CN101366205A - Method and apparatus for enabling soft handoff in an ofdma-based communicatin system - Google Patents

Method and apparatus for enabling soft handoff in an ofdma-based communicatin system Download PDF

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CN101366205A
CN101366205A CNA2007800019307A CN200780001930A CN101366205A CN 101366205 A CN101366205 A CN 101366205A CN A2007800019307 A CNA2007800019307 A CN A2007800019307A CN 200780001930 A CN200780001930 A CN 200780001930A CN 101366205 A CN101366205 A CN 101366205A
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soft
sector
handoff
travelling carriage
base station
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CN101366205B (en
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戴维·康斯托克
卢建民
安东尼C.K.·宋
杨云松
容志刚
李政云
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Huawei Technologies Co Ltd
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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W36/00Hand-off or reselection arrangements
    • H04W36/16Performing reselection for specific purposes
    • H04W36/18Performing reselection for specific purposes for allowing seamless reselection, e.g. soft reselection
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W36/00Hand-off or reselection arrangements
    • H04W36/24Reselection being triggered by specific parameters
    • H04W36/30Reselection being triggered by specific parameters by measured or perceived connection quality data
    • H04W36/304Reselection being triggered by specific parameters by measured or perceived connection quality data due to measured or perceived resources with higher communication quality

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  • Computer Networks & Wireless Communication (AREA)
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  • Mobile Radio Communication Systems (AREA)

Abstract

A method of enabling a soft handoff in a communication system, wherein the communication system includes a plurality of sectors and each of the plurality of sectors includes at least one base station is disclosed. The method includes: providing at least one mobile station; setting identical resources for serving the mobile station from each of the plurality of base stations in each sector; designating at least a plurality of base stations in at least one sector to participate a soft handoff; and performing a soft handoff.

Description

A kind of method and device of in based on the communication system of OFDMA, realizing soft handover
Technical field
The present invention relates to wireless communication system, relate in particular to a kind of new method and device of in wireless communication system, realizing soft handover.
Background technology
In the cellular communications networks based on OFDM (OFDM), the base station is with the signal of quadrature on the frequency and the mobile communications in its coverage.In addition, the current third generation (3G) system utilizes multi-user diversity gain to make its throughput compare the second generation (2G) system significantly increases.That is to say that for point-to-multi-point system, as forward link system (forward link systems), all resources of base station are that unique user (claiming travelling carriage again) is special-purpose.
Scheduler in the scheduler base station (scheduler) is selected a user of wireless receiving the best from one group of user when needing.If it is independently that the user organizes channel fading enough big and each user, just almost always there is a user that wireless receiving is good.The loss that has caused thereby the base station has been avoided information sent to the user of wireless receiving difference..
In addition, in order to promote mobility (travelling carriage moving in service area), adopted quick sector to select.This technology makes travelling carriage apace transfer of data to be transformed into another sector from a sector.Importantly, though travelling carriage is changed between the sector, travelling carriage is only from a sector received signal.
To being in the travelling carriage of cell edge (fringe regions between two or more sectors), even the base station sends signal with maximum power to travelling carriage, received signal power is also always very little.Therefore, the wireless receiving of travelling carriage is very poor, makes its data throughout very little.
This causes some influences to systematic function.An influence is, if certain travelling carriage requires certain service quality (QoS), base station palpus consumption ample resources travelling carriage for this reason provides service.Cause overall system throughput significantly to reduce thus.Another influence is, owing to continue very lowly with the data rate of this link, the service that the user of this travelling carriage is experienced is very poor.This is a major issue, because the user wishes no matter to be positioned at the service that where can both obtain same level of sector.
Summary of the invention
In view of the situation of aforementioned prior art, it is considered herein that present needs can increase the method and the device of Cell Edge User throughput.Correspondingly, the invention discloses, particularly based on the completely new approach and the device that carry out soft handover in the communication system of OFDMA in communication system.
According to the present invention, the resource that is used to serve travelling carriage must be identical, and no matter these resources are positioned at the still local district that distributes, distributed allocation district.In addition, identical subcarrier hopping pattern need be set, especially for the resource of distributing by scheduler in the ofdm system.Method of the present invention and device also provide multiple scheme, with pilot signal individual signals or combination soft handover signal are detected, the sector grouping is formed a plurality of soft-handoff groups, generate potential soft handoff sectors tabulation, and manage the sector that participates in soft handover with channel quality information feedback.
Thereby the present invention improves the performance of system with reliable, minimum signaling consumption for the travelling carriage that is in sector-edge provides soft handover.
The invention provides a kind of system, this system is that the travelling carriage that travelling carriage particularly is in sector-edge provides the soft handover function to improve performance with reliable, minimum signaling consumption.
The present invention makes the base station can avoid transmitting the soft handover data of the Common Pilot Channel same asset that occupies any one sector in the soft-handoff groups.
The present invention has stipulated that further the base station can determine which sector belongs to the set of soft handover, and which soft-handoff groups travelling carriage can use in the given time.When distributing the active set of travelling carriage, available soft handover set and group can be discerned in the base station.In the message of allocation activities set, the Message Record field that belongs to the sector in the identical soft handover set can be arranged on an adjacent ground.A field in the record of a sector can indicate whether this sector is the beginning of a new soft handover set.
The present invention further stipulates, the member of himself soft handover set can be discerned in the base station, and this set can be used for the soft-handoff groups operation so that travelling carriage request operating in soft handover when initially setting up data and connect.
The present invention stipulates that further travelling carriage can be determined soft handover set and soft-handoff groups, and serves to the soft-handoff groups request.Thereby soft-handoff groups can be moved platform identification by use scrambler and a message field on the The function of backward power control channel.The present invention also provides a kind of method of discerning the soft-handoff groups sign with scrambler in forward link.
The present invention stipulates that also the channel quality information of the aggregate channel of a soft-handoff groups (CQI) can feed back to the base station by the travelling carriage in the sector.In one embodiment, difference between aggregate channel CQI and the serving sector CQI has been described.
The present invention stipulates that further the soft-handoff groups transmission (SHOG) that is used for the 1xEV-DORev C of the strict backward compatibility of 3GPP2 (SBC) pattern can especially be carried out in traffic data channel on the OFDM part.In the soft-handoff groups transmission, the grand antenna in the group can be as the individual antenna in the sector.Thereby in multiple-input and multiple-output (MIMO) scheme, the group with a plurality of grand antennas can be (AT) service that accesses terminal.
The following description book and accompanying drawing have specifically described illustrative embodiment more of the present invention.These embodiment have only illustrated and have realized in the multiple mode that the present invention can adopt a few.
Description of drawings
For a more complete understanding of the present invention and advantage, can be with reference to following description and in conjunction with the accompanying drawings, the same tag in the accompanying drawing is represented identical part.
Fig. 1 is for having the base station example of master/long-range structure in the communication system of the embodiment of the invention.
Fig. 2 is the example of soft handoff sectors Managed Solution in the communication system of the embodiment of the invention.
Fig. 3 determines the soft-handoff groups (SHOG) of sector and the flow chart of corresponding SHOG ID in the communication system of the embodiment of the invention based on the information that is received.
Fig. 4 provides the flow chart of the soft-handoff groups sign of activity soft-handoff groups for use scrambler in the embodiment of the invention in forward link control channel.
Embodiment
The invention provides peculiar methods and the device of in based on the communication system of OFDMA, realizing soft handover.The content of following discloses has provided many different embodiment or has realized the example of different characteristic of the present invention.The object lesson of assembly, circuit, signal, message, agreement and setting is used in the following description with simplified illustration.But these only can not be used to limit the scope that claim of the present invention is protected as embodiment.For the present invention is understood clearly, known part does not add gives unnecessary details.Omitted unnecessary details concerning complete understanding the present invention largely, because this class details is to belong within those skilled in the art's the technical scope.
In soft handover, travelling carriage receives data from an above sector simultaneously.A plurality of sectors send identical data.The sector that sends identical data is called as the sector that participates in soft handover.The signal that participates in the sector transmission is combined in the wireless channel of ofdm system.
Therefore, according to an aspect of the present invention, though the resource that is used to serve travelling carriage in the distributed allocation district (assignment zone) or local type to distribute Qu Zhongdou be identical.Soft handover participated among the embodiment that the sector is placed on place, a sub-district side by side at one, scheduler in this sub-district (being called distributed scheduler) distributes identical Service Source for travelling carriage, and each participates in the sector and uses this identical resource to send identical data.As long as two signals arrive travelling carriage in a cyclic prefix period, travelling carriage just can detect the composite signal that signal quality significantly improves in an OFDM sends, thereby improves throughput.
According to a further aspect of the invention, when participating in the sector from different districts, centralized scheduler is distributed identical resource in each sector be a travelling carriage service.Therefore, use fast cell dispatch delay to be minimized to cell communication.In one embodiment, the base station comprises a primary module and a plurality of far module.Primary module contains all Base-Band Processing functions of whole sub-district usually, and each of a plurality of far modules contains usually to radio frequency processing function that the sector is all in the sub-district.
Fig. 1 illustrates the base station with following structure.For the sub-district that three sectors 101,102 and 103 are arranged, its structure comprises a primary module 120 and three far modules 111,112 and 113.In one embodiment, primary module 120 on a concentrated position with a plurality of cell combination together.This makes in primary module 120 and the ofdm system between other primary module to communicate by letter by backboard and carries out the minizone and communicate by letter.It will be appreciated by those skilled in the art that,, just can carry out the minizone of multiple alternate manner and communicate by letter in case primary module 120 and each other primary module are all concentrated placements, comprising but be not limited to Fast Ethernet connection between the primary module.
In another embodiment, this minizone communication is what to finish by traditional backhaul communication.In another embodiment of the present invention, utilize that communication link carries out high-speed traffic between dedicated cell.In honeycomb arrangement owing to all primary modules concentrate can not be placed, may need to use simultaneously in the preceding method one with on realize communicating by letter between fast cell.
In order to guarantee that with same asset be the travelling carriage service, all participate in the hopping pattern that the sector has analog structure.In one embodiment of the invention, whether participate in all having identical hopping pattern no matter belong to these sectors, all sectors of same cells.Therefore, thus hopping pattern be predetermined can be with minimum expense and mobile communications.In another embodiment, the relevant hopping pattern of resource that uses frequency hopping controller to make to participate in soft handover be synchronous and with the travelling carriage dynamic communication.In another embodiment, the resource relevant with soft handover got rid of outside frequency hopping.It will be appreciated by those skilled in the art that one or more can in system, the existence simultaneously among these embodiment.
According to a further aspect of the invention, assist the detection of combination soft handover by sending pilot tone.In one embodiment, each base station all sends public guide frequency, but from the phase place difference of the public guide frequency of different base station, and each base station of fellowship soft handover knows that all other participates in the phase place of the public guide frequency of base station.
Convenient for mark, present embodiment is described at the situation that two sectors participate in soft handover.Pilot tone P is transmitted in first sector on the special pilot subcarrier 1, data signal S on the particular data subcarrier 1Pilot tone P is transmitted in second sector on identical pilot sub-carrier 2, data signal S on identical data subcarrier 2Pilot tone P 1With pilot tone P 2Between phase place rotation (phase rotation) represent by A.With first sector is reference base station.The base station can utilize the A value of two adjacent pilot sub-carriers of data subcarrier to obtain the estimated value of the phase place rotation of data subcarrier by interpolation method (interpolation), uses A ' expression.If the equalized data signal S that has phase shift is transmitted in second sector 2=S 1* A ', the pilot signal that travelling carriage receives as shown in the formula:
R pilot=H 1P 1+H 2P 2=(H 1+H 2A)P 1
H wherein 1And H 2Be the channel frequency response that sends from first sector and second sector respectively.Obviously travelling carriage this moment can be by the pilot tone that receives to H=(H 1+ H 2A) value is estimated, and is estimated H '=(H by interpolation method 1+ H 2A ') value.In addition, H ' just in time is the required channel estimating of detection of data signal, because the data-signal R that receives DataAs shown in the formula:
R data=H 1S 1+H 2S 2=(H 1+H 2A’)S 1
Two above sectors can participate in soft handover with similar methods.If such sector expands to more than two in the system, system selects one of them sector as the reference sector.In one embodiment, be appointed as anchor base stations (anchor base station) in the soft handover with reference to the sector.Also can be with other sector as the reference base station.For example, the sector to travelling carriage channel the best can be used as reference base station.
If A iBe the phase difference of the i sector and first sector pilot signals, wherein first sector is with reference to the sector, A ' iBe the phase place rotation of the i sector data subcarrier that obtains by above-mentioned interpolation method, then travelling carriage can press the following formula estimation by pilot sub-carrier
H=(H 1+H 2A 2+H 3A 3+H 4A 4+...)
The data subcarrier is then had
H’=interpolation(H)=(H 1+H 2A 2’+H 3A 3’+H 4A 4’+...)
Wherein interpolation () is an interpolating function.
Obviously, if i base station data signal S i=A i' S 1, then H ' just in time is the required channel estimating of Data Detection.
In another embodiment, dedicated pilot participates in the sector transmission by each.It is all identical that the pilot patterns of dedicated pilot participates in the sector to all.In addition, pilot tone also is identical in frequency and temporal position.Therefore travelling carriage can directly be estimated synthetic pilot channel response.
In another embodiment of the present invention, travelling carriage utilizes a standard pilot tone of having used in any ofdm system.In this embodiment, travelling carriage is estimated the channel that each participates in the sector independently, is combined them the channel estimating that is formed for detecting then.
Though different pilot configurations are described separately, above-mentioned one or more embodiment can exist in system simultaneously.
According to a further aspect of the invention, each participates in the sector and can utilize adjustable transmitting power.In one embodiment of the invention, the transmitting power that each sector that participates in soft handover is set in travelling carriage is identical value.The set point of transmitting power is used to obtain equal gain combining (equal gain combining).In this embodiment, need not the travelling carriage feedback.In another embodiment, can be by obtaining high specific and merge (maximum ratio combining) for the CQI (CQI) of each sector feedback is weighted the transmitting power of this sector according to travelling carriage.
In this embodiment, the link to travelling carriage has bigger transmitting power in the sector preferably.In addition, travelling carriage is measured the CQI that participates in the sector from each and this CQI is reported to the base station.Can be by the different sectors that participate in soft handover be provided with the merging that different transmitting powers obtains other type.For example, can by will arrive power setting that travelling carriage has a sector of best link become maximum simultaneously the transmitting power of all other links be set to zero and obtain to merge.Though above-mentioned every kind of power setting scheme is to describe as independent embodiment, a plurality of these type of schemes can exist in system simultaneously.
According to a further aspect in the invention, can adopt a cover to participate in the administrative mechanism of sector.In one embodiment, travelling carriage is preserved potential handoff sectors tabulation (potential handoff sector list).These sectors might participate in the soft handover of travelling carriage.Can whether a sector be added potential soft handoff sectors tabulation according to the intensity decision of this sector pilot tone.Therefore if this sector can be added potential soft handoff sectors tabulation when the intensity of a sector pilot tone is higher than certain threshold value.It is to realize by the signaling message between travelling carriage and the base station is mutual that the sector is added potential soft handoff sectors tabulation.
As schematic example, travelling carriage receives the pilot tone of each sector transmission and the intensity of each pilot tone is measured, and determines then whether each pilot frequency intensity of each sector is higher than certain threshold value.Travelling carriage is higher than threshold value to the special pilot intensity that the base station sends a sector of a message indication then.After receiving the message of travelling carriage transmission, the base station is beamed back a message to travelling carriage this sector is added potential soft handoff sectors tabulation.
In addition, the base station is arranged in the sector in this tabulation and forms one or more soft-handoff groups together.That is subclass that soft-handoff groups is potential soft handoff sectors tabulation.A soft-handoff groups can comprise one or more base stations.The number of soft-handoff groups is determined by the base station.Base station or access network can determine how one or more sector combination are formed soft-handoff groups according to many factors.These factors include but not limited to sector position and sector load.
For example, base station or access network can be grouped into all possible combination with the sector in the soft handover tabulation.Fig. 2 illustrates an example.In this example, travelling carriage 250 is in five tunnel soft handover area 200.This exchange area 200 comprises five sectors 201,202,203,204 and 205.Sector 201 and sector 202 are grouped into soft-handoff groups 210, and sector 203 is formed soft-handoff groups 220 separately, and sector 230 is formed in sector 204 and sector 205.This grouping is finished by this way, and the sector that promptly belongs to identical soft-handoff groups adopts soft handoff procedure to communicate by letter with travelling carriage 250.
Particularly, sector 201 adopts soft handoff procedure to communicate by letter with travelling carriage 250 with sector 202.But sector 203 does not adopt soft handoff procedure to communicate by letter with travelling carriage 250, only comprises a member because organize 220, and promptly the sector 203.
In addition, sector 204 adopts soft handoff procedure to communicate by letter with travelling carriage 250 with sector 205.But a time travelling carriage 250 in office is all only by a soft-handoff groups service.On the other hand, change every now and then for the soft-handoff groups of travelling carriage 250 services.This can guarantee that travelling carriage 250 provides service by the group of the best.
For the soft-handoff groups of travelling carriage 250 services can select the mode of (fast sectorselection) to change according to being similar to quick sector.In one embodiment of the invention, travelling carriage 250 is measured the combined pilot intensity (combined pilot strength) of sector in each soft-handoff groups.In this example, travelling carriage 250 is measured the combined pilot intensity of soft-handoff groups 210,220 and 230, selects to have the soft-handoff groups of the soft-handoff groups of greatest combined pilot frequency intensity as travelling carriage 250 then.This soft-handoff groups is called as the expectation soft-handoff groups.Travelling carriage 250 conveys to the base station to the expectation soft-handoff groups by signaling then.
For example, first example, travelling carriage 250 determines that soft-handoff groups 210 has the highest combined pilot intensity 215, travelling carriage 250 selects soft-handoff groups 210 as the expectation soft-handoff groups.Travelling carriage 250 is by sending out message and base station communication then.For travelling carriage 250 serving base station are used soft-handoff groups 210.If the expectation soft-handoff groups only comprises a member, data just only send from that sector.But if the expectation soft-handoff groups comprises an above sector, then all member sectors all send these data in the group.
Second example, travelling carriage 250 determines that soft-handoff groups 230 has the highest combined pilot intensity 235, selects soft-handoff groups 230 as the expectation soft-handoff groups, and obtains service from soft-handoff groups 230.The 3rd example, travelling carriage 250 determine that soft-handoff groups 220 has the highest combined pilot intensity and selects soft-handoff groups 220 as the expectation soft-handoff groups, and obtain service from soft-handoff groups 220.When it expects that soft-handoff groups change and base station need be transformed into new expectation soft-handoff groups from expectation soft-handoff groups before when the travelling carriage informing base station, just need carry out quick sector and switch.
In one embodiment of the invention, the communication of expectation soft-handoff groups realizes by the Walsh sign indicating number in the CQI feedback channel.That is, the base station makes each soft-handoff groups related with a unique Walsh sign indicating number, and conveys to travelling carriage by the signaling message Walsh sign indicating number that this is unique.Travelling carriage expects that by transmission on the CQI feedback channel it is the expectation soft-handoff groups that the Walsh sign indicating number of soft-handoff groups association comes which soft-handoff groups of informing base station then.This embodiment is a kind of method of passing on the expectation soft-handoff groups, also can adopt additive method.This class additive method can comprise that load is not limited to adopt the 3rd layer signaling message.
The base station may not provide service for travelling carriage with the selected expectation soft-handoff groups of travelling carriage for various reasons.In one embodiment of the invention, the base station can determine whether to accept this expectation soft-handoff groups by signaling message.In this embodiment, when the base station receives new expectation soft-handoff groups from travelling carriage, determine whether this base station is used new expectation soft-handoff groups and provided service for this travelling carriage.
If the base station is agreed to provide service with new expectation soft-handoff groups for travelling carriage, then to travelling carriage transmission acknowledge message and begin to provide service for travelling carriage with the new expectation soft-handoff groups of travelling carriage appointment.The base station can suitably be postponed the time that begins with new expectation soft-handoff groups is the travelling carriage service, has received acknowledge message up to definite travelling carriage.
For example, the base station can add acknowledge message with the time of action.This action time representation base station begins to utilize the time of new expectation soft-handoff groups for the travelling carriage service.Like this, travelling carriage and base station are synchronous when conversion.If the base station detects, the overload of power of for example new expectation soft-handoff groups, and determine refusal to utilize new expectation soft-handoff groups to provide service for travelling carriage, the base station just sends refuse information to travelling carriage.At this moment, the base station is not accepted to provide service with new expectation soft-handoff groups for travelling carriage, and any service that send this base station continues to be provided by previous expectation soft-handoff groups.
According to a further aspect in the invention, can in system, utilize the CQI feedback.In one embodiment of the invention, travelling carriage will synthesize CQI (composite CQI) and send to the base station as feedback, and wherein synthetic CQI represents to expect the CQI of the synthetic soft handover signal of soft-handoff groups.This synthetic CQI is the intensity of total synthetic pilot tone of each sector in the soft-handoff groups.Also can adopt other means of synthetic CQI.
For example, synthetic CQI can be the weighted sum of received power of the pilot tone of each sector in the soft-handoff groups.The modulation and the encoding scheme (MCS) of transfer of data selected to be used in the base station with this CQI then.In another embodiment, travelling carriage will send to the base station as feedback based on the MCS or the MCS collection of combined pilot intensity.If what send is fed back to the MCS collection, the base station just concentrates MCS of selection to be used to send data from this MCS.
In yet another embodiment of the present invention, travelling carriage sends to the base station with one group of independent pilot frequency intensity of each sector in the corresponding soft-handoff groups as feedback.At this moment, the base station merges pilot frequency intensity, for example in the mode of weighted sum, selects a kind of MCS to be used for transfer of data according to the pilot frequency intensity of combination then.
In another embodiment of the present invention, travelling carriage sends to the base station with the pilot frequency intensity of each sector in the potential soft handover tabulation as feedback.MCS or MCS collection are selected according to this feedback in the base station.
To being in the user of cell edge, i.e. the user of fringe region between two or more sectors, even the base station sends signal to travelling carriage with maximum power, the signal power of receiving is also always very little.Thereby the base station is under the abominable radio communication condition, and its data throughout is very little.This has some influences to systematic function.At first, if travelling carriage requires certain service quality (QoS), ample resources must be consumed in the base station provides service for travelling carriage, and the result significantly reduces throughput of system.Secondly, because that the data rate of this link continues is very low, it is very poor that the service that user of mobile station is experienced is experienced.This is a major issue, because the user wishes no matter to be positioned at where can both experience identical service in the sector.
Therefore, need provide a kind of system that increases the sector-edge user throughput.In addition, thus need provide a kind of realizes that at ofdm system the system of soft handover improves the performance of sector-edge user.
For making things convenient for the following term of description of the invention definition.The active set of travelling carriage (Active Set) is the sets of sectors that transfer of data was provided for travelling carriage in a period of time.The serving sector of travelling carriage (serving sector) is a sector in its active set, and this travelling carriage receives the assignment information of air interface resource from this sector.Soft handover (Soft Handoff, SHO) transmission is by the data that above base station transmits is identical, the identical transmission time and the air interface resource of frequency dependence are used in these base stations, this expression transmission is synchronous, the soft handover subcarrier allocation is carried out with identical forward link hopping pattern in the base station, and adopts identical scrambler sequence.Soft handover collection (SHO Set) is a subclass of active set, and its member sector is satisfied and to be carried out the requirement of soft handoff transmission.Soft-handoff groups (SHOG) is a subclass of soft handover collection.
According to the present invention, the detection for auxiliary combination soft handover signal needs pilot signal transmitted.In one embodiment, when only using dedicated pilot, each soft-handoff groups sector can utilize frequency and time to go up identical interface-free resources and send dedicated pilot.In this embodiment, data and dedicated pilot are in the combination of eating dishes without rice or wine, and the dedicated pilot of reception can be used for detecting.In another embodiment, when only using public guide frequency, each soft-handoff groups sector can send a public guide frequency.The public guide frequency with different side-play amounts can be used in each sector, so that common pilot signal appears at different frequency/time locations.Channel estimating to each sector must be determined respectively to be made up then in receiver.The channel estimating of each combination can be used for separating the data of code combination.When using public guide frequency, each soft handoff sectors must send public guide frequency according to its side-play amount.Data can be transmitted in these positions in other soft-handoff groups sectors.If the sector is sending public guide frequency, this sector should be got rid of from the public guide frequency estimation and the data splitting that are used for SHOG.
In another embodiment, occupy with soft-handoff groups in the base station of Common Pilot Channel same asset of other sector can not transmit the soft handover data.The resource that is used for any public guide frequency of soft-handoff groups should be deleted from the resource that can be used for the soft handover transfer of data.These resources can be used for the transfer of data of the non-soft handover in the single sector.
System of the present invention also manages soft handover set and soft-handoff groups.That is, the soft handover set and the soft-handoff groups of travelling carriage can be determined and discern in the base station.In one embodiment, the base station can determine in which sector of given time which soft-handoff groups travelling carriage may use in the soft handover set.When having distributed active set for travelling carriage, available soft handover set and soft-handoff groups can be discerned in the base station.In the message of allocation activities set, can place on an adjacent ground at the Message Record field (message record field) of the sector in the identical soft handover set.The record field of a sector indicates whether this sector is the beginning of new soft handover set.Table 1 provides the usage example of this class field.
Table 1
Figure A200780001930D00171
Figure A200780001930D00181
Each sector record comprises that one is used to discern the scrambler sequence field of this sector and indicates whether this sector is the field at new soft handover set beginning.Fig. 3 illustrates travelling carriage and utilizes the SHOSetStart field to determine the flow chart of SHOG ID mapping method (100).Travelling carriage can be determined the soft-handoff groups and the corresponding soft-handoff groups ID of sector with this flow process.Travelling carriage in initial condition receives a message, the sequence arrangement (a messagecontaining sectors in the Active Set ordered in the message by Soft HandoffSets) that this message comprises the sector in the active set and gathers with soft handover in message.Can also comprise the field relevant, be used to indicate the beginning of new soft handover set with each sector, as shown in table 1.The variable description of using in the flow chart (100) is as follows.ActiveSetIndex is the index that is used for the active set sector.ActiveSetIndex is initialized to 0, and increases when taking out new sector (AssignedSector) from message.It is used for the sector of identification activity set, when for example SHOG ID being mapped to the sector.It is to comprise array SHOGID[0..3] record, wherein each array element comprises the SHOG ID of a list of sectors and sector correspondence.The sector record of AssignedSector for taking out from the active set assignment messages recently comprises the SHOSetStart field.The SHOSetStart field is associated with each sector, indicates whether this sector is the beginning of new soft handover set.SHOSetSectorIndex is the index that is in each sector in the identical soft handover set.It is initialized to 0 at the beginning of new soft handover set, and increases when taking-up is not the new sector (AssignedSector) at new soft handover set beginning.NumPilots is the sector number in this active set.
This flow process comprises a series of actions.ActiveSetIndex is initialized as 0 in the beginning step (S102) of flow process.Whether step (S110) inspection takes out all sectors then.If taken out all sectors of active set from message, this flow process finishes in step (S112).If also do not take out all sectors, then from message, take out another sector in step (S114).To all sectors, the SHOGID that is worth for " 00 " represents that this soft-handoff groups only comprises this sector.The SHOGID[0 of current sector] in step (S116), be set to self.
Step (S120) determines whether current sector is the beginning of new soft handover set.If current sector is the beginning of new soft handover set, then SHOSetSectorIndex is changed to 0 in step (S122), then execution in step (S140) increases progressively ActiveSetIndex, and repeating step (S110) obtains next sector.If current sector is not the beginning of new soft handover set, then SHOSetSectorIndex increases progressively in step (S124).
Step (S130) is determined SHOG ID according to sector number in the current soft handover set.If SHOSetSectorIndex is 1, then current soft handover set comprises 2 sectors, promptly current sector and previous sector at least.At step (S132), with each relevant SHOGID[1 of first and second sectors in the soft handover set] for comprising the set of these two sectors.Then ActiveSetIndex increases progressively in step (140), and obtains next sector by repeating step (S110).If SHOSetSectorIndex is 2, then current soft handover set comprises 3 sectors; Current sector and preceding two sectors.(S134) be provided with the soft handover set in each relevant SHOGID[2 of second and third sector] be the set that comprises second and third sector.The SHOGID[2 of first sector is set in step (S136)] and the SHOGID[1 of the 3rd sector] be the set that comprises first and third sector.In step (S138) SHOGID[3 of all 3 sectors in the soft handover set is set] for comprising the set of all 3 sectors.Then ActiveSetIndex increases progressively in step (140), and obtains next sector by repeating step (S110).
At the example that table 1 provides, table 2 illustrates at each sector and and the SHOG that obtains of corresponding SHOG ID thereof.
Table 2
Figure A200780001930D00191
Figure A200780001930D00201
Figure A200780001930D00202
Figure A200780001930D00204
Figure A200780001930D00205
Figure A200780001930D00211
In the table 1, first sector of message has and is set to ' 1 ' field, is the beginning of new soft handover set to indicate it.Following two sectors are the part of identical soft handover set, so this field is changed to ' 0 '.Sector 4,5 is in the new soft handover set, so this field of sector 4 is changed to ' 1 ', this field of sector 5 is changed to ' 0 '.Sector 6 is in the soft-handoff groups of being made up of 1 sector, so field is set to ' 1 '.If comprise another sector in the active set, just its field is set to ' 1 ', because sector 6 is single sector soft-handoff groups.In this embodiment, to any message, in any specific time, the soft handover set all is limited to three sectors.If three above sectors form soft handover set (as six sector cells), three sectors of soft handover set are possibly by sending the new information correct.Though it will be understood by those skilled in the art that soft-handoff groups is limited to 3 sectors among this embodiment, the present invention does not force.Those of ordinary skill in the art will appreciate that additive method also can adopt, and for example indicates which sector to form the soft handover set with bitmap.
Equally, in this embodiment, the member of soft handover set of the soft-handoff groups the accepted operation of himself can be discerned in the base station, is convenient to travelling carriage that free of data connects request operating in soft handover when just setting up data and connect.This available broadcast sector message realizes.
In this embodiment, the threshold value that travelling carriage may be asked the serving sector channel quality of operating in soft handover can be discerned in the base station.The threshold value of the greatest combined channel quality (maximallycombined channel quality) of soft-handoff groups also can be discerned in the base station.These parameters can be considered in the base station when allocation activities is gathered.
According to the present invention, travelling carriage can be determined soft handover set and soft-handoff groups, the service of request soft handover.In one embodiment, travelling carriage can utilize reverse chain channel message, and for example reverse channel quality index channel (R-CQICH) is asked operating in soft handover.Table 3 illustrates the message that can be used for asking the soft-handoff groups operation.
Table 3
Figure A200780001930D00212
Table 4
Figure A200780001930D00222
In table 3, soft-handoff groups sign (SHOG ID) can be discerned the requested soft-handoff groups (a Soft Handoff Group identifier (SHOG ID) may identify which Soft Handoff Group associated with a sectoridentified by a R-CQICH scrambling sequence which is being requested) that is associated with the determined sector of R-CQICH scrambler sequence.In this embodiment, the R-CQICH channel uses the scrambling of R-CQICH scrambler sequence with the identification sector.SHOG ID can be determined by the information that receives in the active set assignment messages.If request only provides service by a sector (serving sector), the SHOG id field is changed to " 00 ", and the soft-handoff groups of being asked can include only the sector of being determined by the R-CQICH scrambler sequence.For a sector in two sectors in addition in the soft-handoff groups of asking to comprise serving sector and the three sector soft handovers set, SHOG ID is changed to " 01 " asks the sector higher, position in the active set assignment messages than other sector.And being changed to " 01 ", SHOG ID asks to comprise other sector.SHOG ID is changed to " 11 " comprise all three sectors of three sector soft handover set with request SHOG.
In another embodiment, the base station can be each soft-handoff groups a R-CQICH scrambler sequence is provided, and travelling carriage uses this scrambler sequence to ask the soft-handoff groups operation.In this embodiment, comprise the soft-handoff groups sector mark in the R-CQICH message with identification and forward link channel quality report (ForwardLink Channel Quality report) relevant soft-handoff groups sector, and in soft switching process, discern switching target.
In another embodiment, travelling carriage can and be provided with a bit soft handover field by a sector of indication in the The function of backward power control channel and ask to add this sector to a soft-handoff groups.In this embodiment, do not need in the request to use overhead to specify soft-handoff groups.The soft-handoff groups sector can directly be decoded and add to serving sector to R-CQICH message, also can receive message (with being similar to the mode that is used to switch) from indicated sector by backhaul, and this message request adds soft handoff transmission with this sector.Travelling carriage can be left out a sector by The function of backward power control channel indication sector requests from soft-handoff groups, and a bit soft handover field is set.Because in soft-handoff groups, this bit represents to delete the sector in the sector.When soft-handoff groups is active state, switching mark is changed to ' 1 '.This new soft handover bit is used to refer to travelling carriage and whether wishes to keep current soft-handoff groups or only operate with target sector.
According to the present invention, the soft-handoff groups that the base station can indicative of active.This point was very important when public guide frequency was used for channel estimating, because access terminal (AT) need know the channel that should use which sector to estimate data splitting.In one embodiment, the base station can provide SHOG ID to be used for dividing timing identification soft-handoff groups at transfer resource.Can utilize scrambler to discern SHOG ID in the forward link.This point is shown in Fig. 4, has added functional block (360) among the figure and has been used for the message data scrambling behind the process CRC.Same meaning among this embodiment in the meaning of SHOG ID and the travelling carriage request.
In another embodiment, can the SHOG id information be set to a field in the message of allocation of transmission resources, this message is according to the request of travelling carriage allocation of transmission resources in the manner described above.
In another embodiment, scrambling shown in the functional module 330 among SHOG ID scrambler and Fig. 4 can be combined.
According to the present invention, travelling carriage can feed back to the base station with the channel quality information (CQI) of the aggregate channel of a soft-handoff groups.In one embodiment, travelling carriage sends the CQI of a sector, also sends CQI poor of this CQI and aggregate channel.
Table 3 illustrates the message that comprises these fields, and table 4 illustrates may the encoding of field of expression CQI poor (CQI difference).
In another embodiment, can be simultaneously or divide several times CQI report to send to the base station with the single sector of soft-handoff groups.The base station can utilize these CQI reports to estimate the CQI of aggregate channel.
According to the present invention, can keep the same services sector and change soft-handoff groups, also can keep identical soft-handoff groups and change serving sector, soft-handoff groups and serving sector also can all change.In one embodiment, message shown in the free list 3 satisfies the needs of these situations.In order to change serving sector but keep identical soft-handoff groups, the R-CQICH scrambler sequence is made into and a sequence that target sector is relevant, and comprise forward direction (FL) channel quality of this target sector, SHOG ID is made as the value that a target sector corresponding with the current service soft-handoff groups is associated, and the handoff request bit is set to ' 1 '.Simultaneously, in order to change soft-handoff groups, SHOG ID can be set to an expectation soft-handoff groups.
According to the present invention, the base station with an above transmitting antenna also can constitute a soft-handoff groups.At this moment, one group of antenna in this soft-handoff groups can be configured for the grand antenna (macro antenna) that (group transmission) penetrated in mass-sending.Give one example, suppose that sector A has two antenna A1 and A2, sector B has two antenna B1 and B2.Suppose that group G comprises sector A and B.The identical waveform of antenna A1 and B1 emission (also can adopt the diversity of certain form such as CDD etc.).Because the soft combined characteristic of OFDM, this emission can be moved platform and think an inseparable grand antenna.Therefore, antenna A1 and B1 can constitute grand antenna G1.Similarly, antenna A2 and B2 can constitute grand antenna G2.Therefore, travelling carriage can think that group G is identical with the sector with 2 antenna G1 and G2.As alternative, the group G one group of grand antenna of can stopping using is as G2.At this moment, have only a grand antenna to provide service for travelling carriage.
In the strict backward compatible mode of 3GPP2 framework, operating in soft handover may be identical with 1xEV-DO, to be that AT can only monitor that its serving sector sends, based on the control channel of conventional code division multiplexing (CDM) pilot tone, AT covers (DRC cover) by DRC and proposes handoff request and change serving sector.Handover operation can be independent of the SHOG operation.
Except that conventional handover operation, on the definable traffic data channel, especially in the OFDM part, the SHOG transmission.In the SHOG transmission, the individual antenna that a grand antenna in the group can be used as in the sector uses.Thereby the group with a plurality of grand antennas can be the AT service in MIMO mechanism.Must be with the SHOG aggregate information, which sector can constitute one group and group id (Group ID) etc. as, be communicated to AT.SHOG collection information can be broadcasted in Common Control Channel, also can clean culture in Traffic Channel.An example that adopts broadcasting is that this information is added the adjacent sectors tabulation, makes each AT can know that current SHOG is provided with.The example of clean culture is that access node (AN) and AT are held consultation by top signaling behind call setup.
The feedback that conventional 1xEV-DO switches can keep identical with 1xEV-DO.The grand antenna that the feedback of MIMO can be penetrated for mass-sending in group equals an antenna (Feedback for MIMOin a group may be that a macro antenna for a group transmission equals antennain a sector) in the sector.AT can be considered as the group with a plurality of grand antennas to support the virtual sectors of MIMO.A MIMO operation in the group can be identical with the operation in the sector.The feedback that is used for the SHOG selection can be based on measured value, and AT can be to access network (AN) request SHOG service.In order to feed back preferred group and preferred service sector, certain data rate is essential.The physical channel that definable is new carries this information.Equally, can re-use original 1xEV-DO feedback channel.For example, AN and AT can consult extra DRC channel, and DRC can regard the virtual forward link carriers of the asymmetric mode that is used for 1xEV-DO rev B as.But this channel called after group rate controlled (GRC) channel has the GRC_Cover (3 bit) of indication preferred group sign and the GRC content (4 bit) of carrying the data rate control information that is used for this group.
In the embodiment of SHOG operation, AT can measure the channel quality of single sector from public space pilot tone (Common SpatialPilot), and calculates potential group aggregate channel quality.In case satisfy standard, AT can notify AN by GRC being converted to desired GRC.AN can utilize the SHOG that is asked to serve for AT after knowing this conversion.
The disclosure has also been described in order to realize the required technology of soft handover in wireless mobile ofdm communication system, especially for the strictness of 3GPP2 AIE (3GPP2 Air Interface Evolution) compatible dorsad (Strictly Backward Compatible, SBC).Before this is described, at first provide some background informations.
[multi-user diversity among the DO] current 3G mobile communication system as DO rev A and rev B, utilizes multi-user diversity gain that sector throughput is significantly increased.That is, for point-to-multi-point system, as the situation of forward link, all resources of base station are exclusively used in single user at every turn.Scheduler selects the user of radio condition the best to send the data to it as far as possible from one group of user.If it is independently that the user organizes channel fading enough big and each user, just almost always exist the good user of radio condition.Therefore, the base station is avoided information is sent to the bad loss that the user caused of radio condition, makes throughput be significantly higher than the 2G wireless system.
[FCS among the DO] in addition, in current 3G system, when the data user when the service area of a sector moves to another, adopt quick sector to select transfer of data is transformed into another sector rapidly from a sector.These are different with voice user's situation in the cdma system that adopts soft handover, and two sectors that relate to switching this moment send to travelling carriage with identical information simultaneously.Travelling carriage utilizes this extra diversity to receive.Because the throughput that the data user, offers the cell edge data user only to use quick sector to select is significantly less than the data user of center of housing estate.Therefore wish to improve service performance and user experience for Cell Edge User.This can make the expense of sector throughput be in admirable proportion, because the expectation that operator can need to satisfy most of users promptly wishes to be positioned at where all have equal service.
[multiplexing DRC among the DO r B] in order to indicate forward link channel quality, feeds back to AN with DRC.According to the DRC feedback, which AT transmission AN determines arrange to, and should send bag with which kind of packet format.DO rev B also supports asymmetric mode, and wherein single reverse carrier wave can be associated with a plurality of forward carriers.Therefore, a reverse link can carry a plurality of DRC and feed back to its relevant forward link.The multiplexing scheme of many DRC can be the multiplexing and code division multiplexing (CDM) of long PN sign indicating number, the I/Q branch of scrambling.
[DSC in the switching] introduced DSC for the delay of shortening switching, because DO rev A.DSC carries preferred sector auxiliary information, AN knows the handoff request of AT by this information, begins data are sent to by certain path the expectation sector of AT.
[RL in the DO switching] DO makes each sector in the active set can receive, confirm the RL business datum, and can send the RL power control bit.The responsibility of AT comprises collection, understands these signals from different sectors.
In compatible dorsad (SBC) pattern of the strictness of [introduction of SBC] 3GPP2 AIE, CDM data division, pilot tone and FL MAC channel and DO rev A, B are consistent substantially.Evolution partly is that the OFDM symbol may appear at data division, especially by MIMO, promotes high speed data transfers.In order to support the application of MIMO in the forward link, some extra The function of backward power control channels have been introduced, spatial signature channel (Spatial Signature Channel for example, SSC) and spatial level channel (Spatial Rank Channel, SRC) and forward link public space pilot tone (Common Spatial Pilot, CSP) and the private space pilot tone (Dedicated Spatial Pilot, DSP).
[SHOG among the SBC] can utilize soft handover significantly to improve the throughput of cell edge switching zone customer because ofdm system can not disturb self.Send same signal and arrive receiver from the same signal of different base station within the one-period of Cyclic Prefix as long as relate to the sector of switching, receiver just can utilize this point to improve to detect and do not produce and self disturb.The sector of this group cooperation in this handover scheme is called soft-handoff groups (SHOG).
Conventional criteria is followed in the management of [AS, AGS and service groups] active set (AS).We active set the notion of face introducing activity group set (AGS), movable group set is the set of the AT potential service SHOG that should initiatively monitor.This group can have one or more sectors as its member.The synchronization business always sends from a SHOG, promptly serves SHOG.
When the increase of [AGS Managed Solution 1: adding group in AGS] AGS only appears at new sector is added active set.In case certain pilot frequency intensity is higher than threshold value in a period of time, AT just reports as handoff request pilot frequency intensity and this Pilot PN (sector) to AN.If allow, AN can add this sector in the active set.At this moment, AN will add the group information notice AT that will upgrade behind this sector.For example, sector A has been in the active set, and the intensity of sector B increases to and meets the demands at this moment, and AT has reported that sector B and AN have allowed.At this moment, if sector A and sector B can the formation groups, AN thinks to I haven't seen you for ages two new groups, i.e. sector B and A+ sector, sector B, and assign group sign.Wherein, " at least " then can distribute more group if expression sector B can constitute new group with other existing member of active set.If sector B is fully independent and can't be connected with other members in the activity group, AN just only is group id of sector B distribution.In this way, AT and AN keep one potential group tabulation, i.e. movable group set (AGS).
[AGS Managed Solution 1: deletion group from AGS] AGS reduces only to appear at when the sector left out from active set.In case the intensity of a pilot tone is lower than threshold value in the active set in a period of time, AT will report this Pilot PN (sector) in removal request to AN.If allow, AN leaves out this sector and notifies AT from active set.At this moment, AN reconfigures SHOG among the AGS to delete this sector and to notify the new AGS of AT configuration.If SHOG is deletion fully from AGS, its group id will be released in order to using in the future.
[AGS: scheme 2] also has an alternative usefulness that generates AGS, and this scheme will be described in three joints below: group of notifications information, in AGS the adding group and from AGS the deletion group.In such scheme, AT and AN safeguard the management of conventional active set, and in addition, AT and AN will safeguard the activity group set (AGS) that directly obtains from active set.In this alternative, there is not the operation of active set, but by the intensity of AT report group and the directly management of request group (adding and deletion).
Which sector [AGS scheme 2 group of notifications possibilities] at first AN need notify to constitute SHOG, thereby make AT can monitor or predict that the composite channel quality of this group proposes handoff request or exchange request (switch request).A kind of Notification Method is should group information by the broadcast overhead channel radio.Another kind method is to pass through clean culture signaling in the band after setting up Traffic Channel.
After [AGS scheme 2: adding group in AGS] obtained this potential Groups List, AT continued monitoring and predicts each channel quality of potential group by conventional pilot tone or CSP.In case meet the requirements, promptly channel quality is higher than certain threshold value in a period of time, and AT proposes handoff request to AN and requires this group is added to movable group set (AGS).If allow, AN sends a message to AT and comes to be this set of dispense sign and MAC ID.In addition, can also distribute or distinctive scrambler of this group of predefine.
[AGS scheme 2 :] from AGS deletion group otherwise, from AGS the deletion group also be with good conditionsi.For example, if the composite channel quality of a group is lower than certain threshold value in a period of time, AT can send a removal request.As response, AN can represent to allow by acknowledge message.
All there is and only have a group to provide service among [service groups] any time AGS for AT.Each sector sends identical signal in this group in identical time-frequency resources.This needs the assistance of intelligent scheduler.The same signal that a plurality of group memberships send can be cyclic delay diversity (cyclic delay diversity) or phase place switched diversity (phase swap diversity).As alternative, AN can make some group memberships not transmit to avoid interference between group, especially when these group member's transmitting powers are not enough.
[CE among the AT] because partly there is dedicated pilot in OFDM, and AT is easy to synthetic channel status is estimated and business is decoded.But, also can estimate and they are made up channel in groups single group membership's channel by calculating.
[the synthetic DRC that is used for data, services] is preferred in order to have accurate forward link packet format control according to the synthetic synthetic DRC (C-DRC) that organizes channel quality.For AT, C-DRC covers (cover) and points to preferred group.
[DSC that is used for group exchange (group switch)] for AT, DSC points to the preferred service group.In case receive and former different DSC, AN is considered as organizing conversion request with it.
[group conversion (group switch) option one] a kind of group of conversion method is as follows.In case AT plans to propose conversion request, it just will expect that group id is carried among the DSC.After the certain hour, AT will make DRC/SRC/SSC point to the expectation group.If permit conversion, AN will be provided with DRC_Lock and emission bag in new service groups.Otherwise AN is not provided with DRC_Lock, and this expression refusal AT enters new group.
The other method of [group conversion options 2] group conversion is as follows.In case AT plans to propose conversion request, it just will expect that group id is carried on the DSC.If allow, AN will send a message to AT.Then, AT is transformed into the expectation group with DRC/SRC/SSC.If AT does not receive message after a period of time, will be considered as refusal.Equally, also can use explicit refuse information.
The third method of [group conversion options 3] group conversion is as follows.In case AT plans to propose conversion request, it just will expect that group id is carried on the DSC.At this moment, AT makes SRC/SSC point to the expectation group, but DRC value and covering are still at current group.Therefore do not have spatial information this moment, and spatial information has considerable influence to channel quality, and spatial information should send to new group as early as possible to new group of transmission.Before new winding pipe, former group can be continued to keep the spatial information before it and continue as AT service is provided.As alternative, make DRC/SRC/SSC point to expectation group or current group and equally also be fine.Receive after the DSC, AN manages the route in the network.In case newly organize readyly, it just sends data after lead code, and wherein lead code is organized distinctive scrambler scrambling through this.AT monitors current lead code and expectation lead code simultaneously, and these two lead codes are respectively by current scrambler and the scrambling of expectation scrambler.In case receive the expectation lead code, just permit conversion SHOG.In order to improve the efficiency of transmission in the transition, can generate more SRC/SSC/DRC, be cost with back emitted power and interference.For example, system can have the two cover SRC/SSC/DRC that point to current group and new group respectively.
[RL represents the sector] for the DO backward compatibility, attempting the reverse link traffic data are decoded and confirmed in all sectors that participate in AGS, and by FL MAC channel (DRC_Lock/ACK/RPC) reverse link is carried out power and control.In order to save transmitting power and to reduce the AT complexity,, need not all sectors and all send these control signals because the identical information in the soft handover may be shared in all sectors among BTS.Therefore, importantly only allow those sectors of representing the sector representative to share identical information send FL MAC channel.In fact, each BTS/Cell has one to represent the sector among the possible AGS.
[FL MAC is carried out the R-DRC that power is controlled] for the ease of FL MAC channel being carried out power control, the DRC (being called R-DRC) that reverse (RL) represents the sector is pointed in the transmission that needs equally.Therefore, may need to send a plurality of DRC for different purposes.For for simplicity, the present invention is considered as each DRC to point to the DRC of a virtual FL carrier wave of asymmetric mode among the DO rev B.Therefore, different DRC can utilize the scrambling of long PN sign indicating number, I/Q branch is multiplexing or code division multiplexing (CDM) carries out multiplexing.When interpolation RL represented the sector, AN and AT should consult multiplexing mechanism.Similar with DO, it is to point to preferably to represent the sector that R-DRC covers.
On behalf of the sector, [RL represents conversion] can change.AT measures the FL channel quality and selects the representative sector of each BTS/ sub-district.Represent the sector if AT plans to revise RL, just R-DRC is covered and be modified as the expectation sector.Notice that AN will send FL MAC channel by new sector, because the MAC ID of this new sector distributes.In case receive above-mentioned channel, AT just knows that on behalf of the sector conversion, RL be accepted.Option can be finished this function by signaling.But obviously, use the cost of signaling higher.
On behalf of the conversion of sector, RL can be independent of the conversion of service groups.
Identical principle also is applicable to multicarrier system, and wherein SHOG comprises the one group of sector that can transmit in identical time-frequency resources.
And the invention is not restricted to the SBC among the 3GPP2.
According to an embodiment, given 3 bit DRC cover (cover) and DSC covers, and the group number just is limited to 8.Therefore, the idea of small active area set is inapplicable, because its group number may be easy to excessive.Replacing has proposed movable group of set, and wherein each group is added by three layers of (L3) signaling or deleted.AT selects the representative of grappling sector as each sub-district just.And AN should be each grappling sector report and distributes an additional DRC.Equally, the grappling conversion has been proposed.Propose option 3 (802.20) and be used for the group conversion.
In order to improve the performance of Cell Edge User, the SHOG of SBC pattern has been proposed.To the SFN transmission of switching AT, can consider to utilize various forms of diversity for example to postpone diversity etc. in the AN management group, and AN guarantee to switch AT and can not be subjected to any interference from the group membership.AT safeguards the tabulation of a GroupID who comprises the potential SHO group of AN broadcasting and distribute, and measures accordingly from CSP.In case reach channel quality thresholds, AT is to AN report SHO request.AN makes the final decision that allows SHOG.DSP will make the SFN transmission steadily carry out.
As for SHOG FL, two other notion of level: AGS and service SHOG are arranged, only provide service by a group at every turn.Therefore, two other flow process of level: AGS operations and SHOG operation are arranged.The AGS operation comprises calling out to be initiated, and group is added and deletion.The SHOG operation comprises the SHOG conversion.Group id is distributed by AN.MAC ID is by set of dispense.Organize the combination that distinctive scrambler can make its group membership's scrambler.
As for SHOG RL, in the movable group attempt the RL business is decoded and monitored the RL quality in all sectors.But, to each small active area, have only a grappling sector to send MAC channel (RPC/DRC_lock/ACK) with the MAC ID of this group, wherein, this group has only this grappling sector.AT measures the FL quality and selects the grappling sector of each sub-district.AT reports its grappling sector mark and FL quality by DRC simultaneously, because each grappling sector all belongs to a virtual carrier among the DO rev B.Grappling DRC (ADRC) be used for reporting grappling sector mark and forward link channel quality.
In an example, AGS comprises B2, B3, B2+B3, A1.Service groups comprises B2+B3.The grappling sector comprises A2 and B2.Move if AT deviates from B2+B3, AT will be transformed into A2 with DSC/SSC/SRC.DRC stays among the B2+B3, and ADRC remains unchanged.In case receive new preamble, AT just changes DRC.AN supervising the network route continues to send data from B2+B3 according to current DRC and previous SRC/SSC, in case readyly just send data according to current SRC/SSC and DRC from A2.
When calling out initiation, calling is always set up a sector (group that a member is only arranged).Group id, MAC ID and ARDRC distribute by AN.With DO rev category-B seemingly, DRC/SRC/SSC points to service SHOG and the DRC value is a combined value, DSC then points to preferred SHOG.In addition, as mentioned above, AT reports its grappling sector mark and FL quality by ARDRC.
One of AGS operation is the adding and the deletion of group.Be that with the difference of conventional DO rev A operated unit is not the sector but organizes.AT keeps the search listing in abutting connection with sector and group, and this table is broadcasted by broadcast.In case group is enough good, AT reports to AN by the message of for example present PilotStrengthReport.AN permit request and by as the message of present traffic channel assignments (TrafficChannel Assignment) come assign group to identify and MAC ID.In addition, if this group belongs to new sub-district, AN should distribute an ADRC.The deletion flow process is similar.
In the grappling sector changes, to each sub-district, for AT distributes an ADRC to report its grappling sector mark and FL quality.The grappling sector sends the representative of MAC channel (RPC/DRC_Lock/ACK) as this sub-district.In case AT wishes to change grappling, it covers ADRC and is converted to expectation grappling sector, and the MAC channel of monitoring expectation grappling sector.In case detect expectation MAC channel, AT is considered as allowing conversion grappling sector.
In the group conversion, AT will expect that ID is carried at DSC and upward and with SRC/SSC points to the expectation group, and DRC value and covering then still are used for current group and former SRC/SSC.Reason is not have space message to send to new sector this moment, and SSC can have a strong impact on channel quality.AN is with the route in the supervising the network.In transfer process, the source group continues to keep former SRC/SSC information and continues to transmit data, the current DRC of w.r.t.In case the source group is ready, it will send data with expectation SRC/SSC.AT monitors current lead code and expectation lead code simultaneously, and these two lead codes are respectively by current scrambler and the scrambling of expectation scrambler.In case AT receives the expectation lead code, just think that the SHOG conversion is permitted.
In order to make those skilled in the art can understand or use the present invention, more than provided the detailed description of disclosed embodiment of the present invention.Those skilled in the art are easy to these embodiment are made multiple modification, and General Principle described here is applicable among other embodiment that are included within spirit of the present invention and the protection range.Therefore, protection scope of the present invention is not limited only to described embodiment, but comprises that all meet the wideest protection range of principle of the present invention and new feature.

Claims (38)

1. the method for a management data transmission in the communication system soft switching process is characterized in that described communication system comprises a plurality of base stations, and each base station comprises at least one sector and at least one travelling carriage, and described method comprises,
Travelling carriage generates each sector pilot signals intensity report;
The potential soft handoff sectors tabulation of described travelling carriage is safeguarded in the base station according to the pilot signal strength report that receives from the travelling carriage with described base station communication;
The sector in the described tabulation is formed the soft-handoff groups of described travelling carriage in the base station;
The information of described soft-handoff groups is delivered to travelling carriage;
The combined pilot signal strength signal intensity of each described soft-handoff groups of moving table measuring;
Select an expectation soft-handoff groups based on the combined pilot signal strength signal intensity;
Upgrade member sector in the current soft-handoff groups of described travelling carriage according to described expectation soft-handoff groups.
2. method according to claim 1 is characterized in that described soft-handoff groups comprises at least one sector.
3. method according to claim 1 is characterized in that, the grouping of sector in the described potential soft handoff sectors tabulation is determined in described base station according to the physical location of each sector.
4. method according to claim 1 is characterized in that, the grouping of sector in the described potential soft handoff sectors tabulation is determined in described base station according to quick return communication capacity between the sector.
5. method according to claim 1 is characterized in that, the grouping of sector in the described potential soft handoff sectors tabulation is determined in described base station according to the traffic load of each sector.
6. method according to claim 1 is characterized in that, described travelling carriage sends to described base station to described expectation soft-handoff groups information with reverse channel quality indicator (CQI) channel.
7. method according to claim 6 is characterized in that, further comprises,
Be the reverse CQI channel allocation sequence coverage covering sequence of each soft-handoff groups, described soft-handoff groups is that described base station is that described travelling carriage generates;
The sequence coverage of distributing to each soft-handoff groups is sent to described travelling carriage;
Described travelling carriage is with the sequence coverage coverage reverse CQI channel of selected desired service soft-handoff groups association;
Described travelling carriage sends reverse CQI channel, is the transmitting power that is provided with of the base station in the designated groups.
8. method according to claim 7 is characterized in that, described sequence coverage is a Walsh Walsh sign indicating number.
9. method according to claim 1 is characterized in that, the member sector of expectation soft-handoff groups that described base station basis indicates and the current soft-handoff groups of ability update of supporting this group thereof.
10. method according to claim 9, it is characterized in that, if described expectation soft-handoff groups can be supported in described base station, then accept described expectation soft-handoff groups as the current service soft-handoff groups, if described expectation soft-handoff groups can't be supported in described base station, then refusal is accepted described expectation soft-handoff groups, and continues with existing current service soft-handoff groups as current soft-handoff groups.
11. method according to claim 10 is characterized in that, further comprises, the decision of accepting the expectation soft-handoff groups is passed in described base station to described travelling carriage.
12. method according to claim 1 is characterized in that, further comprises, identical hopping pattern is used in the member sector of the identical soft-handoff groups that described base station generates.
13. method according to claim 1 is characterized in that, further comprises,
Described travelling carriage reports to the base station with the combined pilot intensity and the CQI (CQI) of the member sector of selected soft-handoff groups,
The modulation and the encoding scheme MCS of data selected to be used for transmitting to travelling carriage in described base station according to the described combination CQI report that obtains from travelling carriage.
14. a base station device that is used for to the travelling carriage transmission data of soft handover is characterized in that, comprises,
Scheduler is used for the resource of a plurality of sectors of participating in soft handover distributed and transmits particular data to specific travelling carriage;
A plurality of far modules, each far module comprises the RF processing unit of at least one sector that is used for the base station;
Primary module comprises the baseband processing unit of a plurality of far modules that are used at least one sub-district; And
Communicating to connect between far module and the primary module.
15. device according to claim 14 is characterized in that, comprises that further backboard is used for other primary module of primary module and at least one is connected.
16. device according to claim 14 is characterized in that, further comprises, connects between fast base station, is used for the primary module of first base station is connected with the primary module of second base station.
17. device according to claim 14 is characterized in that, further comprises, single frequency-hopping mode uses for the common sector of the soft handover that participates in travelling carriage.
18. be used for the method for the resource of soft handoff transmission on base station and travelling carriage cooperation control and the management forward link, it is characterized in that, travelling carriage is used scrambler sequence on the The function of backward power control channel, come to particular sector request soft handoff transmission in conjunction with the field of protocol message.
19. method according to claim 18, it is characterized in that, the message that the base station is used for the allocation activities set comprises the scrambler sequence field of being correlated with in each sector of active set, and described scrambler sequence is used for the scrambling of The function of backward power control channel, with the identification soft-handoff groups.
20. method according to claim 18 is characterized in that, the message that the base station is used for the allocation activities set comprises the field relevant with sector in the active set, and identical soft handover concentrates the field of sector to be arranged in the message continuously.
21. method according to claim 18 is characterized in that, in the base station was used for the message of allocation activities set, each sector in the active set had a message field, and described field is used to indicate whether respective sectors is the beginning of new soft handover set; Described new soft handover set comprises sector continuous in the message, and the described continuous relevant field in sector is indicated the beginning of the non-new soft handover collection in this sector.
22. method according to claim 21 is characterized in that, the relevant field of active set at new soft handover set beginning of described indication is used for determining and the relevant soft-handoff groups in each sector of described active set.
23. method according to claim 18, it is characterized in that, travelling carriage reverse chain channel message, the request operating in soft handover, wherein soft-handoff groups sign (SHOG ID) message field is used to discern the sector relevant soft-handoff groups corresponding with the R-CQICH scrambler sequence.
24. method according to claim 18 is characterized in that, the cqi of travelling carriage by The function of backward power control channel reporting sector, and the CQI that also reports described sector is poor with the CQI's that is used to make up the soft-handoff groups channel.
25. method according to claim 18 is characterized in that, with the CQI report separately of each sector in the soft-handoff groups simultaneously or divide and send to the base station several times.
26. method according to claim 18, it is characterized in that, the member of himself soft handover set of broadcast identification is used in the base station, and the member of described identification can be used for the soft-handoff groups operation, so that travelling carriage request operating in soft handover when initially setting up data and connect.
27. method according to claim 18 is characterized in that, the resource that is used for any public guide frequency in the member sector with soft-handoff groups is deleted from the resource that can be used for the transmission of soft handover data.
28. method according to claim 18 is characterized in that, travelling carriage is asked soft handoff transmission when satisfying certain condition.
29. method according to claim 26 is characterized in that, the identification of base stations travelling carriage can be asked the threshold value of the serving sector channel quality of operating in soft handover.
30. method according to claim 26 is characterized in that, identification of base stations allows the greatest combined channel quality of soft-handoff groups operation, and described greatest combined channel quality is used to limit the operation of travelling carriage request soft-handoff groups.
31. method according to claim 18, it is characterized in that, the base station provides The function of backward power control channel scrambler sequence for each soft-handoff groups, travelling carriage is asked operating in soft handover with described The function of backward power control channel scrambler sequence, described The function of backward power control channel massage comprises the soft-handoff groups sector mark, is used to discern the soft-handoff groups sector relevant with switching target with the FL channel quality reporting.
32. method according to claim 18, it is characterized in that, the travelling carriage request adds soft-handoff groups with a sector and is used for soft handoff transmission, wherein discerns the sector of being asked by a scrambler sequence on the The function of backward power control channel and a bit soft handover field.
33. method according to claim 18 is characterized in that, adopts scrambler to come the identification activity soft-handoff groups in forward link, wherein said scrambler is used for adding the message data scrambling of CRC.
34. method according to claim 18 is characterized in that, described message field is used for forward link with the identification activity soft-handoff groups.
35. method according to claim 18 is characterized in that, scrambler is used for the identification activity soft-handoff groups in the forward link, and wherein said scrambler is used for adding the message data scrambling of CRC.
36. method according to claim 18 is characterized in that,
Keep serving sector, revise soft-handoff groups; Or
Keep soft-handoff groups, revise serving sector; Or
Revise soft-handoff groups and serving sector.
37. the strict backward compatible mode of the 3GPP2 with 1xEV-DO Rev.C is used for carrying out the soft-handoff groups method of operating at OFDM, comprises,
Access network AN notice access terminal AT soft-handoff groups SHOG aggregate information comprises SHOG member and ID;
The group that AT will have a plurality of grand antennas is considered as supporting the sector of MIMO;
AT is according to the measurements and calculations decision conversion SHOG to the aggregate channel quality;
AT is by GRC channel feedback SHOG request, and described channel is the DRC channel among the 1xEV-DO Rev.B.
37. carry out the method for soft handover in the orthogonal frequency division multiplex OFDM mobile radio system, comprise,
Generation comprises the activity group set A GS of a plurality of sectors;
When surpassing threshold value in the given time, the pilot frequency intensity of new sector in AGS, adds new group;
When being lower than threshold value in a period of time, from AGS, deletes the pilot frequency intensity of sector at least one group;
Wherein, only have a group that service is provided for accessing terminal at any time, the member of group transmits identical signal with SFN mode or a kind of diversity scheme;
Wherein, terminal reports that this group DRC indicates group and the FL transformat of selecting for use in terminal described in the available sending time slots of the next one;
Wherein, represent the sector to send the forward link MAC channel to a wireless access terminal for one in the sub-district, the representative sector of described sub-district is by terminal request; And
Wherein, the DRC of the described representative of terminal report sensing sector assists access network to guarantee the transmission quality of FL MAC channel.
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