CN100372258C - Determination method of reference power in downlink power balance technology in the case of soft hand-off - Google Patents
Determination method of reference power in downlink power balance technology in the case of soft hand-off Download PDFInfo
- Publication number
- CN100372258C CN100372258C CNB038262010A CN03826201A CN100372258C CN 100372258 C CN100372258 C CN 100372258C CN B038262010 A CNB038262010 A CN B038262010A CN 03826201 A CN03826201 A CN 03826201A CN 100372258 C CN100372258 C CN 100372258C
- Authority
- CN
- China
- Prior art keywords
- node
- power
- downlink
- soft handover
- cpich
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000000034 method Methods 0.000 title claims abstract description 47
- 238000005516 engineering process Methods 0.000 title description 6
- 238000005259 measurement Methods 0.000 claims abstract description 25
- 230000005540 biological transmission Effects 0.000 claims description 16
- 238000010586 diagram Methods 0.000 description 8
- 238000004364 calculation method Methods 0.000 description 4
- 238000004891 communication Methods 0.000 description 4
- 238000012937 correction Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 2
- 230000011664 signaling Effects 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 1
- 101000802640 Homo sapiens Lactosylceramide 4-alpha-galactosyltransferase Proteins 0.000 description 1
- 102100035838 Lactosylceramide 4-alpha-galactosyltransferase Human genes 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- GVVPGTZRZFNKDS-JXMROGBWSA-N geranyl diphosphate Chemical compound CC(C)=CCC\C(C)=C\CO[P@](O)(=O)OP(O)(O)=O GVVPGTZRZFNKDS-JXMROGBWSA-N 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/06—TPC algorithms
- H04W52/12—Outer and inner loops
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/16—Performing reselection for specific purposes
- H04W36/18—Performing reselection for specific purposes for allowing seamless reselection, e.g. soft reselection
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/38—TPC being performed in particular situations
- H04W52/386—TPC being performed in particular situations centralized, e.g. when the radio network controller or equivalent takes part in the power control
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/38—TPC being performed in particular situations
- H04W52/40—TPC being performed in particular situations during macro-diversity or soft handoff
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W48/00—Access restriction; Network selection; Access point selection
- H04W48/16—Discovering, processing access restriction or access information
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/08—Access point devices
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/12—Access point controller devices
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
The present invention discloses a method for determining downlink reference power under soft handoff condition, which comprises the following steps: the first step, a radio network controller RNC obtains transmitting code power and a measurement parameter used for reflecting the size of relative path loss from a plurality of nodes B participating in the soft handoff of user equipment UE; the second step, the RNC utilizes an obtained result to determine the downlink reference power P<ref><i> allocated to the UE by the i node B under the condition that the current total received power of the UE remains unchanged. The present invention also discloses a corresponding device for determining the downlink reference power under the soft handoff condition.
Description
Technical Field
The present invention relates to Code Division Multiple Access (CDMA) communication systems, and more particularly, to a method and system for determining reference power in downlink power balancing technology in a CDMA system under soft handoff.
Background
In a CDMA communication system, the capacity and coverage performance of the system is highly dependent on the interference experienced by the users. Among them, the power control technique has become a key technique of the CDMA communication system as an effective means for reducing the inter-channel interference. In practical CDMA systems, closed loop power control is the primary means of power control, and typically consists of an inner and an outer loop.
Fig. 1 shows a schematic diagram of downlink inner loop power control in the prior art. The inner loop power control receiving end obtains an estimated value of signal-to-interference ratio (SIR) by measuring a received signal, compares the estimated value with an SIR target value obtained by outer loop power control to generate a power control command for transmitting power of the transmitting end, transmits the command to the transmitting end through a reverse channel, and increases or decreases the current transmitting power according to the command and a certain adjustment step length. Thus, inner loop power control is a feedback type power control technique. The outer loop power control is responsible for generating the required target SIR for the inner loop power control by adjusting the SIR target value to track changes in the radio channel environment, thereby maintaining the quality of service (QoS) agreed by the system at the time of service establishment.
Inner loop power control is applicable to both the uplink and downlink. Hereinafter, an inner loop power control procedure of a downlink will be described by taking a Wideband Code Division Multiple Access (WCDMA) system of the third generation partnership project (3 GPP) as an example.
