CN1507710A - Methods and apparatuses for using mobile GPS station to synchronize basestations - Google Patents
Methods and apparatuses for using mobile GPS station to synchronize basestations Download PDFInfo
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- CN1507710A CN1507710A CNA018232981A CN01823298A CN1507710A CN 1507710 A CN1507710 A CN 1507710A CN A018232981 A CNA018232981 A CN A018232981A CN 01823298 A CN01823298 A CN 01823298A CN 1507710 A CN1507710 A CN 1507710A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
- H04B7/26—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
- H04B7/26—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
- H04B7/2662—Arrangements for Wireless System Synchronisation
- H04B7/2671—Arrangements for Wireless Time-Division Multiple Access [TDMA] System Synchronisation
- H04B7/2678—Time synchronisation
- H04B7/2687—Inter base stations synchronisation
- H04B7/2693—Centralised synchronisation, i.e. using external universal time reference, e.g. by using a global positioning system [GPS] or by distributing time reference over the wireline network
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L7/00—Arrangements for synchronising receiver with transmitter
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management
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Abstract
Methods and apparatuses for synchronozing basestations in a cellular network. One exemplary method performs time synchronization between at least tow basestations, a first basestation and a second basestation, of a cellular communication system. In this exemplary method, a first time-of-day and a first geographical location of a first mobile cellular receiver station (MS) are determined from a first satellite positioning system (SPS) receiver which is co-located with the first MS, and the first time-of-day and first location are transmitted by the first MS to a first basestation which determines a time-of-day of the first basestation from the first time-of-day and first location and from a known location of the first basestation. Also in this exemplary method, a second time-of-day and a second geographical location of a second MS are determined from a second SPS receiver which is co-located with the second MS, and the second time-of-day and the second location are transmitted to a second basestation which determines a time-of-day of the second basestation from the second-time-of-day and the second location and a known location of the second basestation. Other methods and apparatuses are also described for synchronizing basestations in a cellular network.
Description
Background of invention
The present invention relates to field of cellular communication systems, relate in particular to those systems of the position of having determined cellular mobile communication station (MS).
In order to carry out the location positioning in the cellular network (as, cellular radio network), used the several method that carries out triangulation according to the timing information that sends between each base station and mobile device.In a kind of method that is called the time of advent poor (TDOA), measure the time from the mobile radio station received signal at place, several base stations, these times are sent to position determination entity, are called location server, and it calculates the position of this mobile radio station.For this method can be worked, position fixing is to provide position accurately in the time of need be to day at place, each base station.And, need know the position of base station exactly.Fig. 1 illustrates TDOA system one example, and wherein location server 24 is measured the time of reception (TR1, TR2 and TR3) from the same signal of cellular mobile telephone 22 at cellular basestation 12,14 and 16 places.Thereby the location server 24 that has been coupled receives data by mobile switching centre 18 from the base station.Mobile switching centre 18 to land line public switched telephone system (PSTS) provide signal (as, Speech Communication) or therefrom obtain signal, make signal to be passed to or be passed to other phone (as, the land line phone on PSTS or other mobile phone) from mobile phone.
In some cases, location server may also be communicated by letter with mobile switching centre by cellular link.Location server may also be monitored the emission from several base stations, and the relative timing of these emissions is determined in attempt.
The another kind of method that is called EOTD is measured the time of advent from each signal that sends of several base stations at the mobile radio station place.Fig. 1 is applicable to this situation, the arrow counter-rotating of imagination TR1, TR2 and TR3.If the timing information that mobile radio station obtains is sent to this server by this link, then this calculating can be at mobile radio station from being in or finishing at the location server place.Equally, must be to the when day calibration of base station, and their position of assessment exactly.In arbitrary method, the position of base station is determined by standard method of measurement, and can be stored in place, base station or the server in some type computer internal memory.
The third location positioning method has used the receiver of the interior global positioning system (GPS) of mobile radio station or other global position system (SPS).This method may be autonomous fully, perhaps provides the auxiliary data in the position calculation with cellular network or shares.The example of this method is described in U.S. Patent number 5841396,5945944 and 5812087.We call " SPS " to these methods.
The combination of arbitrary EOTD or TDOA or SPS system is called as " mixing " system.
From foregoing description as seen, for EOTD or TDOA, the time coordinate between each cellular basestation is necessary for the position of accurate calculating mobile radio station.Accuracy depends on employed localization method details during day that the place, base station needs.In one approach, be sent to mobile radio station from the base station and the signal that returns has time-delay two-way time (RTD).In similar alternative method, be sent to the base station and the signal that returns has time-delay two-way time from mobile radio station.These two round trip delay times are respectively divided by two estimations with definite unidirectional time delays.Know that base station location adds that one-way delay is mobile station location constraint on earth in the circumference.Then, another measurement of second base station causes the common factor of two circumference, and this is again position constraint 2 points on earth.This third measurement has solved ambiguity.According to coming and going regularly, it is important that the measurement of several base stations is scaled to several seconds, if make the mobile radio station fast moving at least, measures the value that still can occur in same position corresponding to those.
In other cases, can not come and go measurement to each of two or three base stations, but only may, the dominant base with mobile station communicate be come and gone measurement.The situation of IS-95 North America cdma cellular standard that Here it is.Perhaps, perhaps, equipment or signaling protocol may not come and go regularly measurement because limiting.In this case, the more important thing is if carry out the triangulation operation and just keep accurate timing that this is because of the time difference of only having used between mobile radio station-path, base station at the place, base station.
In another reason of base station place accurate timing is to be used to help position calculation based on GPS for mobile radio station provides the time; This information may cause time decreased to the first fixed point, and/or improved sensitivity.The required accuracy of these situations can become about 10 milliseconds from several microseconds, and this depends on desired improvement in performance.In hybrid system, the base station regularly is used to improve TOA or TDOA operation and GPS operation.
The art methods of network timing adopts fixing especially position timing system, is called location measurement unit (LMU) or timing measuring unit (TMU).These unit generally comprise a GPS receiver, when it can be determined accurately day.The position of unit can be measured, for example may finish according to measuring equipment with GPS.
Generally speaking, LMU or TMU observe timing signal, and for example existing framing sign in the cellular communication signal that sends from the base station, and attempt uses the local zone time of finding by GPS device or definite At All Other Times device to add the time label for these timing signals.Then, may send to base station (or other infrastructure component) to message, allow these entities to follow the tracks of the time that passes.Then, particular message may or periodically be sent to mobile radio station by network service according to instruction on cellular network, the framing structure of expression and signal relevant day the time.This is especially easy for the system as GSM, and total framing structure continues to surpass 3 hours time period in this system.Notice that location measurement unit may serve other purpose, serve as for example that location server-promptly, LMU may actually carry out from measuring the time of advent of mobile radio station, so that determine the position of mobile radio station.
A problem of LMU or TMU method is that they set up new special fixture at each place, base station or other place in several base station communication scopes.This can cause very high installation and maintenance expense.
Summary of the invention
The invention provides the whole bag of tricks and device at cellular network inter-sync cellular basestation.A kind of illustrative methods is carried out this synchronous at least between two base stations of cellular communication system: first base station and second base station.In this illustrative methods, when being positioned at first global position system (SPS) receiver that exists together and determining first day an of MS and primary importance with the first honeycomb mobile receiver station (MS), and in the time of first day and primary importance be sent to first base station by a MS, the latter is during from first day and primary importance and when the known location of first base station is determined the day of first base station.Equally in this illustrative methods, when being positioned at the 2nd SPS receiver that exists together and determining second day of the 2nd MS and the second place with the 2nd MS, and in the time of second day and the second place be sent to second base station by the 2nd MS, the latter is during from second day and the second place and when the known location of second base station is determined the day of second base station.Because these mobile radio stations may be used for proper communication operation and unnecessary building or the structure of being fixed on, so they are used for timing network and have avoided safeguarding the fixedly high cost grade of timing device.Also describe other method and apparatus and come the interior base station of synchronous cellular network.
The accompanying drawing summary
The present invention illustrates by example, and is not limited to the description in the accompanying drawing, and components identical represented in index identical in the accompanying drawing.
Fig. 1 illustrates prior art cellular network one example, and it has determined the position of honeycomb mobile device.
Fig. 2 illustrates and can use cellular mobile communication of the present invention station one example, and it comprises GPS receiver and cellular communication transceiver.
Fig. 3 illustrates cellular basestation one example that can be used in the various embodiments of the present invention.
Fig. 4 is the flow chart that illustrates according to an embodiment of the inventive method.
Fig. 5 A and 5B are the flow charts that illustrates according to another embodiment of the inventive method.
Fig. 6 A illustrates two signals handling according to the present invention's one illustrative methods.
Fig. 6 B illustrates the signal indication at base station place, thereby it illustrates the base station and how to upgrade its clock and other base station synchronization.
Fig. 7 illustrates location server one example that can be used for certain embodiments of the invention.
Fig. 8 illustrates the framing structure of GSM cellular signal.
Describe in detail
The whole bag of tricks and the device that are used for determining the cellular basestation place time and are used for the cellular basestation in the synchronous cellular network have been described here.In the following description, many specific detail have been proposed so that thorough understanding of the present invention to be provided.For example, the various structures of base station that is provided and mobile communication station are not to be restriction of the present invention for illustration purpose.Yet, it will be apparent to those skilled in the art that the present invention can not have these specific detail and realizes.In other cases, with the block diagram form known construction and device is shown so that explain.
In described a kind of method, used the mobile communication station that comprises (or being coupled to) GPS receiver here, when being used for determining day and position.Fig. 2 illustrates an example of this mobile communication station.If the signal that receives is very big, this GPS handles and just can finish under automatic mode, if the signal to noise ratio that perhaps receives is very low, just can help with the equipment (server) in the foundation structure.Notice when server apparatus (as, location server shown in Figure 7 and described in detail below) may also help needs to improve day under the performance situation and (seeing U.S. Patent number 5945944,5841396 and 5812087) determined in the position.
In the network such such as GSM, can come with date and time information from the GPS receiver to the communication that receives (as, GSM) framing structure of signal is done time tag.For example, can use the initial of specific GSM frame boundaries, a (see figure 8) takes place every 4.6 milliseconds in it.Each superframe has 2048 such frames, and each superframe continues 3.48 hours.Therefore, if this timing information through the normal cellular signaling be passed to base station (BS) (as, it is cellular basestation shown in Figure 3), last in the transmission time that main mistake is only arranged is propagation time from mobile radio station (MS) (as, the cellular mobile communication station of Fig. 2) to BS.Certainly, may be left some other residual error,, the method for these residual errors of compensation is described below for example by the multipath delay and the transmission delay of MS hardware.
Can use several different methods to estimate the propagation delay of above-mentioned MS to BS.When MS and/or server through the GPS unit determined MS position and BS position accurately known (as, through the predetermined understanding of measuring) time, can adopt at first method with pin-point accuracy.Under certain conditions, can be by the BS-MS scope be determined (generally at some the network entity place) propagation time divided by the light velocity.Then, BS can deduct the propagation time of being calculated regularly by the flag of frame that provides from MS simply and determines the timing of the flag of frame that it sends.This method further describes in conjunction with Fig. 5 A, 5B, 6A and 6B below.
Existing " timing advance " can realize estimating the secondly more inaccurate method of MS to the BS propagation delay in MS and the BS.The original purpose of this information relates to traffic coordinate in the unit.Yet, produce these MS to BS time-delay estimation thereby can handle timing advance tolerance with direct mode.The accuracy that this time unifying parameter provides is mainly determined by the time series analysis of related communication bit interval.Therefore, may realize being accurate to the propagation delay estimation of several microseconds or tens microseconds.Although second method is more inaccurate than first kind of time-delay method of estimation, however its advantageous particularly under the situation of the network manipulation of getting rid of accurate MS position.
As previously mentioned, in some applications, the base station does not need to be synchronized to the accuracy of microsecond type, and only need be synchronized to the millisecond or even to second type.For these situations, compensation MS may be ineffective to the BS time-delay, because these little time-delays on the ten microsecond orders of magnitude are inessential with respect to required timing accuracy.Therefore, the MS place obtain rough day the time can be used simply as from label between the signal timing of BS.This is sent to BS and does not need BS-MS range data accurately.This situation is favourable, because can carrying out rough time scaling with the signal level required far below the correct time label, the GPS receiver (sees combined by reference U.S. Patent number 5812087 therewith, and combined by reference therewith pending U.S. Patent Application sequence number 09/062232, the latter submitted on April 16th, 1998).And, in case carried out rough time scaling, just can on long-time section, keep its accuracy, this is because the height frequency stability of data is sent in the base station.
Fig. 4 illustrates a kind of illustrative methods according to one embodiment of the invention.In operation 151, the expression when cellular mobile system determines that its day located at the cellular mobile communication station.In one embodiment, wherein in the cellular mobile communication station, use GPS receiver as GPS receiver 52 (as shown in Figure 2 50 specified), can obtain gps time by read the gps time that leaves gps signal from gps satellite.Perhaps, can use being used for described in United States Patent (USP) 5812087 to determine the technology of time.In the method, the sampling of the gps signal that the mobile radio station place receives can be sent to location server or to some other server, wherein handle this and write down to determine time of reception, as described in United States Patent (USP) 5812087.And, can or calculate during the day of operation in 151 with one of the U. S. application sequence number 09/062232 described the whole bag of tricks that awaits the reply, this application was submitted on April 16th, 1998.Method shown in Figure 4 proceeds to operation 153, has wherein determined the propagation delay between cellular mobile communication station and the cellular basestation, cellular basestation cellular basestation as shown in Figure 3.Be appreciated that this operation is chosen wantonly in above-mentioned some embodiment, wherein operate the time ratio propagation delay of determining in 151 and have relative more multiple error.Similarly, as described above, this propagation delay can be determined by the position (by handling gps signal) and the position of definite cellular basestation of determining mobile radio station.Propagation delay in 153 can be determined to operate divided by the light velocity in position between these two positions.
In operation 155,, then determine the time of cellular basestation from when day of mobile radio station (being issued) and from operating the propagation delay of determining 153 from cell mobile communication systems if used this optional operation.
Each cellular basestation in the network can adopt this step to come all base stations with respect to a time standard and synchronously, such as gps time.In this way, can be according to using the timing information that sends between each base station and mobile radio station to obtain improved triangulation or scope.Can make many other uses of timing information.These comprise allow mobile radio station communication from a base station more effectively " more district conversion " to next base station, and permission transmits the clear and definite time for various purposes by network.
Fig. 5 A, 5B, 6A and 6B will describe the further example according to one embodiment of the invention.This method can be carried out with cell mobile communication systems, system 50 for example shown in Figure 2 and cellular basestation 101 shown in Figure 3.
Cellular mobile communication station 50 shown in Figure 2 comprises GPS receiver 52 and cellular communication transceiver 54, and the former has gps antenna 51, and the latter comprises antenna 53.Perhaps, GPS receiver 52 can be included in (and not being integrated in the chassis of the assembly of holding mobile radio station 50 assembly such as cellular communication transceiver 54) in another chassis, but with cellular communication transceiver 54 coupling and adjacent with transceiver 54; In this case, mobile radio station 50 does not comprise the GPS receiver, does not need the GPS receiver yet, as long as GPS receiver and mobile radio station are coupled and be positioned at it and exist together.GPS receiver 52 can be based on the GPS receiver of routine, hardware correlator, perhaps it can be based on the GPS receiver of matched filter, perhaps it can be a GPS receiver of storing the Digital GPS signal of handling with fast convolution with buffer, perhaps it can be the GPS receiver described in United States Patent (USP) 6002363, wherein the assembly of the assembly of GPS receiver and cellular communication transceiver is shared (see Fig. 7 B of United States Patent (USP) 6002363, this patent is incorporated into this by reference).Cellular communication transceiver 54 can be a cellular phones, it comprises GSM cellular standards or PDC communication standard or PHS communication standard or AMPS analog communication standard or North America IS-136 communication standard or not synchronous wide-band spread spectrum CDMA standard with arbitrary known standard work.Thereby GPS receiver 52 offers cellular communication transceiver 54 (it is sent to the base station to this information then) to gps time and position in one embodiment with cellular communication transceiver 54 couplings.And cellular communication transceiver 54 can offer the auxiliary data as doppler information or temporal information the GPS receiver, as described in United States Patent (USP) 5841396 or 5945944.Also can come record is sent to cellular basestation or receiving record therefrom with the coupling between GPS receiver 52 and the cellular communication transceiver 54, so that this is recorded in another record coupling, thereby determine the time at GPS receiver place, as described in United States Patent (USP) 5812087.Under those situations or among the embodiment, wherein the use location server offers the cellular mobile communication station to auxiliary data, so that determine the position or the time at system 50 places, the perhaps shared information processing of location server (as, location server is determined the time or the final position calculating of mobile system 50), be appreciated that location server (as shown in Figure 7 and be further described below) links to each other with cellular basestation to help data processing by communication link.The position of mobile radio station is not generally fixed, and generally is not predetermined.
Fig. 3 illustrates an example of cellular basestation, and it can be used among each embodiment of the present invention.Base station 101 comprises transceiver 102, and it has at least one antenna 102a, be used for the region memory of being served to cellular basestation 101 cellular mobile communication station receiving and transmitting signal.For example, cellular mobile communication station 50 can be one of cellular basestation 101 mobile radio station of being served, and this depends on the range of signal that is generally sent by mobile system 50.Cellular transceiver 102 can be the conventional transceiver that is used to send and receive cellular signal, cellular signal such as GSM cellular signal or cdma cellular signal.Clock 103 can be to keep the conventional system clock of cellular basestation place during day.The accuracy of this clock can the method according to this invention be improved, so that make this clock according to other clock synchronization in method described here and other cellular basestation.In many cases, this clock may be high stability, but in a period of time, clock returns any relatively initial time setting and the very big amount of drifting about.Cellular basestation 101 generally also comprises network interface, and it is to cellular transceiver 102 transceive data, so that cellular transceiver is coupled to mobile switching centre, as known in the art.Cellular basestation 101 may also comprise digital processing system 105, and it may or be positioned at away from cellular basestation, perhaps can be positioned at cellular basestation self to exist together.Digital processing system 105 is coupled to clock 103 with adjusting or recalibration clock time, thereby makes clock synchronous according to method of the present invention and other cellular basestation.In many cases, but the highly stable idle running of clock, and it can influence network operation and the actual time whop that changes all the time.Can regulate the time relevant on the contrary with time point.The implication that Here it is " recalibration ".Digital processing system 105 also is coupled with network interface 104, so that to mobile switching centre's transceive data or communication, and receive data from cellular transceiver 102,, be used for other clock synchronization in other cellular basestation of clock 103 territories for example from the added-time target flag of frame that mobile system sends.
When cellular basestation sent to the cellular mobile communication station to cellular signal, the method shown in Fig. 5 A and the 5B was from operating 201.Randomly, this signal can comprise the request from the synchronizing information of mobile system, so that allow cellular basestation himself to be synchronized to other cellular basestation.Cellular basestation provides markers or sign in it is sent to the signal of mobile system.This sign can be the intrinsic part of sets of signals frame structure.This also illustrates at Fig. 6 A, and wherein base station 1 sends a signal, and the framing structure of signal comprises sign M1, M2, M3, M4, M5, M6, M7, M8 and M9, shown in the signal 301 of Fig. 6 A.Mobile system in the operation 203 of Fig. 5 A receives the cellular signal that has sign.With the reception while of this cellular signal, mobile radio station also receives a gps signal from the gps satellite that comprises gps time, as known in the art.Then, mobile radio station may be made markers to the sign in the cellular signal that receives from the base station with gps time, and it is illustrated in the time that the mobile system place receives sign in gps time.This is further illustrated by signal 303 in Fig. 6 A, and signal 303 expression mobile radio stations 1 are 1 signal that receives from the base station, the propagation delay 307 of having delayed time.As shown in Figure 6A, markers 305 has been applied in sign M1, the gps time that this expression is associated with the time of reception that the mobile system place should indicate.In mobile radio station in the operation 205 and the cellular signal sign is added markers and determine its position simultaneously.GPS receiver possibility in the mobile radio station or spontaneous definite its position (as, may oneself determines its position by reading astronomical ephemeris from gps satellite based on the GPS receiver of conventional hardware correlator), perhaps can determine its position with the help of server, such as location server shown in Figure 7, it and cellular network are coupled.In operation 207, mobile radio station sends to cellular basestation with its position (perhaps pseudo-range is determined its position to allow location server) and the gps time relevant with sign, and sign is with mobile radio station added-time target.
In operation 209, cellular basestation is by determining the propagation delay between mobile radio station and base station with the position of mobile radio station and known predetermined location thereof, thereby when calculating its day.From the gps time relevant, deduct this propagation delay and send the gps time of sign to determine it with sign.This is shown in Fig. 6 B, and wherein base station 1 receives markers TR1 from mobile system.This markers TR1 represents the relevant gps time with sign M1.Deduct propagation delay 307 to derive relevant time T 1 from gps time TR1 with sign M1.That is, time T 1 is in the relevant markers 309 of the sign T1 at place, base station.Then, can be by relevant with present frame M9 producing the current time 311 shown in Fig. 6 B the gps time in the markers 309, thus the current time that the renewal base station is located.That is, during the framing structure of known signal 301, between sign M9 in the signal 301 and the sign M1 known time relationship is arranged.Time difference during the known group frame structure between these two signs is added into time T 1 to produce the current time 311.Therefore, from the current time that the gps time relevant with the institute designation of emission upgrades cellular basestation, the sign of being launched adds markers by mobile radio station.This operation 211 at Fig. 5 B illustrates.Then in operation 213, randomly preserve clock the cellular basestation place synchronous on time once, thereby so that determine when that being fit to refresh clock makes clock and other interior clock synchronization of other cellular basestation.In operation 215, the remote entity of cellular basestation or supporting cellular base station can determine when subsynchronous again.For example, several seconds fixed time can automatically be triggered another synchronizing process.Perhaps, can with other technology determine when the clock at base station place once more with other clock synchronization of other cellular basestation.
Fig. 7 illustrates the example of the location server 350 that can be used for each embodiment of the present invention.For example, as described in No. 5841396 United States Patent (USP), server can offer GPS receiver in the mobile radio station 50 to the auxiliary data as Doppler or other satellite assistance data, perhaps location server and non-mobile station 50 can carry out the final position and calculate (after receiving pseudo-range or other data, from other data, can determine) from mobile radio station, then the base station is determined to be transmitted in this position, make the base station can calculate propagation delay.Location server generally comprises data processing unit, for example computer system 351, modulator-demodulator or other interface 352, modulator-demodulator or other interface 353, modulator-demodulator or other interface 354, mass-memory unit 355 (as, be used for storing software and data) and optional GPS receiver 356.This location server 350 can be coupled with three heterogeneous networks, shows and makes network 360,362 and 364.Network 360 can comprise honeycomb switching center or a plurality of honeycomb switching center and/or based on the telephone system switch of land face; Perhaps, modulator-demodulator 353 can be directly and the cell site coupling, and for example cellular basestation 101.Be appreciated that and generally arranged a plurality of cellular basestations to cover a geographic area that base station that these are different and the coupling of at least one mobile switching centre are as prior art field known (as shown in Figure 1) with radio.Therefore, a plurality of examples of base station 101 can distribute geographically, but are coupled by mobile switching centre.Network 362 can be the network with reference to the GPS receiver, and it provides differential GPS information and the GPS ephemeris data may be provided, and is used to calculate the position of mobile system.This network is coupled to data processing unit 351 by modulator-demodulator or other communication interface 354.Network 364 comprises other computer or networking component, for example data handling system 105 (by the unshowned optional interconnections of Fig. 3) shown in Figure 3.And network 364 can comprise the operated computer system by the emergency operation person, for example the public safety answering point that 911 calls are replied.In many United States Patent (USP)s and patent application, describe the various examples of use location server 350, comprised United States Patent (USP) 5841396; 5874914; 5812087; And the U.S. Patent Application Serial Number 09/062232 of submission on April 16th, 1998, all these is therewith combined by reference.
Said method has been determined the effective transmission time towards the BS antenna.The MS of use larger amt may be tending towards reducing the error by averaging process.This supposition can be eliminated system deviation.
By a plurality of MS being placed on each position and periodically making calling, can improve and support regularly enough MS activities of (as) time in the morning.
Because the single MS GPS of place handles the general timing error that produces may be on the order of magnitude of 10-30 nanosecond.Therefore, may prevail as other error sources such as multipaths.
The stability of BS oscillator may influence need make and propagate the frequency of regularly measuring.May carry out modeling to the drift relative time of BS oscillator, thereby reduce such renewal.
Use description to calibrate the several method of mobile station receiver error now.In certain embodiments of the invention, mobile radio station (as, the cellular mobile communication station 50 of Fig. 2) is determined its position P
Mobile=[x
m, y
m, z
m], and the time T relevant with this position
MobileBy measure simply from the position time decision (as, with gps time) to the time-delay of framing sign time, can be associated this time with the framing sign of the cellular communication signal that receives.Perhaps, can make the position judgement at the time place that equals this framing sign time.Therefore, suppose T with being without loss of generality
MobileEqual the being seen framing sign time of mobile radio station.
Suppose that this mobile radio station also knows the position P of base station
Base=[x
b, y
b, z
b].Then, if multipath delay can be ignored time T then
MobileThe scope of place from the base station to the mobile radio station is
R
Tm＝[(x
m-x
b)
2，(y
m-y
b)
2，(z
m-z
b)
2，]
1/2。
Now, if not time-delay in the receiving circuit, then the scope of propagation delay can be R between base station and mobile radio station
Tm/ c, wherein c is the light velocity.
For more clear, we call the time of origin of this sign in face of base station transmit antennas to the transmission time of place, base station framing sign.Thereby if there is not multipath delay (being the receiver time-delay), the transmission time of antenna for base station surface flag of frame can be T
Base=T
Mobile-R
Tm/ c.
Now, the GPS receiver may have the time-delay relevant with Digital Signal Processing with its RF, is called b
GPSSimilarly, have the time-delay relevant with Digital Signal Processing, be called b with the RF of communication control processor
CommTherefore, with reference to figure 2, b
GPSCause by the time-delay in the GPS receiver 52, and b
CommCause by the time-delay in the cellular communication transceiver 54.And, because may there be the extra propagation delay from the base station to the communication control processor in multipath, be called b
MultSuppose that this has arranged and GPS measures relevant any multipath delay.Thereby,
It is b that a kind of deviation is provided
Mult+ b
Comm-b
GPSMeasurement, but not provide the nothing in base station place transmission time to measure partially.General b
MultMay arrange other error source, if when particularly carrying out the receiver calibration operation (following discussion).Therefore, the estimated framing sign transmission time can laten under the normal condition.
Can measure b by only using base station simulator
Comm-b
GPS, this simulator is launched cellular signal with its framing structure, and the direct time of reception that links to each other with the antenna part of mobile radio station and measure mobile radio station place flag of frame.In this process, flag of frame is added markers (gps time that receives with the GPS receiver of mobile radio station) with the GPS receiver of mobile radio station.Here it is synchronous to suppose that base station simulator is transmitted in the gps time that this GPS receiver provides with the GPS receiver with it.Because the transmission delay from the base station to the receiver is zero, this method can be determined b error freely
Comm-b
GPS(except a small amount of measurement noise).This calibration steps can be fully automatically, and is combined in easily in the receiver test step during manufacture.Some simple modification to this process is feasible, for example from the simulator that is in close proximity to mobile radio station the signal through simulation is transmitted into mobile radio station.
Excessive multipath delay b
MultWhen synchronising base station, continue to become the domination error source.For the path in the sight line, this time-delay has deviation, and average is zero.For reflection path or in conjunction with directly or for the path of transmission path, average is greater than zero (value that records is delayed time with respect to actual directapath).In short time, the base station generally can be from several mobile units, perhaps also from the many times estimations relevant with each flag of frame of each mobile unit.Be estimated as D when claiming these days
1, D
2..., D
KMinimum value during these are estimated is generally than any independent measurement or to measure average mean bias all much lower.If it is very big to measure number of times K, then may arrange measured value from low to high, and may get the measured value minimum 10% average, or some similar statistic.This can reduce mean bias greatly, but has utilized some average.
If the base station has high stability clock, then can keep from the time between the renewal of long-range mobile unit with this clock.Can in smoothing process, use clock to eliminate owing to the not good measurement of multipath from mobile radio station.And, can be with measuring from the measurement of mobile radio station owing to long-time stability as the aging base station clock that causes.For example, the GSM superframe is about 3.48 hours, and big frame is 6.12 seconds.Thereby superframe is about 12528 seconds.There is not the typical gps time measurement of difference error correction should be accurate near 100 nanoseconds.This accuracy allows to measure the long run frequency of basestation oscillator, and it equals about 100 nanosecond/12528 second=8 * 10
-126.12 the measurement on second time period even allow to be about 1.6 * 10
-8The long run frequency accuracy.Measure when making some days and finished this long-time stability best and measured with same mobile receiver.Therefore, mobile radio station static or that slowly move is best suited for this.The continuous measurement meeting of mobile station location provides required and dynamic relevant information mobile radio station.
If the significant user motion is arranged, it is important that then any Doppler's correlation effect does not influence above-mentioned timing measurement.Particularly, if mobile radio station place's Measuring Time and prediction with occur in the cellular signal frame boundaries that do not exist together relevant day the time, then can produce error because of the motion of mobile radio station.When this especially appears at mobile radio station fast moving and/or these time point places widely different.There are many modes to handle this class problem.For example, if mobile radio station can be determined its speed, then these data can be provided for the base station, then the base station can compensate owing to mobile radio station and base station between the error that produces of the relevant Doppler of scope speed.
Although described method and apparatus of the present invention, yet be appreciated that inventive principle also can be applied to use the navigation system of pseudo satellite, pseudolite or satellite and pseudo satellite, pseudolite combination with reference to gps satellite.Pseudo satellite, pseudolite is based on the transmitter on ground, and it broadcasts PN sign indicating number (being similar to gps signal), and the PN sign indicating number may be modulated on L frequency band carriers signal, and is general and gps time is synchronous.Each transmitter can be assigned to unique PN sign indicating number, so that allow the identification of remote receiver.Pseudo satellite, pseudolite may be useful under the disabled situation from the gps signal of orbiter, for example in the tunnel, mine, building or other cingens zone.Here employed term " satellite " comprises the equivalent of pseudo satellite, pseudolite or pseudo satellite, pseudolite, and employed here term " gps signal " comprises the class gps signal from pseudo satellite, pseudolite or pseudo satellite, pseudolite equivalent.
In the discussion in front, with reference to about U.S.'s global positioning satellite (GPS) system description the present invention.Yet it is evident that these methods can be applicable to similar global position system equally, especially Russian Glonass system.The main difference of Glonass system and gps system is, by using different slightly carrier frequencies but not use different pseudo noise codes, comes thereby make to distinguish to each other from the emission of different satellites.Here employed term " GPS " comprises so optional global position system, comprises Russian Glonass system.
In the above description, the present invention has been described with reference to the certain exemplary embodiments of invention.Yet it is evident that, can make various modifications and variations to this and do not deviate from broad spirit and scope of the present invention as proposing in the claims.Thereby specification and accompanying drawing should be considered to be illustrative, and nonrestrictive.
Claims (34)
1. method of between two base stations, carrying out time synchronized at least, described at least two base stations comprise first base station and second base station of cellular communication system, described method comprises:
Determine when day and the position of first cellular mobile station;
By first cellular communication link when day of described first cellular mobile station and position are sent to described first base station;
When determining the day of described first base station during from described first cellular mobile station described day and the known location of described position and described first base station;
Determine when day and the position of second cellular mobile station;
By second cellular communication link when day of described second cellular mobile station and position are sent to described second base station;
When determining the day of described second base station during from described second cellular mobile station described day and the known location of described position and described second base station;
When wherein said first cellular mobile station and described second cellular mobile station have respectively used and be positioned at the satellite positioning system receiver that exists together and determine described first and second cellular mobile stations described day and described position.
2. the method for claim 1, it is characterized in that, during described first cellular mobile station described day is measured period about the frame synchronization that exists in the cellular communication signal, and described cellular communication signal is sent from described first base station and received by described first cellular mobile station.
3. the method for claim 1 is characterized in that, the described frame synchronization period determined about cellular communication signal in exist of described first base station during day, described cellular communication signal is sent from described first base station.
4. the method for claim 1, it is characterized in that described cellular communication link is used gsm communication standard, PDC communication standard, PHS communication standard, AMPS analog communication standard, North America IS-136 communication standard or do not had one of synchronous wide-band spread spectrum CDMA standard.
5. the method for claim 1 is characterized in that, described first cellular mobile station is identical station with described second cellular mobile station.
6. the method for claim 1 is characterized in that, described first cellular mobile station is a cellular mobile station different, that separate with described second cellular mobile station.
7. system that between two base stations, carries out time synchronized at least, described at least two base stations comprise first base station and second base station of cellular communication system, described system comprises:
First global position system (SPS) receiver, it can determine when day and the position of first cellular mobile station, first cellular mobile station and a described SPS receiver are positioned at and exist together, and wherein said first cellular mobile station and described position can be the described first honeycomb mobile receiver described day the time is delivered to described first base station;
With first measurement mechanism of described first base station coupling, when determining the day of described first base station when described first measurement mechanism can be from described day of described first cellular mobile station and the known location of position and described first base station;
Second global position system (SPS) receiver, it can determine when day and the position of second cellular mobile station, second cellular mobile station and described the 2nd SPS receiver are positioned at and exist together, and wherein said second cellular mobile station and described position can be the described second honeycomb mobile receiver described day the time is delivered to described second base station;
With second measurement mechanism of described second base station coupling, when determining the day of described second base station when described second measurement mechanism can be from described day of described second cellular mobile station and the known location of position and described second base station.
8. system as claimed in claim 7 is characterized in that, a described SPS receiver is integrated within described first cellular mobile station centers on.
9. system as claimed in claim 8 is characterized in that, a described SPS receiver and described first cellular mobile station are shared at least one common component.
10. system as claimed in claim 7, it is characterized in that, during described first cellular mobile station described day about frame synchronization period of existing in the cellular communication signal and measured, described cellular communication signal is sent to described first cellular mobile station from described base station.
11. system as claimed in claim 7 is characterized in that, the described frame synchronization period determined about cellular communication signal in exist of described first base station during day, described cellular communication signal is sent from described first base station.
12. system as claimed in claim 7, it is characterized in that described cellular communication link is used gsm communication standard, PDC communication standard, PHS communication standard, AMPS analog communication standard, North America IS-136 communication standard or do not had one of synchronous wide-band spread spectrum CDMA standard.
13. system as claimed in claim 7 is characterized in that, described first cellular mobile station is identical station with described second cellular mobile station.
14. system as claimed in claim 7 is characterized in that, described first cellular mobile station is a cellular mobile station different, that separate with described second cellular mobile station.
15. the method for claim 1 is characterized in that also comprising further method inclined to one side when determining cellular mobile station in the cellular mobile station, it combines and is positioned at the SPS receiver that exists together, and wherein said further method comprises:
Described cellular mobile station is placed near the cellular basestation simulator;
Described cellular basestation simulator is synchronized to the correct time reference;
Be positioned at when day that the SPS receiver that exists together is determined described cellular mobile station with described;
Inclined to one side when determining described cellular mobile station during with described day;
Be stored in partially in the memory that is attached to described cellular mobile station during described cellular mobile station.
16. method as claimed in claim 15, it is characterized in that, described cellular mobile station comprises and described first cellular mobile station and the identical in fact circuit of SPS receiver thereof, and comprises and described second cellular mobile station and the identical in fact circuit of SPS receiver thereof.
17. set up place, first base station time method for one kind in cellular communication system, described method is carried out in the cellular mobile communication station, described method comprises:
Determine the positional information at described cellular mobile communication station, wherein determine the position at described cellular mobile communication station from described positional information;
Time designator when determining place, the described cellular mobile communication of expression station day, wherein said time designator are about the described first base station available signal in place and be determined;
Send at least one in described positional information and the described position, and send described time designator from described cellular mobile communication station, at least one is used to set up the time at place, described first base station in described time designator and described positional information and the described position, makes other base station synchronization in described first base station and the described cellular communication system.
18. method as claimed in claim 17, it is characterized in that, described cellular mobile communication station comprises a global position system (SPS) receiver, its definite described positional information that is included in the pseudo-range of SPS satellite at least, and be cellular communication signal wherein at the available described signal in place, described first base station, this signal is sent to described cellular mobile communication station from described first base station, and the sign in wherein said time designator and the described signal is associated.
19. method as claimed in claim 18 is characterized in that, at least one when described time designator comprises in the sampling of the sps signal that is received by described SPS receiver and the described sps signal day in the message.
20. method as claimed in claim 19 is characterized in that, location server receives described positional information and determines described position, and described position is offered described first base station.
21. set up place, first base station time method for one kind in cellular communication system, described method remotely is performed with respect to the cellular mobile communication station, described method comprises:
From described cellular mobile communication station time of reception designator, when it represented the day at place, described cellular mobile communication station, wherein said time designator was determined with respect to the available signal in place, described first base station;
Determine time of described first base station to make described first base station and other base station synchronization from described time designator.
22. method as claimed in claim 21 is characterized in that, described signal is a cellular communication signal, and it is sent to described cellular mobile communication station from described first base station.
23. method as claimed in claim 21 is characterized in that also comprising:
Receive the position at described cellular mobile communication station, wherein from the described position at described cellular communication station and known, the precalculated position of described first base station also determined described time of described first base station.
24. method as claimed in claim 23, it is characterized in that, because described cellular mobile communication station do not fix, therefore described position is not predetermined, and described position and described known preposition are determined the propagation delay between described cellular mobile communication station and described first base station.
25. method as claimed in claim 24, it is characterized in that, described other base station receive At All Other Times designator by from described cellular mobile station and other cellular mobile station at least one and with described first base station synchronization, wherein said designator At All Other Times is based on identical time standard with described time designator.
26. method as claimed in claim 25 is characterized in that, described identical time standard is the global positioning system time.
27. a base station apparatus that is used for cellular communication system, described base station apparatus comprises:
The radio honeycomb transceiver;
Network interface with described radio honeycomb transceiver coupling; And
Clock with described radio honeycomb transceiver coupling, described radio honeycomb transceiver is from remote cellular mobile communication station time of reception designator, when representing the day at place, described cellular mobile communication station, the signal that can use with respect to described base station apparatus and determine described time designator wherein, and wherein determine the time of described clock, make described base station apparatus and other base station synchronization from described time designator.
28. base station apparatus as claimed in claim 27 is characterized in that, described signal is the cellular communication signal that is sent to described cellular mobile communication station from described base station apparatus.
29. base station apparatus as claimed in claim 28, it is characterized in that, described network interface is delivered to described cellular mobile communication station to the communication based on the land face by described radio honeycomb transceiver, and wherein said radio honeycomb transceiver receives the position of described mobile communication station, wherein the described time of also having determined described clock from the described position and the known precalculated position of described first base station.
30. base station apparatus as claimed in claim 29 is characterized in that also comprising:
Digital processing system, the coupling of it and described clock and with described radio honeycomb transceiver and described network interface at least one coupling, described digital processing system is determined propagation delay from described position and described known precalculated position, and sets the time on the described clock or provide correction to described clock with described propagation delay and described time designator.
31. base station apparatus as claimed in claim 28, it is characterized in that, described other base station receives by from described cellular mobile communication station and described other cellular mobile communication station at least one that designator is and synchronous with described base station apparatus At All Other Times, and wherein said designator At All Other Times is based on identical time standard with described time designator.
32. a cellular mobile communication station comprises:
The radio honeycomb transceiver;
Global position system (SPS) receiver with described radio honeycomb transceiver coupling, described SPS receiver is determined a time designator, when this designator is represented day at described cellular mobile communication station place and with respect to the base station available signal in place and be determined, wherein said radio honeycomb transceiver sends to described base station to described time designator, described time designator is used to set up the time at place, described base station, makes described base station and energy and described cellular mobile communication station carry out other base station synchronization of radio communication.
33. cellular mobile communication as claimed in claim 32 station, it is characterized in that, described SPS receiver is determined a position, and described radio honeycomb transceiver sends to described base station to described position, described signal is the signal that is sent to described cellular mobile communication station from described base station, and the sign in wherein said time designator and the described signal is associated.
34. cellular mobile communication as claimed in claim 33 station is characterized in that, message when described time designator is day in the sps signal that is received by described SPS receiver.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/US2001/017113 WO2002098024A1 (en) | 2001-05-26 | 2001-05-26 | Methods and apparatuses for using mobile gps stations to synchronize basestations |
Publications (2)
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| CN1507710A true CN1507710A (en) | 2004-06-23 |
| CN1294708C CN1294708C (en) | 2007-01-10 |
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|---|---|---|---|
| CNB018232981A Expired - Lifetime CN1294708C (en) | 2001-05-26 | 2001-05-26 | Methods and apparatuses for using mobile GPS station to synchronize basestations |
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| Country | Link |
|---|---|
| JP (1) | JP4860901B2 (en) |
| KR (1) | KR100881869B1 (en) |
| CN (1) | CN1294708C (en) |
| AU (1) | AU2001261816B2 (en) |
| CA (1) | CA2447914C (en) |
| HK (1) | HK1063889A1 (en) |
| IL (1) | IL158850A0 (en) |
| WO (1) | WO2002098024A1 (en) |
Cited By (7)
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| CN100421367C (en) * | 2004-07-26 | 2008-09-24 | 华为技术有限公司 | Method for implementing synchronous transmission for base station |
| WO2009076895A1 (en) * | 2007-12-12 | 2009-06-25 | Huawei Technologies Co., Ltd. | Method, device, base station and network system for sharing the satellite card resource |
| CN102379144A (en) * | 2009-04-08 | 2012-03-14 | 高通股份有限公司 | Minimizing the impact of self synchro-nization on wireless communication devices |
| CN102379143A (en) * | 2009-04-08 | 2012-03-14 | 高通股份有限公司 | Conveying synchronization stratum information |
| CN103576122A (en) * | 2013-11-04 | 2014-02-12 | 中国科学院光电研究院 | Rescue locating method based on burst distress signal |
| CN105897330A (en) * | 2016-04-01 | 2016-08-24 | 严炜 | Signal synchronization method used for UWB high-precision positioning system |
| CN110753298A (en) * | 2018-07-05 | 2020-02-04 | 中移物联网有限公司 | Positioning method and device, equipment and storage medium thereof |
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| US6937872B2 (en) | 2002-04-15 | 2005-08-30 | Qualcomm Incorporated | Methods and apparatuses for measuring frequencies of basestations in cellular networks using mobile GPS receivers |
| JP3794413B2 (en) | 2003-02-28 | 2006-07-05 | セイコーエプソン株式会社 | Positioning system and positioning terminal |
| US20040202119A1 (en) * | 2003-04-10 | 2004-10-14 | Edge Stephen William | Base station synchronization in a wireless network |
| KR101099175B1 (en) | 2004-01-26 | 2011-12-27 | 캠브리지 포지셔닝 시스템스 리미티드 | Transfer of calibrated time information in a mobile terminal |
| WO2006088472A1 (en) * | 2005-02-11 | 2006-08-24 | Trueposition, Inc. | Base transceiver station (bts) synchronization |
| JP4577036B2 (en) * | 2005-02-15 | 2010-11-10 | セイコーエプソン株式会社 | Communication base station |
| GB2450680B (en) * | 2007-06-22 | 2012-05-30 | Ubiquisys Ltd | Controlling timing of synchronization updates |
| KR102235544B1 (en) * | 2016-12-28 | 2021-04-01 | 후아웨이 테크놀러지 컴퍼니 리미티드 | Channel delay determination method, positioning method, and related apparatus |
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- 2001-05-26 KR KR1020037015407A patent/KR100881869B1/en active IP Right Grant
- 2001-05-26 CA CA002447914A patent/CA2447914C/en not_active Expired - Lifetime
- 2001-05-26 JP JP2003501096A patent/JP4860901B2/en not_active Expired - Lifetime
- 2001-05-26 IL IL15885001A patent/IL158850A0/en unknown
- 2001-05-26 AU AU2001261816A patent/AU2001261816B2/en not_active Expired
- 2001-05-26 WO PCT/US2001/017113 patent/WO2002098024A1/en active Application Filing
- 2001-05-26 CN CNB018232981A patent/CN1294708C/en not_active Expired - Lifetime
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Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100421367C (en) * | 2004-07-26 | 2008-09-24 | 华为技术有限公司 | Method for implementing synchronous transmission for base station |
| WO2009076895A1 (en) * | 2007-12-12 | 2009-06-25 | Huawei Technologies Co., Ltd. | Method, device, base station and network system for sharing the satellite card resource |
| CN102379144A (en) * | 2009-04-08 | 2012-03-14 | 高通股份有限公司 | Minimizing the impact of self synchro-nization on wireless communication devices |
| CN102379143A (en) * | 2009-04-08 | 2012-03-14 | 高通股份有限公司 | Conveying synchronization stratum information |
| CN102379144B (en) * | 2009-04-08 | 2015-01-28 | 高通股份有限公司 | Minimizing the impact of self synchro-nization on wireless communication devices |
| CN102379143B (en) * | 2009-04-08 | 2016-08-03 | 高通股份有限公司 | Transmission synchronization stratum information |
| CN103576122A (en) * | 2013-11-04 | 2014-02-12 | 中国科学院光电研究院 | Rescue locating method based on burst distress signal |
| CN105897330A (en) * | 2016-04-01 | 2016-08-24 | 严炜 | Signal synchronization method used for UWB high-precision positioning system |
| CN110753298A (en) * | 2018-07-05 | 2020-02-04 | 中移物联网有限公司 | Positioning method and device, equipment and storage medium thereof |
| CN110753298B (en) * | 2018-07-05 | 2022-02-01 | 中移物联网有限公司 | Positioning method and device, equipment and storage medium thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| IL158850A0 (en) | 2004-05-12 |
| CN1294708C (en) | 2007-01-10 |
| CA2447914C (en) | 2008-07-22 |
| JP4860901B2 (en) | 2012-01-25 |
| WO2002098024A1 (en) | 2002-12-05 |
| KR100881869B1 (en) | 2009-02-06 |
| JP2004533177A (en) | 2004-10-28 |
| AU2001261816B2 (en) | 2008-05-08 |
| CA2447914A1 (en) | 2002-12-05 |
| HK1063889A1 (en) | 2005-01-14 |
| KR20040003013A (en) | 2004-01-07 |
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