CN217883402U - DRM digital broadcast transmitting system - Google Patents
DRM digital broadcast transmitting system Download PDFInfo
- Publication number
- CN217883402U CN217883402U CN202222402914.3U CN202222402914U CN217883402U CN 217883402 U CN217883402 U CN 217883402U CN 202222402914 U CN202222402914 U CN 202222402914U CN 217883402 U CN217883402 U CN 217883402U
- Authority
- CN
- China
- Prior art keywords
- drm
- signal
- sampling
- radio frequency
- output
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Transmitters (AREA)
Abstract
The application discloses DRM digital broadcast transmitting system, which comprises a DRM content server, a DRM code modulator, a power amplifier, a radio frequency signal sampling monitoring circuit and a broadcast transmitting antenna which are connected in sequence. According to the method and the device, the radio frequency signal sampling monitoring circuit is adopted to monitor data such as the standing-wave ratio of the antenna, the zero position of the antenna and the like, and the supervision efficiency of the whole DRM digital broadcasting transmitting system is improved.
Description
Technical Field
The present application relates to the field of digital broadcasting technologies, and in particular, to a DRM digital broadcasting transmission system.
Background
The wireless broadcast in China is one of the most popular and most influenced mass media, and meets the ever-increasing spiritual culture requirements of the people. The rapid development of emerging media in the information age causes the traditional analog broadcast to be greatly impacted, and in addition, the listening effect of the analog short-wave broadcast is poor, and the fact that audiences are continuously reduced is not in conflict, so that the digitization of the broadcast is in need.
In the traditional analog broadcasting, an audio signal is transmitted to a broadcasting transmitter, the audio signal is carried on a carrier signal in an analog modulation mode, and the carrier signal is amplified and then transmitted to an antenna through a feeder line to transmit radio waves. The analog broadcasting has low cost and large coverage, but has the defects of poor listening quality, waste of spectrum resources and the like. DRM is an international standard for wireless digital broadcasting, is the only open digital broadcasting standard in the world, and implements digital coding modulation of broadcast signals by applying a digital compression coding technique and a digital channel coding modulation technique that are mature in the field of communications. The existing DRM broadcast transmitting system is generally subjected to digital transformation based on an analog broadcast transmitting system, so that the transmission requirement of DRM digital broadcast is met. When in modification, firstly, the audio analog coding modulation board of analog broadcasting is replaced by a DRM content server and a DRM coding modulator, and then digital coding and OFDM modulation of broadcasting signals are realized to obtain COFDM baseband signals.
After DRM digitization transformation is performed on a conventional analog broadcast transmitter, an output monitoring circuit of the original analog transmitter is used, and real-time monitoring and control cannot be effectively performed on a content server and a coded modulator which are specific to DRM broadcast.
SUMMERY OF THE UTILITY MODEL
The embodiment of the application provides a DRM digital broadcast transmitting system, which is used for solving the problem that the traditional output monitoring circuit in the prior art cannot effectively monitor a content server and a code modulator in real time.
In one aspect, an embodiment of the present application provides a DRM digital broadcast transmitting system, including:
a DRM content server encoding the user-defined broadcast multiplexing information into a data stream;
the DRM coding modulator is in communication connection with the DRM content server, channel coding and orthogonal modulation are carried out on the data stream by the DRM coding modulator to obtain a DRM baseband transmission signal, and radio frequency modulation is carried out on the DRM baseband transmission signal by the DRM coding modulator to obtain a DRM radio frequency signal;
the power amplifier is electrically connected with the DRM code modulator and is used for amplifying the DRM radio-frequency signal;
the radio frequency signal sampling monitoring circuit is electrically connected with the power amplifier and is used for sampling the amplified DRM radio frequency signal to obtain a sampling signal and carrying out state monitoring according to the sampling signal;
and the broadcast transmitting antenna is electrically connected with the radio frequency signal sampling monitoring circuit and transmits the amplified DRM radio frequency signal.
In one possible implementation manner, the method further includes: and the network switch is respectively connected with the DRM content server and the DRM code modulator in a communication way.
In one possible implementation manner, the method further includes: and an exciter electrically connected to the power amplifier, the exciter controlling a power level and a frequency band of the power amplifier.
In one possible implementation manner, the method further includes: and the control computer is in communication connection with the network switch and the exciter respectively, and controls the DRM content server and the DRM coding modulator through the network switch and controls the exciter.