In WCDMA systems, downlink closed loop power control is mainly applied to the downlink Dedicated Physical Channel (DPCH). In the uplink Dedicated Physical Control Channel (DPCCH), there is a Transmit Power Control (TPC) field that conveys power control commands generated by the mobile station (i.e., user equipment UE) to the downlink DPCH channel transmitted by the base station (i.e., node B). TPC =1 if the node B is required to increase the downlink transmit power, and TPC =0 if the node B is required to decrease the downlink transmit power.
In a specific implementation, the execution of the downlink inner loop power control commands is typically done by node B. According to the 3GPP protocol TS25.214, first, the node B receives the uplink DPCCH channel from the UE and estimates the TPC commands. Then, the current transmission power P (k-1) is updated according to the following formula:
P(k)＝P(k-1)+P TPC (k)+P bal (k) (1)
wherein each parameter is expressed in decibels (dB), P TPC (k) If Δ is ordered, the inner loop power adjustment amount generated according to the TPC command TPC For the step size adjustment of the inner loop power control, P is the power increase limit when there is no power increase TPC (k) Calculated as follows:
p in formula (1) bal (k) To prevent the amount of correction of downlink power drift in soft handover situations. To clarify the reason for the correction amount, the following is directed to the macro diversity technique in soft handover in CDMA system and soft handoverThe problem of downlink power drift in the case will be explained.
An important technical feature unique to CDMA systems is the support of soft handover, i.e. the mobile station does not immediately interrupt the radio link with the original node B when it starts to establish a new radio link with a target node B during handover, i.e. the mobile station is able to maintain communication with two or more node bs simultaneously. Fig. 2 shows a schematic diagram of a soft handover of a WCDMA system, where node bs are controlled by a Radio Network Controller (RNC) and a UE communicates with two node bs simultaneously. Here, only two node bs are depicted for convenience of illustration, but in practice there may be more.
The uplink and downlink signals are received in soft handoff by using macro diversity technique specific to soft handoff, and the resulting soft handoff gain can improve the performance of coverage and capacity of CDMA network. As shown in fig. 2, in the downlink direction, the UE may perform maximum ratio combining on downlink signals from different node bs. In the uplink direction, each node B separately processes the same uplink signal received from the UE, and the data frames after channel decoding are finally sent to the RNC for further combining, where a selective combining method is usually adopted.
Although the uplink data frames can be macro-diversity combined in the RNC, the TPC fields of the uplink DPCCH are individually detected by the node bs and applied to the respective inner-loop power control units, and cannot be combined by the RNC. Otherwise, the inner loop power control will generate a great delay, and the control rate and tracking performance of the inner loop power control will be greatly reduced. Thus, the reception of downlink power control commands does not have the soft handoff gain created by macro diversity. Thus, although there is only one downlink power control command generated by the UE, since the signals arriving at different base stations on the uplink DPCCH channel carrying the command take different paths, they have different SIRs, and since no soft handover gain is available, the reliability of the power control bits TPC is less than that of the data bits. Therefore, each node B may have a certain error in decoding the downlink power control command, and the error may occur differently. One possible scenario is: one base station reduces the transmit power to a UE while another base station increases the transmit power to the UE. That is, during soft handover, downlink power drift occurs in the downlink due to erroneous decoding of downlink power control commands by different base stations.
Downlink power drift is unacceptable because it greatly reduces the performance of downlink soft handoff. To compensate for the effect of power drift, it is common practice to add a power balance adjustment loop to the inner loop power control, which is also used in WCDMA, and the correction P in equation (1) bal (k) It is based on this technology introduction. In the 3GPP Standard TS25.433 and in the document TSGR1-01-0197, P is given bal (k) The conditions to be satisfied are:
the sum on the left side in equation (3) represents the total power balance adjustment amount, P, during an adjustment period ref Is the downlink reference power, P init Is the initial value of the downlink power at the beginning of the adjustment period, and r is a convergence factor between 0 and 1, which is used to control the proportion of the total power adjustment in each adjustment period. Parameter adjustment period, P, in equation (3) ref And r is transmitted by the RNC to the node B via a signalling path NBAP (node B application part) between the RNC and the node B. Where the adjustment period and r are generally relatively fixed parameters taken empirically, and P is ref Are calculated by the RNC based on the dedicated measurements of the node B. And P ref The specific measurements for calculating the relevant node B mainly include SIR and transmitted code power, and the protocols of TS25.433, TS25.215 and TS25.133 of 3GPP can be referred to for the specific measurements for the node B.
Patent application WO02/25836 to "Downlink Power control in cellular Telecommunications networkA node B determines the correction amount P of the power balance adjustment loop by using the parameter provided by the RNC under the condition of satisfying the formula (3) bal (k) The method of (1). Meanwhile, patent application WO01/71941 "determination of reference power level in diversity handover base station" gives a downlink reference power P ref The method of (3). The downlink reference power P proposed in patent application WO01/71941, among others ref The calculation method of (2) is summarized to take the downlink reference power as the average of the sum of the average transmitted code powers of all base stations, or the average transmitted code power of the leading base station (the base station with the largest uplink received signal SIR).
The following problems exist with the aforementioned downlink reference power calculation method: the result of the downlink power balance adjustment loop is to make the average value of the downlink power of each base station tend to the downlink reference power, thereby changing the distribution ratio of the current base station transmitting power. Thus, even if the total transmission power of each base station is controlled by the inner-loop power before the power balance adjustment to satisfy the reception SIR requirement of the mobile station, since the calculation of the downlink reference power in the related art does not take into account the fact that the downlink path loss of each base station to the mobile station is different, it is difficult for the total transmission power after the adjustment to satisfy the reception SIR requirement of the mobile station. That is, the unreasonable downlink reference power may cause the power balance adjustment loop to adversely affect the inner loop power control, thereby degrading the tracking performance of the downlink inner loop power control.
On the other hand, patent applications WO01/47145 and US6104933, etc. relate to methods for allocating downlink transmit power in soft handover. They all propose an allocation scheme for optimizing the downlink transmission power of each base station in soft handover, which is inversely proportional to the downlink path loss, i.e. a base station with larger downlink path loss should allocate less power, and a base station with smaller downlink path loss should allocate more power under the condition of ensuring the same mobile station receiving rate. Therefore, the total downlink transmitting power can be minimized, thereby reducing the interference to other channels and being beneficial to increasing the channel capacity.
As can be seen from the above-mentioned downlink transmission power optimization allocation scheme, the prior art does not consider the optimized downlink reference power allocation in determining the downlink reference power, and uses the same downlink reference power, as a result, each base station tends to transmit the same power, which is also disadvantageous.
Disclosure of Invention
In order to overcome the above problems, the present invention provides a method for determining a reference power in a downlink power balancing technique under an effective soft handover condition.
The method for determining the downlink reference power in the soft handover condition comprises the following steps: a first step in which a radio network controller RNC obtains transmission code power from a plurality of node Bs involved in soft handover of a user equipment UE and obtains measurement parameters reflecting the magnitude of relative path loss; and a second step in which the RNC uses the obtained result to determine the downlink reference power P allocated to the UE by the ith node B under the condition that the current total received power of the UE remains unchanged ref i 。
The method of the invention considers the current total receiving power value of the UE to be switched, and determines the downlink reference power under the premise of keeping the value unchanged, thereby not influencing the inner loop power control balance of the UE.
In a preferred embodiment of the present invention, the downlink reference power P allocated to the UE by the ith node B is determined by the following equation in consideration of the optimized downlink reference power allocation scheme ref i ：
Where m denotes a node B participating in soft handoverNumber, L j Indicating the average downlink loss from the jth node to the UE. The parameter α is introduced here i (indicating the downlink power ratio of the ith node B allocated by the RNC relative to the 1 st node B) enables each node B to allocate downlink reference power at different ratios. When alpha is i When the values of all the node Bs participating in the soft handover are 1, the adopted mode is still the traditional equal-power distribution mode. If make alpha i The values of different node Bs are different, then the value can pass through alpha i To achieve an optimized downlink reference power allocation scheme.
According to still another preferred embodiment of the present invention, the downlink reference power P allocated to the UE by the ith node is determined by ref i ：
Wherein the SIR j Indicating the SIR of any one node B. The measured SIR of the node B is preferably used here j To replace the measured value L of the UE j The reason for this is that the measurement report of the node B does not occupy radio channel resources compared to the measurement of the UE, and the problem that it is difficult to keep the UE and the node B measurement values consistent in time is avoided.
The present invention also provides an apparatus for determining a downlink reference power in a soft handover situation, comprising: obtaining means for obtaining a first step of transmitting code power from a plurality of node Bs involved in a soft handover of a user equipment UE and obtaining means for reflecting relativeA measurement parameter of the path loss magnitude; and determining means for determining the downlink reference power P allocated to the UE by the ith node B under the condition that the current total received power of the UE remains unchanged according to the result obtained by the obtaining means ref i 。
Drawings
The above and other advantages of the present invention will become more apparent by describing in detail preferred embodiments of the present invention with reference to the attached drawings. In the drawings:
FIG. 1 is a schematic diagram of a downlink inner loop power control in the prior art;
FIG. 2 is a schematic diagram of a soft handover procedure;
FIG. 3 is a block diagram of a method according to the invention;
FIG. 4 is a block diagram of a system according to the present invention;
fig. 5 is a detailed representation of the method shown in fig. 3.
Detailed Description
Fig. 3 is a block diagram of a method according to the invention. As mentioned previously, the downlink reference power P ref Is determined by the RNC based on node B specific measurements. In step 302, the RNC may request each node B involved in the soft handover to report the respective transmit code power. At the same time, the RNC may control the node B to perform a predetermined smoothing filtering process before the measurement report, or may perform further averaging and other processes on the measurement report result in the RNC, so that the obtained power value may be used as an estimated value of the current downlink transmission code power of the node B.
In addition, the RNC also needs to obtain measurement parameters reflecting the relative magnitude of the downlink path loss. It will be appreciated by those skilled in the art that these measured parameters may be varied and obtained in a variety of ways, for example, by direct measurement or by conversion with other values. The measurement parameter may include (but is not limited to) UE measured received signal code power RSCP of common pilot channel CPICH CPICH，i UE measured downlink path loss, or received signals measured by each of the node BsSIR。
Next, in step 304, the RNC determines the downlink reference power allocated by each node B under the condition that the current total received power of the UE remains unchanged, so as to be used for obtaining the power balance adjustment amount subsequently.
Fig. 4 illustrates in detail a block diagram of an arrangement according to the invention. The RNC includes an acquiring means for acquiring the transmission code power reported by each node B and acquiring the aforementioned measurement parameter reflecting the relative magnitude of the downlink path loss, and a determining means for determining the downlink reference power allocated to the UE by each node B in case that the current total received power of the UE remains unchanged, so as to be used in the subsequent power balance adjustment loop. It should be understood that the lines shown in fig. 4 represent logical connections only.
Hereinafter, the principle of the method according to the present invention will be described in detail.
First, for the sake of analysis, all power-related parameters below are represented by a linear expression. It will be appreciated by those skilled in the art that the present invention is not limited to linear representations and is equally applicable where other representations are used, such as logarithmic.
If there are m node Bs in soft handover connection with the UE, the estimation value of the current downlink transmission code power of each node B can be represented as P i TX Average path loss of downlink from each node B to the UE is L i Then the total power P currently received by the UE total RX Comprises the following steps:
as mentioned above, the result of the downlink power balance adjustment loop is to make the average value of the downlink power of each node B tend to the downlink reference power, so that the downlink power of each node B when the downlink power balance adjustment loop converges, i.e. the downlink reference transmission power P of each node B set by RNC ref i The following equation should be satisfied:
it can be seen that equation (5 a) indicates that the total power received by the UE after the downlink power balance adjustment should be kept unchanged, so that the downlink power balance adjustment loop does not affect the inner loop power control. In the formula (5 b), α i The ratio of the downlink reference power of the ith node B allocated to the RNC to the downlink reference power of one first node B. It should be noted that the first node B may be determined to be any node B involved in the soft handover procedure. Note that the method of allocating downlink power in soft handover is not limited here. The downlink reference transmit power for each node B can be found from the above equation:
if reference is made to the node B downlink transmission power schemes in the case of soft handover as proposed in patent application WO01/47145 and patent US6104933, etc., it is advisable:
at this time, the downlink reference transmit power of each node B is:
if according to the usual equal power distribution, take alpha i =1,2,... M, then each node B downlink reference transmit power is:
here, the average path loss L of the downlink from the ith node B to the UE i Is unknownThe compound (2) can be obtained by the following two methods. One method is to calculate by the following formula:
in the formula, P CPICH，i TX RSCP for each node B common pilot channel CPICH downlink transmit power CPICH，i The corresponding CPICH received signal code power measured for the UE. The calculation of this equation can be done by the UE, which obtains the known P from the cell broadcast CPICH，i TX (ii) a Or calculated by RNC, when UE directly reports RSCP CPICH，i Measured value of, P CPICH，i TX Is a known quantity for the RNC.
On the other hand, different node bs receive the same uplink signal from the UE in the uplink direction. Therefore, the ratio of the uplink average path loss is the ratio of the uplink received code power of each node B. Although the uplink received code power is not the node B measurement specified in the standard, if the difference in uplink interference level between the node bs is ignored, the ratio of the uplink average pathloss can be approximated by the ratio of the uplink received signal SIR. Meanwhile, in the frequency division duplex WCDMA system, the uplink and downlink wireless links have approximately equal average path loss because the carrier frequencies are closer and experience the same spatial propagation path. Thus, the ratio of the downlink average path loss can be expressed as:
using the result, the downlink reference transmission power of each node B shown in equation (6) is:
here measured SIR using node B is compared to measured RSCP using UE CPICH，i Better, because the measurement report of the node B does not occupy unlimited channel resources compared with the measurement report of the UE, and the problem that it is difficult to keep the UE and the node B measurement values consistent in time is avoided.
Similarly, if referring to the node B downlink transmit power schemes in soft handover situations proposed in patent application WO01/47145 and patent US6104933, etc., the node B downlink reference transmit power shown in equation (8) can be calculated by the following equation:
if the power is allocated normally, the downlink of each node B is referred to the transmission power as shown in equation (9):
fig. 5 describes in detail a method for determining reference power in the downlink power balancing technology under the soft handover condition proposed by the present invention. As shown, when the UE is in a soft handover state, the RNC obtains parameters required to determine downlink reference power of each node B in step 502. According to one embodiment, the RNC may instruct the node bs involved in the UE soft handover to measure and report the received signal SIR and the transmitted code power in a certain manner (e.g., typically repeated at a certain period) through dedicated measurement signaling of the NBAP. Alternatively, the RNC can obtain transmit code power from each node B only, while the CPICH received signal code power RSCP is obtained from the UE CPICH，i Or downlink path loss.
In step 504, the RNC decides whether to use a conventional equal power allocation scheme or an optimized power allocation scheme. If the decision at step 504 is "yes", the process proceeds to step 506 where the downlink reference power for each node B is determined according to the aforementioned formula (9) or (14). If the decision at step 504 is "no," the process proceeds to step 508 where the downlink reference power for each node B is determined according to the aforementioned equation (8) or (13).
Then, in step 510, the RNC transmits each parameter of the downlink power balance adjustment loop including the downlink reference power of each node B to each node B participating in the soft handover of the UE through a downlink power control command of the NBAP, and each node B performs downlink power control according to the formula (1) according to the adopted downlink power balance adjustment loop algorithm.
The preferred embodiment of the present invention has been described with reference to the WCDMA system, but it should be understood by those skilled in the art that the method for determining the reference power in the downlink power balancing technology in the case of soft handover proposed by the present invention can also be applied to other CDMA mobile communication systems applying the downlink closed loop power control, which include, but are not limited to, IS-95 systems, WCDMA systems, CDMA2000 systems, TD-SCDMA systems, etc.
The preferred embodiments given in the foregoing detailed description are for illustrative purposes only and should not be construed as limiting the invention in any way. The present invention may be implemented in software, hardware or a combination of both. Any variations and modifications of the present invention may be effected by a person skilled in the art in light of the foregoing description, and are intended to be included within the scope and spirit of the invention as defined by the appended claims.
Claims (22)
1. A method of determining a downlink reference power in a soft handover situation, comprising:
a first step in which a radio network controller RNC obtains transmission code power from a plurality of node Bs involved in soft handover of a user equipment UE and obtains a measurement parameter for reflecting a relative magnitude of a path loss; and
a second step, in which the RNC utilizes the result obtained in the first step to determine the downlink reference power P allocated to the UE by the ith node B under the condition that the current total received power of the UE is kept unchanged ref i 。
2. The method of claim 1, wherein the method further comprises the step ofThe measurement parameter for reflecting the relative magnitude of the path loss comprises at least one of the following: the UE measures the Received Signal Code Power (RSCP) of a common pilot channel (CPICH) CPICH，i Downlink loss measured by the UE and received signal SIR measured by each of the node bs.
3. The method according to claim 1 or 2, characterized in that: the second step includes determining a downlink reference power P allocated to the UE by the ith node B according to ref i ：
Where m denotes the number of node Bs involved in the soft handover, α i Denotes the downlink power ratio, L, of the i (i =1, 2.., m) th node B assigned by the RNC to the first node B j Indicating the average downlink loss, P, from any one node B participating in soft handover to the UE j TX An estimate representing the current downlink transmit code power of any one of the nodes involved in the soft handover, and wherein the first node B may be set to any one of the plurality of node bs involved in the soft handover.
4. The method according to claim 1 or 2, characterized in that: the second step includes determining a downlink reference power P allocated to the UE by the ith node B according to ref i ：
Where m denotes the number of node Bs involved in the soft handover, α i Indicating RNC allocationi (i =1, 2.. Said., m) downlink power ratios of node bs to the downlink power of the first node B, SIR j Indicating the received signal SIR, P of any node B involved in soft handover j TX An estimate representing the current downlink transmit code power of any one node involved in a soft handover, and wherein the first node B is settable to any one of a plurality of node bs involved in the soft handover.
5. The method of claim 3, wherein: average downlink loss L from the ith node B to the UE i Determined by the RNC according to:
wherein P is CPICH，i TX Represents the downlink transmission power of CPICH (common Pilot channel) of each node B known by RNC (radio network controller), wherein RSCP (received Signal Power control) CPICH，i The received signal code power of the common pilot channel CPICH measured for the UE.
6. The method of claim 3, wherein: average downlink loss L from the ith node B to the UE i Determined by the UE according to:
wherein P is CPICH，i TX Obtained by UE through cell broadcast, where RSCP CPICH，i The received signal code power of the common pilot channel CPICH measured for the UE.
7. The method of claim 3, wherein: average downlink loss L from the ith node B to the UE i Determined by the RNC according to:SIR i indicating the received signal SIR of the ith node B.
8. The method of claim 3, wherein: alpha is alpha i ＝1，i＝1，2，...，m。
9. The method of claim 3, wherein: alpha is alpha i Determined according to the following formula: 
i＝2，3，...，m，α 1 ＝1。
10. the method of claim 4, wherein: alpha is alpha i ＝1，i＝1，2，...，m。
11. The method of claim 4, wherein: alpha is alpha i Determined according to the following formula:i＝2，3，...，m，α 1 ＝1。
12. an apparatus for determining a downlink reference power in a soft handover situation, comprising:
obtaining means for obtaining a first step of transmit code power from a plurality of node bs participating in a UE soft handover and obtaining a measurement parameter reflecting a relative magnitude of path loss; and
determining means for determining the total current reception at the UE according to the result obtained by the obtaining meansDetermining the downlink reference power P allocated to the UE by the ith node B under the condition that the power is kept unchanged ref i 。
13. The apparatus according to claim 12, wherein the measurement parameter for reflecting the relative magnitude of the path loss comprises at least one of: the UE measures the received signal code power RSCP of the CPICH CPICH，i Downlink loss measured by the UE and received signal SIR measured by each of the node bs.
14. The apparatus according to claim 12 or 13, wherein: the determining means determines the downlink reference power P allocated to the UE by the ith node B according to ref i ：
Where m denotes the number of node Bs involved in the soft handover, α i Denotes the downlink power ratio, L, of the i (i =1, 2.., m) th node B assigned by the RNC to the first node B j Indicating the average downlink loss, P, from any one node B participating in soft handover to the UE j TX An estimate representing the current downlink transmit code power of any one of the nodes involved in the soft handover, and wherein the first node B may be set to any one of the plurality of node bs involved in the soft handover.
15. The apparatus of claim 12 or 13, wherein: the determining means determines the downlink reference power P allocated to the UE by the ith node B according to ref i ：
Where m denotes the number of node Bs involved in the soft handover, α i Indicates the downlink power ratio, SIR, of the i (i =1, 2.., m) th node B allocated by the RNC with respect to the downlink power of the first node B j Indicating the received signal SIR, P, of any node B involved in soft handover j TX An estimate representing the current downlink transmit code power of any one of the nodes involved in the soft handover, and wherein the first node B may be set to any one of the plurality of node bs involved in the soft handover.
16. The apparatus of claim 14, wherein: average downlink loss L from the ith node B to the UE i Determined by the RNC according to:
wherein P is CPICH，i TX Indicating the downlink transmission power of the CPICH of the common pilot channel of each node B known by the RNC, wherein RSCP CPICH，i The received signal code power of the common pilot channel CPICH measured for the UE.
17. The method of claim 14, wherein: average downlink loss L from the ith node B to the UE i Determined by the UE according to:
wherein P is CPICH，i TX Obtained by UE through cell broadcast, where RSCP CPICH，i The received signal code power of the common pilot channel CPICH measured for the UE.
18. The apparatus of claim 14, wherein: average downlink loss L from the ith node B to the UE i Determined by the RNC according to:
SIR i indicates the received signal SIR of the ith node B.
19. The apparatus of claim 14, wherein: alpha is alpha i ＝1，i＝1，2，...， m。
20. The apparatus of claim 14, wherein: alpha is alpha i Determined according to the following equation:
i＝2，3，...，m，α 1 ＝1。
21. the apparatus of claim 15, wherein: alpha (alpha) ("alpha") i ＝1，i＝1，2，...， m。
22. The apparatus of claim 15, wherein: alpha is alpha i Determined according to the following equation:
i＝2，3，...，m，α 1 ＝1。
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2003/000226 WO2004086650A1 (en) | 2003-03-28 | 2003-03-28 | A method for determining reference power in the downlink power balance technology in the case of soft hand-off |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1759544A CN1759544A (en) | 2006-04-12 |
| CN100372258C true CN100372258C (en) | 2008-02-27 |
Family
ID=33035127
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB038262010A Expired - Fee Related CN100372258C (en) | 2003-03-28 | 2003-03-28 | Determination method of reference power in downlink power balance technology in the case of soft hand-off |
Country Status (3)
| Country | Link |
|---|---|
| CN (1) | CN100372258C (en) |
| AU (1) | AU2003221237A1 (en) |
| WO (1) | WO2004086650A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100426696C (en) * | 2005-01-30 | 2008-10-15 | 中兴通讯股份有限公司 | Down link power balancing method under macro diversity status |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1166760A (en) * | 1996-05-22 | 1997-12-03 | Ntt移动通信网株式会社 | Scheme for controlling transmission powers during soft handover in CDMA mobile communication system |
| WO2001047145A2 (en) * | 1999-12-20 | 2001-06-28 | Telefonaktiebolaget Lm Ericsson (Publ) | Downlink power control at soft handover |
| WO2001065724A1 (en) * | 2000-02-28 | 2001-09-07 | Telefonaktiebolaget Lm Ericsson (Publ) | Downlink transmit power synchronization during diversity communication with a mobile station |
| US6351650B1 (en) * | 1999-01-28 | 2002-02-26 | Qualcomm Incorporated | System and method for forward link power balancing in a wireless communication system |
| US6473624B1 (en) * | 2000-03-21 | 2002-10-29 | Telefonaktiebolaget Lm Ericsson (Publ) | Determining a reference power level for diversity handover base stations |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5586170A (en) * | 1994-08-19 | 1996-12-17 | Georgia Tech Research Corporation | Cellular devices, systems and methods using intercell macro-diversity and dynamic channel allocation |
| US5926747A (en) * | 1996-09-05 | 1999-07-20 | Airnet Communications Corp. | Method and apparatus for dynamically optimizing the forward-link transmit power of a broadband multi-carrier radio signal |
| US6104933A (en) * | 1997-06-23 | 2000-08-15 | Telefonaktiebolaget Lm Ericsson | Method and apparatus for control of base stations in macro diversity radio systems |
| EP1758266A3 (en) * | 1998-03-03 | 2014-04-23 | NEC Corporation | Method of controlling transmission power in a cellular type mobile communication system |
| FI114060B (en) * | 1998-04-03 | 2004-07-30 | Nokia Corp | Method and apparatus for power control in a mobile communication system |
-
2003
- 2003-03-28 CN CNB038262010A patent/CN100372258C/en not_active Expired - Fee Related
- 2003-03-28 WO PCT/CN2003/000226 patent/WO2004086650A1/en not_active Application Discontinuation
- 2003-03-28 AU AU2003221237A patent/AU2003221237A1/en not_active Abandoned
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1166760A (en) * | 1996-05-22 | 1997-12-03 | Ntt移动通信网株式会社 | Scheme for controlling transmission powers during soft handover in CDMA mobile communication system |
| US6351650B1 (en) * | 1999-01-28 | 2002-02-26 | Qualcomm Incorporated | System and method for forward link power balancing in a wireless communication system |
| WO2001047145A2 (en) * | 1999-12-20 | 2001-06-28 | Telefonaktiebolaget Lm Ericsson (Publ) | Downlink power control at soft handover |
| WO2001065724A1 (en) * | 2000-02-28 | 2001-09-07 | Telefonaktiebolaget Lm Ericsson (Publ) | Downlink transmit power synchronization during diversity communication with a mobile station |
| US6473624B1 (en) * | 2000-03-21 | 2002-10-29 | Telefonaktiebolaget Lm Ericsson (Publ) | Determining a reference power level for diversity handover base stations |
Also Published As
| Publication number | Publication date |
|---|---|
| AU2003221237A1 (en) | 2004-10-18 |
| CN1759544A (en) | 2006-04-12 |
| WO2004086650A1 (en) | 2004-10-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4435983B2 (en) | Method and apparatus for distributed optimal reverse link scheduling of resources such as rate and power in a wireless communication system | |
| JP4316801B2 (en) | Base station transmit power control in a CDMA cellular telephone system | |
| US8712460B2 (en) | Methods of reverse link power control | |
| KR100289568B1 (en) | Method and apparatus for controlling downlink transmission power in mobile communication system using site diversity | |
| TW469708B (en) | Transmit power control time delay compensation in a wireless communications system | |
| JP5001344B2 (en) | Wireless communication rate formation | |
| US7647050B2 (en) | Method of adjusting a power level of communications over a channel in a wirelss communications network | |
| US7203510B2 (en) | CDMA mobile communication system in which updating of a reference value for controlling closed-loop transmission power is realized in a base transceiver station | |
| US6594499B1 (en) | Downlink power control in a cellular telecommunications network | |
| US7194280B2 (en) | Mobile station assisted forward link open loop power and rate control in a CDMA system | |
| JP2002510933A (en) | Downlink power control in a cellular mobile radio communication system | |
| JP2003533935A (en) | Transmission rate change in communication network | |
| EP1618757A1 (en) | Uplink load determination and signaling for admission and congestion control | |
| US20080051126A1 (en) | Method for allocating transmit power in a wireless communication system | |
| EP1526652A1 (en) | A method for setting a power offset for power control of a downlink shared channel in a mobile radiocommunication system | |
| US20080132266A1 (en) | Maximum Allowable Transmission Rate Deciding Method, Mobile Station And Wireless Base Station | |
| JP2006516861A (en) | Control method of uplink transmission power | |
| EP2056642A2 (en) | Power control algorithm for a femtocell device | |
| WO2002045291A1 (en) | Allocation of shared channel data rates in a communication system | |
| US20050232177A1 (en) | Method for transmission power control of a multicast signal | |
| CN100372258C (en) | Determination method of reference power in downlink power balance technology in the case of soft hand-off | |
| JP2009538035A (en) | Best effort type macro diversity | |
| JP2002368685A (en) | Electric telecommunication network, method for adjusting maximum downlink transmission power, base station, and radio telecommunication network controller | |
| JP2008505511A (en) | The process of allocating radio resources among multiple multiplexed transport channels within a physical channel | |
| KR100736603B1 (en) | Method for power control of tfci field for dsch |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080227 Termination date: 20120328 |