User's handover between the multiple access communication system
Invention field
The present invention relates generally to radio communications system, relate in particular to and finish the method and system that between cellular communication system, carries out the improvement of handover with different multiple access (multiple access) scheme.
Background of invention
In order to use and multiplexing radio frequency frequency spectrum the biglyyest, radio communications system adopts multiple scheme to allow simultaneously or the approaching accessing communication resource side by side of a plurality of users.For example, in cell phone system, the air interface (air interface) that a lot of phone users are allowed to by a plurality of user captures of multiple permission visits wire communication resource (being public switched telephone network (PSTN)).
A multiple access (rdma) scheme can be defined as sending or time of reception by distributing, channel frequency, and channel width, chnnel coding, a communication resource is shared in the combination of transmission or receiving position or the like, for example one of the radio frequency frequency spectrum group of rule.The example of known multiple access (rdma) scheme comprises: AMPS (Advanced Mobile Phone System), NAMPS (arrowband AMPS), TACS (omnidirectional is pressed into network communication system), GSM (global system for mobile communications), TDMA (time division multiple access (TDMA)) and CDMA (CDMA).These multiple access (rdma) schemes much in telecommunications industry association of cellular telecommunication industrial association (CTLA) (TIA), or in the industrial standard announced of other standard entity good description is arranged.One of them example is the standard I S-95 of CDMA cellular communication system.
Along with coming into operation of newer multiple access (rdma) scheme, the overlay area of new multiaccess system does not generally have system big of old different multiple access (rdma) schemes of the use of having set up.Therefore, in order to offer more wide communication service area of user with new multiple access (rdma) scheme, having developed the dual-mode subscriber unit makes the user can have the service of new multiaccess system, and when they roam into outside the areal coverage of newer multiaccess system, subscriber unit can with one older or optionally multiaccess system communicate.
Referring now to Fig. 1,, shows the covering of communication system and use a typical relation between the covering of communication system of second multiple access (rdma) scheme with first multiple access (rdma) scheme.Specifically, the honeycomb area coverage 20 of Fig. 1 illustrates the cellular system of an employing code division multiple access (CDMA) scheme, illustrates with hexagonal cell 22, for convenience of explanation, represents an optional multiple access (MA) scheme with circular sub-district 24.Zone that cdma cellular 22 covers and optional MA are illustrated with thick line by limit 26 with the border between the zone of optional sub-district 24 coverings.
When user 28 is mobile between CDMA sub-district 22, the handover between 30 guidances of cdma base station controller or the management CDMA sub-district 22.Similarly, when user 28 was mobile between optional MA sub-district 24, optional MA base station controller 32 instructed or manages handover between the optional MA sub-district 24.A handover is a processing in the cellular communication system, by Traffic Channel of this processing from switching to and another cell communication with a cell communication.
The problem to be solved in the present invention appears when the communication system that adopts a MA wants that a user is handed over to the communication system that adopts the 2nd MA.This problem occurs when user 28 passes boundary line 26 and moves to an optional MA sub-district 24 from CDMA sub-district 22 in Fig. 1.This problem may not take place under user 28 does not pass the situation of boundary line 26 yet, when a for example MA communication system is want user 28 is handed in the optional MA sub-district 24 that a MA communication system covers.
In the prior art, when a for example MA is CDMA, pilot beacon (pilot beacon) is used to the edge (being boundary line 26) of warning cdma base station controller 30 users 28 just covering near CDMA.Pilot beacon 34 used herein is definition or general by transmitting that parts among the MA receive in a MA, and wherein this MA is the source of handover.For example, when CDMA was source MA, pilot beacon 34 was pilot channel beacons, and it makes outside the boundary line 26 or looks like it is another CDMA sub-district 22 near the optional MA sub-district 24 of boundary line 26.This means user 28 according to the rule of CDMAIS-95 appearance and intensity, make it to arrange a handover with optional MA base station controller 32 by the base station controller communication link between MA 36 to cdma base station controller 30 report pilot beacons 34.Detailed description is please granted Weaver referring on January 14th, 1997, and Jr. waits people's 5,594,718 the United States Patent (USP) of being numbered.
Pilot beacon 34 is placed on a lot of problems in the sub-district near the boundary line outside the boundary line 26.The first, it is very expensive, and each pilot beacon 34 needs one and is connected to the transmitter that the suitable construction antenna is installed.
