CN102469469A - Vehicle-mounted double-channel correcting repeater - Google Patents
Vehicle-mounted double-channel correcting repeater Download PDFInfo
- Publication number
- CN102469469A CN102469469A CN2010105482411A CN201010548241A CN102469469A CN 102469469 A CN102469469 A CN 102469469A CN 2010105482411 A CN2010105482411 A CN 2010105482411A CN 201010548241 A CN201010548241 A CN 201010548241A CN 102469469 A CN102469469 A CN 102469469A
- Authority
- CN
- China
- Prior art keywords
- downlink
- channel
- converter
- signal
- uplink
- 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 claims description 8
- 238000006243 chemical reaction Methods 0.000 claims description 7
- 230000009977 dual effect Effects 0.000 claims description 7
- 238000012545 processing Methods 0.000 claims description 6
- 238000001514 detection method Methods 0.000 claims description 5
- 230000003044 adaptive effect Effects 0.000 claims description 2
- 239000011248 coating agent Substances 0.000 claims 1
- 238000000576 coating method Methods 0.000 claims 1
- 238000002360 preparation method Methods 0.000 claims 1
- 238000004891 communication Methods 0.000 abstract description 5
- 238000012937 correction Methods 0.000 abstract description 3
- 238000012360 testing method Methods 0.000 description 12
- 238000010295 mobile communication Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 6
- 238000005562 fading Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000035515 penetration Effects 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 230000002238 attenuated effect Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000009533 lab test Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
Images
Landscapes
- Radio Relay Systems (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
The invention relates to a vehicle-mounted double-channel correcting repeater, which comprises a first duplexer, a second duplexer, a repeat end duplexer, a double-channel downlink and a double-channel uplink, wherein the first duplexer is connected with a first donor antenna, the automatic frequency control (AFC) module, and the double-channel uplink comprises an uplink low noise amplifier (LNA), an uplink frequency selection unit, a power divider and two uplink power amplifiers; and the vehicle-mounted double-channel correcting repeater has an AFC correction function and an automatic gain control (AGC) function, a main downlink signal of at least one of the two channels is appropriately selected to have the frequency compensation through the AFC module, so the influence of Doppler frequency shift on subdistrict signal switch in high speed movement can be avoided, a terminal which moves at a high speed is guaranteed to normally demodulate a signal of a base station, and the problems such as call drop of the terminal, poor communication quality and slow data download, caused by the frequency deviation, can be solved. The vehicle-mounted double-channel correcting repeater can be matched with the double donor antennas to be widely applied to the high-quality coverage of the communication signal in a moving body such as a high-speed rail carriage.
Description
Technical Field
The invention relates to a double-channel deviation rectifying repeater for a high-speed railway carriage, which is suitable for mobile communication signal coverage in a high-speed railway carriage and can ideally solve the problem of cell switching of mobile communication.
Background
In a high-speed scene, for example, the highest moving speed of a user in a high-speed railway car can reach 430Km/h, the moving speed will have the following effects on a mobile communication network: 1. the speed is increased to bring larger Doppler frequency shift and Doppler frequency dispersion to a certain degree, so that the signal-to-noise ratio of downlink signals is reduced; 2. the high-speed movement increases the times of cell switching in unit time; 3. high speed motion will deteriorate the success rate of cell handover; 4. signals in a high-speed motion environment generate a fast fading phenomenon, so that a call of a terminal is dropped; 5. since the high speed railway cars are closed, the penetration loss of the cars will affect the quality of the signal coverage.
When the terminal is in a high-speed environment and a train reaches 400Km/h, according to the scheme of high-speed rail private network coverage, the maximum frequency deviation of GSM reaches 450Hz, and TD-SCDMA reaches 750 Hz. Referring to fig. 5 of a terminal operating environment, when a radio remote unit RRU1 and a radio remote unit RRU2 are the same cell, a signal received by the terminal is a signal of the same frequency band of RRU1 and RRU2, but since the terminal receives a signal of the same cell in which the RRU1 is negatively biased and the RRU2 is positively biased in high-speed motion, for the terminal, due to doppler frequency offset, when the frequency offset is large and exceeds the frequency offset receiving range of the mobile phone, the mobile phone will drop the call; meanwhile, between the RRU1 and the RRU2, one path of signal mainly used by the terminal regards the other path of signal as a co-frequency interference signal, and at this time, in the handover zones of the RRU1 and the RRU2, the strength of the main signal is equivalent to that of the interference signal, and at this time, the terminal is likely to drop the call.
When the RRU1 and the RRU2 are signals of different cells, and the high-speed rail private network is an inter-frequency network, the RRU1 and the RRU2 are signals of two different frequency bands. When the terminal is carried by the RRU1 to the RRU2 at a high speed, the active signal will be switched from the RRU1 to the RRU 2. When the terminal is in the handover band, the frequency offset of the RRU1 is larger and weaker, the frequency offset of the RRU2 is smaller and weaker, and the signal is stronger and stronger. If the frequency offset of the RRU1 exceeds the frequency offset receiving range of the mobile phone, and the field strength is rapidly weakened due to fast fading, if the frequency offset of the RRU2 does not reach the frequency offset receiving range of the mobile phone at this time, and the field strength does not reach the handover threshold, the call drop may occur due to unsuccessful handover.
