CN1914826A - Outer loop power control using multiple channels - Google Patents

Abstract

Outer loop power control(OLPC) for the reverse link considers frame information associated with at least two reverse link traffic channels, the transmit power of which is referenced to the transmit power of a reverse link pilot channel R-PICH. A traffic OLPC setpoint is determined based on information such as target frame error rate(FER) and actual frame errors associated with each traffic channel, and the traffic OLPC setpoint is converted to a R-PICH OLPC setpoint. The traffic OLPC setpoint may be calculated from weighted frame information generated by combining the received frame information. Alternatively, a traffic channel OLPC setpoint may be determined for each channel, and a weighted traffic OLPC setpoint calculated from the individual traffic channel OLPC setpoint. The setpoint adjustment may depend on received frame errors, where the power up step size is a multiple of the power down step size, the multiple calculated from target FERs.

Description

Use multi channel exterior ring power control

Related application

The application requires the priority of the interim U.S. Patent application 60/540114 of submission on January 28th, 2004, and it is hereby incorporated by.

Background technology

The present invention relates generally to wireless communication system, particularly be used for the system and method for the exterior ring power control of a plurality of communication channels, the power of each communication channel is relevant with public pilot channel.

Most of cordless communication networks use the power control of certain form, and the order of the controller (for example, radio base station) in network mobile radio station increases or reduce their transmitting power thus.The mobile radio station near antenna for base station can be to be lower than the power level transmission signal away from the mobile radio station of antenna, so that realize identical received signal intensity.In the multiplexing wireless system of frequency of utilization, the interference in the identical frequency minimizing neighbor cell is used in power control.In interference-limited spread spectrum radio system, in order to support a large amount of simultaneous users, power control is critical.In all cases, effectively power is controlled the battery life that has kept mobile radio station.

In observing the wireless network of cdma2000 standard, in order to keep the quality of wide range of services, for example sound, data, image, video, interactive application or the like is necessary to carry out power control.Typically, closed loop power control attempts to keep required frame error rate (FER).This realizes by two different closed control loops: inner loop power control and exterior ring power control.Inner loop power control is risen and is descended to order by transmitted power and adjusts the mobile radio station transmitting power, so that follow the tracks of required set point or the received power level on the noise.Required set point is adjusted in exterior ring power control, is used for the required FER of communication channel so that keep.In other words, exterior ring power control target setting, and inner loop power control is adjusted power so that meet this target.

In the cdma2000 forward link, when multichannel exists jointly, for example forward fundamental channel (F-FCH) and forward supplemental channel (F-SCH), the interior ring and the exterior ring power control that are used for each channel are independently.That is to say that the power and the set point adjustment that are used for F-FCH are adjusted unconnected with power that is used for F-SCH and set point.

Yet, in the cdma2000 reverse link, by the dynamic power adjustment realization inner loop power control of Reverse Pilot Channel (R-PICH).Other all channels, for example Reverse Fundamental Channel (R-FCH), reverse supplemental (R-SCH), reverse packet data channel (R-PDCH) or the like power level transmission to be maintained fixed with respect to R-PICH.That is to say to have the single inner loop power control that is used for all channels.This makes to be difficult in keeps target FER in each channel, because different channel condition and features (for example, sudden).Each dedicated channel can be configured by the 3rd layer signaling message with respect to the gain of R-PICH.Yet this is a kind of invalid controlling mechanism, and can not respond fast transient behaviour.

Summary of the invention

The present invention relates to a kind of method of power control in wireless communication system.Obtain with a plurality of radio communication channels in each signal that is associated reception information, the transmitting power of this radio communication channel is relevant with pilot channel.Receive information based on the signal relevant, determine the set point of pilot channel exterior ring power control (OLPC) with at least two radio communication channels.

The invention still further relates to a kind of wireless communication system.This system comprises at least one mobile radio station of transmission reverse link pilot channel and at least two reverse link communications channels, and wherein the transmitting power of each communication channel is relevant with pilot channel.This communication system also comprises the base station of power control command transmitting being delivered to mobile radio station, and this power control command is based on the received frame information that is associated with at least two reverse link communications channels.

