CN101958734B - Integrated wireless coverage solution - Google Patents
Integrated wireless coverage solution Download PDFInfo
- Publication number
- CN101958734B CN101958734B CN201010511680.5A CN201010511680A CN101958734B CN 101958734 B CN101958734 B CN 101958734B CN 201010511680 A CN201010511680 A CN 201010511680A CN 101958734 B CN101958734 B CN 101958734B
- Authority
- CN
- China
- Prior art keywords
- signal
- frequency
- tracking
- doppler
- descending
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Radio Relay Systems (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
The invention discloses an integrated wireless coverage solution which is used for realizing signal relay and eliminating Doppler frequency offset caused by high-speed operation in a signal. The solution comprises the following steps: a Doppler frequency offset tracking unit is added for obtaining a frequency error function between a downlink pilot signal contained in a downlink intermediate-frequency signal and a reference signal, and the function value is maintained at zero by adjusting the frequency of the signal generated by a controlled frequency source so as to control the downlink tracking signal generated by the controlled frequency source; the downlink tracking signal is mixed with the downlink signal via a lower variable frequency channel of a down link to eliminate forward Doppler frequency offset; and an uplink tracking signal, namely a backward Doppler frequency offset signal of the downlink tracking signal is mixed with an uplink signal via an upper variable frequency channel of an uplink to preset backward Doppler frequency offset. The solution of the invention can help effectively eliminate the Doppler frequency offset in communication between a mobile station in a high-speed motion carrier and a base station or a remote radio unit, thus playing a role in ensuring communication quality.
Description
[technical field]
The present invention relates to the wireless network coverage optimization field of mobile communication, relate in particular to a kind of without Doppler frequency shift relay and corresponding trunking method, and then a kind of bullet train wireless shrouding system, scheme are proposed, to be applicable to the mobile communication application on high-speed mobile carrier.
[technical background]
In high-speed railway mobile communication environment, if adopt base station directly to carry out wireless coverage to railway region, for fear of handover frequently, the covering radius of each base station need to reach more than ten kilometers, for the railway region of wire, the efficiency of the direct coverage mode in this base station is very low.In order to improve covering efficiency, the mode that can adopt base station to add Remote Radio Unit realizes wireless coverage.A base station can configure a plurality of Remote Radio Unit, in one line along railway.For the covering radius of base station, the covering radius of each Remote Radio Unit is little, therefore can be easy to realize the effective covering to ten kilometers of above wire railway regions.
Because a base station has configured a plurality of Remote Radio Unit, therefore, in the overlapping area of coverage of two Remote Radio Unit, the travelling carriage in railway car will be received the signal of the same base station sending from two different directions Remote Radio Unit.If travelling carriage cannot be distinguished the signal of this both direction, just these two signals have formed artificial multipath interference each other so, make communication quality degradation.(note: in add the high-speed railway mobile communication environment of Remote Radio Unit covering with base station, signal has very strong direct path between from Remote Radio Unit to train, therefore natural multipath disturbs much more weak than artificial multipath interference, therefore main, considers that artificial multipath disturbs here.)
Suppose that travelling carriage can distinguish the artificial multipath signal of this both direction, so just can utilize these signals by the method that rake merges.Due under the environment of high-speed mobile, the signal of this both direction has all been introduced very large Doppler frequency shift, and the opposite direction of frequency displacement, therefore before merging, needs to eliminate respectively this both direction signal Doppler frequency shift separately.
In sum, in order to improve the quality of communicating by letter in high-speed railway mobile communication environment, need to effectively solve following problem, that is:
1, distinguish the signal of different directions.
2, eliminate different directions signal Doppler frequency shift separately.
3, merge the signal of different directions, thereby eliminate artificial multipath, disturb.
In order to eliminate Doppler frequency shift, improve the communication quality between travelling carriage and fixed base stations or Remote Radio Unit in the high-speed mobile vehicles, have the following mode can be for reference:
The first is introduced Doppler correction function in base station, in this mode, therefore base station need to need to follow the tracks of respectively and offset for direction and the size of different mobile stations Doppler frequency shift in the face of the travelling carriage of a plurality of different moving directions and rate travel, implements comparatively complicated;
It two is in travelling carriage, to introduce Doppler correction function, consider the factor such as cost, volume, power consumption, heat radiation of travelling carriage, thereby and be placed in the high-speed mobile vehicles and affected effect correction precision etc. by vehicles shielding action when travelling carriage, therefore its feasibility is relatively not high;
Moreover a repeater can be placed as relay in the basis being suggested as the present invention on the vehicles, the signal of fixed base stations or Remote Radio Unit is directly put and rear vehicle interior covered.Now, repeater static or low speed for the travelling carriage of vehicle interior moves, but for base station or Remote Radio Unit, is but high-speed mobile.
The fundamental difference of this mobile repeater and traditional fixedly repeater is just that mobile repeater need to possess the function of distinguishing signal, eliminating Doppler frequency shift and combined signal, for communicating by letter between fixed base stations or Remote Radio Unit and travelling carriage in the high-speed mobile vehicles provides one without the wireless coverage environment of Doppler frequency shift.Wherein eliminating the realization of Doppler frequency shift function, is emphasis of the present invention place.
[summary of the invention]
Echo mutually with aforementioned, it is a kind of without Doppler frequency shift relay that primary and foremost purpose of the present invention will provide exactly, the signal of equipment room that makes to realize the two ends of relaying by it can be removed the Doppler shift factor producing because of high-speed mobile or other reason, guarantees the proper communication quality of signal.
Another object of the present invention is to provide a kind of without Doppler frequency shift trunking method, in the signal path of intercommunication mutually, remove the Doppler frequency shift because of high-speed mobile or the caused signal of other reason, ensure communication quality.
A further object of the present invention is to provide a kind of bullet train wireless shrouding system, and travelling carriage and the car realization of the signal between mobile communications network outward in bullet train are transmitted without Doppler frequency shift, guarantees the communication quality of travelling carriage.
A further object of the present invention is to provide a kind of bullet train wireless coverage scheme, to scheme the needs of applicable high ferro development.
Last object of the present invention is to provide a kind of doppler frequency shift tracking unit, to realize the versatility of product of the present invention, is convenient to standardized production, installation and maintenance.
For realizing this object, the present invention adopts following technical scheme:
A kind of doppler frequency shift tracking of the present invention unit, for following the tracks of the Doppler shift of the signal causing because of high-speed motion of relay, this tracking cell comprises:
Coupler, is coupled out a road downstream signal for the radio-frequency front-end at relay down link;
Controlled frequency source produces the descending tracking signal that comprises the descending forward Doppler frequency shift factor under the control of correcting unit;
Down-conversion passage, the frequency of the descending tracking signal that controlled frequency source produces of take is benchmark, and downstream signal is carried out to down-conversion;
Reference unit, for generation of a reference signal for correcting unit reference;
Correcting unit, the frequency error function between the down-bound pilot frequency signal comprising for the downstream signal of asking for after down-conversion and described reference signal, and regulate the frequency of the descending tracking signal of controlled frequency source generation to make this functional value be maintained zero;
Converter unit, is transformed to this descending tracking signal the up tracking signal that comprises the up reverse Doppler frequency shift factor.