Disclosure of Invention
In order to solve the influence on the coverage quality of mobile communication signals in a high-speed environment, such as the high-speed railway train carriage, the invention provides a vehicle-mounted double-channel rectification repeater so as to solve the problem of mobile communication signal coverage in the high-speed railway train carriage, especially the problem of cell switching of mobile communication.
The invention discloses a vehicle-mounted double-channel rectification repeater, which comprises: the first duplexer is connected with the first donor antenna, the second duplexer is connected with the second donor antenna, and the retransmission terminal duplexer is connected with the second donor antenna; wherein the dual channel downlink includes: a downlink PA (power amplifier) and AFC (automatic frequency control) module, wherein two input ends of the AFC module are respectively connected with a downlink signal output end of the first duplexer and a downlink signal output end of the second duplexer, and the output end of the AFC module is connected with the downlink signal input end of the duplexer at the retransmission end through the downlink PA; the AFC module is used for selecting a main downlink signal of at least one of the two channels to perform frequency compensation, transmitting the compensated downlink signal backwards and providing a downlink ALC start-control depth numerical control attenuation signal for uplink; the dual channel uplink includes: the power divider comprises an uplink LNA (uplink low noise amplifier), an uplink frequency selection unit and a power divider which are sequentially connected, wherein one path of output of the power divider is connected with an uplink signal input end of a first duplexer through a first uplink power amplifier, the other path of output of the power divider is connected with an uplink signal input end of a second duplexer through a second uplink power amplifier, and control ends of the first uplink power amplifier and the second uplink power amplifier are connected with a downlink ALC (adaptive logic controller) start-control depth numerical control attenuation signal output by an AFC (automatic frequency control) module.
Wherein the AFC module in the dual channel downlink comprises: the first down-link LNA (low noise amplifier) and the first down-link converter are connected in sequence and used for amplifying and down-converting a down-link signal in one channel; the second downlink LNA and the second down converter are sequentially connected and used for amplifying and down-converting a downlink signal in another channel; the input ends of the two A/D converters are respectively connected with the outputs of the first down converter and the second down converter and are used for respectively converting the intermediate frequency signals output by the first down converter and the second down converter into digital intermediate frequency signals; the FPGA is respectively connected with the two A/D converters, carries out frequency detection on the digital intermediate frequency signals output by the two A/D converters, compares the digital intermediate frequency signals with a reference frequency, obtains a Doppler frequency offset value and compensates the Doppler frequency offset value; and the D/A converter and the up-converter are connected, the D/A converter is connected between the FPGA and the up-converter, converts the digital intermediate frequency signals compensated by the FPGA into analog intermediate frequency signals, and transmits the analog intermediate frequency signals to the downlink PA after the up-converter performs up-conversion processing.
The AFC module further comprises a first downstream filter connected between the first downstream LNA and the first down-converter 1 and a second downstream filter connected between the second downstream LNA and the second down-converter 2.
An AFC module for a vehicle-mounted dual-channel rectification repeater, comprising: the first down-converter and the first down-LNA are connected in sequence and used for amplifying and down-converting a down-signal in one channel; the second downlink LNA and the second down converter are sequentially connected and used for amplifying and down-converting a downlink signal in another channel; the input ends of the two A/D converters are respectively connected with the outputs of the first down converter and the second down converter and are used for respectively converting the intermediate frequency signals output by the first down converter and the second down converter into digital intermediate frequency signals; the FPGA is respectively connected with the outputs of the two A/D converters, carries out frequency detection on the digital intermediate frequency signals output by the two A/D converters, compares the digital intermediate frequency signals with a reference frequency, obtains a Doppler frequency offset value and carries out compensation; and the D/A converter and the up-converter are connected, the D/A converter is connected between the FPGA and the up-converter, converts the digital intermediate frequency signals compensated by the FPGA into analog intermediate frequency signals, and transmits the analog intermediate frequency signals to the downlink PA after the up-converter performs up-conversion processing.
The vehicle-mounted double-channel rectification repeater has an AFC rectification function, and timely selects the main downlink signal of at least one channel in double channels to perform frequency compensation through the AFC module, so that the influence of Doppler frequency shift in high-speed motion on cell signal switching is avoided, the signal of a base station can be normally demodulated by a terminal moving at high speed, and the problems of terminal call drop, poor call quality and slow data downloading caused by frequency offset are solved.
Meanwhile, the automatic gain control device has an AGC function, ensures that indoor signals of a carriage moving at high speed are relatively stable, and the uplink gain and the downlink gain are kept balanced.
The repeater station is matched with the double-donor antenna, so that the coverage quality of the mobile communication network in the train carriage room moving at high speed is obviously improved. Laboratory comparison tests show that: 1. after the repeater is added, the GSM voice error rate and the TD-SCDMA voice block error rate are obviously reduced; 2. after the repeater is added, the data block error rate of EGDE and the data block error rate of TD-SCDMA are obviously reduced; 3. after the repeater is added, the data throughput of EGDE and the data throughput of TD-SCDMA are obviously improved.
In order to meet the vehicle-mounted requirement, the repeater adopts a 19-inch standard case, has low power consumption and wide voltage application range, can work at the ambient temperature of minus 25 ℃ to plus 70 ℃, and can resist the severe environments of vibration, dust blowing, salt fog and mold.
The repeater can reduce the cost of an operator: taking the whole course as 1318km jinghu high-speed rail as an example, the terminal meets the conditions: GSM, -75 dBm; TD-SCDMA, -80 dBm. The number of carriages is as follows: 1600 ~ 4000 sections of carriages. According to COST-HATA model theory calculation, the equipment pair needed by the vehicle-mounted rectifying repeater without the invention and the vehicle-mounted rectifying repeater with the invention is as follows:
| deviation rectifying repeater without vehicle | Vehicle-mounted rectification repeater (station) | |
| GSM BTS | 1830 | 439 |
| TD-SCDMA RRU | 2745 | 878 |
| Vehicle-mounted deviation rectifying repeater | 0 | 200～500 |
| Vehicle-mounted dry-laying device | 0 | 400～1000 |
| Sum of | 4575 | 1917～2817 |
Obviously, after the vehicle-mounted rectification repeater is used, the number of GSM base stations and TD-SCDMA RRUs is obviously reduced, the total number of all equipment is also obviously reduced, the cost of building stations by operators is greatly reduced, and various property problems are reduced.
Drawings
FIG. 1 is a schematic block diagram of a vehicle-mounted dual-channel rectification repeater of the present invention;
FIG. 2 is an enlarged view of the AFC module of FIG. 1;
FIG. 3 is a schematic diagram of a scheme for implementing stable coverage of mobile communication signals in a high-speed rail by installing the repeater shown in FIG. 1 in the high-speed rail compartment;
FIG. 4 is a schematic diagram of the repeater shown in FIG. 1 cooperating with two donor antennas to achieve dual channel signal reception;
fig. 5 is a schematic diagram of a conventional terminal receiving in a high-speed operating environment.
Detailed Description
The following detailed description is made with reference to the accompanying drawings.
Referring to fig. 1 and 2, the vehicle-mounted dual-channel rectification repeater comprises: the first duplexer 1, the second duplexer 2 and the retransmission terminal duplexer 5 are respectively provided with a dual-channel downlink and a dual-channel uplink therebetween. The dual channel downlink includes: a downlink PA4 and an AFC (automatic frequency control) module 3; two input ends of the AFC module 3 are respectively connected with a downlink signal output end of the first duplexer 1 and a downlink signal output end of the second duplexer 2, and the output end of the AFC module is connected with a downlink signal input end of the retransmission duplexer 5 through a downlink PA 4; the AFC module is used for selecting the main downlink signal of at least one of the two channels to perform frequency compensation and providing a downlink ALC start-control depth numerical control attenuation signal for uplink. The dual-channel uplink comprises an uplink LNA6, an uplink frequency selection unit 7 and a power divider 8 which are sequentially connected, wherein one output of the power divider 8 is connected with an uplink signal input end of a first duplexer 1 through a first uplink power amplifier 10, the other output of the power divider 8 is connected with an uplink signal input end of a second duplexer 2 through a second uplink power amplifier 9, and a downlink ALC start-control depth numerical control attenuation signal output by an AFC module 3 is connected to control ends of the first uplink power amplifier 10 and the second uplink power amplifier 9, so that the gain of the uplink is adjusted according to the gain of the downlink, and the relative stability of the uplink level is ensured.
The AFC module 3 in the above-described dual-channel downlink includes: the first downlink LNA30, the first downlink filter 31 and the first down-converter 32 are connected in sequence and used for amplifying and down-converting downlink signals in one channel; the second downlink LNA33, the second downlink filter 34 and the second down-converter 35 are connected in sequence and used for amplifying and down-converting the downlink signal in the other channel; the input ends of the A/D converters 36 and 37 are respectively connected with the outputs of the first down converter 32 and the second down converter 35 and are used for converting the intermediate frequency conversion signals output by the first down converter and the second down converter into digital intermediate frequency signals; the FPGA38 is connected with the A/D converters 36 and 37, performs frequency detection on the digital intermediate frequency signals output by the two A/D converters, compares the digital intermediate frequency signals with a reference frequency, and obtains and compensates a Doppler frequency offset value; and the D/A converter 39 and the up converter 3A, the D/A converter 39 is connected between the FPGA38 and the up converter 3A, and converts the digital intermediate frequency signal compensated by the FPGA38 into an analog intermediate frequency signal, and the analog intermediate frequency signal is up-converted by the up converter 3A and transmitted to the downstream PA 4.
According to practical test conditions, the lateral penetration loss is about 20 dB. When the terminal is in a high-speed motion state, signals are in a fast fading state, and the terminal cannot normally communicate with the terminal at any time when the terminal receives the signals in the carriage due to the penetration loss of the carriage. Therefore, to solve the signal coverage in the passenger compartment, the following technical measures must be taken:
in the measure 1, as shown in fig. 3 and 4, a vehicle-mounted dual-channel rectification repeater as shown in fig. 1 is added in a carriage, so that the signal strength can meet the communication requirement of a terminal, and the signal stability is kept. A first donor antenna and a second donor antenna are arranged on the top of the carriage, the first donor antenna and the second donor antenna are respectively connected with a first duplexer and a second duplexer of the repeater, downlink signals of two adjacent RRUs received by the first donor antenna are input into a channel 1 of a two-channel downlink, and downlink signals of two adjacent RRUs received by the second donor antenna are input into a channel 2 of the two-channel downlink; after the repeater is processed and amplified, signals can be respectively connected into a pair of leaky cables through an external power divider, and the leaky cables enable the leaked signals to cover a carriage.
As shown in fig. 5, a terminal operating at high speed receives signals of RRU1 and RRU2 at the same time, and if the repeater only uses one donor antenna, the repeater cannot perform frequency correction on RRU1 and RRU2 at the same time. Therefore, the scheme proposes a dual-channel design scheme, as shown in fig. 4, two donor antennas face two adjacent RRUs 1 and 2, respectively, downlink signals of the two adjacent RRUs received by a first donor antenna are input into a channel 1 of a dual-channel downlink, and downlink signals of the two adjacent RRUs received by a second donor antenna are input into a channel 2 of the dual-channel downlink; the repeater detects different strengths of the RRU1 and the RRU2 according to each channel, judges and selects a main downlink signal of each channel through the AFC module 3, selects the main downlink signal of one or two channels of the two channels to perform frequency compensation, and transmits the main downlink signal to a terminal through a downlink PA (power amplifier), an external power divider and a leaky cable after the frequency compensation.
In the step 2, because of fast fading of signals, the signals received by the user terminal are unstable, when signal coverage is increased in a car, the repeater must realize a downlink ALC function to meet the 20dB range of downlink ALC control, and the downlink automatically adjusts gain according to output power to keep the level in the car relatively stable and ensure that the receiving level requirement of the terminal is met.
In the step 3, due to fast fading of the signal, the downlink input power has a large variation range, and the output power of the repeater remains constant, so that the downlink gain varies constantly, and the uplink and downlink gain linkage function, i.e., the uplink AGC function, must be realized to keep the uplink and downlink gain balance. The repeater adjusts the gain of an uplink according to the gain of a downlink, ensures the relative stability of an uplink level, and specifically designs to realize uplink numerical control attenuation by using the downlink control depth, namely when the downlink ALC controls delta x dB, the gain of the uplink is attenuated by delta x dB.
In the step 4, because the terminal will generate doppler frequency offset during high-speed transportation, the maximum frequency offsets of GSM and TD-SCDMA at four hundred kilometers of high speed reach 450Hz and 750Hz respectively, the mobile phone receives that the doppler frequency offset is within 200Hz, and the quality of the call over 200Hz will be affected. The doppler shift also has a large effect on data downloading, and the larger the doppler shift, the slower the data downloading. Therefore, the vehicle-mounted double-channel deviation rectifying repeater adds an AFC (automatic frequency control) deviation rectifying function, compensates the frequency of the deviated frequency point, and ensures that the mobile phone can demodulate the signal of the base station normally.
And 5, because of high-speed movement, the times of cell switching in unit time are increased, so that the vehicle-mounted double-channel rectification repeater is introduced to expand the coverage area of the cell, and the times of cell switching in unit time are reduced.
The signals of the RRU1 and the RRU2 received by the vehicle-mounted repeater are detected by the AFC module, and when the two are at the same frequency, that is, the frequency difference between the RRU1 and the RRU2 is not more than 2KHz (currently developed systems are GSM900 and TD-SCDMA B frequency band devices, the maximum frequency offset of GSM900 is 450Hz at 400Km/h, the maximum frequency offset of TD-SCDMA is 750Hz at 400Km/h, and the frequency difference can be changed in a software program), at this time, the RRU1 and the RRU2 are the same cell, and otherwise, the two are different cells.
The method for switching the same-frequency cells of the communication signals comprises the following steps:
a. the vehicle-mounted repeater station moves from the front RRU1 to the rear RRU2, the downlink signal of the RRU1 entering the channel 1 of the dual-channel downlink is very strong (received by the front of the first donor antenna), the signal of the RRU2 entering the channel 1 is very weak (received by the front of the first donor antenna), and the channel 1 mainly uses the signal of the RRU 1; the RRU2 downlink signal entering channel 2 (received by the front of the second donor antenna) is much less than 6dB (the threshold value may be set, for example, to 8dB or 3dB) than the downlink signal of RRU1 entering channel 2 (received by the back of the second donor antenna), and channel 2 mainly uses the signal of RRU 1; and the downlink signal of the RRU1 entering the channel 1 is much larger than the downlink signal of the RRU1 entering the channel 2, so the AFC module performs frequency compensation with the frequency of the RRU1 downlink signal in the channel 1 as a reference, so that the rectified downlink signal is transmitted to the retransmission terminal, and the signal of the channel 2 is detected; meanwhile, a terminal uplink signal is uploaded through a dual-channel uplink;
b. when a train moves forward, when a downlink signal (received by the front of the second donor antenna) of the RRU2 entering the channel 2 exceeds a downlink signal (received by the back of the second donor antenna) of the RRU1 entering the channel 2, the channel 2 mainly uses the RRU2 downlink signal, and at this time, the channel 1 mainly uses the RRU1 downlink signal is still 6dB (or 8dB or 3dB) stronger than the channel 2 mainly uses the RRU2 downlink signal, so that the AFC module performs frequency compensation by using the frequency of the channel 1 downlink signal of the RRU1 as a reference, so that the rectified downlink signal is transmitted to a retransmission terminal, and detects the channel 2 signal; meanwhile, a terminal uplink signal is uploaded through a dual-channel uplink;
c. when a downlink signal of the RRU2 mainly used in the channel 2 (received by the front of the second donor antenna) is 6dB (or 8dB or 3dB) greater than a downlink signal of the RRU1 mainly used in the channel 1 (received by the front of the first donor antenna), the downlink signal of the RRU2 (received by the back of the first donor antenna) in the channel 1 and the downlink signal of the RRU1 (received by the back of the second donor antenna) in the channel 2 are much smaller than the downlink signal of the RRU2 mainly used in the channel 2 (received by the front of the second donor antenna), so that the AFC module performs frequency compensation with the frequency of the downlink signal of the RRU2 in the channel 2 as a reference, transmits the rectified downlink signal to the retransmission terminal, and detects the signal of the channel 1; meanwhile, the terminal uplink signal is uploaded through a dual-channel uplink until the repeater is perpendicular to the RRU 2.
In steps a and b, the AFC module takes the frequency of the downlink signal of the RRU1 in channel 1 as a reference frequency compensation method, which is as follows: the RRU1 downlink signal is amplified by the first downlink LNA30, filtered by the first downlink filter 31, and input to the first down converter 32 for down-conversion processing, and the obtained intermediate frequency signal is converted into a digital intermediate frequency signal by the a/D converter 36; the FPGA38 detects the frequency of the digital intermediate frequency signal, compares the detected value with a reference frequency to obtain a Doppler frequency offset value, and performs frequency compensation according to the Doppler frequency offset value; the frequency-compensated digital intermediate frequency signal is converted into an analog intermediate frequency signal by a D/a converter 39, and then up-converted by an up-converter 3A and transmitted to a downstream PA 4.
In step c, the AFC module takes the frequency of the downlink signal of the RRU2 in channel 2 as a reference frequency compensation method, which is as follows: the downlink signal of the RRU2 is amplified by a second downlink LNA33, filtered by a second downlink filter 34, and input to a second down converter 35 for down-conversion processing, and the obtained intermediate frequency signal is converted into a digital intermediate frequency signal by an a/D converter 37; the FPGA38 detects the frequency of the digital intermediate frequency signal, compares the detected value with a reference frequency to obtain a Doppler frequency offset value, and performs frequency compensation according to the Doppler frequency offset value; the frequency-compensated digital intermediate frequency signal is converted into an analog intermediate frequency signal by the D/a converter 39, and then up-converted by the up-converter 3A and transmitted to the downstream PA 4.
The communication signal pilot frequency cell switching method comprises the following steps:
firstly, the vehicle-mounted repeater station moves from a front RRU1 to a rear RRU2, downlink signals of RRU1 entering channels 1 and 2 are very strong (respectively received by the front side of a first donor antenna and the back side of a second donor antenna), the downlink signal of RRU1 entering channel 1 is far larger than the downlink signal of RRU1 entering channel 2, both channels 1 and 2 use RRU1 downlink signals, and an AFC module performs frequency compensation by taking the frequency of the RRU1 downlink signal in channel 1 as a reference, so that the downlink signal after rectification is transmitted to a retransmission end, and the signal of channel 2 is detected; meanwhile, a terminal uplink signal is uploaded through a dual-channel uplink;
when the downlink signal of the RRU2 entering the channel 2 is more than or equal to 6dB (the threshold value can be set, such as 8dB or 3dB) than the downlink signal of the RRU1 entering the channel 2, the channel 2 mainly uses the RRU2 downlink signal, the AFC module respectively performs frequency compensation by taking the frequency of the RRU1 downlink signal in the channel 1 as a reference and the frequency of the RRU2 downlink signal in the channel 2 as a reference, and transmits the downlink signal of the RRU1 and the downlink signal of the RRU2 after deviation correction to a retransmission end; meanwhile, a terminal uplink signal is uploaded through a dual-channel uplink;
when the downlink signal of the RRU1 entering the channel 1 is less than or equal to 6dB (or 8dB or 3dB) than the downlink signal of the RRU2 entering the channel 1, the channel 1 mainly uses an RRU2 downlink signal, at this time, the downlink signal of the RRU2 mainly used by the channel 1 is far less than 6dB (or 8dB or 3dB) of the downlink signal of the RRU2 mainly used by the channel 2, the AFC module only uses the frequency of the RRU2 downlink signal in the channel 2 as a reference to perform frequency compensation, and the compensated RRU2 downlink signal is transmitted to a retransmission end; and simultaneously, the uplink signal of the terminal is uploaded through a dual-channel uplink.
The AFC module in the first and second steps uses the frequency of the downlink signal of the RRU1 in the channel 1 as a reference frequency compensation method, and the AFC module in the first and second steps uses the frequency of the downlink signal of the RRU1 in the channel 1 as a reference frequency compensation method.
The AFC module in the second step is the same as the AFC module in the third step in the first step in the frequency compensation method using the frequency of the downlink signal of the RRU2 in the channel 2 as the reference frequency, and the AFC module in the third step in the second step uses the frequency of the downlink signal of the RRU2 in the channel 2 as the reference frequency.
The laboratory test results were as follows:
1. regardless of the multipath interference test results:
a comparison of data before and after testing of GSM900 (downlink: 936-954 MHz, uplink: 891-909 MHz) is shown in Table 1.
TABLE 1
The data are compared before and after the test in table 1 to obtain: under the condition of not considering multipath interference, the higher the speed of the GSM900 terminal is, the more serious the voice error rate, the data block error rate and the data throughput are deteriorated when the repeater shown in figures 1 and 4 is not provided, the more obvious the voice error rate, the data block error rate and the data throughput are improved when the repeater shown in figures 1 and 4 is added, and the higher the speed is, the more obvious the improvement effect is
The data before and after the TD-SCDMA (2010-2015 MHz) test are compared in Table 2.
TABLE 2
The data are compared before and after the test in table 2 to obtain: under the condition of not considering multipath interference, the higher the speed of the TD-SCDMA terminal is, the more serious the voice error rate, the data block error rate and the data throughput are deteriorated when the repeater shown in figures 1 and 4 is not provided, the more obvious the voice error rate, the data block error rate and the data throughput are improved when the repeater shown in figures 1 and 4 is added, and the higher the speed is, the more obvious the improvement effect is
2. Considering the multipath interference test results:
a comparison of data before and after testing of GSM900 (downlink: 936-954 MHz, uplink: 891-909 MHz) is shown in Table 3.
TABLE 3
The data are compared before and after the test in table 3: under the condition of considering multipath interference, the higher the speed of the GSM900 terminal is, the more serious the voice error rate, the data block error rate and the data throughput are deteriorated when the repeater shown in FIGS. 1 and 4 is not provided, and after the repeater shown in FIGS. 1 and 4 is added, the voice error rate and the data block error rate are obviously improved, but the improvement effect of the data throughput is poor.
The comparison of data before and after the test of TD-SCDMA (2010-2015 MHz) is shown in Table 4.
TABLE 4
The data before and after the test in tables 1 and 4 are compared to obtain: under the condition of considering multipath interference, the higher the speed of the TD-SCDMA terminal is, the more serious the voice error rate, the data block error rate and the data throughput are deteriorated when the repeater shown in FIG. 4 is not provided, the voice error rate, the data block error rate and the data throughput are obviously improved when the repeaters shown in FIGS. 1 and 4 are added, and the higher the speed is, the more obvious the improvement effect is.
Claims (5)
1. A vehicle-mounted double-channel deviation rectifying repeater is characterized by comprising:
the first duplexer is connected with the first donor antenna, the second duplexer is connected with the second donor antenna, and the retransmission terminal duplexer is connected with the second donor antenna; wherein,
the dual channel downlink includes: the system comprises a downlink PA module and an AFC module, wherein two input ends of the AFC module are respectively connected with a downlink signal output end of a first duplexer and a downlink signal output end of a second duplexer, the output end of the AFC module is connected with the downlink signal input end of a repeater duplexer through the downlink PA, and the AFC module is used for selecting a main downlink signal of at least one of the two channels to perform frequency compensation and providing a downlink ALC start-control depth numerical control attenuation signal for uplink;
the dual channel uplink includes: the power divider comprises an uplink LNA, an uplink frequency selection unit and a power divider which are sequentially connected, wherein one path of output of the power divider is connected with an uplink signal input end of a first duplexer through a first uplink power amplifier, the other path of output of the power divider is connected with an uplink signal input end of a second duplexer through a second uplink power amplifier, and control ends of the first uplink power amplifier and the second uplink power amplifier are connected with a downlink ALC (adaptive logic controller) start-control depth numerical control attenuation signal output by an AFC (automatic frequency control) module.