In one possible implementation, the control computer is communicatively connected to the exciter via an RS232 serial port.
In one possible implementation, the power amplifier employs a class d bridge circuit to amplify the DRM rf signal.
In one possible implementation, the radio frequency signal sampling monitoring circuit comprises a transformer, a current sampling circuit, an output monitoring circuit and an output sampling circuit; the amplified DRM radio frequency signal output by the power amplifier is input into the transformer, the signal output by the transformer is respectively input into the current sampling circuit and the output sampling circuit, the current sampling circuit carries out current sampling on the signal and then inputs the signal into the output monitoring circuit, and the output sampling circuit carries out incident current voltage, reflected current voltage and antenna current voltage sampling on the signal and then inputs the signal into the output monitoring circuit.
In one possible implementation, the broadcast transmitting antenna is an omnidirectional skywave antenna.
The DRM digital broadcast transmitting system has the following advantages:
1. the digital coding and modulation of the broadcast signals are carried out by adopting a special DSP chip for digital signal processing, so that the complete digitization of the broadcast signals is realized, and the listening experience of a user is improved while the frequency spectrum resources are effectively utilized.
2. The DRM content server and the DRM coding modulator are connected through the network switch, the control computer is connected to the network switch to realize local and remote control of the DRM content server and the DRM coding modulator, the exciter is communicated with the control computer through a serial port to control the power level and the frequency band of the power amplifier, and meanwhile, the radio frequency signal sampling monitoring circuit monitors data such as the standing-wave ratio of the antenna, the zero position of the antenna and the like, so that the monitoring efficiency of the whole DRM digital broadcasting transmitting system is improved.
3. The high-frequency transmission of DRM radio-frequency signals is carried out by adopting the omnidirectional sky-wave antenna which is approximately vertically incident, and the high-frequency transmission has strong propagation capacity.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic diagram illustrating a DRM digital broadcast transmitting system according to an embodiment of the present application;
fig. 2 is a schematic diagram of a radio frequency signal sampling monitoring circuit according to an embodiment of the present application;
FIG. 3 is a schematic diagram of an output sampling circuit according to an embodiment of the present disclosure;
FIG. 4 is a schematic diagram of an output monitoring circuit according to an embodiment of the present disclosure;
fig. 5 is a radiation diagram of an omnidirectional skywave antenna according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.
Fig. 1-5 are schematic diagrams of a DRM digital broadcast transmitting system according to an embodiment of the present application. The present application provides a DRM digital broadcast transmission system, which includes:
a DRM content server encoding user-defined broadcast multiplexing information into a data stream;
the DRM coding modulator is in communication connection with the DRM content server, channel coding and orthogonal modulation are carried out on the data stream by the DRM coding modulator to obtain a DRM baseband transmission signal, and radio frequency modulation is carried out on the DRM baseband transmission signal by the DRM coding modulator to obtain a DRM radio frequency signal;
the power amplifier is electrically connected with the DRM code modulator and is used for amplifying the DRM radio-frequency signal;
the radio frequency signal sampling monitoring circuit is electrically connected with the power amplifier and is used for sampling the amplified DRM radio frequency signal to obtain a sampling signal and monitoring the state according to the sampling signal;
and the broadcast transmitting antenna is electrically connected with the radio frequency signal sampling monitoring circuit and transmits the amplified DRM radio frequency signal.
Illustratively, after channel coding and quadrature modulating the data stream to obtain the DRM baseband transmission signal, the DRM coded modulator needs to configure a required carrier frequency, and modulate the DRM baseband transmission signal based on the carrier frequency to obtain the DRM radio frequency signal. The radio frequency signal sampling monitoring circuit samples the DRM radio frequency signal and feeds the DRM radio frequency signal back to the DRM coding modulator, and the DRM coding modulator can also control the transmitting power of the power amplifier.
In an embodiment of the present application, further comprising: and the network switch is in communication connection with the DRM content server and the DRM coding modulator respectively. The network switch has access to the internet.
Specifically, the DRM code modulator comprises a DSP chip TMS320C6748 and a peripheral circuit, user-defined broadcast multiplexing information is sent to a network interface of the DRM code modulator from a network switch, the DRM code modulator analyzes input data and then carries out channel coding and OFDM modulation, meanwhile, the DRM code modulator is configured with a required carrier frequency, a real part can obtain a DRM radio frequency signal after carrying out radio frequency modulation on a DRM baseband transmission signal, and then the DRM radio frequency signal is sent to an input end of the power amplifier through a cable.