According to one embodiment of the invention, disclose, described reference unit comprises frequency multiplier and the intrinsic reference frequency source of relay, and the signal that reference frequency source produces becomes described reference signal after frequency multiplier frequency multiplication.
According to another embodiment of the present invention, disclose, described reference unit comprises frequency multiplier and described controlled frequency source, and the descending tracking signal that controlled frequency source produces becomes described reference signal after frequency multiplier frequency multiplication.
Corresponding to correcting unit, be operated in analog domain or numeric field, described controlled frequency source is VCXO (VCXO) or numerically-controlled oscillator (NCO).
Between described controlled frequency source and down-conversion passage, be connected in series the descending tracking signal that a frequency multiplier produces controlled frequency source and carry out frequency multiplication computing.
This tracking cell also comprises filter, and it is serially connected with between down-conversion passage and correcting unit, and the downstream signal after down-conversion is carried out being transferred to described correcting unit after filtering.
Described converter unit comprises:
Frequency multiplier, carries out the frequency multiplication computing of preset multiple for the signal that the existing reference frequency source of relay is produced;
Frequency mixer, produces described up tracking signal thereby utilize the operation result of this frequency multiplier and descending tracking signal to carry out mixing;
Filter, for carrying out exporting after filtering to described up tracking signal.
Of the present invention a kind of without Doppler frequency shift relay, for realizing signal relaying, also eliminate the Doppler shift of the signal causing because of high-speed motion, it comprises down link and up link, also comprises:
Aforesaid doppler frequency shift tracking unit;
Down-conversion passage in down link, the descending tracking signal of this tracking cell output of take is carried out mixing to eliminate the forward Doppler frequency shift in downstream signal to the downstream signal in down link as local oscillator;
Up-conversion passage in up link, the up tracking signal of this tracking cell output of take is carried out mixing with preset reverse Doppler frequency shift in upward signal to the upward signal in up link as local oscillator.
This device comprises donor antenna and is subject to main antenna, donor antenna for and base station or the wireless electric connection of Remote Radio Unit, be subject to main antenna for the wireless electric connection of travelling carriage.Described donor antenna adopts omnidirectional or directional antenna, described in be subject to main antenna to adopt the leaky cable of one lengthwise.
Described reference frequency source adopts the crystal oscillator of be better than ± 0.01ppm of stability.
Of the present invention a kind of without Doppler frequency shift trunking method, the Doppler shift causing because of high-speed motion for realizing signal relaying erasure signal, it comprises the steps:
1) from down link radio-frequency front-end, be coupled out a road downstream signal;
2) produce line trace signal;
3) following line trace signal is that benchmark downconverts to intermediate frequency or zero intermediate frequency territory by this radio frequency downstream signal;
4) ask for down-bound pilot frequency signal and the frequency error function supplying between the reference signal of reference that this intermediate frequency or zero intermediate frequency territory downstream signal comprise, and regulating step 3) the middle frequency that produces descending tracking signal, so that this functional value is maintained zero;
5), for down link, take this descending tracking signal carries out mixing to eliminate the forward Doppler frequency shift in downstream signal to downstream signal as local oscillator;
6), for up link, first this descending tracking signal is transformed to the up tracking signal of preset reverse Doppler frequency shift, then take this up tracking signal and upward signal is carried out to up-conversion as local oscillator, with preset reverse Doppler frequency shift in upward signal.
According to one embodiment of the invention, disclose described step 4) in the signal that produced by a reference frequency source of reference signal after frequency multiplication computing, obtain.
According to another embodiment of the present invention, disclose described step 4) in reference signal by described step 2) descending tracking signal after frequency multiplication computing, obtain.
Step 4), if adopt analog form to carry out, described descending tracking signal is produced by a controlled VCXO (VCXO), if adopt digital form to carry out, by numerically-controlled oscillator, produces (NCO).
Described step 3) the descending tracking signal in has been passed through frequency multiplication computing.
Described step 4) frequency domain in or zero intermediate frequency territory downstream signal are after filtering.
Step 6) in, filtering after the frequency multiplication operation result mixing of the signal that described up tracking signal is produced by described descending tracking signal and a reference frequency source and obtaining.
A kind of bullet train wireless shrouding system of the present invention, it adopts aforesaid without Doppler frequency shift relay, and its donor antenna is placed on bullet train top, and it is laid along the compartment one lengthwise of bullet train by main antenna.
A kind of bullet train wireless coverage scheme of the present invention, is applicable to the train of relative radio repeater station high-speed mobile, and it comprises the steps:
1) on bullet train, install repeater, and base station or Remote Radio Unit signal that this repeater receives only a direction are at any time set, ignore the signal of other direction;
2) down link for this repeater provides the descending tracking signal that can follow the tracks of forward Doppler frequency shift, is the up link of this repeater up tracking signal of reverse Doppler frequency shift that provides preset.
3) down-conversion passage and the up-conversion passage for this repeater down link by descending tracking signal, the Doppler frequency shift that elimination is introduced in downstream signal because train relatively moves, so that travelling carriage receives the downstream signal without Doppler frequency shift in train;
4) down-conversion passage and the up-conversion passage for the up link of this repeater by up tracking signal, preset reverse Doppler frequency shift in upward signal, so that radio repeater station receives the upward signal without Doppler frequency shift.
Compared with prior art, because the present invention has realized Doppler correction function on relay, be applicable to the repeater such as frequency-selecting, shift frequency, wideband, on the radio repeater stations such as base station or Remote Radio Unit and travelling carriage without any impact, therefore can directly apply in any existing mobile communications network with planning to build, be also that it has higher portability and application feasibility.Conventional art is eliminated the technology of Doppler frequency shift in base station and Remote Radio Unit or travelling carriage relatively, and it has obvious progressive, is in particular in:
One, in relay, introduce Doppler correction function and compare and mainly contain following advantage with this function of introducing in base station (or Remote Radio Unit):
1, therefore base station need to need to follow the tracks of respectively and offset for direction and the size of different mobile stations Doppler frequency shift in the face of the travelling carriage of a plurality of different moving directions and rate travel, implements complexity; And relay (mobile repeater) only needs base station or the Remote Radio Unit in the face of a direction, therefore only need follow the tracks of and offset a direction and big or small Doppler frequency shift, implement simple;
2, relay (mobile repeater) can make full use of the correction that down-bound pilot frequency signal is carried out Doppler frequency shift; And in base station, if there is no pilot signal in upward signal, cannot accomplish this point, cause technology to realize the birth defects that cannot overcome.
Its two, in relay (mobile repeater), introduce Doppler correction function and in travelling carriage, introduce this function and compare that advantage is more obvious:
1, travelling carriage has harsh requirement to cost, volume and power consumption, much loose for mobile repeater.Mobile repeater is equivalent to, for all travelling carriages in the vehicles provide a public radio-frequency front-end, the Doppler correction function of each travelling carriage be focused in a mobile repeater and realized, than be dispersed in each travelling carriage realize more reasonable;
2, mobile repeater can be used the directed tracing antenna (mainly referring to its donor antenna) that is placed in outside the vehicles and the reference frequency source of high stability, eliminates the shielding action of the vehicles, improves the precision of Doppler correction; And in travelling carriage, these are all difficult to realize.