2. The vehicle-mounted dual-channel deskew repeater according to claim 1, wherein said AFC module comprises:
the first down-converter and the first down-LNA are connected in sequence and used for amplifying and down-converting a down-signal in one channel;
the second downlink LNA and the second down converter are sequentially connected and used for amplifying and down-converting a downlink signal in another channel;
the input ends of the two A/D converters are respectively connected with the outputs of the first down converter and the second down converter and are used for respectively converting the intermediate frequency signals output by the first down converter and the second down converter into digital intermediate frequency signals;
the FPGA is respectively connected with the outputs of the two A/D converters, carries out frequency detection on the digital intermediate frequency signals output by the two A/D converters, compares the digital intermediate frequency signals with a reference frequency, obtains a Doppler frequency offset value and carries out compensation; and a process for the preparation of a coating,
the D/A converter is connected between the FPGA and the up-converter, converts the digital intermediate frequency signals compensated by the FPGA into analog intermediate frequency signals, and transmits the analog intermediate frequency signals to the downlink PA after the up-converter performs up-conversion processing.
3. The vehicle-mounted dual-channel rectification repeater according to claim 2, characterized in that: the AFC module further includes a first downlink filter coupled between the first downlink LNA and the first downconverter and a second downlink filter coupled between the second downlink LNA and the second downconverter.
4. An AFC module for on-vehicle binary channels repeater of rectifying, characterized by includes: the first down-converter and the first down-LNA are connected in sequence and used for amplifying and down-converting a down-signal in one channel; the second downlink LNA and the second down converter are sequentially connected and used for amplifying and down-converting a downlink signal in another channel; the input ends of the two A/D converters are respectively connected with the outputs of the first down converter and the second down converter and are used for respectively converting the intermediate frequency signals output by the first down converter and the second down converter into digital intermediate frequency signals; the FPGA is respectively connected with the outputs of the two A/D converters, carries out frequency detection on the digital intermediate frequency signals output by the two A/D converters, compares the digital intermediate frequency signals with a reference frequency, obtains a Doppler frequency offset value and carries out compensation; and the D/A converter and the up-converter are connected, the D/A converter is connected between the FPGA and the up-converter, converts the digital intermediate frequency signals compensated by the FPGA into analog intermediate frequency signals, and transmits the analog intermediate frequency signals to the downlink PA after the up-converter performs up-conversion processing.
5. The vehicle-mounted dual-channel rectification repeater according to claim 4, characterized in that: the AFC module further includes a first downlink filter coupled between the first downlink LNA and the first downconverter and a second downlink filter coupled between the second downlink LNA and the second downconverter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010105482411A CN102469469A (en) | 2010-11-17 | 2010-11-17 | Vehicle-mounted double-channel correcting repeater |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010105482411A CN102469469A (en) | 2010-11-17 | 2010-11-17 | Vehicle-mounted double-channel correcting repeater |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102469469A true CN102469469A (en) | 2012-05-23 |
Family
ID=46072496
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010105482411A Pending CN102469469A (en) | 2010-11-17 | 2010-11-17 | Vehicle-mounted double-channel correcting repeater |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102469469A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102571165A (en) * | 2010-12-14 | 2012-07-11 | 迈普通信技术股份有限公司 | Method and movable repeater for realizing signal reception in high speed moving environment |
| CN102710270A (en) * | 2012-06-15 | 2012-10-03 | 深圳国人通信有限公司 | Radio remote unit and automatic frequency pre-controlling method and device thereof |
| CN103220032A (en) * | 2013-03-15 | 2013-07-24 | 上海交通大学 | Self-adaption Doppler frequency offset resisting time modulation array antenna system |
| CN104580295A (en) * | 2013-10-17 | 2015-04-29 | 宁波视竣信息科技有限公司 | Intelligent broadband communication method and system used for high-speed train in moving state |
| CN112615634A (en) * | 2020-12-29 | 2021-04-06 | 江苏铁锚玻璃股份有限公司 | Vehicle window with public mobile communication signal enhancement function |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101060357A (en) * | 2007-06-07 | 2007-10-24 | 上海交通大学 | Single frequency network signal line style coverage method for rail traffic |