The network switch may be a rack-mounted structure, and the DRM code modulator and the DRM content server are connected to the rack-mounted network switch.
In a possible embodiment, further comprising: and an exciter electrically connected to the power amplifier, the exciter controlling a power level and a frequency band of the power amplifier. And the control computer is respectively in communication connection with the network switch and the exciter, and controls the DRM content server and the DRM coding modulator through the network switch and controls the exciter at the same time.
Illustratively, the control computer and the exciter communicate through an RS232 serial port. The exciter is located in a large cabinet frame about 3 meters from the control computer, and a serial cable connects the control computer to the rear of the exciter through a rear door of the cabinet. And a jumper needs to be provided on the exciter to connect the exciter in series through RS 232.
The power amplifier can adopt a class D bridge circuit to carry out power amplification on DRM radio-frequency signals, 8 IRF360 field-effect tubes in the class D bridge circuit work in a switching state to form two-way amplifiers, and each way of amplifier is efficiently amplified by 4 field-effect tubes. The output signal of the DRM coding modulator is sent to one input port of the power amplifier, the exciter serial port outputs a signal for controlling the power level and the frequency band of the power amplifier and sends the signal to the other input port of the power amplifier, the two paths of signals are subjected to final power amplification in the power amplifier, and the output port of a transformer in the power amplifier is sent to a broadcast transmitting antenna for transmitting and transmitting.
Also, the DRM content server, the code modulator, and the power amplifier may be controlled locally and remotely at the station by laying an ethernet cable overhead, connecting a network switch to a router accessible to the internet, and connecting the network switch to a control computer.
In one possible embodiment, the radio frequency signal sampling monitoring circuit comprises a transformer, a current sampling circuit, an output monitoring circuit and an output sampling circuit; the amplified DRM radio frequency signal output by the power amplifier is input into the transformer, the signal output by the transformer is respectively input into the current sampling circuit and the output sampling circuit, the current sampling circuit carries out current sampling on the signal and then inputs the signal into the output monitoring circuit, and the output sampling circuit carries out incident current voltage, reflected current voltage and antenna current voltage sampling on the signal and then inputs the signal into the output monitoring circuit.
Illustratively, the output monitoring circuit mainly monitors various signals sent by current sampling and output sampling, wherein the standing wave ratio of the antenna and the null position of the antenna are used as indexes for measuring impedance matching between an antenna feeder system and a transmitter, and the numerical value change of the antenna and the null position directly influences the output power of the transmitter. The output monitoring circuit firstly adjusts the amplitude of the antenna voltage from the output sampling circuit, adjusts the phase of the antenna current, and matches the normal state when the sampling waveforms of the output sampling circuit and the antenna current are equal in size and consistent in phase. At this time, the voltage at TP1 is substantially zero as in fig. 4. When the voltage on the TP1 is detuned, the voltage becomes larger, when the voltage exceeds the standing-wave ratio threshold voltage of the antenna in the figure, the comparator LM360 is turned over, the high level output from the pin 6 is directly fed back to a relay protection device of the DRM code modulator, and the data stream transmission of the DRM code modulator is blocked.
In one possible embodiment, the broadcast transmitting antenna is an omnidirectional skywave antenna.
By way of example, DRM rf signal transmission may be performed using a near-normal incidence omni-directional skywave antenna that provides skywave coverage over a wide frequency range while having strong short-range broadcast capability, particularly in mountains and other locations where obstructions may be present.
While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the present application.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.
Claims (8)
1. A DRM digital broadcast transmission system, comprising:
a DRM content server encoding the user-defined broadcast multiplexing information into a data stream;
the DRM coding modulator is in communication connection with the DRM content server, performs channel coding and quadrature modulation on the data stream to obtain a DRM baseband transmission signal, and performs radio frequency modulation on the DRM baseband transmission signal to obtain a DRM radio frequency signal;
the power amplifier is electrically connected with the DRM code modulator and is used for amplifying the DRM radio-frequency signal;
the radio frequency signal sampling monitoring circuit is electrically connected with the power amplifier and is used for sampling the amplified DRM radio frequency signal to obtain a sampling signal and carrying out state monitoring according to the sampling signal;
and the broadcast transmitting antenna is electrically connected with the radio frequency signal sampling monitoring circuit and transmits the amplified DRM radio frequency signal.