[accompanying drawing explanation]
Fig. 1 is that the present invention is without Doppler frequency shift relay application scenarios schematic diagram.
Fig. 2 be in first embodiment of the invention without the theory diagram of Doppler frequency shift relay, this embodiment is applicable to intermediate frequency scheme.
Fig. 3 is the theory diagram of doppler frequency shift tracking unit in first embodiment of the invention.
Fig. 4 be in second embodiment of the invention without the theory diagram of Doppler frequency shift relay, this embodiment is applicable to zero intermediate frequency scheme.
Fig. 5 is the theory diagram of doppler frequency shift tracking unit in second embodiment of the invention.
Fig. 6 be in third embodiment of the invention without the theory diagram of Doppler frequency shift relay, its intermediate frequency scheme by the first embodiment derives a unified intermediate frequency scheme.
Fig. 7 be in fourth embodiment of the invention without the theory diagram of Doppler frequency shift relay, its zero intermediate frequency scheme by the second embodiment derives a unified zero intermediate frequency scheme.
[embodiment]
Below in conjunction with drawings and Examples, the present invention is further illustrated:
As a comprehensive bullet train wireless coverage scheme, the application scenarios that its concrete application is bullet train wireless shrouding system of the present invention as shown in Figure 1.On the carrier of the high-speed mobile vehicles of train and so on of high-speed railway (take be example) 101,111,112, two mobile repeaters 111,112 of two mobile repeaters are installed and by the present invention is described later, without Doppler frequency shift relay, are realized.Each mobile repeater respectively has a donor antenna that possesses directed tracing ability or shared Yi Ge omnidirectional donor antenna, receive respectively the signal of former and later two nearest base stations or Remote Radio Unit 122,121, realize and communicating by letter with base station or the wireless electric connection of Remote Radio Unit.Two mobile repeaters share one by mixer (not shown) and are subject to main antenna (realizing the antenna of communicating by letter with the wireless electric connection of travelling carriage), and this is subject to main antenna to adopt one to cover the leaky cable that carrier inside is laid along railway car longitudinally one lengthwise.
No matter adopt directed tracing or omnidirectional's donor antenna, all will guarantee that each mobile repeater can only receive base station or the Remote Radio Unit signal of a direction in former and later two directions of train, the signal of other direction is little of ignoring.The former is used for guaranteeing by spatial division multiplexing, and latter is to guarantee by frequency division, time-division or code division multiplexing.Therefore can be similar to and think that each mobile repeater only introduced the Doppler frequency shift of a direction, once each mobile repeater has been eliminated Doppler frequency shift, the wireless coverage environment on bullet train is considered as the wireless coverage environment without Doppler frequency shift.
As previously mentioned, mobile repeater, comprises frequency selecting repeater, frequency-shift repeater and wideband repeater etc., adopts of the present inventionly without Doppler frequency shift relay, to realize.This relay is used for realizing signal relaying, and eliminate by the Doppler frequency shift of the signal of relaying, the key of eliminating Doppler frequency shift is to follow the tracks of the Doppler frequency shift factor, the process of following the tracks of the Doppler frequency shift factor realizes by a doppler frequency shift tracking unit, have two kinds of implementations, the first is followed the tracks of frequency domain downstream signal, claims intermediate frequency scheme, another is that zero intermediate frequency territory downstream signal is followed the tracks of, and claims zero intermediate frequency scheme.In the present invention, two schemes is specifically described with the first and second embodiment respectively.
Below with Fig. 2 and common the first embodiment that discloses employing intermediate frequency scheme of the present invention of Fig. 3.
First embodiment of the invention without Doppler frequency shift relay by donor antenna 201, be subject to main antenna 202, duplexer 211,212, amplifier 221,222,223,224,225,226,227,228, frequency mixer 231,232,233,234, if bandpas filter 241,242, frequency multiplier 251,252,253,254, reference frequency source 261, doppler frequency shift tracking unit 271, and coupler 281 forms.Wherein, amplifier 221, frequency mixer 231, amplifier 222 form the descending down-conversion passage of mobile repeater; Amplifier 225, frequency mixer 233, amplifier 226 form the descending up-conversion passage of mobile repeater.Descending down-conversion passage, if bandpas filter 241, descending up-conversion passage form the down link of mobile repeater together.Amplifier 228, frequency mixer 234, amplifier 227 form the up down-conversion passage of mobile repeater; Amplifier 224, frequency mixer 232, amplifier 223 form the up up-conversion passage of mobile repeater.Up down-conversion passage, if bandpas filter 242, up up-conversion passage form the up link of mobile repeater together.Coupler 281, doppler frequency shift tracking unit 271, reference frequency source 261, frequency multiplier 251,252,253,254 form the frequency synthesizer of mobile repeater, are called for short synthetizer.Wherein, doppler frequency shift tracking unit 271 has doppler frequency shift tracking ability, for descending down-conversion passage and up up-conversion passage provide local frequency source; And reference frequency source 261 for example, is served as by the crystal oscillator (the constant-temperature crystal oscillator TCXO of be better than ± 0.01ppm of stability) of high stability, for descending up-conversion passage and up down-conversion passage provide local frequency source.
From the downlink radio-frequency signal of base station or Remote Radio Unit, after donor antenna 201 and duplexer 211, deliver to descending down-conversion passage and carry out down-conversion.Down-conversion adopts low local oscillator lower sideband scheme, and the descending intermediate-freuqncy signal obtaining is delivered to descending up-conversion passage and carried out up-conversion after if bandpas filter 241.Up-conversion is used low local oscillator upper sideband scheme, and the downlink radio-frequency signal obtaining is through duplexer 212 and be subject to main antenna 202 to send to the travelling carriage in compartment.
From the up radiofrequency signal of travelling carriage in compartment, stand to deliver to up down-conversion passage after main antenna 202 and duplexer 212 and carry out down-conversion, down-conversion adopts low local oscillator lower sideband scheme, and the up intermediate-freuqncy signal obtaining is delivered to up up-conversion passage and carried out up-conversion after if bandpas filter 242.Up-conversion adopts low local oscillator upper sideband scheme, and the up radiofrequency signal obtaining sends to base station or Remote Radio Unit after duplexer 211 and donor antenna 201.
The doppler frequency shift tracking unit 271 of the present embodiment adopts the signal of local reference frequency source 261 generations directly as the reference signal of inner automatic frequency correction unit, and its theory diagram as shown in Figure 3.The controlled frequency source 461 that doppler frequency shift tracking unit 271 is served as by amplifier 421,422, frequency mixer 431,432, if bandpas filter 441,442, automatic frequency correction (AFC) unit (calling correcting unit in the following text) 471, use VCXO (VCXO), frequency multiplier 451,452,453 form.It should be noted that, amplifier 421 wherein, 422 have formed down-conversion passage with frequency mixer 431, and coupler 281 can downconvert to frequency domain by the downstream signal of radio frequency domains with this down-conversion passage and this if bandpas filter 441, thereby offer described correcting unit 471, use.Described frequency multiplier 453, frequency mixer 432 and 442, filter have formed converter unit jointly, for the direction of the Doppler frequency shift factor of figure signal.