| CN201004639Y (en) * | 2006-12-27 | 2008-01-09 | 京信通信技术(广州)有限公司 | An intelligent frequency band selection repeater system based on digital middle frequency |
| CN201479134U (en) * | 2009-06-11 | 2010-05-19 | 福建三元达通讯股份有限公司 | GSM wireless repeater station with ascending noise inhibition function |
| CN101719771A (en) * | 2009-11-30 | 2010-06-02 | 华为技术有限公司 | Frequency deviation processing method and system and repeater |
| EP2234290A2 (en) * | 2009-03-27 | 2010-09-29 | Fujitsu Limited | Relay station, relay method, receiving station and receiving method |
-
2010
- 2010-11-17 CN CN2010105482411A patent/CN102469469A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201004639Y (en) * | 2006-12-27 | 2008-01-09 | 京信通信技术(广州)有限公司 | An intelligent frequency band selection repeater system based on digital middle frequency |
| CN101060357A (en) * | 2007-06-07 | 2007-10-24 | 上海交通大学 | Single frequency network signal line style coverage method for rail traffic |
| EP2234290A2 (en) * | 2009-03-27 | 2010-09-29 | Fujitsu Limited | Relay station, relay method, receiving station and receiving method |
| CN201479134U (en) * | 2009-06-11 | 2010-05-19 | 福建三元达通讯股份有限公司 | GSM wireless repeater station with ascending noise inhibition function |
| CN101719771A (en) * | 2009-11-30 | 2010-06-02 | 华为技术有限公司 | Frequency deviation processing method and system and repeater |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102571165A (en) * | 2010-12-14 | 2012-07-11 | 迈普通信技术股份有限公司 | Method and movable repeater for realizing signal reception in high speed moving environment |
| CN102571165B (en) * | 2010-12-14 | 2014-09-17 | 迈普通信技术股份有限公司 | Method and movable repeater for realizing signal reception in high speed moving environment |
| CN102710270A (en) * | 2012-06-15 | 2012-10-03 | 深圳国人通信有限公司 | Radio remote unit and automatic frequency pre-controlling method and device thereof |
| CN102710270B (en) * | 2012-06-15 | 2014-04-30 | 深圳国人通信有限公司 | Radio remote unit and automatic frequency pre-controlling method and device thereof |
| CN103220032A (en) * | 2013-03-15 | 2013-07-24 | 上海交通大学 | Self-adaption Doppler frequency offset resisting time modulation array antenna system |
| CN103220032B (en) * | 2013-03-15 | 2015-10-14 | 上海交通大学 | A kind of time-modulation array antenna system of self adaptation anti-Doppler frequency deviation |
| CN104580295A (en) * | 2013-10-17 | 2015-04-29 | 宁波视竣信息科技有限公司 | Intelligent broadband communication method and system used for high-speed train in moving state |
| CN112615634A (en) * | 2020-12-29 | 2021-04-06 | 江苏铁锚玻璃股份有限公司 | Vehicle window with public mobile communication signal enhancement function |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7961689B2 (en) | Method and apparatus for determining an end of a subframe in a TDD system | |
| US8265551B2 (en) | Relay station, mobile station, and relay transmission method in mobile communication system | |
| US10320468B2 (en) | Repeater system for use on a moveable object | |
| US11784735B2 (en) | Booster gain adjustment based on user equipment (UE) need | |
| US20100136900A1 (en) | Radio Relay Device and Method | |
| US20110235571A1 (en) | Method and apparatus of transmitting backhaul signal in wireless communication system including relay station | |
| US20170019279A1 (en) | Wireless communication apparatus | |
| CN101557620B (en) | Method, device and system for realizing terminal handover | |
| CN102469469A (en) | Vehicle-mounted double-channel correcting repeater | |
| CN102469540A (en) | Cell switching method for communication signals in high-speed railway carriages | |
| CN101741432A (en) | L1 multi-antenna relay station and power control method thereof | |
| JP2002185382A (en) | Radio repeater | |
| CN101277480A (en) | Direct amplifier station eliminating self-excitation interference | |
| US20130033992A1 (en) | Radio base station apparatus and scheduling method | |
| CN112672311A (en) | Communication device and train | |
| CN101217324A (en) | A test system and method of WIMAX upstream cooperation MIMO | |
| JP3742372B2 (en) | In-building wireless communication system and method for suppressing reverse link interference | |
| KR100758883B1 (en) | Digital multiple path signal matching device of repeater | |
| CN201039179Y (en) | Base band feedback self-excitation resistance module | |
| US20240137778A1 (en) | Signal forwarding method and related apparatus | |
| CN201044490Y (en) | Repeater for eliminating self-excitation disturbance | |
| CN201937585U (en) | Self-excitation interference resistant repeater station | |
| CN101277479B (en) | Baseband feedback type self-excitation resistance module | |
| KR101603137B1 (en) | Communication terminal for repeating, m2m terminal for repeating and repeater apparatus having wireless communication module | |
| KR101486855B1 (en) | Method and apparatus for controlling output level of mobile telecommunication signal |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20120523 |