The method of power control under the discontinuous emitting state
Technical field
The present invention relates to a kind of wireless communication system that is applied to, be particularly related to a kind of TD SDMA (Time Division Synchronous Code-Division Multiple Access that is applied to, abbreviation TD-SCDMA) in the mobile communication system, the method of the power control of base station equipment under discontinuous emission (DiscontinuousTransmission is called for short DTX) state.
Background technology
Along with development of times, people comprise the requirement to communication quality and class of business etc. to the requirement of communication, and are also more and more higher.The third generation (3G) mobile communication system is grown up in order to satisfy this requirement just.It is as basic point of departure with global general-use, system synthesis, and attempt to set up the mobile comprehensive service digital network in a whole world, the function of various mobile communication system such as comprehensive honeycomb, wireless, paging, cluster, mobile data, mobile-satellite, aerial and sea, provide and the professional compatibility of fixed telecommunication network, multiple speech and the non-speech service that quality is suitable, carry out the global roaming of pocket personal terminal, thus realize human dream of anywhere, any time and anyone ideal that communicates.
That most critical is radio transmission techniques (RTT) in the 3-G (Generation Three mobile communication system).The RTT candidate motion that International Telecommunications Union in 1998 collects: except that 6 satellite interface technical schemes, the terrestrial wireless interfacing has 10 schemes, is divided into two big class: CDMA and TDMA, and wherein CDMA occupies an leading position.In CDMA technology, International Telecommunications Union has accepted 3 kinds of standards at present altogether, i.e. the TD-SCDMA standard of the CDMA 2000 of the W-CDMA of Europe and Japan, the U.S. and China.
Compare with other 3G (Third Generation) Moblie standard, TD-SCDMA has adopted many exclusive advanced technologies, and all has outstanding advantage aspect the technology, economic two.TD-SCDMA adopts time division duplex (Time Division Duplex, TDD), smart antenna (Smart Antenna), joint-detection technology such as (JointDetection), availability of frequency spectrum height, can solve the problem of high population density area frequency resource anxiety, and have potential advantages aspect the multimedia services such as asymmetric mobile data such as internet browsing and video request program.
With other cdma systems with the same, TD-SCDMA also is a kind of CDMA multi-user mobile system, a plurality of users carry out message transmission by different binary code sequences by the mode of spread spectrum under same frequency, any one user's information transmits and all can cause interference to other users like this, all is a kind of noise jamming concerning other users.Therefore each user's information delivering power will accomplish all promptly to guarantee that quality that own information transmits reduces the interference to other users again as far as possible, and power control, rate-matched and discontinuous emission (DTX) technology that TD-SCDMA adopts have been made contribution for these purposes.
According to 3GPP standard TS 25.221 (Release 4) and the relevant definition of TS 25.224 (Release 4), in the TD-SCDMA system:
Use rate-matched to fill up Resource Unit fully, because have only partially filled data sometimes.Execute rate-matched and multiplexing after, if do not launch any data in a Resource Unit, then this Resource Unit fully from the emission abandon, unless special burst (Special Bursts) will send in this Resource Unit.This has been for only having distributed a Resource Unit, and also is suitable for without any the situation that data need be launched.
The time slot format of special burst is identical with the high-rise employed burst of data that provides.Special burst is filled with any bit mode, indicate (TFCI) and power control command (TPC) bit if use inner loop power control then comprise transformat combination, and be defined as on the physical channel that carries TFCI at the emission separately of each coded combination transmission channel (CCTrCH).The TFCI of special burst fills up with bit " 0 ".The transmitting power of special burst is identical with the power of the physical channel of the coded combination transmission channel (CCTrCH) of replaced carrying TFCI.
When high level after the link establishment does not have transmission block to offer any given CCTrCH to be used to launch, need be in the frame of first distribution of cut-off of injection special burst of emission.Comprise first frame, if arranged the continuous period of special burst period (SBP), the transport module that does not wherein have high level to provide then needs to generate another special burst, and launches in the possible frame of the next one.This pattern must last till high-rise for till CCTrCH provides transport module.Special burst period (SBP) need be provided by high level.
Closed power control utilizes the TPC symbol of layer 1.In the dynamic range of 80dB altogether, power control step-size can value 1,2,3dB.The network side Initial Trans of signaling terminal up channel.
Closed power control can be carried out based on signal interference ratio (SIR).Base station side need be estimated the up channel signal interference ratio SIRest that receives.Then, the base station generates by following rule and emission TPC order: if SIRest>SIRtarget, the TPC that then will launch order is set to " down "; If SIRest<SIRtarget, the TPC that then will launch order is set to " up "; Wherein, SIRtarget is the target signal interference ratio.
At user terminal, when the TPC order judgement of receiving was " down ", mobile terminal emitting power reduced a power control step-size; And if the TPC order is adjudicated when being " up ", power control step-size of mobile terminal emitting power rising.A high-rise outer shroud is adjusted target signal interference ratio (SIR).This scheme can realize the power control based on quality.
When under the situation that does not have relevant upstream data emission between two corresponding downstream TPC orders, user terminal should be ignored the TPC order that receives.The transmitting power that next time slot/CCTrCH is right should use open loop control to be provided with as initial transmission.
After the process rate-matched, the Resource Unit that is not filled will not be launched.This means that if user terminal has been assigned with the resource of a plurality of time slots, and the data transfer rate of actual transmissions will cause having only the part time slot to be launched, and other time slots is not launched when very low, then these time slots that are not launched just are in discontinuous emitting state.
In a plurality of time slots that are assigned with, the process of having only the part time slot to be launched is called the discontinuous emission of part (Partial DTX); And then will there be data transmission fully and the process of the time-out that causes launching or emission special burst (Special Bursts) is called complete discontinuous emission (Full DTX).
As shown in Figure 1, be the example of a typical cell mobile communication systems.This system is by a plurality of sub-districts 100
1-100
N(100) constitute, a base station (Base Station) 101 is wherein respectively arranged in each sub-district
1-101
N(101), the subscriber terminal equipment (User Equipment is abbreviated as UE) 102 that in this sub-district service range, has some simultaneously
1-102
K(102).Each subscriber terminal equipment 102 by with affiliated Serving cell 100 in base station 101 keep being connected, finish and other communication equipment between communication function.The channel that communicates between subscriber terminal equipment 102 and the base station 101, its direction no matter be from terminal equipment 102 to the base station 101 or from the base station 101 to terminal equipment 102, all may work in discontinuous emission (DTX) state, the former is called as up discontinuous emission, and the latter is called as descending discontinuous emission.
As shown in Figure 2, be the frame structure schematic diagram of TD-SCDMA system.This structure is according to providing in low spreading rate time division duplex (LCR-TDD) pattern (1.28Mcps) among 3G collaborative project (3GPP) the standard TS 25.221 (Release 4).The spreading rate of TD-SCDMA system is 1.28Mcps, and the length of each radio frames (Radio Frame) 200 is 10ms, and is divided into two subframes 201 that structure is identical
0, 201
1(201), the length of each subframe is 5ms, i.e. 6400 chips.Wherein, the subframe 201 in each TD-SCDMA system can be divided into 7 time slots again (TS0~TS6) 202
0-202
6, two pilot time slots: descending pilot frequency time slot (DwPTS) 203 and uplink pilot time slot (UpPTS) 205, and protection interval (Guard) 204.Further, the TS0 time slot 202
0Be used to bearing system broadcast channel and other possible downlink traffic channel; And TS1~TS6 time slot 202
1-202
6Then be used to carry the uplink and downlink Traffic Channel.It is synchronous that uplink pilot time slot (UpPTS) 205 and descending pilot frequency time slot DwPTS time slot 203 are used to set up initial uplink and downlink respectively.TS0~TS6 time slot 202
0-202
6Length is 0.675ms or 864 chips, wherein comprise data segment Data Part1 (208) and Data Part2 (210) that two segment lengths are 352 chips, and a middle segment length is the training sequence of 144 chips---in lead sign indicating number (Midamble) sequence 209.The Midamble sequence is significant at TD-SCDMA, comprise cell ID, channel estimating and synchronously modules such as (comprising Frequency Synchronization) all to use it.The protection that DwPTS time slot 203 comprises 32 chips at interval 211 and one long be descending synchronous code (SYNC-DL) code word 206 of 64 chips, its effect is cell ID and sets up initial synchronisation; And the UpPTS time slot comprise one long be uplink synchronous code (SYNC-UL) code word 207 of 128 chips, subscriber terminal equipment utilizes it to carry out relevant up access procedure.At TS1~TS6 time slot 202
1-202
6Between a Switching Point (transfer point) 212 is arranged.When the up-downgoing ratio was 3: 3, Switching Point (transfer point) 212 was positioned at TS3~TS4 time slot 202
3-202
4Between, at this moment, the employed up Dedicated Traffic Channel of user terminal is dispensed on TS1~TS3 time slot 202
1-202
3In, the descending TS4~TS6 time slot 202 that then is distributed in usually
4-202
6In.
The method of power control is one of emphasis in the TD-SCDMA system design.On the one hand, because even subscriber terminal equipment will guarantee to face more abominable channel circumstance, for example, when the user is in cell edge or is in the shadow region, information between it and the base station also will be transmitted reliably, therefore requires base station and user terminal will adopt sufficiently high power to launch; On the other hand, in order to reduce interference,, require base station and user terminal to adopt the little power of trying one's best, launch less as far as possible again in order to save the energy to other users or other sub-districts.Especially, even under the state of complete discontinuous emission and the discontinuous emission of part, also require rapid and reliable power control.
As shown in Figure 3, S+1 radio frames 300 arranged
0-300
S, its System Frame Number (SFN) is from 0 to S, and each radio frames 300 is divided into two subframes 301 again, and its subframe numbers is respectively 0 and 1; Suppose descendingly to have sent two TPC symbols in each subframe 301, the TPC command sequence number 302 that receives in a subframe is respectively 0 and 1; And an ascending time slot is being controlled in these two TPC orders respectively, and controlled ascending time slot sequence number 303 is made as 0 and 1 respectively, and these two time slots are assigned to same user terminal.Through after the rate-matched, be not all necessarily emissions of ascending time slot in the subframe, when real data quantity is very low, will there be the part time slot not launch, in Fig. 3, indicate the ascending time slot of actual transmission with transmit identification 304.System frame number SFN is from 0 to S 300
0-300
SPairing sequence of time slots is 305
0-300
4S+3As seen from Figure 3, from system-frame No. 1 300
1Beginning, controlled ascending time slot sequence number 303 are that 1 time slot is launched, and last till System Frame Number S 300 always
SRecover, controlled ascending time slot sequence number 303 is that 0 time slot then is in emission state always; Therefore, this is the situation of the discontinuous emission of part (PartialDTX).
For sake of convenience, in distributing to a plurality of time slots of user terminal, first time slot is defined as main time slot, other all time slots are defined as auxilliary time slot.With Fig. 3 is example, the time slot that the controlled ascending time slot sequence number 303 of main time slot equals 0, and other time slots both had been auxilliary time slot.
In the prior art, power control on each time slot is independently carried out, under the situation that does not have relevant upstream data emission between two corresponding downstream TPC orders, user terminal should be ignored the TPC order that receives, and uses open Loop Power control when recovering emission.With Fig. 3 is example, and system-frame S numbers 300
S Subframe numbers 301 is 0 o'clock, controlled ascending time slot 305
4S+1Transmitting power use open loop to be provided with, and controlled ascending time slot 305
4STransmitting power then be provided with by closed-loop control.This means, belong to two time slots of same user terminal, main time slot adopts closed loop, and auxilliary time slot adopts open Loop Power control.Obviously, effective TPC command information of main time slot is not made full use of by auxilliary time slot.Press the design of existing system, even System Frame Number S 300
SJust be slightly larger than 1, that is the just lasting several frames of the discontinuous emission of part (PartialDTX) state, when launching, the auxilliary time slot recovery of discontinuous emission also to take open loop approach that power is set, and this can bring bigger power fluctuation undoubtedly.On the other hand, because the TPC order of the auxilliary time slot of control this moment is invalid, auxilliary time slot also can be adjusted power according to the TPC order of main time slot fully, but this can lose the independence of power control between the time slot again.Especially under the long-term situation of the discontinuous emission of part (Partial DTX), auxilliary time slot is adjusted power according to the power control mode of main time slot fully, the situation that the set transmitting power of portable terminal can not actually satisfy the power requirement of this time slot can occur.