2. The DRM digital broadcast transmitting system of claim 1, further comprising:
and the network switch is in communication connection with the DRM content server and the DRM code modulator respectively.
3. The DRM digital broadcast transmitting system of claim 2, further comprising:
an exciter electrically connected to the power amplifier, the exciter controlling a power level and a frequency band of the power amplifier.
4. The DRM digital broadcasting transmission system of claim 3, further comprising:
and the control computer is in communication connection with the network switch and the exciter respectively, and controls the DRM content server and the DRM coding modulator through the network switch and controls the exciter.
5. The DRM digital broadcast transmitting system of claim 4 wherein the control computer is communicatively coupled to the exciter via an RS232 serial port.
6. The DRM digital broadcast transmission system of claim 1, wherein the power amplifier amplifies the DRM rf signal using a class d bridge circuit.
7. The DRM digital broadcasting transmission system of claim 1, wherein the rf signal sampling monitoring circuit comprises a transformer, a current sampling circuit, an output monitoring circuit and an output sampling circuit;
the amplified DRM radio frequency signal output by the power amplifier is input into the transformer, the signal output by the transformer is respectively input into the current sampling circuit and the output sampling circuit, the current sampling circuit carries out current sampling on the signal and then inputs the signal into the output monitoring circuit, and the output sampling circuit carries out incident current voltage, reflected current voltage and antenna current voltage sampling on the signal and then inputs the signal into the output monitoring circuit.
8. The DRM digital broadcast transmission system of claim 1, wherein the broadcast transmission antenna is an omni-directional skywave antenna.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222402914.3U CN217883402U (en) | 2022-09-09 | 2022-09-09 | DRM digital broadcast transmitting system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222402914.3U CN217883402U (en) | 2022-09-09 | 2022-09-09 | DRM digital broadcast transmitting system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217883402U true CN217883402U (en) | 2022-11-22 |
Family
ID=84082169
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202222402914.3U Active CN217883402U (en) | 2022-09-09 | 2022-09-09 | DRM digital broadcast transmitting system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217883402U (en) |
-
2022
- 2022-09-09 CN CN202222402914.3U patent/CN217883402U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101409590B (en) | Mobile phone radio frequency test method | |
| CN110098840B (en) | Radio frequency device and terminal equipment | |
| CN103580720A (en) | Same-frequency full-duplex self-interference offset device | |
| CN105744333A (en) | LNB module used for receiving satellite television signals and corresponding satellite television set top box | |
| CN201233956Y (en) | Fast alignment device for antenna | |
| MXPA02012441A (en) | Method and apparatus for multiple band transmission. | |
| CN102412917A (en) | Multiple-antenna measurement system and method based on network analyzer and RF (radio frequency) switch | |
| CN2859935Y (en) | Digital frequency wireless sending receiving device | |
| CN108011641A (en) | A kind of aerial retransmission unit of LTE base station | |
| CN217883402U (en) | DRM digital broadcast transmitting system | |
| CN201274467Y (en) | Indoor signal coverage system and repeater applied to the system | |
| CN203872199U (en) | Self-interference elimination circuit of wireless combination system | |
| WO2023082837A1 (en) | Terminal chip, base station device, and bidirectional wireless communication system | |
| CN201536424U (en) | Wireless digital induction broadcasting station | |
| CN111565054B (en) | Variable frequency communication transmission method and system | |
| CN201887917U (en) | Wireless microphone and receiver for teaching | |
| CN101742214A (en) | Method and device for transmitting 100BASE-T Ethernet signals and CATV signals by utilizing coaxial cable | |
| CN210200962U (en) | Receiving antenna for enhancing Wi-Fi signals | |
| CN204967998U (en) | Clear audio frequency surround processor that imbeds of high standard | |
| CN208424639U (en) | A kind of wireless audio-video transmission equipment | |
| CN113225132A (en) | 5G base station coupling zoom-out system | |
| CN102904657B (en) | Frequency modulation broadcast listening monitoring receiver | |
| WO2019101024A1 (en) | Network routing device, network data transmission method, and network access device | |
| CN208836315U (en) | A kind of wireless video transmission system | |
| CN204596129U (en) | Miniaturized high-speed number for state net II type concentrator passes communication module |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |