CN202737877U - Optical fiber repeater of mobile multimedia broadcast and signal transmission system thereof - Google Patents
Optical fiber repeater of mobile multimedia broadcast and signal transmission system thereof Download PDFInfo
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- CN202737877U CN202737877U CN 201120529986 CN201120529986U CN202737877U CN 202737877 U CN202737877 U CN 202737877U CN 201120529986 CN201120529986 CN 201120529986 CN 201120529986 U CN201120529986 U CN 201120529986U CN 202737877 U CN202737877 U CN 202737877U
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Abstract
The utility model discloses an optical fiber repeater of mobile multimedia broadcast, sharing a base station with mobile communication. The optical fiber repeater comprises a photo-electric conversion device, a first filter, a low-noise amplifier module, a medium-frequency processing module, a power amplifier module and a second filter which are connected in sequence. Optical signals enter the photo-electric conversion device through an optical fiber and are converted into radio frequency signals; the radio frequency signals are sent into the first filter; the first filter filters the signals of a mobile communication channel and selects useful CMMB signals; the CMMB signals are sent into the low-noise amplifier module for amplification; the amplified CMMB signals are then sent into the medium frequency processing module for processing; and the processed signals are amplified by the power amplifier module and re-filtered by the second filter to be output. The utility model further discloses a transmission system of the optical fiber repeater. The device and the entire transmission system thereof provided by the utility model provide a solution for the problem that transmitter-receiver isolation has great difficulty and have the advantages of easy construction, no self-excitation, omnidirectional or directional coverage, large coverage area and low investment cost.
Description
Technical field
The utility model relates to the technical field of Mobile Multimedia Broadcasting, is a kind of specifically and the optical fiber repeater of the Mobile Multimedia Broadcasting of mobile communication sharing base station and the emission system of signal thereof.
Background technology
CMMB is that the abbreviation of English China Mobile Multimedia Broadcasting is called for short, and means China Mobile multimedia broadcasting.CMMB mainly provides radio and television services towards terminals such as the small screen portable hand-held terminals such as mobile phone, PDA and in-car TVs.Mobile Multimedia Broadcasting CMMB is the broadcast type mobile phone television standard of being formulated by China, and its signal coverage mode mainly is to carry out outdoor cover on a large scale by transmitting base station, mends a little and the blind area covering by wireless intra-frequency repeater.
Transmitting base station cover to adopt optical fiber or microwave mode transmission code stream, builds aloft machine room and launching tower, provides reference clock synchronous by the GPS receiver, and code stream through modulation and after amplifying by the antenna transmission on launching tower top out.It is the mode of retransmitting by aerial coupled signal and amplification that wireless intra-frequency repeater covers, such as Fig. 1, build Simple machinery room in footprint edges, receive aerial CMMB signal and send into wireless discharging-directly station and amplify by the directional antenna that is positioned at eminence, be covered to by directional transmitting antenna again and treat the overlay area.Wireless intra-frequency repeater covers and signal is not changed, transparent transmission just, after the radiofrequency signal of introducing amplified again by transmission antennas transmit out.The signal of finishing between repeater equipment and the antenna with radio frequency coaxial-cable transmits.
The advantage of wireless intra-frequency repeater is that addressing is easier to, and the computer room construction difficulty is lower, and it is synchronous to need not GPS, and auxiliary facility is comparatively simple, and the construction period is short, and cost of investment is low.But there is following shortcoming in it: with frequently amplifying the dual-mode antenna isolation difficult, easily self-excitation is subjected to transmitting-receiving isolation restriction, can't adopt high-power repeater, coverage is little and can only oriented cover.Wherein major defect is large with frequently transmitting transmitting-receiving isolation difficulty, can only carry out among a small circle directed fan-shaped covering; Need build Simple machinery room simultaneously, solve the problems such as power supply, lightning protection, ground connection.Therefore it is had relatively high expectations to field condition, and range of application is limited, can't realize the zone that need omnidirectional covers or need cover on a large scale.
The utility model content
The purpose of this utility model provides a kind of large problem of transmitting-receiving isolation difficulty that solves, but and construction easily, without the optical fiber repeater of self-excitation omnidirectional or oriented cover, that coverage is large, cost of investment is low and the Mobile Multimedia Broadcasting mobile communication sharing base station.
The utility model is realized by following technical proposals.
A kind of optical fiber repeater of Mobile Multimedia Broadcasting of and mobile communication sharing base station, it is characterized in that: the optical fiber repeater of the Mobile Multimedia Broadcasting of described and mobile communication sharing base station is input as light signal, be output as radiofrequency signal, optical fiber repeater comprises the light-electrical switching device that connects in turn, filter, the LNA module, the intermediate frequency process module, power amplifier module and filter, light signal enters light-electrical switching device by optical fiber, light signal is converted into radiofrequency signal, send into filter, signal by its filtering mobile communication frequency range, select useful CMMB signal, after sending into again the intermediate frequency process module and processing, through the power amplifier amplification and through again exporting after the filtering, described intermediate frequency process module is by down-conversion, intermediate frequency filtering, three parts of up-conversion consist of, its Main Function is that the CMMB signal frequency is downconverted to intermediate-frequency band by uhf band, carry out more thorough, clean filtering changes back to uhf band again through filtered intermediate-freuqncy signal.
Described LNA module comprises the in turn low noise amplification unit of circuit connection, the ALC control unit, gain adjustment unit and second level amplifying unit, the ALC control unit is provided with external control interface, wherein the low noise amplification unit is used for satisfying the amplification of CMMB 470-800MHz full frequency band, lower noise factor and good inband flatness are provided, described ALC control unit is controlled by external control interface, when the power detection of power amplifier module and control unit detect power output when excessive, then can send corresponding control signal, be conveyed to the ALC control unit by external control interface, it is had an effect, invariable with the power output that keeps power amplifier module, described gain adjustment unit is used for gain-adjusted, to guarantee that the complete machine gain is as suitable scope, described second level amplifying unit provides wider bandwidth and good inband flatness for the gain amplifying unit.
Described intermediate frequency process module comprises the first mixing unit, first order amplifying unit, the intermediate frequency filtering unit, second level amplifying unit and the second mixing unit and the first local oscillator unit and the second local oscillator unit, the first local oscillator unit is connected with the first mixing element circuit, the second local oscillator unit is connected with the second mixing element circuit, the first mixing unit is connected with first order amplifying unit circuit, first order amplifying unit is connected with the intermediate frequency filtering element circuit, the intermediate frequency filtering unit is connected with second level amplifying unit circuit, second level amplifying unit is connected with the second mixing element circuit, wherein the first mixing unit carries out mixing by local oscillation signal and the CMMB signal that the first local oscillator unit produces, be the IF-FRE signal with the CMMB signal frequency conversion, described first order amplifying unit amplifies intermediate-freuqncy signal, remedy the gain loss that the intermediate frequency filtering unit brings, described intermediate frequency filtering unit carries out intermediate-freuqncy signal thoroughly, clean filtering is processed, described second level amplifying unit amplifies intermediate-freuqncy signal, remedy the gain loss that the intermediate frequency filtering unit brings, described the second mixing unit carries out mixing by local oscillation signal and intermediate-freuqncy signal that the second local oscillator unit produces, is the primary frequency signal with CMMB intermediate-freuqncy signal again frequency conversion.
Described power amplifier module comprises promotion amplifying unit, power amplifier unit and power detection and control unit, described promotion amplifying unit gains the CMMB signal and power amplification, described power amplifier unit is amplified to desired value with signal power, and finally send into antenna-feedback system and export, described power detection and control unit calculate output power value by the mode of coupled power and by software, simultaneously send corresponding control signal according to the real output situation, to reach the purpose of constant output.
Described optical fiber repeater input optical fibre wavelength 1.55 μ m/1.31 μ m, reference frequency output 470～798MHz, maximum gain 〉=60dB, gain-adjusted scope 〉=30dB, automatic electric-level control 〉=30dB, output voltage standing-wave ratio≤1.5, inband flatness ± 0.5dB (@8M bandwidth of fc ± 3.756MHz), propagation delay time≤5 μ s, noise factor≤5dB, stray radiation≤-36dBm.
The utility model also provides a kind of emission system of optical fiber repeater of Mobile Multimedia Broadcasting of launching aforementioned and mobile communication sharing base station, and it is characterized in that: described emission system comprises optical sender, optical cable, light along separate routes or optical coupler, Mobile Multimedia Broadcasting optical fiber repeater and transmitting antenna.Optical sender converts the Mobile Multimedia Broadcasting radiofrequency signal light signal to and sneaks into the mobile communication optical-fiber network, arrive behind the mobile communication base station by light along separate routes or optical coupler take out a part of light signal, by optical fiber repeater convert radiofrequency signal to and amplify after again by transmission antennas transmit out.
The utility model compared with prior art has the following advantages.