Under discontinuous emission (Partial DTX) situation, how both having utilized the effective power control command information of main time slot fully, and guaranteed the independence of power control between each time slot again, is one of subject matter that is faced.
Summary of the invention
The objective of the invention is to, the method for power control under a kind of discontinuous emitting state is provided, be used for TDS-CDMA system base station down part; Can be when making full use of effective power control information of main time slot, take into account power and be controlled at independence on each time slot; And can choose different parameters and adjust the effect that these two factors are played in power control, make the present invention have stronger adaptability, reach the purpose of the power control of flexibility and reliability more.
For reaching above-mentioned purpose, the invention provides the method for power control under a kind of discontinuous emitting state, be used for TDS-CDMA system base station down part; This method mainly comprises following steps:
Step 1, by the regulation of standard, current business is distributed to M descending time slot/CCTrCH in the frame of base station to Initial Trans P is set
i, wherein, i=1,2 ..., M; If M is greater than 1, it is M-1 that a length then is set, and all elements value is 1 one-dimension array S;
Step 2, according to the power emission downstream signal that is provided with, and note down each descending time slot whether the emission data arranged;
Step 3, judge whether the descending main time slot of current subframe launches data:
If not, then press code requirement and carry out the DTX flow process: press the physical channel emission special burst of code requirement in the minimum sequence number of main time slot, and when recovering the emission data, carry out the open Loop Power control process, promptly adopt open loop approach that the power of each descending time slot/CCTrCH when recovering emission is set; And return step 2;
If then receive and resolve the up TPC order of corresponding time slot correspondence, and be stored in C
i, wherein, i=1,2 ..., M; If the TPC order then makes C for " up "
i=1, if the TPC order then makes C for " down "
i=-1;
Step 4, press the transmitting power P of next subframe of closed power control setting master time slot
1If corresponding up TPC order is " up ", the transmitting power of then main next subframe of time slot increases the power control step-size TPC_Stepsize of a system configuration, if corresponding up TPC order is " down ", the transmitting power of then main next subframe of time slot reduces the power control step-size TPC_Stepsize of a system configuration, that is: P
1=P
1+ C
1* TPC_Stepsize;
Step 5, judge whether to exist auxilliary time slot, judge that promptly whether M is greater than 1:
If not, then show not have auxilliary time slot, return execution in step two;
If, then show to have auxilliary time slot, j=1 is set;
Step 6, judge whether j auxilliary time slot launches data:
If step 6.A shows that promptly this time slot of having launched data is not in the part discontinuous emitting state, press the closed power control procedure, the transmitting power of this auxilliary time slot in next subframe is set, that is: P
1+j=P
1+j+ C
1+j* TPC_Stepsize; And S is set
j=1;
Step 6.B, if not, show that promptly this auxilliary time slot of not launching data is in the part discontinuous emitting state, the effective power control command factor that receives according to current transmit power, open Loop Power control and the main time slot of current auxilliary time slot is provided with the transmitting power of current auxilliary time slot in next subframe; It is short more that current auxilliary time slot is in the time of part discontinuous emitting state, and the influence that the adjustment of its next subframe transmitting power is subjected to main time slot power control command is big more, and the influence that is subjected to open Loop Power control is more little; It is long more that current auxilliary time slot is in time of part discontinuous emitting state, and it is more little that the adjustment of its next subframe transmitting power is subjected to the influence of main time slot power control command, and the influence that is subjected to open Loop Power control is big more;
Step 7, j=j+1 is set, and whether judges j+1, if not, then return execution in step six greater than M; If then return execution in step two.
