讯股份有限公司 | Frequency offset correction method and device |
| CN105610752A (en) * | 2015-12-28 | 2016-05-25 | 休斯网络技术有限公司 | Doppler compensation method for high-speed rail or aircraft VSAT broadband satellite communication |
| CN105847203B (en) * | 2016-03-18 | 2019-05-31 | 熊猫电子集团有限公司 | Onboard satellite communicates the detection of Doppler frequency shift high-precision and compensation method |
| CN207460175U (en) * | 2017-11-08 | 2018-06-05 | 南京天际易达通信技术有限公司 | A kind of satellite communication Doppler shift compensation device and satellite communication system |
| CN207896993U (en) * | 2018-01-31 | 2018-09-21 | 中国电子科技集团公司第五十四研究所 | A kind of burst demodulating equipment suitable for the communication of helicopter gap |
| CN108683621B (en) * | 2018-03-29 | 2021-07-30 | 西安蜂语信息科技有限公司 | Doppler frequency shift correction method and device |
| CN109039970B (en) * | 2018-08-03 | 2021-06-01 | 西安电子科技大学 | Real-time communication method for large dynamic Doppler scene of hypersonic aircraft |
| CN110224743B (en) * | 2019-06-24 | 2021-04-13 | 中国电子科技集团公司第五十四研究所 | Dynamic scene-based forming method of satellite-borne ADS-B test signal |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1949692A (en) * | 2005-10-13 | 2007-04-18 | 北京泰美世纪科技有限公司 | Multi-carrier digital satellite broadcasting system and digital information transmission method thereof |
| CN101137020A (en) * | 2006-09-01 | 2008-03-05 | 夏普株式会社 | Broadcast receiving apparatus |
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