There are two input signals and two output signals in doppler frequency shift tracking unit 271.Two input signals are respectively that the downlink radio-frequency signal that contains down-bound pilot frequency signal obtaining by coupler 281 couplings from down link radio-frequency front-end and the frequency being provided by reference frequency source 261 are f
0reference frequency signal; Two output signals are respectively that the frequency that can follow the tracks of descending forward Doppler frequency shift is f '
0descending tracking signal and the frequency of preset up reverse Doppler frequency shift be f "
0up tracking signal, up tracking signal and descending tracking signal all stem from this controlled frequency source 461, the signal that wherein up tracking signal is original tracking signal after converter unit conversion.
In doppler frequency shift tracking unit 271, the signal that controlled frequency source (VCXO) 461 is subject to correcting unit 471 to control output is descending tracking signal, its frequency f '
0be subject to the control of the control signal of automatic frequency correction unit 471 generations.471 mono-road input signal in automatic frequency correction unit is the intermediate frequency pilot signal obtaining after the frequency-doubled signal mixing, filtering of the signal of down-bound pilot frequency signal and controlled frequency source (VCXO) 461 outputs; Another road input signal of automatic frequency correction unit 471 is that reference signal is the frequency-doubled signal of reference frequency source signal.The function of automatic frequency correction unit 471 is exactly to detect the existence of down-bound pilot frequency signal, and in the situation that down-bound pilot frequency signal exists, calculate the frequency error function between down-bound pilot frequency signal (through frequency conversion) and local reference frequency signal (through frequency multiplication), produce the output frequency that corresponding control signal regulates controlled frequency source (VCXO) 461, maintaining said frequencies error is zero.
In converter unit, descending tracking signal is carried out mixing with 2 frequency-doubled signals of local reference frequency source signal again, and getting and obtaining frequency after the latter and the former difference frequency signal filtering is f "
0=2f
0-f '
0up tracking signal.
In conjunction with Fig. 2 and Fig. 3, the standard frequency of establishing downlink radio-frequency signal carrier wave is f
d, the standard frequency of up radiofrequency signal carrier wave is f
u, the standard frequency of down-bound pilot frequency signal is f
p, the standard frequency of descending intermediate-freuqncy signal carrier wave is f
id, the standard frequency of up intermediate-freuqncy signal carrier wave is f
iu, the standard frequency of descending intermediate frequency pilot signal is f
ip.Make x=f
d/ f
0, y=f
u/ f
0, z=f
p/ f
0, w=f
id/ f
d=f
iu/ f
u=f
ip/ f
p.The multiplier parameter of getting frequency multiplier 251,253 is d=d '=x (1-w), the multiplier parameter of frequency multiplier 252,254 is u=u '=y (1-w), the multiplier parameter of frequency multiplier 451 is p=z (1-w), the multiplier parameter of frequency multiplier 452 is q=zw, and the multiplier parameter of frequency multiplier 453 is 2.
The frequency of the down-bound pilot frequency signal that mobile repeater is received is f
p+ Δ f
p, Δ f wherein
pfor its Doppler frequency shift.This signal and frequency are f '
0the frequency-doubled signal pf ' of descending tracking signal
0after mixing, filtering, obtaining frequency is f '
ip=f
p+ Δ f
p-pf '
0intermediate frequency pilot signal.Automatic frequency correction unit 471 calculates intermediate frequency pilot signal and frequency is f
ip=qf
0the frequency-doubled signal of reference frequency source signal between frequency error function, and control according to this controlled frequency source 461, take sustain pulse frequency error as zero, i.e. f '
ip-f
ip=0.Therefore,, when automatic frequency correction unit 471 enters tracking mode, there is pf '
0=f
p+ Δ f
p-f
ip.Now, the frequency of descending tracking signal is f '
0=(f
p+ Δ f
p-f
ip)/p=f
0(1+ Δ/(1-w)), and the frequency of up tracking signal is f "
0=2f
0-f '
0=f
0(1-Δ/(1-w)).As can be seen here the frequency f of descending tracking signal '
0in contain down-Doplet frequency-shifting operator+Δ, and in the frequency f of up tracking signal "
0in contain the up reverse Doppler frequency shift factor-Δ.
In down link, descending tracking signal being obtained after d frequency multiplication to frequency is df '
0=f
d+ Δ f
d-f
idlocal oscillation signal for descending down-conversion passage; The frequency that reference frequency source signal is obtained after d ' frequency multiplication is d ' f
0=f
d-f
idlocal oscillation signal for descending up-conversion passage.And in up link, it is u ' f that reference frequency source signal is obtained to frequency after u ' frequency multiplication
0=f
u-f
iulocal oscillation signal for up down-conversion passage; Up tracking signal being obtained after u frequency multiplication to frequency is uf "
0=f
u-Δ f
u-f
iulocal oscillation signal for up up-conversion passage.
For down direction, what by base station or Remote Radio Unit, send to mobile repeater is that carrier wave standard frequency is f
ddownlink radio-frequency signal.Due to the high-speed mobile of train, the downlink radio-frequency signal carrier frequency that arrives mobile repeater is f
d+ Δ f
d, Δ f wherein
dit is the Doppler frequency shift of introducing.Downlink radio-frequency signal is f through local oscillation signal frequency
d+ Δ f
d-f
iddescending down-conversion passage to become carrier frequency be f
iddescending intermediate-freuqncy signal, then be f through local oscillation signal frequency
d-f
iddescending up-conversion passage to become carrier frequency be f
ddownlink radio-frequency signal, send to the travelling carriage in compartment.Because the relative movement speed of travelling carriage in mobile repeater on train and compartment is negligible, thus travelling carriage receive will be standard downlink radio-frequency signal without Doppler frequency shift.
Otherwise for up direction, what in compartment, travelling carriage sent to mobile repeater on train is that carrier wave standard frequency is f
uup radiofrequency signal.Because the relative movement speed of travelling carriage in mobile repeater on train and compartment is negligible, so the carrier frequency of the up radiofrequency signal received of mobile repeater is still f
u.Up radiofrequency signal is f through local oscillation signal frequency
u-f
iuup down-conversion passage to become carrier frequency be f
iuup intermediate-freuqncy signal, then be f through local oscillation signal frequency
u-Δ f
u-f
iuup up-conversion passage to become carrier frequency be f
u-Δ f
uup radiofrequency signal, send to base station or Remote Radio Unit.Due to mobile repeater preset reverse Doppler frequency shift-Δ f in up radiofrequency signal
u, the Doppler frequency shift Δ f causing with train high-speed mobile
uoffset, therefore arrive the up radiofrequency signal of standard that there is no Doppler frequency shift by being of base station or Remote Radio Unit.
Please continue to refer to Fig. 4 and Fig. 5, its common second embodiment of the present invention that discloses, the main difference part of this embodiment and last embodiment can obviously draw by the contrast between figure and figure, be: first, the relay of the present embodiment is operated in zero intermediate frequency territory but not frequency domain; Secondly, the reference signal of the automatic frequency correction unit 571 of the present embodiment is derived from the feedback signal in controlled frequency source 561 (descending tracking signal) but not local reference frequency source signal; Moreover, the signal processing variation of the inside, doppler frequency shift tracking unit being caused by aforementioned two places difference.