Adopt technical scheme described in the utility model, the CMMB radiofrequency signal is converted to light signal and sneaks into mobile communication optical fiber by optical sender, arrive behind the mobile communication base station by light along separate routes or optical coupler take out a part of light signal, by the optical receiver of optical fiber repeater convert radiofrequency signal to and amplify after again by orientation or omni-directional antenna transmission out.The utility model is the optical fiber information source owing to what introduce, and namely its signal of CMMB optical fiber repeater is input as light signal, is output as radiofrequency signal.There is not the problem that needs the transmitting-receiving isolation with frequently covering, is subjected to such environmental effects little, can carry out orientation or omnidirectional and cover, yet the available high-power large tracts of land or large-scale with frequently covering of carrying out.
The CMMB optical fiber repeater emission system of the utility model and mobile communication sharing base station itself and mobile communication share optical cable transmission signal, therefore do not need again to lay optical cable again, have save many links, and have saved in a large number cost.
The CMMB optical fiber repeater emission system of the utility model and mobile communication sharing base station itself and mobile communication base station sharing base resource, comprise the facilities such as machine room, steel tower, power supply, lightning protection, ground connection, can not only effectively save cost of investment, also shorten the engineering construction cycle.
Equipment described in the utility model and whole emission system thereof have solved the large problem of transmitting-receiving isolation difficulty, but have construction easily, without self-excitation omnidirectional or oriented cover, coverage is large, cost of investment is low advantage.
Description of drawings
Fig. 1 is that the wireless intra-frequency repeater of prior art covers theory diagram;
Fig. 2 is the optical fiber repeater functional-block diagram of the Mobile Multimedia Broadcasting of the utility model and mobile communication sharing base station;
Fig. 3 is the emission system theory diagram of optical fiber repeater of the Mobile Multimedia Broadcasting of the utility model and mobile communication sharing base station;
Fig. 4 is the LNA module principle block diagram of optical fiber repeater of the Mobile Multimedia Broadcasting of the utility model and mobile communication sharing base station;
Fig. 5 is processing module functional-block diagram frequently among the optical fiber repeater of Mobile Multimedia Broadcasting of the utility model and mobile communication sharing base station;
Fig. 6 is the power amplifier module functional-block diagram of optical fiber repeater of the Mobile Multimedia Broadcasting of the utility model and mobile communication sharing base station.
Embodiment
The below is described in further detail the optical fiber repeater of the Mobile Multimedia Broadcasting of the utility model and mobile communication sharing base station.
Such as Fig. 2, the optical fiber repeater of the Mobile Multimedia Broadcasting of the utility model and mobile communication sharing base station, it is input as light signal, be output as radiofrequency signal, optical fiber repeater comprises the light-electrical switching device that connects in turn, filter, the LNA module, the intermediate frequency process module, power amplifier module and filter, light signal enters light-electrical switching device by optical fiber, light signal is converted to radiofrequency signal, send into filter, signal by its filtering mobile communication frequency range, select useful CMMB signal, sending into the LNA module amplifies again, sending into the intermediate frequency process module processes again, through the power amplifier amplification and through again exporting after the filtering, described intermediate frequency process module is by down-conversion, intermediate frequency filtering, three parts of up-conversion consist of, and its Main Function is that the CMMB signal frequency is downconverted to intermediate-frequency band by uhf band, carry out more thoroughly filtering, again change back to uhf band through filtered intermediate-freuqncy signal.
Such as Fig. 4, the LNA module comprises the in turn low noise amplification unit of circuit connection, the ALC control unit, gain adjustment unit and second level amplifying unit, the ALC control unit is provided with external control interface, wherein the low noise amplification unit is used for satisfying the amplification of CMMB 470-800MHz full frequency band, lower noise factor and good inband flatness are provided, the ALC control unit is controlled by external control interface, when the power detection of power amplifier module and control unit detect power output when excessive, then can send corresponding control signal, be conveyed to the ALC control unit by external control interface, it is had an effect, invariable with the power output that keeps power amplifier module, described gain adjustment unit is used for gain-adjusted, to guarantee that the complete machine gain is as suitable scope, described second level amplifying unit provides wider bandwidth and good inband flatness for the gain amplifying unit.
Such as Fig. 5, the intermediate frequency process module comprises the first mixing unit, first order amplifying unit, the intermediate frequency filtering unit, second level amplifying unit and the second mixing unit and the first local oscillator unit and the second local oscillator unit, the first local oscillator unit is connected with the first mixing element circuit, the second local oscillator unit is connected with the second mixing element circuit, the first mixing unit is connected with first order amplifying unit circuit, first order amplifying unit is connected with the intermediate frequency filtering element circuit, the intermediate frequency filtering unit is connected with second level amplifying unit circuit, second level amplifying unit is connected with the second mixing element circuit, wherein the first mixing unit carries out mixing by local oscillation signal and the CMMB signal that the first local oscillator unit produces, be the IF-FRE signal with the CMMB signal frequency conversion, described first order amplifying unit amplifies intermediate-freuqncy signal, remedy the gain loss that the intermediate frequency filtering unit brings, described intermediate frequency filtering unit carries out intermediate-freuqncy signal thoroughly, clean filtering is processed, described second level amplifying unit amplifies intermediate-freuqncy signal, remedy the gain loss that the intermediate frequency filtering unit brings, described the second mixing unit carries out mixing by local oscillation signal and intermediate-freuqncy signal that the second local oscillator unit produces, is the primary frequency signal with CMMB intermediate-freuqncy signal again frequency conversion.
Such as Fig. 6, power amplifier module comprises promotion amplifying unit, power amplifier unit and power detection and control unit, promoting amplifying unit gains the CMMB signal and power amplification, power amplifier unit is amplified to desired value with signal power, and finally send into antenna-feedback system and export, power detection and control unit: calculate output power value by the mode of coupled power and by software, send corresponding control signal according to the real output situation simultaneously, to reach the purpose of constant output.
The operation principle of optical fiber repeater described in the utility model: light signal enters light-electrical switching device by optical fiber, light signal is converted into radiofrequency signal, send into filter, signal by its filtering mobile communication frequency range, select useful CMMB signal, sending into the LNA module amplifies again, send into again the intermediate frequency process module, intermediate frequency process comprises down-conversion, intermediate frequency filtering, three parts of up-conversion, its Main Function is that the CMMB signal frequency is downconverted to intermediate-frequency band by uhf band, carry out more thoroughly filtering, again change back to uhf band through filtered intermediate-freuqncy signal, through the power amplifier amplification and through again exporting after the filtering.The utility model is the optical fiber information source owing to what introduce, so does not have the problem of transmitting-receiving isolation, can realize omnidirectional's covering and covering on a large scale.Existing mobile communication base station resource be can take full advantage of simultaneously, machine room and steel tower need not to build again.
Such as Fig. 3, the utility model also provides a kind of emission system of optical fiber repeater of Mobile Multimedia Broadcasting of aforementioned and mobile communication sharing base station, and namely this emission system comprises optical sender, optical cable, light along separate routes or optical coupler, Mobile Multimedia Broadcasting optical fiber repeater and transmitting antenna.Optical sender converts the Mobile Multimedia Broadcasting radiofrequency signal light signal to and sneaks into the mobile communication optical-fiber network, arrive behind the mobile communication base station by light along separate routes or optical coupler take out a part of light signal, by optical fiber repeater convert radiofrequency signal to and amplify after again by transmission antennas transmit out.
The circuit parameter that the utility model optical fiber repeater reaches optimal performance has
| Project | Technical indicator |
| The input optical fibre wavelength | 1.55μm/1.31μm |
| Reference frequency output | 470～798MHz |
| Maximum gain | ≥60dB |
| The gain-adjusted scope | ≥30dB |
| Automatic electric-level control | ≥30dB |
| The output voltage standing-wave ratio | ≤1.5 |
| Inband flatness | ± 0.5dB (the@8M bandwidth of fc ± 3.756MHz) |
| Propagation delay time | ≤5μs |
| Noise factor | ≤5dB |
| Stray radiation | ≤-36dBm (5MHz～1GHz is beyond the spectrum mask) |
Claims (5)
1. optical fiber repeater with the Mobile Multimedia Broadcasting of mobile communication sharing base station is characterized in that: the optical fiber repeater of the Mobile Multimedia Broadcasting of described and mobile communication sharing base station is input as light signal, is output as radiofrequency signal,
Optical fiber repeater comprises the light-electrical switching device that connects in turn, filter, the LNA module, the intermediate frequency process module, power amplifier module and filter, light signal enters light-electrical switching device by optical fiber, light signal is converted to radiofrequency signal, send into filter, signal by its filtering mobile communication frequency range, select useful CMMB signal, sending into the LNA module amplifies again, after sending into again the intermediate frequency process module and processing, through the power amplifier amplification and through again exporting after the filtering, described intermediate frequency process module is by down-conversion, intermediate frequency filtering, three parts of up-conversion consist of, its Main Function is that the CMMB signal frequency is downconverted to intermediate-frequency band by uhf band, carry out more thoroughly filtering, again change back to uhf band through filtered intermediate-freuqncy signal.
2. the optical fiber repeater of the Mobile Multimedia Broadcasting of according to claim 1 and mobile communication sharing base station, it is characterized in that: described LNA module comprises the in turn low noise amplification unit of circuit connection, the ALC control unit, gain adjustment unit and second level amplifying unit, the ALC control unit is provided with external control interface, wherein the low noise amplification unit is used for satisfying the amplification of CMMB 470-800MHz full frequency band, lower noise factor and good inband flatness are provided, described ALC control unit is controlled by external control interface, when the power detection of power amplifier module and control unit detect power output when excessive, then can send corresponding control signal, be conveyed to the ALC control unit by external control interface, it is had an effect, invariable with the power output that keeps power amplifier module, described gain adjustment unit is used for gain-adjusted, to guarantee that the complete machine gain is as suitable scope, described second level amplifying unit provides wider bandwidth and good inband flatness for the gain amplifying unit.
3. the optical fiber repeater of the Mobile Multimedia Broadcasting of according to claim 1 and mobile communication sharing base station, it is characterized in that: described intermediate frequency process module comprises the first mixing unit, first order amplifying unit, the intermediate frequency filtering unit, second level amplifying unit and the second mixing unit and the first local oscillator unit and the second local oscillator unit, the first local oscillator unit is connected with the first mixing element circuit, the second local oscillator unit is connected with the second mixing element circuit, the first mixing unit is connected with first order amplifying unit circuit, first order amplifying unit is connected with the intermediate frequency filtering element circuit, the intermediate frequency filtering unit is connected with second level amplifying unit circuit, second level amplifying unit is connected with the second mixing element circuit, wherein the first mixing unit carries out mixing by local oscillation signal and the CMMB signal that the first local oscillator unit produces, be the IF-FRE signal with the CMMB signal frequency conversion, described first order amplifying unit amplifies intermediate-freuqncy signal, remedy the gain loss that the intermediate frequency filtering unit brings, described intermediate frequency filtering unit carries out intermediate-freuqncy signal thoroughly, clean filtering is processed, described second level amplifying unit amplifies intermediate-freuqncy signal, remedy the gain loss that the intermediate frequency filtering unit brings, described the second mixing unit carries out mixing by local oscillation signal and intermediate-freuqncy signal that the second local oscillator unit produces, is the primary frequency signal with CMMB intermediate-freuqncy signal again frequency conversion.
4. the optical fiber repeater of the Mobile Multimedia Broadcasting of according to claim 1 and mobile communication sharing base station, it is characterized in that: described power amplifier module comprises the promotion amplifying unit, power amplifier unit and power detection and control unit, described promotion amplifying unit gains the CMMB signal and power amplification, described power amplifier unit is amplified to desired value with signal power, and finally send into antenna-feedback system and export, described power detection and control unit: calculate output power value by the mode of coupled power and by software, simultaneously send corresponding control signal according to the real output situation, to reach the purpose of constant output.
5. emission system of launching the optical fiber repeater of the described Mobile Multimedia Broadcasting with the mobile communication sharing base station of the arbitrary claim of claim 1-4, it is characterized in that: described emission system comprises optical sender, optical cable, light shunt or optical coupler, Mobile Multimedia Broadcasting optical fiber repeater and transmitting antenna, optical sender converts the Mobile Multimedia Broadcasting radiofrequency signal light signal to and sneaks into the mobile communication optical-fiber network, arrive behind the mobile communication base station by light along separate routes or optical coupler take out a part of light signal, by optical fiber repeater convert radiofrequency signal to and amplify after again by transmission antennas transmit out.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201120529986 CN202737877U (en) | 2011-12-16 | 2011-12-16 | Optical fiber repeater of mobile multimedia broadcast and signal transmission system thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201120529986 CN202737877U (en) | 2011-12-16 | 2011-12-16 | Optical fiber repeater of mobile multimedia broadcast and signal transmission system thereof |
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| Publication Number | Publication Date |
|---|---|
| CN202737877U true CN202737877U (en) | 2013-02-13 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201120529986 Expired - Lifetime CN202737877U (en) | 2011-12-16 | 2011-12-16 | Optical fiber repeater of mobile multimedia broadcast and signal transmission system thereof |
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| Country | Link |
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| CN (1) | CN202737877U (en) |
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2011
- 2011-12-16 CN CN 201120529986 patent/CN202737877U/en not_active Expired - Lifetime
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20130213 |
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| CX01 | Expiry of patent term |