Description of drawings

Fig. 1 is the functional block diagram of wireless communication system.

Fig. 2 is the block diagram that the exterior ring power of definite backward channel is controlled the art methods of set point.

Fig. 3 is based on the received frame information of two or more reverse chain channels, determines the block diagram of method of the exterior ring power control set point of backward channel.

Fig. 4 be by combined frames information determining traffic setpoint, thereby determine the block diagram of method of the exterior ring power control set point of backward channel.

Fig. 5 is by the communication channel set point that calculates each channel and makes up this communication channel set point with definite weighting traffic setpoint, thus the block diagram of the method for the exterior ring power of definite backward channel control set point.

Specific embodiment

Fig. 1 has illustrated typical cordless communication network, and it is often referred to Reference numeral 10.In typical embodiment, network 10 is based on cdma2000, the 1xEVDO/DV standard of being announced by telecommunications industry association (TIA), though the invention is not restricted to this realization.At this, network 10 is coupled to Public Switched Telephone Network (PSTN) 14, integrated data services network (ISDN) 16 and/or PDN(Public Data Network) 18, for example internet communicatedly with one or more mobile radio stations (MS) 12.Under this functional support, network 10 comprises the wireless access network (RAN) 20 that is connected to packet core network (PCN) 22 and IS-41 network 24.

RAN20 generally includes one or more base station controllers (BSC) 26, each base station controller comprises one or more controllers 28 or other treatment system, and associative processor 30, described memory is used to store necessary data and the parameter relevant with ongoing communication activity.Usually, each BSC26 is associated with one or more base stations (BS) 32.Each BS32 comprises one or more controllers 34, or other treatment system, and support and MS12 various transceiver resources 36 of carrying out radio communication, for example modulator/demodulator, baseband processor, radio frequency (RF) power amplifier, antenna or the like.

BS32 can be called base station transceiver system (BTS) or radio base station (RBS).In operation, BS32 will control on forward link channel and communication data is transferred to MS12, and receive control and communication data from them on reverse chain channel.BS32 can carry out power control on MS12.BSC26 provides the coordination control of different B S32.BSC26 also is coupled to PCN22 communicatedly with RAN20.

PCN22 comprises packet data serving node (PDSN) 38, and this packet data serving node comprises one or more controllers 40, or other treatment system; Home agent (HA) 42; And authentication (AAA) server 44.Typically, PCN22 is coupled to PDN18 by IP network management 46, and this IP network management 46 is operated under the control of network 10.PDSN38 is by setting up, keep and stop point-to-point protocol (PPP) link and operate as the tie point between RAN16 and the PDN18, and further provides external agent (FA) function for web visitor's registration and service.HA42 and PDSN38 co-operation, so that the authentication mobile IP registration, and in supporting grouping tunnel and other communication redirection activity, keep existing positional information.At last, aaa server 44 provides the support to authentification of user, mandate and the service of chargeing.

BSC26 also is coupled to IS-41 network 24 communicatedly with RAN20.IS-41 network 24 comprises mobile switching centre (MSC) 48, and described mobile switching centre is for subscriber position and profile information visit attaching position register (HLR) 50 and Visited Location Registor (VLR) 52.MSC48 sets up circuit switching and packet switching communication between RAN20 and PSTN16 and ISDN16.

The control of traditional exterior ring power be designed to be used for a dedicated channel for example the frame error rate of Reverse Fundamental Channel R-FCH (FER) as target.In order to realize being used for the target FER of other dedicated channel (for example R-SCH, R-PDCH or the like), BS32 must depend on the correct setting of these channels with respect to the gain of Reverse Pilot Channel R-PICH.Because the characteristic of radio channel condition, best relative gain are dynamic, and be different to another MS12 from a MS12.The adjustment of relative gain can realize by the 3rd rare relatively layer signaling message.

This situation is described in Fig. 2.Receive the frame information that is associated with R-FCH and (for example, FER), and adjust outer shroud R-FCH set point so that keep required FER.Usually, if the frame that receives is good frame, then this set point reduces step-length Step _dWhen the frame that receives was bad frame, this set point increased step-length Step _uIn order to keep target FER, Step _dAnd Step _uBetween relation typically satisfy relation of plane down:

$\frac{{\mathrm{Step}}_u}{{\mathrm{Step}}_d}=\frac{1}{t\arg \mathrm{etFER}}-1---\left(1\right)$

Convert the R-FCH set point to the R-PICH set point then, and use the R-PICH set point to adjust the power of R-PICH.Adjust the power of R-FCH indirectly with respect to the gain of R-PICH according to R-FCH.

Yet, with other effective reverse dedicated channel for example the frame information that is associated of reverse packet data channel R-PDCH can not be used for power control at all.The unique method of adjusting R-PDCH power is exactly to change the gain of channel with respect to R-PICH by the 3rd layer of signaling.

According to one embodiment of present invention, be used to produce backward channel exterior ring power control set point, as shown in Figure 3 from the frame information of at least two dedicated reverse channel.In Fig. 3, combination from the frame information of R-FCH and R-PDCH to adjust traffic setpoint.Convert this traffic setpoint to the R-PICH set point then, and adjust the power of R-PICH.The adjustment of traffic setpoint can be considered the target FER demand of different channels, the relative importance of channel, and other factors.Usually, one of ordinary skill in the art appreciates that the frame information that can make up different backward channels in many ways.

Fig. 4 has described one embodiment of the present of invention.By the received frame information that function f (.) combination is effective with all, reverse, dedicated channel is associated.As mentioned above, f (.) depends on " sudden " of relative importance, channel of target FER, each channel of each channel or other characteristic or the like.Usually, channel is important more, and its weighting in calculating is big more.Function f (.) can be linearity or nonlinear.For example, f (.) can comprise coefficient arrays C=[c (1), c (2) ... c (N)] so that diverse frame information is combined as:

The frame information of weighting is adjusted the multichannel communication set point then, and converts thereof into the set point of P-PICH.Adjust each transmitting power in N the reverse link communications channels according to each channel with respect to the gain of P-PICH then.Can notice that some communication channels are happening suddenly in nature, therefore demonstrate discontinuous transmission.If these channels are discontinuous (DTX-ed), then they should be got rid of from equation (2).In other words, the quantity N of reverse link communications channels can be dynamic on the basis of each frame.

Fig. 5 has described an alternative embodiment of the invention.Based on the frame information of channel FER for example, each channel is carried out exterior ring power control independently.By the set point of a plurality of channels of weighting function g (.) combination, this weighting function is considered the relative importance of channel, and/or other factors then.Function g (.) can be linearity or nonlinear.For example, this function comprises coefficient arrays D=[d (1), d (2) ..., d (N)], therefore set point is combined as:

Then the traffic setpoint of weighting is converted to the set point of P-PICH.Adjust the transmitting power of N reverse link communications channels then with respect to the gain of P-PICH according to each channel.As mentioned above, some communication channels are happening suddenly in nature, thereby demonstrate discontinuous transmission.If these channels are discontinuous (DTX-ed), then discontinuous channel should be got rid of from equation (3).That is to say that the quantity N of reverse link communications channels is dynamic on the basis of each frame.

No matter calculate the method for required set point, comprise step-length Step by sending _uAnd Step _dThe power order of rising and descend adjust set point so that increase or reduce power respectively.When in set point is adjusted, considering multichannel, step-length Step _uAnd Step _dQuantity, each channel target FER and other factors of depending on channel.

On the duration of N frame, the frame information in equation (2) or (3) comprises under the situation of FER that purpose is to keep equation (2) or (3) given target FER.For example, 2% and target FER be interpreted as two frame erasings in 100 frames.Concerning two simultaneous channels, two frame erasings can occur twice on a channel, and do not have bad frame on one other channel, perhaps replacedly, occur once on each that can be in two channels.Under latter event, can on the independent time frame erasing appear, perhaps can occur simultaneously.The latter event of these situations (that is the situation that, occurs frame erasing simultaneously) requires lamp power control set point is carried out bigger adjustment than the situation of independent received frame error (that is the situation of the frame that receives with each bad frame).

In one embodiment of the invention, when only receiving good frame on whole channels, set point reduces Step _dIf receive a bad frame, the Step that the equation below then set point increases provides _U1:

Step _u1＝Step _d*(1-SumTargetFER)/SumTargetFER (4)

Wherein SumTargetFER is the weighted sum of the FER demand of each independent communication channel, with equation (2) or (3) similar forms, that is to say:

If two channels transmit, and receive two frame erasings simultaneously, then set point increases the Step that is provided by equation _U2:

Step _u2＝Step _d*(1-MeanTargetFER)/MeanTargetFER (6)

MeanTargetFER=SumTargetFER/N wherein, and

The quantity of N=efficient channel.

For example, if R-FCH and R-PDCH transmit simultaneously, and the target FER of each channel is 1%, and then SumTargetFER is 2%, and MeanTargetFER is 1%.This can produce Step _U1=49*Step _d, Step _U2=99*Step _dOn the other hand, if only R-FCH transmission on the given cycle, and the target FER of P-FCH is 1%, and then SumTargetFER is 1%, and Step _U1=99*Step _dTherefore, the situation for two errors on the setpoint correction of an error on the channel of operation and two channels (perhaps N channel on N simultaneous error) is identical.(that is, when receiving at least some good frames) changes under the situation of quantity less than the quantity of simultaneous channel of the error that the step-length that rises only exists at the same time.

Exterior ring power control of the present invention has improved at the power control performance that has under the multi channel situation by considering the frame information that is associated with multichannel.It is effectively that power of the present invention is controlled among the target FER that keeps each channel in a plurality of channels, and has reduced by the 3rd layer of signaling and adjusted the needs of dedicated channel with respect to the gain of R-PICH.

At this, though described the present invention with respect to its special feature, aspect and embodiment, obviously, many distortion, modification and other embodiment also may be in wide regions of the present invention, therefore, all distortion, modification and embodiment should regard as within the scope of the invention.Therefore, present embodiment is interpreted as all exemplary and unrestriced aspects, and will the institute in the meaning of claims and full scope of equivalents changes and all think to be included in wherein.

Claims (23)

1, the method for power control in a kind of wireless communication system comprises:

Obtain and each received frame information that is associated in a plurality of reverse link communications channels, the transmitting power of described reverse link communications channels is relevant with the pilot channel of reverse link; And

Based on at least two frame informations that described reverse link communications channels is relevant, determine the exterior ring power control set point of reverse link pilot channel.

2, method according to claim 1, determine that wherein the exterior ring power control set point of described reverse link pilot channel comprises:

Based on at least two frame informations that described reverse link communications channels is relevant, determine communication exterior ring power control set point; And

Described communication exterior ring power control set point is converted to the exterior ring power control set point of described reverse link pilot channel.

3, method according to claim 2, determine that wherein communication exterior ring power control set point comprises:

Based on at least two frame informations that described reverse link communications channels is relevant, determine the frame information of weighting; And

Based on the frame information of described weighting, determine described communication exterior ring power control set point.

4, method according to claim 3, the frame information of wherein determining weighting is included on described two reverse link communications channels at least, to the long-pending summation of frame information relevant with each described reverse link communications channels and the weighting factor that is associated with each described reverse link communications channels.

5, method according to claim 4, wherein each described weighting factor is relevant with the importance of each reverse link communications channels that is associated.

6, method according to claim 2, wherein based on at least two frame informations that described reverse link communications channels is relevant, determine that communication exterior ring power control set point comprises:

Definite communication channel exterior ring power control set point that is associated with each described reverse link communications channels; And

Based on described communication channel exterior ring power control set point, determine the communication exterior ring power control set point of weighting.

7, method according to claim 6, the communication exterior ring power control set point of wherein determining described weighting is included on the described reverse link communications channels, to the long-pending summation of described communication channel exterior ring power control set point and the weighting factor that is associated with each described reverse link communications channels.

8, method according to claim 7, wherein each described weighting factor is relevant with the importance of each reverse link communications channels that is associated.

9, method according to claim 1, wherein said frame information comprises frame error information.

10, method according to claim 9, determine that wherein the exterior ring power control set point of reverse link pilot channel comprises:

For each described reverse link communications channels is determined target frame error rate (FER);

Determine decline step-length Step _d

Respond the target FERs of described reverse link communications channels, calculate rising step-length Step _u

If do not have to find error on the described reverse link communications channels frame in front, then predetermined reverse link pilot channel exterior ring power control set point is reduced Step _dAnd

If find error at least one described reverse link communications channels frame in front, then the exterior ring power control set point with described predetermined reverse link pilot channel increases Step _u

11, method according to claim 10, wherein Step _uBe Step _dMultiple.

12, method according to claim 11, wherein said Step _dMultiple depend on the quantity of finding the described reverse link communications channels of error in front the frame.

13, method according to claim 12 is if wherein run into a frame error, then by Step _u=Step _d* (1-SumTargetFER)/SumTargetFER provides Step _u, wherein SumTargetFER is the weighting FER of each described reverse link communications channels.

14, method according to claim 12 is if wherein run into a plurality of frame errors, then by Step _U2=Step _d* (1-MeanTargetFER)/MeanTargetFER provides Step _u, MeanTargetFER=SumTargetFER/N wherein, N is the quantity of channel.

15, method according to claim 1, further comprise power rising or power decline order are sent to the mobile radio station of transmission reverse link pilot channel and a plurality of reverse link communications channels, so that the transmitting power of described reverse link pilot channel is adjusted to the exterior ring power control set point of described reverse link pilot channel.

16, a kind of wireless communication system comprises:

At least one mobile radio station of transmission reverse link pilot channel and at least two reverse link communications channels, the transmitting power of each described communication channel is relevant with described pilot channel; And

Power control command transmitting is delivered to the base station of described mobile radio station, and described power control command is based on the received frame information that is associated with at least two described reverse link communications channels.

17, system according to claim 15, wherein said base station is based on the received frame information calculations that is associated with at least two the described reverse link communications channels exterior ring power control set point of communicating by letter, convert described traffic setpoint the exterior ring power control set point of reverse link pilot channel to, and send described power control command so that described reverse link pilot channel transmitting power is adjusted to the exterior ring power control set point of described reverse link pilot channel.

18, system according to claim 16, wherein said base station is based on the weighted array of the received frame information calculations frame information that is associated with at least two described reverse link communications channels, and, determine described communication exterior ring power control set point based on the weighted array of described frame information.

19, system according to claim 16, wherein said base station is that each described reverse link communications channels is calculated communication channel exterior ring power control set point, and, determine the communication exterior ring power control set point of weighting based at least two described communication channel exterior ring power control set points.

20, system according to claim 16, wherein said power control command based target frame error rate (FER) and the received frame information that is associated with at least two described reverse link communications channels are adjusted the transmitting power of described reverse link pilot channel.

21, system according to claim 20, if wherein do not have to find error on the described reverse link communications channels frame in front, then described power control command reduces predetermined step-length Step with the transmitting power of described reverse link pilot channel _d, and response receives at least one frame error at least one described communication channel, described transmitting power is increased step-length Step _u, described Step _uBe Step _dMultiple.

22, system according to claim 21 is if wherein run into a frame error, then by Step _u=Step _d* (1-SumTargetFER)/SumTargetFER provides Step _u, wherein SumTargetFER is the weighting FER of each described reverse link communications channels.

23, system according to claim 21 is if wherein run into a plurality of frame errors, then by Step _U2=Step _d* (1-MeanTargetFER)/MeanTargetFER provides Step _u, MeanTargetFER=SumTargetFER/N wherein, N is the quantity of channel.

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