Described step 6.B specifically comprises following steps:
Step 6.B.1, the acquisition open loop transmit power P_Open that top signaling disposed;
Step 6.B.2, basis should be assisted the current transmit power P of time slot
1+j, the effective power control command C that receives of open loop power parameter P_Open and main time slot
1, the transmitting power of this auxilliary time slot in next subframe is set, that is: P
1+j=S
j* (P
1+j+ C
1* TPC_Stepsize)+(1-S
j) * P_Open.
Wherein, after step 6.B.2, further also comprise step 6.B.3: the time length that is in the part discontinuous emitting state according to current auxilliary time slot is provided with S
j, dynamically adjust open loop power parameter and main time slot power control command weight proportion in real time to the influence of the whole transmitting power of current auxilliary time slot next son.
Among the described step 6.B.3, S is set
jMethod can be: S
j=S
j* R, wherein, the span of R is [0,1].
Further, when auxilliary number of time slot has at least 2 time slots to be under the situation of continuous emission state in greater than " descending time slot/CCTrCH to " in 1 and frame, among the described step 6.B.2, but also on the reference time the effective TPC of the most controlled time slot of close this time slot order the transmitting power of this time slot in next subframe be set, but not only with reference to the TPC order of main time slot.That is to say, among the above-mentioned step 6.B.2, when judgement obtains the current auxilliary time slot of not launching data and is in the part discontinuous emitting state, also the transmitting power of this time slot in next subframe: P can followingly be set
1+j=S
j* (P
1+j+ C
t* TPC_Stepsize)+(1-S
j) * P_Open, and S is set
j=S
j* R, wherein, the span of t is 1≤t<1+j, C
tExpression is the most close current auxilliary time slot in time, and the time slot of emission data is arranged.
Wherein, after step 6.B.2, further also comprise step 6.B.3: the time length that is in the part discontinuous emitting state according to current auxilliary time slot is provided with S
j, adjust in real time dynamically the open loop power parameter and on the time the effective power control command of the most controlled time slot of close current auxilliary time slot to the weight proportion of the influence of the whole transmitting power of current auxilliary time slot next son.
Among the described step 6.B.3, S is set
jMethod can be: S
j=S
j* R, wherein, the span of R is [0,1].
The method that is used for the power control under the part discontinuous emitting state of TD-SCDMA system base station equipment that realizes according to the present invention, simply, be easy to realize, not only make full use of the effective closed power control information that obtains at main time slot, also guaranteed the relative independentability of each time slot power control.Not only avoided auxilliary time slot power than great fluctuation process, also reduced simultaneously interference to other users.
Description of drawings
Fig. 1 is the rough schematic of typical cell mobile communication systems in the background technology.
Fig. 2 is the frame structure schematic diagram of TD-SCDMA system in the background technology.
Fig. 3 is the schematic diagram of the timeslice in the background technology.
Fig. 4 is applied in the TD-SCDMA system flow chart of Poewr control method under the part discontinuous emitting state for the present invention.
Embodiment
Below by Fig. 4, introduce a specific embodiment of the present invention in detail, so that further understand this
The content of invention.
As shown in Figure 4, the method for power control under a kind of discontinuous emitting state of the present invention is used for TDS-CDMA system base station down part; Comprise the steps:
Step 1, a variable R is set, its span is [0,1]; And obtain the number M that current business is distributed to " descending time slot/CCTrCH to " U in the frame of user terminal; Difference initialization array D and array C, its length all is M; Difference initializing variable i and j;
Step 2, whether judge M greater than 1, if M≤1, direct execution in step 3 then; If M>1, then execution in step 2.1: length of initialization is M-1, and the value of all elements is 1 one-dimension array S, and then execution in step 3;
Step 3, by the regulation of standard, to described M descending time slot/CCTrCH to Initial Trans P is set respectively
i, i=1 wherein, 2 ..., M-1, M;
Step 4, D is set
i=0, i=1 wherein, 2 ..., M-1, M; If descending time slot/CCTrCH is to U
iOn have data to need to send, then by the Initial Trans P that sets
iThe emission data, and accordingly with D
iBe set to 1;
Step 5, judgement D
1Whether equal 1, judge promptly whether main time slot launches data:
Step 5.1, if D
1≠ 1, then press code requirement and carry out the DTX flow process, comprising pressing the physical channel emission special burst (Special Bursts) of code requirement in minimum sequence number, and when recovering the emission data, carry out the open Loop Power control process, each descending time slot/CCTrCH returns execution in step 4 then to the power of U when promptly adopting open loop approach that the recovery emission is set;
Step 5.2, if D
1=1, then receive and resolve the up TPC order of corresponding time slot correspondence: if TPC then makes C for " up "
i=1, if TPC is " down ", then make C
i=-1;
Step 6, press the transmitting power of next subframe of closed power control setting master time slot: P
1=P
1+ C
1* TPC_Stepsize, wherein, TPC_Stepsize is the power control step-size that system disposes;
Step 7, whether judge M greater than 1, if then show to have auxilliary time slot, execution in step 7.1: j=1 is set, and execution in step 8; If not, then show not have auxilliary time slot, and return execution in step 4;
Step 8, judgement D
1+jWhether equal 1, promptly judge and should whether launch data by auxilliary time slot:
If step 8.1 shows that promptly this time slot of having launched data is not in the part discontinuous emitting state, press the closed power control procedure, the transmitting power of this time slot in next subframe is set, i.e. P
1+j=P
1+j+ C
1+j* TPC_Stepsize, and S is set
j=1;
Step 8.2, if not shows that promptly this time slot of not launching data is in the part discontinuous emitting state, at first obtains the initial open loop transmitting power P_Open of upper-layer protocol configuration; Comprehensively should assist the current transmit power P of time slot then
1+j, the effective TPC order C that receives of open loop power parameter P_Open and main time slot
1, the transmitting power of this time slot in next subframe is set, i.e. P
1+j=S
j* (P
1+j+ C
1* TPC_Stepsize)+(1-S
j) * P_Open; And S is set
j=S
j* R;
Step 9, j=j+1 is set, and whether judges j+1, if not, then return execution in step 8 greater than M; If then return execution in step 4.
In the present embodiment, the comprehensive transmitting power that next subframe of the auxilliary time slot that is in the part discontinuous emitting state is set of effective TPC order that receives according to auxilliary time slot current transmit power, open loop power parameter and main time slot; This time slot is short more if be in time of part discontinuous emitting state, and then to be subjected to the influence of main time slot TPC order just big more in the adjustment of its next subframe power, and it is just more little to be subjected to the influence of open Loop Power control; If it is long more that this time slot is in time of part discontinuous emitting state, it is just more little that then the adjustment of its next subframe power is subjected to the influence of main time slot TPC order, and it is just big more to be subjected to the influence of open Loop Power control.Therefore in the step 8 of present embodiment, parameter S j is used to adjust the weight proportion of open loop parameter and main time slot TPC command affects, and along with current time slots is in the prolongation of part discontinuous emitting state time and changes.
In addition, when auxilliary number of time slot has at least 2 time slots to be under the situation of continuous emission state in greater than " descending time slot/CCTrCH to " U in 1 and frame, but also on the reference time the effective TPC of the most controlled time slot of close this time slot order the transmitting power of this time slot in next subframe be set, but not only with reference to the TPC order of main time slot.That is to say that the step 8.2 in the foregoing description also can followingly be provided with the transmitting power of this time slot in next subframe: P
1+j=S
j* (P
1+j+ C
t* TPC_Stepsize)+(1-S
j) * P_Open, and S is set
j=S
j* R, wherein, the span of t is 1≤t<1+j, and at D
tGet the maximum of t under=1 the condition.
The method that is used for the power control under the part discontinuous emitting state of TD-SCDMA system base station equipment that realizes according to the present invention, simply, be easy to realize, not only make full use of the effective closed power control information that obtains at main time slot, also guaranteed the relative independentability of each time slot power control.Not only avoided auxilliary time slot power than great fluctuation process, also reduced interference to other users.
Though above described the present invention by embodiment, those of ordinary skills know, the present invention has many distortion and variation and does not break away from spirit of the present invention, appended claim will comprise these distortion and variation.