The second, it has increased the complicacy of communication system.The CDMA pilot beacon must identify synchronously and with unique time migration with the other parts of system.Power level must correctly be set.
The 3rd, must rent or buy additional antenna website.Sometimes, for the space of the usefulness that on rival's tower, obtains to fix up an aerial wire, identify that such Site Protocol may need to negotiate with the cellular system rival.
The 4th, pilot beacon may increase the intrinsic noise level of the system that is runed by another grantee on same radio band.
The 5th, by first or the pilot beacon measured of source MA communication system differ and show the communication quality of the radio frequency link that uses the 2nd MA communication system surely well.That is to say that the signal quality of (collocated) AMPS sub-district emission that is set together by and the CDMA pilot beacon that measures at customer location is the AMPS signal quality of corresponding same customer location accurately; The AMPS signal may be decayed and CDMA radio frequency beacon is unattenuated.This may owing to the CDMA pilot beacon a frequency and the propagation differences of AMPS signal on another frequency causes.
Another optional method that uses pilot beacon to carry out handover between different MA systems is the handover of any existing knowledge of the Traffic Channel of handover-do not need the 2nd MA communication system blindly.This possibility is easy to cause call drop.And when having a plurality of sub-districts can handle this Traffic Channel in the 2nd MA communication system, there is not better Intelligence Selection to select a handover candidate cells preferably.
For above-mentioned reasons, need a method and apparatus of finishing in improvement with the handover that carries out between the different multiple access (rdma) schemes.
Brief description of drawings
Being considered to the distinctive new characteristics of the present invention lists in appending claims.But the present invention itself and the preference pattern that uses, further purpose with and advantage by being understood well with reference to the detailed description of hereinafter carrying out with reference to 1 pair of illustrated embodiment of accompanying drawing.
Fig. 1 illustrates one by two schematic overlay areas that communication system provided of using two different multiple access (rdma) schemes, and wherein according to prior art, the handover between two systems has used pilot beacon;
Fig. 2 is a principle skeleton diagram of the method according to this invention and the system device of finishing the handover between the different multiple access communication systems;
Fig. 3 shows the optional embodiment that the method according to this invention and system finish a device of the handover between the different multiple access communication systems;
Fig. 4 shows the method according to this invention and system and finishes principle skeleton diagram with a code division multiple access system of the handover of an optional MA communication system;
Fig. 5 is the detailed diagram of first embodiment of a signal characteristic metering circuit that can be used for realizing method and system of the present invention;
Fig. 6 shows second embodiment of the signal characteristic metering circuit that can be used for realizing method and system of the present invention;
Fig. 7 is that the high-level logic flowchart with the method for the handover of an optional MA communication system is finished in an explanation according to the present invention;
Fig. 8 is the more detailed process flow diagram of explanation according to the initialization process of subscriber unit of the present invention;
Fig. 9 is the processing of a signal characteristic in the optional MA communication system is measured in explanation according to the present invention a more detailed process flow diagram; And
Figure 10 is that the more detailed process flow diagram that a receiver is measured the processing of a signal characteristic in the optional MA communication system is disposed in explanation according to the present invention.
Detailed description of the invention
Referring now to accompanying drawing,, especially Fig. 2 shows the principle skeleton diagram that the method according to this invention and system finish a device of the handover between the different multiple access communication systems.As shown in the figure, subscriber unit 50 generally comprises the first multiple access transmitter-receiver 52 and the second multiple access transmitter-receiver 54, and the both is connected to antenna 56.The one MA transmitter-receiver 52 is used for communicating with the honeycomb of first communication system that adopts first multiple access (rdma) scheme.Similarly, the 2nd MA transmitter-receiver 54 is used for communicating with the honeycomb of the second communication system that adopts second multiple access (rdma) scheme.Suitable diplexer (not shown) can be used for isolating the transmission signal from received signal.The frequency of the one MA transmitter-receiver 52 is by local oscillator 58 controls, and the frequency of the 2nd MA transmitter-receiver 54 is by local oscillator 60 controls.Local oscillator 58 and 60 all can be by the frequency that is set at a selection from one of circuit 62 order of control or signal.
Also show the 2nd MA metering circuit 64 among the embodiment of Fig. 2, it has one to be connected to the input of antenna 56 and measurement that one is connected to control circuit 62 output.The 2nd MA metering circuit 64 also receives control signal by a control line from control circuit 62.
Referring again to first transmitter-receiver 52, downlink traffic 66 is by a MA transmitter-receiver 52 outputs and may be connected to control circuit 62 and clock 68 now.Downlink traffic 66 can comprise control information, clock or synchronizing information, and voice data or other data by unshowned processing of circuit in the subscriber unit.
Uplink service 70 is inputs of first transmitter-receiver 52.Uplink service 70 can comprise speech or other user data, and from the control information of control circuit 62.
The 2nd MA transmitter-receiver 54 may comprise the output of an output downlink traffic 72 and the input of an input uplink service 74 in an identical manner.Downlink traffic 66 and 72 and uplink service 70 and 74 processed in the known mode in phone user's monotechnics field in the not shown part of subscriber unit 50 so that speech or Computer Data Communication service to be provided.
In operation, subscriber unit 50 is by a cell communication in the transmitter-receiver 52 and first multiple access communication system.Subscriber unit 50 is instructed to a MA transmitter-receiver 52 is tuned as a specific frequency, and this frequency is set or derived by local oscillator 58.Control circuit 62 can receive termly and start the instruction of switching or being handed over to the processing of a Traffic Channel in second multiple access communication system.After receiving this instruction, the signal characteristic that control circuit 62 is measured from a signal of the 2nd MA communication system the 2nd MA metering circuit 64.This signal characteristic generally is a signal intensity.The measured handover of the 2nd MA signal characteristic to determine whether between a MA communication system and the 2nd MA communication system, to carry out success.The measurement of the 2nd MA signal generally is at the preset time according to clock 68, preferably a time of not interrupting downlink traffic 66 or uplink service 70.The 2nd MA metering circuit is to the signal of control circuit 62 report pattern measurements.Control circuit 62 determines whether then and how to report the measurement of the 2nd MA signal characteristic by a up-link 70 and a MA transmitter-receiver 52 to a MA base station controller.
The survey frequency of the 2nd MA metering circuit 64 is controlled by the frequency of local oscillator 60, and wherein the frequency of local oscillator 60 can be set by control circuit 62.
In case the base station controller in the MA communication system receives the report of the 2nd MA signal measurement, whether base station controller may be determined suitable and can deny success to the handover of the 2nd MA communication system.Alternatively, this handover determines and can be undertaken by subscriber unit, in this case user's request time of arranging this handover by a MA base station controller.
User's switching to the 2nd MA communication system is started by an order that receives by an antenna 56 and a MA transmitter-receiver 52.In the time of agreement, control circuit 62 switches to the 2nd MA transmitter-receiver 54 with downlink traffic in the subscriber unit 50 and uplink service from a MA transmitter-receiver 52, finishes like this from the handover of a MA communication system to the two MA communication systems.
Referring now to Fig. 3,, wherein shows the optional embodiment that the method according to this invention and system finish a device of the handover between different multiple access communication systems.In this embodiment, the measurement from the signal of second multiple access communication system is finished by the 2nd MA transmitter-receiver 80.The available RSSI of this measurement (received signal strength indicator) realizes as the RSSI that those are comprised in a lot of AMPS transmitter-receivers.Measure in order correctly to carry out the 2nd MA signal characteristic, control circuit 62 can send control information to the 2nd MA transmitter-receiver 80.This control information can comprise gain setting, frequency, frequency range, the type of measured multiple access signal, time period information, and the time of the 2nd MA signal measurement.
The embodiment of Fig. 3 also comprises a local oscillator 82.Like this, the transmitter-receiver 52 of the first and second MA communication systems and 58 is shared same local oscillator 82 by control circuit 62 controls.Thereby local oscillator 82 should be able to be apace makes the 2nd MA signal characteristic can be measured under the situation that can interrupt downlink traffic 66 and uplink service 70 rightly switching between two frequencies and settle out in a short period of time.
Referring now to Fig. 4,, wherein shows the method according to this invention and system and finish a senior skeleton diagram with a CDMA (CDMA) system of the handover of an optional communication system.As shown in the figure, subscriber unit 90 comprises that antenna 56 is used to receive or send the signal from the sub-district of a CDMA and an optional MA communication system.In this example, optional MA communication system is the communication system that an employing is different from the multiple access (rdma) scheme of CDMA.CDMA receiver 92 comprises a CDMA downlink traffic path, and this path comprises low-converter 94, gain control 96, wave filter 98, analog to digital (A is to D) converter 100, Solution Expander 102 and CDMA detuner 104.CDMA downlink traffic 106 is by 104 outputs of CDMA detuner.
Low-converter 94 is finished the frequency transformation from the radiofrequency signal of antenna 56 to the lower intermediate frequency that sends gain control 96 to.Local oscillator 108 provides an input reference frequency for low-converter 44.
Gain control 96 can realize with the amplifier of the variable gain of the signal controlling of controlled circuit 110.
A/D converter 100 is with the numerical character of analog signal conversion for being sampled with the discrete time.
This numeric word is transfused to Solution Expander 102, there in general CDMA operating period, this numeric word with multiply each other from the de-spread sign indicating number in Solution Expander sign indicating number source 112.
According to an important aspect of the present invention, the Solution Expander signal is selected by the Solution Expander signal selector 116 of controlled circuit 110 controls.Selected so that Solution Expander signal 114 to be provided when de-spread sign indicating number source 112, the output of Solution Expander 102 is transmitted to CDMA detuner 104, and it is provided at the CDMA down link signal 106 of work under the general CDMA demodulation modes.Under measurement pattern, Solution Expander signal selector 116 is selected despread signal 114 from optional signal source 118.Like this, when the signal from signal source 118 was imported into Solution Expander 102, the output of Solution Expander 102 was transmitted to signal characteristic metering circuit 120.The signal characteristic value 102 that is generated by signal characteristic metering circuit 120 is input to control circuit 110 then.Tell about two embodiment of circuitry for signal measurement 120 below referring to Fig. 5 and Fig. 6.
Also have datum 124 for what control circuit 110 provided input, control signal 126, clock 128, and from the optional measuring-signal 130 of optional MA transmitter-receiver 132.
CDMA transmitter 134 is connected to antenna 56 with emission CDMA uplink service 136.CDMA transmitter 134 is also worked under the control of the signal of control circuit 110.
Optional MA transmitter-receiver 132 is connected to antenna 56, according to optional MA scheme receiving downlink professional 138 and transmission of uplink business 140.Optional MA transmitter-receiver 132 is worked under the control of the signal of control circuit 110.The frequency of the optional MA transmitter-receiver 132 of this control signal may command, the type of the MA that optional MA transmitter-receiver 132 is used, be used to switch to the accurate timing of downlink traffic 138 and uplink service 140, downlink traffic and uplink service receive and send by optional MA transmitter-receiver 132, and other similar control.
During work, control circuit 110 receives an order to start a handover procedure to optional MA communication system by CDMA downlink traffic 106, but it is before carrying out handover, measured and be reported to the cdma base station controller from a signal of this MA communication system.In the embodiment shown in fig. 4, CDMA receiver 92 is with two kinds of pattern work; One is normal CDMA demodulation modes, and one is optional MA signal measurement pattern.
Under normal CDMA demodulation modes, Solution Expander signal selector 116 is selected a Solution Expander signal 112 that is input to Solution Expander 102 from de-spread sign indicating number source 112.Under this pattern, normal CDMA downlink traffic 106 is by 104 outputs of CDMA detuner.This CDMA downlink traffic 106 can comprise control signal 126 and timing signal or formation, and they are input to control circuit 110 and clock 128 respectively.
In optional MA signal measurement pattern, Solution Expander signal selector 116 is selected a Solution Expander signal 114 that is input to Solution Expander 102 from optional signal source 118.Afterwards, the output of Solution Expander 102 is used for measuring signal characteristic from a signal of optional MA system by signal characteristic metering circuit 120.The consequential signal eigenwert of measuring 122 be imported into control circuit 110 and may with compare from several datum 124 datums that draw or that calculate.According to the reporting standards of deciding through consultation, control circuit 110 is reported comparative result by CDMA transmitter 134 to cdma base station controller 30 (see figure 1)s.When collecting when being used for data that handover judges, the judgement of handover is undertaken by subscriber unit or base station controller or some other position.The particular location or the functional unit that judge are determined by the deviser.
When the handover that is instructed to finish between the communication system, subscriber unit 90 will use optional MA downlink traffic 138 and optional MA uplink service 140 from using CDMA downlink traffic 106 and uplink service 136 switch to.
Referring now to Fig. 5,, wherein shows the detailed diagram of first embodiment of the signal characteristic metering circuit that is used to realize method and system of the present invention.As shown in the figure, signal characteristic metering circuit 120 comprises narrow band filter 150, power measurement function 152, and integrator 154.Like this, the output of signal characteristic metering circuit 120 may be an estimating power level that comes out in a period of time integrates.This power level value can be compared with the datum in the control circuit 110.If signal characteristic metering circuit 120 is being measured a signal from an AMPS communication system channel, narrow band filter 150 can be tuned to the bandwidth of AMPS channel, 30kHz.
Referring now to Fig. 6,, wherein shows the detailed diagram of second embodiment of the signal characteristic metering circuit that is used to realize method and system of the present invention.As shown in the figure, 120 of this signal characteristic metering circuit second embodiment comprises broadband filter 156 and frequency analysis circuit 158.During work, broadband filter 156 may for example be set and receive the frequency range that covers several AMPS channels.Frequency analysis circuit 158 can be used for finishing the Fourier transform to trap signal.This Fourier transform can be discerned the several AMPS frequencies from several AMPS base station, the purpose base station that any one can the handover of selected conduct from cdma system to this AMPS system.
Before Fig. 5 or signal characteristic metering circuit shown in Figure 6 120 are measured, must on gain control 96 (see figure 4)s, set a suitable gain.Different according to metering circuit of using and the multiaccess system that will measure, control circuit 110 can be set gain control 96 by rights and make and can carry out an effectively measurement.
Referring now to Fig. 7,, wherein shows the handover of an optional communication system of usefulness is finished in explanation according to the present invention the high-level logic flowchart of method.As shown in the figure, this processing procedure is from piece 200, then at piece 202 initialization subscriber units.This initialization process process comprises and passes a parameter and consult agreement between base station controller and the subscriber unit.This initialization procedure is elaborated with reference to Fig. 8 in the back.
Then, subscriber unit is measured the signal characteristic from a signal of optional multiple access communication system, shown in piece among the figure 204.This measurement can realize by optional MA transmitter-receiver with in the subscriber unit shown in Figure 3, perhaps realize with one in the subscriber unit shown in the example of Fig. 2 optional MA metering circuit.Another method of measuring optional MA signal is to use current MA receiver, and as shown in Figure 4, wherein the CDMA receiver can be reset and put to measure optional MA, as a signal among the AMPS.
After measuring optional MA signal, subscriber unit is measured the signal characteristic from a signal of current MA communication system alternatively, shown in piece 206.In some communication systems, this step is optionally because the judgement of the signal characteristic of the signal of current MA communication system and handover is irrelevant.But, have some systems may be designed to the signal characteristic of the signal of the signal characteristic of signal of more optional MA and current MA.
After carrying out the appropriate signal measurement, subscriber unit is reported these signal characteristic measurement results to base station controller, shown in piece 208.The standard of report signal pattern measurement can be consulted in the initialization procedure in the piece 202.Some are only measured when it surpasses a specific threshold value and are just reported wherein do not have the signal characteristic report to be understood that measured value is lower than this threshold value.
If note will not needing the step of piece 208 when system is designed to allow the user determine when whither to carry out handover, the user may require handover rather than report signal measured value in this case.
After current MA base station controller has been reported all signal characteristic measurement results, this processing procedure determines whether attempt to carry out handover to optional MA communication system, shown in piece 210.As not carrying out handover for a certain reason, this processing procedure is returned piece 204 update signal measurement results circularly.If system determines to carry out the handover from current MA communication system to optional MA communication system, this processing procedure determines then whether optional MA system can receive this customer service, shown in piece 212.
If optional system can not accept this customer service, this processing procedure is returned piece 204 circularly, upgrades measurement result.If optional MA communication system can be accepted customer service, this processing procedure is coordinated the handover with optional MA communication system, shown in piece 204.This step can be realized by the communication between current MA base station controller that is undertaken by base station controller communication link 36 (see figure 1)s between MA and the optional MA base station controller.The coordination of handover can comprise the purpose frequency of a channel in some parameters such as the optional MA communication system and the concrete time that handover takes place.
Coordinated after the handover, this processing procedure is finished the user's handover from current MA communication system to optional MA communication system, shown in piece 216.Because with the handover between the sub-district of cellular communication system arbitrarily, the handover between the communication system with different MA should carry out to such an extent that make user traffic channel do not interrupted inadequately very soon.
The processing of finishing then from communication system with a MA to the handover of the communication system with the 2nd MA finishes at piece 208.
Referring now to Fig. 8,, wherein shows the detail flowchart of explanation processing of a subscriber unit of initialization according to the present invention.As shown in the figure, this initialization process process is from piece 300, in piece 302 these processing procedures the type of optional MA communication system sent to the user afterwards.If being designed to carry out this step of handover to another optional communication system types, subscriber unit can imply.The type of optional communication system can for example be appointed as the AMPS system, tdma system, gsm system or other standardized multiaccess system.
Receive after the type of optional MA communication system, this processing procedure sends list of frequency or the frequency range that an optional MA communication system is used, shown in piece 304.This list of frequency can comprise the tabulation of the frequency of a control channel that for example uses on the different base station in the AMPS system.Alternatively, wherein signal intensity or other signal characteristic of the several frequencies in the scope can be reported back base station controller can to specify a frequency range.
Then, subscriber unit receives the reporting standards of the measurement result of the signal of reporting optional MA communication system, as determining shown in 306.This reporting standards can comprise the instruction of the signal characteristic of not reporting the optional MA that is lower than a threshold value.Like this, not to the report request responding can by base station controller be interpreted as measured value be lower than fixed threshold value, the reason of this reporting standards is in order to reduce the report business between subscriber unit and the base station controller.
Afterwards, the time that this processing procedure and current MA communication system are consulted optional MA signal measurement is shown in piece 308.The possibility of result of this negotiation is to measure or only measure according to request with predetermined time interval.
The initialization process process so far finishes, shown in piece 310.
Referring now to Fig. 9,, wherein shows the detail flowchart of processing that explanation the method according to this invention is measured the signal characteristic of the signal in the optional MA communication system.As shown in the figure, this processing procedure is from piece 400, determined whether to measure time of signal characteristic of the signal of optional MA communication system afterwards in piece 402 these processing.If also be less than the time of measuring, this processing procedure circulates repeatedly up to the time of measuring.The time of measuring can be set at preset time at interval or only just carries out during the base station controller request in current MA communication system.Carrying out the time of optional MA communication system measurement can consult among initialization procedure, referring to Fig. 8.
If to the signal of optional communication system is carried out the time that signal characteristic is measured, this processing procedure is optional MA signal measurement configure user unit, shown in piece 404.In some embodiments of the invention, this layoutprocedure makes signal characteristic circuit 120 perform the preparation of measurement, also may set each wave filter and gain-adjusted and make metering circuit can provide one effectively to measure.This user's layoutprocedure is elaborated with reference to Figure 10 hereinafter.
Then, this processing procedure is measured the signal characteristic of the signal of optional MA communication system, shown in piece 406.In a preferred embodiment, this signal characteristic is a signal intensity.According to the structure of subscriber unit, signal measurement can be by a customized configuration of current MA detuner, or with a dedicated receiver that receives optional MA signal, or assigns to carry out with the acceptance division of optional MA transmitter-receiver.Each user structure is illustrated with reference to Fig. 2-4.
After the measuring-signal pattern measurement, this processing procedure reconfigures subscriber unit in the current MA communication system to carry out general operation, shown in piece 408.Not exclusively be independent of current MA transmitter-receiver if be used for the circuit of measuring-signal feature, the time between the piece 404 and 408 should minimize and make customer service do not interrupted inadequately.
Subscriber unit in reconfiguring current MA communication system is with after carrying out general operation, and this processing procedure determines whether this optional MA signal measurement is effective, as shown in piece 410.If measure effectively, this processing procedure finishes, as is denoted as shown in the piece 412 of " returning ".Conversely, bad if this is measured, configuration parameter is measured in this processing procedure adjustment, as wave filter and gain setting, shown in piece 414.Then, this processing procedure is returned piece 402 and is waited for another Measuring Time.Because obviously, subscriber unit may turn back to normal running when waiting for the chance of measuring next time.
Referring now to Figure 10,, shows explanation and dispose the detail flowchart that receiver is measured the processing procedure of the signal characteristic in the optional MA communication system according to the present invention.As shown in the figure, this processing procedure is suspended the dialogue of CDMA and is answered modulation and demodulation in other words in piece 502 these processing procedures after piece 500 beginnings.Notice that this this processing procedure that describes with reference to Figure 10 relates in particular to the CDMA receiver of the signal characteristic of a signal that is used to measure an optional MA communication system, CDMA receiver as shown in Figure 4.
Then, this processing procedure is set the frequency of local oscillator to receive the frequency of an optional MA communication system, shown in piece 504.This step can be used for setting local oscillator 108 with the control signal of the control circuit 110 in the subscriber unit 90 shown in Fig. 4.
Set after the local oscillator, this processing procedure is for receiving the signal sets signal gain and the wave filter of optional MA communication system, shown in piece 506.Similarly, control circuit 110 can send a signal to gain control 96 and wave filter 98 and prepares for the signal of measuring optional MA communication system.
Notice that step 504 and 506 can be called as configuration one tuner and receive signal from optional MA system.This tuner illustrates with Ref. No. 142 in Fig. 4.Then, this processing procedure selects an optional despread signal to be used in the CDMA Solution Expander, shown in piece 508.With reference to Fig. 4, this step can make Solution Expander signal 114 realize from optional signal source 118 by Solution Expander signal selector 116 being switched to optional source location.Optional signal source 118 can be a string 0 or 1, and constant value signal of they generations suspends the de-spread operation in the Solution Expander 102.
Select after the optional despread signal, this processing procedure can be worked optional MA signal characteristic metering circuit, shown in piece 510.This step can realize by asking register or reset signal pattern measurement circuit 120.Then, configuration procedure finishes, shown in piece 512.
In order to dispose the subscriber unit with structure shown in Figure 3, but configuration procedure execution block 502,504,506 jumps to piece 510 then the metering circuit in the 2nd MA transmitter-receiver 80 can be used.In having the subscriber unit of structure shown in Figure 2, but measure configuration procedure execution in step 506, jump to step 510 then and measure with the 2nd MA metering circuit 64.Do not need to set local oscillator because metering circuit is used an independently local oscillator 60.
Generally speaking, above-mentioned the present invention allows the handover from first multiple access communication system to second multiple access communication system, and this handover is assisted by the signal of measuring second multiaccess system at subscriber unit in one of them dual mode user unit.In the MA of first multiple access communication system scheme, do not need a plurality of pilot beacons to transmit signal, thereby reduced the cost that carries out the necessary infrastructure of inter-system handoff.
Though some above-mentioned object lessons are relevant from the handover of a cdma system to an AMPS system with a user, principle of the present invention and basic structure can be used for realizing taking office the what handover of its MA communication system from any MA communication system.
The various devices of measuring optional MA signal characteristic have been described, comprise: the custom system of using an independent measurement circuit, share the custom system of a local oscillator circuit between the transmitter-receiver of different MA, and use a CDMA receiver that reconfigures to measure the subscriber unit of signal characteristic of the signal of optional MA communication system.This CDMA receiver can be set to make the de-spread operation and be suspended, can be by analyzing at arrowband scope integrates power or by analyzing a wideband frequency frequency spectrum by the optional signal of Solution Expander.
In some embodiments of the invention, optional signal source 118 can be a special signal, and it has an optional MA signal of known features or the measurement of a plurality of MA signals with enhancing.For example, this signal can comprise a plurality of discrete frequencies that can be used for detecting the power of a plurality of optional MA signals.
Description to the preferred embodiments of the present invention is a purpose with explanation and explanation above.It is not that exhaustive, the present invention also is not limited only to this simple form.According to top instruction, may make amendment and change.Selecting and telling about embodiment is for principle of the present invention and practical application thereof are described best, so that the those skilled in the art in present technique field can use the present invention and be applicable to the various modifications of concrete application requirements in different embodiment.When explaining according to the range of being authorized liberally legally equitably, all such modifications and variations are all within the determined scope of the present invention by appending claims.