For helping understand the first embodiment that adopts intermediate frequency scheme and the detailed difference that adopts the second embodiment of zero intermediate frequency scheme, in conjunction with Fig. 4 and Fig. 5, the second embodiment is done to further announcement as follows.
Second embodiment of the invention without Doppler frequency shift relay by donor antenna 301, be subject to main antenna 302, duplexer 311,312, amplifier 321,322,323,324,325,326,327,328, frequency mixer 331,332,333,334, zero intermediate frequency low pass filter 341,342, frequency multiplier 351,352,353,354, reference frequency source 361, doppler frequency shift tracking unit 371, and coupler 381 forms.Wherein, amplifier 321, frequency mixer 331, amplifier 322 form the descending down-conversion passage of mobile repeater; Amplifier 325, frequency mixer 333, amplifier 326 form the descending up-conversion passage of mobile repeater.Descending down-conversion passage, low pass filter 341, descending up-conversion passage form the down link of mobile repeater together.Amplifier 328, frequency mixer 334, amplifier 327 form the up down-conversion passage of mobile repeater; Amplifier 324, frequency mixer 332, amplifier 323 form the up up-conversion passage of mobile repeater.Up down-conversion passage, zero intermediate frequency low pass filter 342, up up-conversion passage form the up link of mobile repeater together.Coupler 381, doppler frequency shift tracking unit 371, reference frequency source 361, frequency multiplier 351,352,353,354 form the frequency synthesizer of mobile repeater.Wherein, doppler frequency shift tracking unit 371 has doppler frequency shift tracking ability, for descending down-conversion passage and up up-conversion passage provide local frequency source; And reference frequency source 361 for example, is served as by the crystal oscillator (the constant-temperature crystal oscillator TCXO of be better than ± 0.01ppm of stability) of high stability, for descending up-conversion passage and up down-conversion passage provide local frequency source.
From the downlink radio-frequency signal of base station or Remote Radio Unit, after donor antenna 301 and duplexer 311, deliver to descending down-conversion passage and carry out down-conversion, the descending zero intermediate frequency signals obtaining is delivered to descending up-conversion passage and is carried out up-conversion after zero intermediate frequency low pass filter 341, and the downlink radio-frequency signal obtaining is thus through duplexer 312 and be subject to main antenna 302 to send to the travelling carriage in compartment.
From the up radiofrequency signal of travelling carriage in compartment, stand to deliver to up down-conversion passage after main antenna 302 and duplexer 312 and carry out down-conversion, the up zero intermediate frequency signals obtaining is thus delivered to up up-conversion passage and is carried out up-conversion after zero intermediate frequency low pass filter 342, and the up radiofrequency signal obtaining sends to base station or Remote Radio Unit after duplexer 311 and donor antenna 301.
The feedback signal that the doppler frequency shift tracking unit 371 of the present embodiment adopts controlled frequency sources (VCXO) 561 to produce be descending tracking signal as the reference signal of inner automatic frequency correction unit 571, its theory diagram is as shown in Figure 5.The controlled frequency source 561 that Doppler frequency shift unit 371 is served as by amplifier 521,522, frequency mixer 531,532, if bandpas filter 541,542, automatic frequency correction (AFC) unit 571, use VCXO (VCXO), frequency multiplier 551,552,553 form.It should be noted that, amplifier 521 wherein, 522 have formed down-conversion passage with frequency mixer 531, and coupler 381 can downconvert to zero intermediate frequency territory by the downstream signal of radio frequency domains with this down-conversion passage and this low pass filter 541, thereby offer described correcting unit 571, use.Described frequency multiplier 553, frequency mixer 532 and 542, filter have formed converter unit jointly, for the direction of the Doppler frequency shift factor of figure signal.
There are two input signals and two output signals in doppler frequency shift tracking unit 371.Two input signals are respectively that the downlink radio-frequency signal that contains down-bound pilot frequency signal obtaining by coupler 381 couplings from down link radio-frequency front-end and the frequency being provided by reference frequency source 361 are f
0reference frequency signal; Two output signals are respectively that the frequency that can follow the tracks of descending forward Doppler frequency shift is f
0' descending tracking signal and the frequency of preset up reverse Doppler frequency shift be f
0" up tracking signal.
In doppler frequency shift tracking unit 371, it is descending tracking signals that controlled frequency source (VCXO) 561 is subject to the signal of the control output of correcting unit 571, its frequency f
0' be subject to the control of the control signal that automatic frequency correction unit 571 produces.571 mono-road input signal in automatic frequency correction unit is the intermediate frequency pilot signal obtaining after the frequency-doubled signal mixing, filtering of the signal of down-bound pilot frequency signal and controlled frequency source (VCXO) 561 outputs.Another road input signal of automatic frequency correction unit 571 is that reference signal is that controlled frequency source 561 feedback signals are the frequency-doubled signal of descending tracking signal.The function of automatic frequency correction unit 571 is exactly to detect the existence of down-bound pilot frequency signal, and in the situation that down-bound pilot frequency signal exists, calculate the frequency error function between down-bound pilot frequency signal (through frequency conversion) and this feedback signal (through frequency multiplication), produce the frequency that corresponding control signal regulates controlled frequency source (VCXO), maintaining said frequencies error is zero.
In converter unit, descending tracking signal is carried out mixing with 2 frequency-doubled signals of local reference frequency source signal again, and getting and obtaining frequency after the latter and the former difference frequency signal filtering is f
0=2f
0-f
0' up tracking signal.
In conjunction with Fig. 4 and Fig. 5, the standard frequency of establishing downlink radio-frequency signal carrier wave is f
d, the standard frequency of up radiofrequency signal carrier wave is f
u, the standard frequency of down-bound pilot frequency signal is f
p, the standard frequency of descending intermediate frequency pilot signal is f
i, make x=f
d/ f
0, y=f
u/ f
0, z=f
p/ f
0, v=f
i/ f
0.The multiplier parameter of getting frequency multiplier 351,353 is d=d '=x, and the multiplier parameter of frequency multiplier 352,354 is u=u '=y, and the multiplier parameter of frequency multiplier 551 is p=z-v, and the multiplier parameter of frequency multiplier 552 is q=v, and the multiplier parameter of frequency multiplier 553 is 2.
The frequency of the down-bound pilot frequency signal that mobile repeater is received is f
p+ Δ f
p, Δ f wherein
pfor its Doppler frequency shift.This signal and frequency are f
0' the frequency-doubled signal pf ' of descending tracking signal
0after mixing, filtering, obtaining frequency is f
i'=f
p+ Δ f
p-pf
0' intermediate frequency pilot signal.Automatic frequency correction unit 571 calculates intermediate frequency pilot signal and frequency is qf
0' the frequency-doubled signal of controlled frequency source feedback signal between frequency error function, and regulate according to this VCXO 561, take sustain pulse frequency error as zero, i.e. qf
0'-f
i'=0.Therefore,, when automatic frequency correction unit 571 enters tracking mode, there is f
p+ Δ f
p-pf
0'=qf
0'.Now, the frequency of descending tracking signal is f
0'=(f
p+ Δ f
p)/(p+q)=f
0(1+ Δ), and the frequency of up tracking signal is f
0"=2f
0-f
0'=f
0(1-Δ).As can be seen here in the frequency f of descending tracking signal
0' in contain the descending forward Doppler frequency shift factor+Δ, and in the frequency f of up tracking signal
0" in contain the up reverse Doppler frequency shift factor-Δ.
In down link, descending tracking signal being obtained after d frequency multiplication to frequency is df
0'=f
d+ Δ f
dlocal oscillation signal for descending down-conversion passage; The frequency that reference frequency source signal is obtained after d ' frequency multiplication is df
0'=f
dlocal oscillation signal for descending up-conversion passage.And in data feedback channel, it is u ' f that reference frequency source signal is obtained to frequency after u ' frequency multiplication
0=f
ulocal oscillation signal for up down-conversion passage; Up tracking signal being obtained after u frequency multiplication to frequency is uf
0"=f
u-Δ f
ulocal oscillation signal for up up-conversion passage.
For down direction, what by base station or Remote Radio Unit, send to mobile repeater is that carrier wave standard frequency is f
ddownlink radio-frequency signal.Due to the high-speed mobile of train, the downlink radio-frequency signal carrier frequency that arrives mobile repeater is f
d+ Δ f
d, Δ f wherein
dit is the Doppler frequency shift of introducing.Downlink radio-frequency signal is f through local oscillation signal frequency
d+ Δ f
ddescending down-conversion passage become descending zero intermediate frequency signals, then be f through local oscillation signal frequency
ddescending up-conversion passage to become carrier frequency be f
ddownlink radio-frequency signal, send to the travelling carriage in compartment.Because the relative movement speed of travelling carriage in mobile repeater on train and compartment is negligible, thus travelling carriage receive will be standard downlink radio-frequency signal without Doppler frequency shift.
Otherwise for up direction, what in compartment, travelling carriage sent to mobile repeater on train is that carrier wave standard frequency is f
uup radiofrequency signal.Because the relative movement speed of travelling carriage in mobile repeater on train and compartment is negligible, so the carrier frequency of the up radiofrequency signal received of mobile repeater is still f
u.Up radiofrequency signal is f through local oscillation signal frequency
uup down-conversion passage become up zero intermediate frequency signals, then be f through local oscillation signal frequency
u-Δ f
uup up-conversion passage to become carrier frequency be f
u-Δ f
uup radiofrequency signal, send to base station or Remote Radio Unit.Due to mobile repeater preset reverse Doppler frequency shift-Δ f in up radiofrequency signal
u, the Doppler frequency shift Δ f causing with train high-speed mobile
uoffset, therefore arrive the up radiofrequency signal of standard that there is no Doppler frequency shift by being of base station or Remote Radio Unit.
By above-mentioned two embodiment, can be found out, of the present inventionly without Doppler frequency shift relay (mobile repeater) and the fundamental difference of traditional fixedly repeater, be to have introduced the doppler frequency shift tracking unit 271 or 371 with doppler frequency shift tracking ability in repeater.If doppler frequency shift tracking unit 271 or 371 is replaced by reference frequency source, mobile repeater is just identical with traditional fixedly repeater so.
It is to be noted, for the broad band repeater that comprises a plurality of frequency division carrier waves, because it only has the up/down row of channels in a broadband, the radiofrequency signal carrier frequency of this up/down row of channels is carried wave frequency with each frequency division can not be all identical, therefore through after Doppler correction, in each frequency division carrier wave, also may have remaining Doppler frequency shift, but residue Doppler frequency shift is no more than Δ B/2, wherein Δ is the Doppler frequency shift factor, and B is the bandwidth of broad band repeater.For the frequency selecting repeater that comprises a plurality of frequency division carrier waves, because it has the up/down row of channels of a plurality of arrowbands, each up/down row of channels is corresponding with a frequency division carrier wave, therefore, through after Doppler correction, can eliminate the Doppler frequency shift in each carrier wave completely.
Doppler frequency shift tracking unit in above two kinds of embodiment, both can adopt analog circuit to realize, and also can adopt digital circuit to realize.If while adopting digital circuit to realize, the above-mentioned VCXO (VCXO) using as controlled frequency source should change numerically-controlled oscillator (NCO) into.If while adopting analog circuit to realize, conventionally adopt intermediate frequency scheme.For the frequency selecting repeater of simulation, conventionally also wish that the IF-FRE of each passage when doing band limiting filtering is identical.But in above-mentioned intermediate frequency scheme, the IF-FRE of each passage is not identical.At this moment can on the basis of above-mentioned two kinds of basic schemes, derive two kinds of unified intermediate frequency schemes, as the third and fourth embodiment of the present invention.
The unified intermediate frequency scheme being derived from by the intermediate frequency scheme of above-mentioned the first embodiment, as the third embodiment of the present invention, as shown in Figure 6.Compare with the scheme of intermediate frequency shown in Fig. 2, in descending up-conversion passage, increased amplifier 625, secondary mixing device 633, amplifier 626, unified intermediate-frequency filter 641 and frequency multiplier 653; And unified intermediate-frequency filter 642, amplifier 628, secondary mixing device 634, amplifier 627 and frequency multiplier 654 in up up-conversion passage, have been increased.Now descending secondary mixing device mixes original different descending intermediate frequency on unified descending intermediate frequency and carries out band limiting filtering again; Up secondary mixing device mixes the up unified intermediate frequency after band limiting filtering and on different up intermediate frequencies, carries out up-conversion again.Multiplier parameter d, u are identical with former intermediate frequency scheme, and multiplier parameter d ", u ", d ', u ' get respectively xw-v, yw-v, x-v, y-v, wherein v=f
i/ f
0, f
ifor unified IF-FRE.
The unified zero intermediate frequency scheme being derived from by the zero intermediate frequency scheme of above-mentioned the second embodiment, as the fourth embodiment of the present invention, as shown in Figure 7.Compare with zero intermediate frequency scheme shown in Fig. 3, increased frequency mixer 735,736, local oscillation signal filter 743,744, frequency multiplier 755, change original zero intermediate frequency low pass filter 341 and 342 into unified zero intermediate frequency filtering device 741 and 742 in addition.Now the local oscillation signal of descending down-conversion changes the signal mixing that the signal that obtained after d frequency multiplication by descending tracking signal and reference frequency obtain after v frequency multiplication and obtains; The local oscillation signal of up up-conversion changes the signal mixing that the signal that obtained after u frequency multiplication by up tracking signal and reference frequency obtain after v frequency multiplication and obtains.Multiplier parameter v=f wherein
i/ f
0, f
ifor unified zero intermediate frequency frequency.
As seen from the above-described embodiment, of the present invention without Doppler frequency shift relay in, automatic frequency correction unit is its core.Of the present invention without Doppler frequency shift relay in, except the function of tracking correction frequency, in down-bound pilot frequency signal, be not (for example in gsm mobile communication system, down-bound pilot frequency signal is intermittently to send) always exist in the situation that, automatic frequency correction unit also needs to detect the existence of pilot signal.Detect the algorithm of pilot signal and can formerly apply for a patent the digitlization automatic frequency detection method > > (patent publication No.: CN101471727) of < < based on real signal with reference to the applicant, and the algorithm of automatic frequency correction can formerly be applied for a patent the digitalized automatic frequency correction > > (patent publication No.: CN101471726), can certainly adopt other algorithm of < < based on true frequency reference signal with reference to the applicant.Those of ordinary skills can know this accommodation after reading over the present invention.
In sum, Doppler frequency shift when the present invention can effectively eliminate travelling carriage in high-speed motion carrier and communicates by letter with base station or Remote Radio Unit, plays the effect that guarantees communication quality.
Above-described embodiment is preferably execution mode of the present invention, but and is not only restricted to the described embodiments.For example in the conversion process of above-described embodiment, can adopt different high and low local oscillators and upper and lower sideband scheme, at this moment as long as the multiplier parameter of corresponding each frequency multiplier of adjustment just can be realized different frequency conversion schemes; In uplink and downlink passage, the local oscillation signal of upper and lower converter unit also can exchange in addition.Therefore other any not deviating from change, the modification done under Spirit Essence of the present invention and principle, substitute, combination, abbreviation, all should be considered as equivalent replacement mode of the present invention, and within being included in protection scope of the present invention.
Claims (16)
1. a doppler frequency shift tracking unit, for following the tracks of the Doppler shift of the signal causing because of high-speed motion of relay, is characterized in that, this tracking cell comprises:
Coupler, is coupled out a road downstream signal for the radio-frequency front-end at relay down link;
Controlled frequency source produces the descending tracking signal that comprises the descending forward Doppler frequency shift factor under the control of correcting unit;
Down-conversion passage, the frequency of the descending tracking signal that controlled frequency source produces of take is benchmark, and downstream signal is carried out to down-conversion;
Reference unit, for generation of a reference signal for correcting unit reference, described reference unit comprises frequency multiplier and the intrinsic reference frequency source of relay, the signal that described reference frequency source produces becomes described reference signal after frequency multiplier frequency multiplication; Or described reference unit comprises frequency multiplier and described controlled frequency source, the descending tracking signal that described controlled frequency source produces becomes described reference signal after frequency multiplier frequency multiplication;
Correcting unit, the frequency error function between the down-bound pilot frequency signal comprising for the downstream signal of asking for after down-conversion and described reference signal, and regulate the frequency of the descending tracking signal of controlled frequency source generation to make this functional value be maintained zero;
Converter unit, 2 frequency-doubled signals of the reference frequency source signal of this descending tracking signal and relay are carried out to mixing, get after 2 frequency-doubled signals of this reference frequency source signal and the difference frequency signal filtering of descending tracking signal, obtain the up tracking signal that comprises the up reverse Doppler frequency shift factor.
2. doppler frequency shift tracking according to claim 1 unit, is characterized in that, described controlled frequency source is VCXO (VCXO) or numerically-controlled oscillator (NCO).
3. doppler frequency shift tracking according to claim 1 unit, is characterized in that, is provided with a frequency multiplier the descending tracking signal of controlled frequency source generation is carried out to frequency multiplication computing between described controlled frequency source and down-conversion passage.
4. according to the doppler frequency shift tracking unit described in any one in claims 1 to 3, it is characterized in that, this tracking cell also comprises filter, and it is serially connected with between down-conversion passage and correcting unit, and the downstream signal after down-conversion is carried out being transferred to described correcting unit after filtering.
5. according to the doppler frequency shift tracking unit described in any one in claims 1 to 3, it is characterized in that, described converter unit comprises:
Frequency multiplier, carries out the frequency multiplication computing of preset multiple for the signal that the existing reference frequency source of relay is produced;
Frequency mixer, produces described up tracking signal thereby utilize the operation result of this frequency multiplier and descending tracking signal to carry out mixing;
Filter, for carrying out exporting after filtering to described up tracking signal.
6. without a Doppler frequency shift relay, for realizing signal relaying, also eliminate the Doppler shift of the signal causing because of high-speed motion, it comprises down link and up link, it is characterized in that, this device also comprises:
Doppler frequency shift tracking unit as described in any one in claim 1 to 5;
Down-conversion passage in down link, the descending tracking signal of this tracking cell output of take is carried out mixing to eliminate the forward Doppler frequency shift in downstream signal to the downstream signal in down link as local oscillator;
Up-conversion passage in up link, the up tracking signal of this tracking cell output of take is carried out mixing with preset reverse Doppler frequency shift in upward signal to the upward signal in up link as local oscillator.
7. according to claim 6 without Doppler frequency shift relay, it is characterized in that, this device comprises donor antenna and is subject to main antenna, donor antenna for and base station or the wireless electric connection of Remote Radio Unit, be subject to main antenna for the wireless electric connection of travelling carriage.
8. according to claim 7ly without Doppler frequency shift relay, it is characterized in that, described donor antenna adopts omnidirectional or directional antenna, described in be subject to main antenna to adopt the leaky cable of one lengthwise.
According to described in any one in claim 6 to 8 without Doppler frequency shift relay, it is characterized in that, described reference frequency source adopts the crystal oscillator of be better than ± 0.01ppm of stability.
10. without a Doppler frequency shift trunking method, for realizing signal relaying erasure signal because of the Doppler shift that high-speed motion causes, it is characterized in that, it comprises the steps:
1) from down link radio-frequency front-end, be coupled out a road downstream signal;
2) produce line trace signal;
3) following line trace signal is that benchmark downconverts to intermediate frequency or zero intermediate frequency territory by this radio frequency downstream signal;
4) ask for down-bound pilot frequency signal and the frequency error function supplying between the reference signal of reference that this intermediate frequency or zero intermediate frequency territory downstream signal comprise, and regulating step 2) the middle frequency that produces descending tracking signal, so that this functional value is maintained zero; In frequency domain, the signal that described reference signal is produced by a reference frequency source obtains after frequency multiplication computing, and in zero intermediate frequency territory, described reference signal is by step 2) descending tracking signal after frequency multiplication computing, obtain;
5), for down link, take this descending tracking signal carries out mixing to eliminate the forward Doppler frequency shift in downstream signal to downstream signal as local oscillator;
6) for up link, 2 frequency-doubled signals of this descending tracking signal and reference frequency source signal are carried out to mixing, get after 2 frequency-doubled signals of this reference frequency source signal and the difference frequency signal filtering of descending tracking signal, obtain the up tracking signal of preset reverse Doppler frequency shift, take this up tracking signal carries out up-conversion to upward signal as local oscillator again, with preset reverse Doppler frequency shift in upward signal.
11. according to claim 10ly is characterized in that without Doppler frequency shift trunking method, and described descending tracking signal is produced by controlled VCXO (VCXO) or a numerically-controlled oscillator (NCO).
12. according to claim 10ly is characterized in that without Doppler frequency shift trunking method, and the descending tracking signal in described step 3) has been passed through frequency multiplication computing.
13. according to claim 10 to described in any one in 12 without Doppler frequency shift trunking method, it is characterized in that, the frequency domain in described step 4) or zero intermediate frequency territory downstream signal are after filtering.
14. according to claim 10 to described in any one in 12 without Doppler frequency shift trunking method, it is characterized in that, in step 6), filtering after the frequency multiplication operation result mixing of the signal that described up tracking signal is produced by described descending tracking signal and a reference frequency source and obtaining.
15. 1 kinds of bullet train wireless shrouding systems, it is characterized in that: its adopt as described in any one in claim 6 to 9 without Doppler frequency shift relay, its donor antenna is placed on bullet train top, and it is laid along the compartment one lengthwise of bullet train by main antenna.
16. 1 kinds of bullet train wireless coverage methods, are applicable to the train of relative radio repeater station high-speed mobile, it is characterized in that, it comprises the steps:
1) on bullet train, install repeater, and base station or Remote Radio Unit signal that this repeater receives only a direction are at any time set, ignore the signal of other direction;
2) with claimed in claim 10 without Doppler frequency shift trunking method, for the down link of this repeater provides the descending tracking signal that can follow the tracks of forward Doppler frequency shift, it is the up link of this repeater up tracking signal of reverse Doppler frequency shift that provides preset;
3) down-conversion passage and the up-conversion passage for this repeater down link by descending tracking signal, eliminates the Doppler frequency shift that relatively moves and introduce in downstream signal because of train, so that travelling carriage receives the downstream signal without Doppler frequency shift in train;
4) down-conversion passage and the up-conversion passage for the up link of this repeater by up tracking signal, preset reverse Doppler frequency shift in upward signal, so that radio repeater station receives the upward signal without Doppler frequency shift.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010511680.5A CN101958734B (en) | 2010-10-19 | 2010-10-19 | Integrated wireless coverage solution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010511680.5A CN101958734B (en) | 2010-10-19 | 2010-10-19 | Integrated wireless coverage solution |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101958734A CN101958734A (en) | 2011-01-26 |
| CN101958734B true CN101958734B (en) | 2014-03-26 |
Family
ID=43485867
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201010511680.5A Expired - Fee Related CN101958734B (en) | 2010-10-19 | 2010-10-19 | Integrated wireless coverage solution |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101958734B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102932808B (en) * | 2011-08-09 | 2015-04-22 | 鼎桥通信技术有限公司 | High-speed scene signal sending method and repeater |
| CN102970067B (en) * | 2011-09-01 | 2016-01-20 | 上海贝尔股份有限公司 | A kind of method for realizing continuous print broadband connections |
| CN102811072B (en) * | 2012-07-26 | 2014-06-04 | 京信通信系统（广州）有限公司 | Signal transmission method and device |
| CN104244296B (en) | 2013-06-13 | 2018-02-06 | 华为技术有限公司 | Channel correcting method and device between more RRU |
| CN106357308A (en) * | 2016-08-31 | 2017-01-25 | 北京钧威科技有限公司 | Receiving method and system based on combination of space diversity and site diversity |
| CN108471617B (en) * | 2017-02-23 | 2020-12-08 | 华为技术有限公司 | Mobility management method of user equipment, user equipment and measurement control point base station |
| CN109819395A (en) * | 2019-01-28 | 2019-05-28 | 电子科技大学 | It is a kind of that the unstable conversion method of high speed carrier communication is improved based on location information |
| ES2716628B2 (en) * | 2019-04-08 | 2019-11-05 | Univ Madrid Politecnica | METHOD AND SYSTEM TO CORRECT THE DOPPLER EFFECT OF A MOBILE COMMUNICATION IN A HIGH-SPEED SYSTEM |
| WO2021093197A1 (en) * | 2020-02-11 | 2021-05-20 | Zte Corporation | Method for parameter configuration of frequency modulation |
| CN112953517A (en) * | 2021-02-24 | 2021-06-11 | 中国电子科技集团公司第十研究所 | Dynamic Doppler frequency offset calibration method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6675013B1 (en) * | 2000-06-26 | 2004-01-06 | Motorola, Inc. | Doppler correction and path loss compensation for airborne cellular system |
| CN2687956Y (en) * | 2004-02-11 | 2005-03-23 | 中国电子科技集团公司第五十四研究所 | Doppler frequency shift correcting device for high speed mobile satellite satellite communication |
| CN101567708A (en) * | 2008-04-22 | 2009-10-28 | 中兴通讯股份有限公司 | Frequency offset compensation method and device |
| CN101814931A (en) * | 2009-02-19 | 2010-08-25 | 中兴通讯股份有限公司 | Doppler frequency shift estimation and compensation method in TD-SCDMA (Time Division-Synchronization Code Division Multiple Access) system |
-
2010
- 2010-10-19 CN CN201010511680.5A patent/CN101958734B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6675013B1 (en) * | 2000-06-26 | 2004-01-06 | Motorola, Inc. | Doppler correction and path loss compensation for airborne cellular system |
| CN2687956Y (en) * | 2004-02-11 | 2005-03-23 | 中国电子科技集团公司第五十四研究所 | Doppler frequency shift correcting device for high speed mobile satellite satellite communication |
| CN101567708A (en) * | 2008-04-22 | 2009-10-28 | 中兴通讯股份有限公司 | Frequency offset compensation method and device |
| CN101814931A (en) * | 2009-02-19 | 2010-08-25 | 中兴通讯股份有限公司 | Doppler frequency shift estimation and compensation method in TD-SCDMA (Time Division-Synchronization Code Division Multiple Access) system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101958734A (en) | 2011-01-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101958734B (en) | Integrated wireless coverage solution | |
| US10419100B2 (en) | Doppler shift correction sub-system for communication device | |
| WO2009110053A1 (en) | Method for transmitting broadcast service signal, and transmitter | |
| CN102970067B (en) | A kind of method for realizing continuous print broadband connections | |
| CN111866878B (en) | Terminal login method in satellite communication system | |
| CN101959261B (en) | Signal selection method and equipment in high-speed moving scene | |
| CN107835052A (en) | Wireless communications method | |
| CN102378191A (en) | Method, system and wireless communication device for conducting auxiliary transmission to adjacent channel | |
| CN106060852A (en) | Parameter adjusting method, base station and mobile terminal | |
| CN104683993A (en) | Multi-domain cooperative communication system of satellites and land | |
| CN103428138A (en) | Doppler precompensation method aiming at uplink channel | |
| CN107528609B (en) | Wireless communication system | |
| RU2715554C1 (en) | Transported tropospheric station | |
| CN112672311A (en) | Communication device and train | |
| CN103428825A (en) | Radio remote unit selecting method | |
| CN102469469A (en) | Vehicle-mounted double-channel correcting repeater | |
| CN107911186A (en) | CORS Radio Data Systems and method | |
| CN102710270B (en) | Radio remote unit and automatic frequency pre-controlling method and device thereof | |
| CN103391587A (en) | High-speed train wireless data transmission method | |
| CN207354281U (en) | Wireless communication system | |
| CN207339864U (en) | CORS Radio Data Systems | |
| Li et al. | Physical layer enhancement for next-generation railway communication systems | |
| CN207354280U (en) | Wireless signal transceiver and wireless signal transmitting-receiving chain | |
| CN102111355A (en) | Method and repeater for transmitting and receiving signal in high-speed moving environment | |
| CN102571165B (en) | Method and movable repeater for realizing signal reception in high speed moving environment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140326 Termination date: 20191019 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |