The mobile communication localization method of wireless environment Network Based
Technical field
The present invention relates to a kind of wireless location technology, relate to a kind of mobile communication wireless localization method of wireless environment Network Based or rather, be used for the wireless location service business that provider uses.
Background technology
Along with the development of mobile communication cause and mobile subscriber's increase, the demand to such as mobile communication positioning services such as intelligent transportation, tour guide, public safety, Emergency Assistances grows with each passing day.For this reason, commercial wireless location service business has been released in the operation commercial city of developed countries such as U.S., Europe, day.In China, " China Mobile " also released commercial wireless location service business in 2002.
The release of commercial wireless location service business and the increase of demand, greatly promoted the development of wireless location technology, the wireless location technology of having developed at present, method substantially can be divided three classes: based on the wireless location method of mobile communications network, based on the wireless location method of global positioning system (GPS) and the wireless location method that mixes with global positioning system based on mobile communications network.
Wherein, the first kind is based on the wireless location method of mobile communications network, be to measure by some parameter to the radio wave that receives, re-use specific algorithm and judge the position of testee, its measurement parameter generally comprises transmission time, signal amplitude, signal phase and angle of arrival or the like.Positioning accuracy depends primarily on method of measurement.Up to the present, the wireless location method based on mobile communications network mainly contains following five kinds:
First kind is to utilize the ID (Cell-ID) of the sub-district or the sector at mobile subscriber place to come the localization method based on Cell ID of definite user geographic location substantially.The advantage of this method is to realize that simply end side does not need to do the modification of any software or hardware, and network side does not need to increase new network positions entity.Shortcoming is that positioning accuracy is not high, and particularly because the existence of multipath effect, its positioning accuracy sometimes even do not reach sub-district or sector-level.
Second kind is to come the angle of arrival of the signal of self terminal to estimate the wireless location method based on incoming wave arrival angle AOA (Angle of arrival) of location of mobile users by two or more base stations by measurement.Receiver is measured the incidence angle of electric wave by aerial array, thereby constitutes a radially line from transmitted from transmitter to receiver, is called Line Of Observed Position, and the two-dimensional position coordinate of travelling carriage can obtain by the intersection point of two Line Of Observed Positions.When in the more environment of barrier, using this method, because there is multipath effect in wireless transmission, cause measure error to increase, positioning accuracy is lower, especially when travelling carriage is far away apart from the base station, the little deviation of base station orientation angle can cause the Line Of Observed Position distance than mistake.
The third is a kind of localization method based on reverse link, by measuring the wireless location method based on the incoming wave TOA time of advent (Time of Arrival) that mobile station signal arrives definite location of mobile users of propagation time of a plurality of base stations.This method needs the signal that base station more than three can receive travelling carriage, utilizes the triangle location algorithm to calculate the position of travelling carriage then.The advantage of this method is to need not to revise existing terminal, but need be at base station additional firmware (LMU), to reach the accurate Calculation burst purpose of the time of advent.Because whole wireless location network need be set up a large amount of LMU, so improved the construction cost of network greatly.
The 4th kind of wireless location method that is based on the incoming wave difference TDOA time of advent (Time Different of Arrival), this method also is a kind of localization method based on reverse link, by detecting the position that mobile station signal arrives definite travelling carriage of time difference of two base stations, the travelling carriage of this moment, must be positioned at two base stations is on the hyperbola of focus, determine that the two-dimensional position coordinate of travelling carriage need set up two above Hyperbolic Equations, that is to say and to receive mobile station signal in the base station more than at least three, and two hyp intersection points are the two-dimensional position coordinate of travelling carriage.
The 5th kind of method is a kind of localization method based on forward link AFLT (Advanced Forward LinkTrilateration), be when positioning action, mobile phone is monitored the pilot frequency information of a plurality of base stations (at least three base stations) simultaneously, utilize the chip time delay to determine the distance of mobile phone, calculate user's position at last with triangulation location near base station.This method need increase new entity in network, new entity need obtain pilot frequency information, utilizes pilot frequency information to calculate the position of travelling carriage again.The entity that increases comprises PDE (Position Deltermining Entity) and MPC (Mobile Positioning Center).Wherein the PDE mode that obtains pilot frequency information mainly contains two kinds: a kind of is that load mode according to the IS-801 protocol definition sends pilot frequency information to mobile switching centre (MSC), send PDE to by MSC again, need the function of the newly-increased IS-801 of support of travelling carriage agreement when implementing this mode.Second kind is the message of utilizing on the A interface, sends the parameter that wherein is used to locate to MSC, sends PDE to by MSC again.
By analyzing above-mentioned five kinds of wireless location methods based on mobile communications network, illustrated because the maximum characteristics of this wireless location method are to describe propagation path between measurement point and signal emitting-source with linear fashion, therefore be difficult to overcome the influence that the multipath effect of electromagnetic wave propagation is brought, and densely populated, commercial flourishing hot zones, wireless environment is often very complicated, multipath effect is very obvious, therefore this precision of describing the localization method of the propagation path between measurement point and signal emitting-source based on linear fashion will reduce greatly, thereby influence the commercialization of this wireless location method.
Second class is based on the wireless location method of global positioning system (GPS).Practical GPS localization method is the GPS location of network assistance at present, promptly when the location, network is by following the tracks of gps satellite signal, demodulate the GPS navigation signal, and send these information to travelling carriage, travelling carriage utilizes these information can search the effective GPS satellite fast, receive satellite-signal after, calculate the work of location of mobile station and can finish by network entity or travelling carriage.Advantage based on the localization method of GPS is that positioning accuracy is higher, and location radii can reach several meters, tens meters, therefore utilizes this kind location technology, can satisfy the needs to the higher business of positioning accuracy request, as explicit user position on electronic chart etc.Its shortcoming is to need modules such as built-in gps antenna of travelling carriage and GPS chip, and needs to support the IS-801 agreement, and network side need increase PDE and MPC; Positioning accuracy is subjected to the influence of terminal environment of living in bigger, as the user indoor or between high-lager building the time, because the gps satellite negligible amounts that can trace into, positioning accuracy will reduce, even can't finish the location.
The 3rd class is a hybrid location determination technology, promptly in a system, comprehensive two or more methods of using in the above-mentioned two class location technologies, the main stream approach of code division multiple access (CDMA) system employing at present is the mode of GPS and AFLT mixed positioning, can abbreviate the network assistance mixed positioning as, advantage that combines based on network non-GPS location technology and advantage based on the network assistance location technology of GPS., can utilize the GPS location that high-precision position information is provided in the open air, network side can provide supplementary to shorten positioning time and improve positioning accuracy simultaneously; In the city, can utilize the intensive advantage in base station, adopt locate mode based on base station signal, perhaps adopt and mix the locate mode of utilizing gps signal and base station signal, be implemented under the complex environment location of (as between indoor, the city high rise building).
Though the positioning accuracy based on the wireless location technology of GPS is higher, need to introduce the GPS receiving system at user terminal, increase the realization difficulty and the cost of user terminal.In addition, because GPS is controlled by US military, fail safe can't guarantee.
The 3rd class wireless location technology is the hybrid wireless location technology, is actually the combination of preceding two class methods, just uses different technology in different environment, does not therefore fundamentally solve the shortcoming of preceding two class technology.
In sum, along with the development of commercial wireless location service business, the user increases day by day to the requirement of positioning accuracy on the one hand; On the other hand, there is the shortcoming of every aspect again in existing wireless location technology, and it is very necessary and urgent therefore developing a kind of new high-precision wireless location method.
Summary of the invention
The objective of the invention is to design a kind of mobile communication localization method of wireless environment Network Based, can overcome at present the multipath effect problem that the wireless location method institute based on mobile communications network can't avoid, thus the precision of raising wireless location.
The objective of the invention is to be achieved through the following technical solutions:
A kind of mobile communication localization method of wireless environment Network Based comprises following treatment step:
A. wireless network is divided into pixel, this pixel is the minimum unit subregion of determining according to precision in the mobile communications network coverage;
B. determine the various features parameter, this characteristic parameter can identify the geographical position of portable terminal in wireless network;
C. in each pixel scene, the various features parameter of all determining is measured, obtained each characteristic ginseng value pixel, identify the pixel position uniquely with the characteristic parameter group, thereby set up characteristic parameter group pixel database to data;
When D. positioning, by portable terminal to be positioned with by more than one described characteristic parameter of network measure, measurement result is gathered to network side, by measurement result and the characteristic parameter group pixel of network side to described more than one characteristic parameters database is shone upon, the pairing pixel of the mapping result when mating full position is the position at portable terminal place to be positioned.
Purpose of the present invention can also be achieved through the following technical solutions:
A kind of mobile communication localization method of wireless environment Network Based comprises following treatment step:
A. wireless network is divided into pixel, this pixel is the minimum unit subregion of determining according to precision in the mobile communications network coverage;
B. determine the various features parameter, this characteristic parameter can identify the geographical position of portable terminal in wireless network;
C. in each pixel scene, the various features parameter of all determining is measured, obtain each characteristic ginseng value pixel to data, identify the pixel position uniquely with the characteristic parameter group, layered configuration obtained with pixel characteristic of correspondence parameter value pixel to data, the stack different layers forms characteristic parameter group @ pixel to vector database, and then composite character parameter electronic chart;
When D. positioning, by portable terminal to be positioned with by more than one described characteristic parameter of network measure, measurement result is gathered to network side, determine the pixel that the measurement result of more than one characteristic parameters is shone upon by network side on the characteristic parameter electronic chart, this pixel position is the position at portable terminal place to be positioned.
Said method is according to needed precision wireless network to be divided into some pixels (unit subregion), utilize portable terminal or network measured value to some characteristic parameter, method composite character parameter electronic chart with the layering mapping utilizes the measured value to a plurality of characteristic parameters to position on the characteristic parameter electronic chart then.
The present invention is divided into some pixels (unit subregion) according to needed precision with wireless network, and identifies pixel uniquely with a stack features parameter.The characteristic parameter of selecting can be field intensity value, phase place or the phase difference of received signal and the incoming wave difference time of advent etc., also can be sub-district, sector identity sign (ID).
In all pixel site environments of dividing, whole characteristic parameters of required measurement are measured, and the measurement result of each characteristic parameter is carried out statistical average handle, finally form characteristic parameter group pixel to database.
With the characteristic parameter pixel to data according to certain criterion (is one deck etc. as each parameter) layered configuration, then with different layers stack, form characteristic parameter group pixel vector database, and then synthetic mobile communication network characterization parameter electronic chart.
The target that needs can be positioned is mapped on the characteristic parameter electronic chart by predetermined criterion the measured value of various features parameter, determines terminal place pixel (unit subregion), thereby carries out wireless location.
Method of the present invention, taken into full account the influence that the multipath effect of electromagnetic wave propagation causes the wireless location precision, be mapped on the geographical position by characteristic parameter the network wireless environment, identify the geographical position uniquely by the various features parameter again, thereby farthest overcome the influence of multipath effect, improved positioning accuracy.
The invention has the beneficial effects as follows: indicate geographical location information uniquely by characteristic parameter, thus the influence of farthest having avoided multipath effect that wireless location is brought; Make full use of the existing network planning and metrical information and carry out wireless location, little to the influence that the terminal software and hardware is realized; Can be according to network change and actual needs, adjust what of pixel (unit subregion) size and characteristic parameter kind at any time, the characteristic parameter electronic chart is evolved upgrade, thereby improve positioning accuracy neatly; Because do not utilize auxiliary networks such as GPS, fail safe is guaranteed.
Description of drawings
Fig. 1 is the wireless location process flow block diagram of being initiated by portable terminal;
Fig. 2 is the wireless location process flow block diagram of being initiated by network.
Embodiment
The inventive method need be handled following key step when specific implementation:
Step 1 is at first determined the needed precision of zone location, according to this precision wireless network is divided into some pixels, i.e. minimum unit subregion in the mobile communications network coverage, the precision that needs is high more, and then the pixel of Hua Fening is many more, and the minimum unit subregion is more little.The pixel zone is changeable, and by positioning accuracy decision, the size in each pixel zone of being divided can be the same or different, and can decide with site environment, can be as the pixel of the intensive hot spot region of the building divided less than the pixel of the flat site of division,
Step 2 is determined the employed characteristic parameter of wireless location then, promptly can identify the parameter of mobile terminal locations.These characteristic parameters can be received signal field intensity value, phase place or phase difference and incoming wave time of advent difference etc., also can be sub-district, sector identity sign (ID).
Step 3, each pixel position at the network scene, all characteristic parameters of determining are measured (measuring with portable terminal or with characteristic parameter measuring equipment such as field strength meter etc.), and the measurement result of each characteristic parameter is carried out statistical average handle, the pixel that forms each characteristic parameter forms characteristic parameter group pixel to database (i.e. locational all characteristic parameter measurement data of all pixels) at last to data.
Step 4, with the characteristic ginseng value pixel to data according to certain criterion layered configuration, be set to one deck as each parameter, or several parameter configuration are one deck etc., with the different layers stack, form characteristic parameter group @ pixel vector database then, but and then with regard to composite character parameter electronic chart.
Step 5, when positioning, pass through reciprocal process between portable terminal and network, respectively by portable terminal in (on the pixel position at place) on its position with by network, according to network requirement all or part of parameter of characteristic parameter group is measured that (measuring condition is with step 3, the characteristic parameter kind is determined by network), and with measurement report, gather to network.
Step 6, network will be mapped to (relation of full coupling) on the characteristic parameter electronic chart to the characteristic parameter measured value, thereby determine the pixel (unit subregion) at portable terminal place, also promptly finish the location.
Network alleged among the present invention should comprise mobile communication system entities such as base station, base station controller, radio network controller and mobile switching centre.
Below in conjunction with accompanying drawing 1,2, be embodiment with terminal location request initiating and network location request initiating respectively, specifically describe the realization flow of this localization method.
Referring to Fig. 1, when portable terminal need be known the geographical position of oneself, the wireless location request process that active is initiated to network.
Step 101, portable terminal are sent the wireless location request;
Step 102, network receive the Location Request of being sent by this portable terminal;
Step 103, network determines the characteristic parameter of required measurement, comprise the quantity of characteristic parameter and specifically be which plants characteristic parameter, the criterion of decision mainly considers to avoid multipath, as under smooth fairly simple wireless network environment and under the environment of the intensive more complicated of housing-group, the characteristic parameter of selection and the quantity of characteristic parameter should be distinguished to some extent;
Step 104, network will need the indication of the characteristic parameter of this portable terminal measurement to send to this portable terminal;
Step 105 after portable terminal receives indication, is measured corresponding characteristic parameter, and measurement result is reported network, if the characteristic parameter that has needs network side to measure, then network side is measured these characteristic parameters simultaneously, as the angle of arrival, arrival bearing etc.;
Step 106, network gather all measurement results;
Step 107, measurement result after network will gather and characteristic parameter group pixel shine upon database, determine the numbering of pixel (unit subregion) on the characteristic parameter electronic chart that these measurement results are shone upon, can be undertaken by predetermined criterion when shining upon, the characteristic parameter ground mapping as whether one by one, whether shine upon responsive characteristic parameter, error requirements etc. earlier;
Step 108, network side is issued this portable terminal with the geographical location information of the pixel (unit subregion) of this portable terminal, finishes once the mobile communication position fixing process of wireless environment Network Based.
Referring to Fig. 2, need know the geographical position of another portable terminal when a certain portable terminal, perhaps carry out the mobile communication positioning service when professional, send the wireless location request process by network to a certain portable terminal.
Step 201, network are sent the wireless location request;
Step 202, network determines the characteristic parameter of required measurement, comprise the quantity of characteristic parameter and specifically be which plants characteristic parameter, the criterion of decision mainly considers to avoid multipath, as under smooth fairly simple wireless network environment and under the environment of the intensive more complicated of housing-group, the characteristic parameter of selection and the quantity of characteristic parameter should be distinguished to some extent;
Step 203, network will need the indication of the characteristic parameter of certain portable terminal measurement to send to this portable terminal;
Step 204 after portable terminal receives indication, is measured corresponding characteristic parameter, and measurement result reported network, if the characteristic parameter that has is measured by network side, then network side is measured these characteristic parameters simultaneously, as the angle of arrival, arrival bearing etc.;
Step 205, network gather all measurement results;
Step 206, measurement result after network will gather and characteristic parameter group pixel shine upon database, determine the numbering of pixel (unit subregion) on the characteristic parameter electronic chart that these measurement results are shone upon, can be undertaken by predetermined criterion when shining upon, the characteristic parameter ground mapping as whether one by one, whether shine upon responsive characteristic parameter, error requirements etc. earlier;
The geographical location information that step 207, network side will be shone upon the pixel (unit subregion) of the portable terminal that obtains is issued this portable terminal, finishes once the mobile communication position fixing process of wireless environment Network Based.
By the step of Fig. 1, Fig. 2, the mobile communication localization method that the present invention is based on the network wireless environment has been described, its process is initiated irrelevant with the location.
The mobile communication localization method of wireless environment Network Based of the present invention, it comes down to a kind of area positioning method: earlier wireless network is divided into some pixels (unit subregion) according to needed precision, also promptly in the mobile communications network coverage, under default precision minimum unit subregion; Utilize portable terminal and network measured value again, with the method composite character parameter electronic chart of layering mapping to some characteristic parameter; Utilize measurement at last, on the characteristic parameter electronic chart, position a plurality of characteristic parameters.
Method of the present invention, the network planned and the information of institute's energy measurement have been made full use of, because what measure is a plurality of characteristic parameters, overcome to a great extent based on the wireless location method of mobile communications network the multipath effect problem that can't avoid, thereby improved the mobile communication wireless locating accuracy, and solved the problems such as terminal realization difficulty, cost height and fail safe that adopt the GPS navigation system to be brought.