WO2009067892A1

WO2009067892A1 - Base station initial power control method, system and device

Info

Publication number: WO2009067892A1
Application number: PCT/CN2008/072960
Authority: WO
Inventors: Liwen Zhang; Zhen Li
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-11-09
Filing date: 2008-11-05
Publication date: 2009-06-04
Also published as: CN101159459B; CN101159459A

Abstract

An initial power control method of base station includes that: calculating a pathloss between a mobile station and a base station (102); predicting downlink signal intensity received by mobile station based on the pathloss and transmission power intensity of a carrier frequency where a calling of the mobile station is located (103); based on the downlink signal intensity received by mobile station, determining the power intensity that the base station transmits initial power, informing the base station to transmit initial power according to the power intensity (104). Besides, an initial power control system and device are disclosed. By indirectly obtaining relatively accurate information of downlink signal intensity received by the mobile station, the technical proposal of the invention realizes the power control at the initial stage and reduces the interference to the system and saves the power consumption of the base station.

Description

[1] This application claims priority to Chinese Application No. 200710188204.2, entitled "Initial Power Control Method, System and Apparatus", filed on November 9, 2007, the entire contents of in.

[2] Technical field

[3] The present invention relates to mobile communication technologies, and in particular, to a base station initial power control method, system and device

[4] Background Art

[5] In mobile communication technology, in order to maintain high-quality communication without causing interference to other users, it is usually necessary to control the transmission power of the base station. Currently, in the power control of Global System For Mobile Communication (GSM), the base station controller (BSC) needs to receive the mobile station (Mobile).

Station, MS) After the measurement report of the channel where a certain number of calls are reported, the received measurement is interpolated, filtered, etc. to process the lost measurement report and eliminate the wild point.

The downlink signal strength value received by the processed MS is obtained. Then, the obtained downlink signal strength value received by the MS is compared with the ideal downlink signal strength value received by the MS, and is calculated by a power control algorithm.

Station, BTS) The power level that should be adjusted. Thereafter, the base station is notified to perform power transmission according to the power level. In addition, considering that the measurement information in the initial situation after the call has just been accessed and after the cell handover has just been completed is usually not accurate enough, after the power control is performed, the initial measurement reports are discarded to ensure the power control algorithm. stability.

[6] It can be seen that in the prior art, after power control is performed on the base station, a certain number of measurement reports need to be collected and several initial measurement reports are discarded, thus making power control very lagging, and at the initial of call access and cell handover. The power control cannot be performed at the stage, and the base station can only transmit at the maximum power. This will inevitably increase the interference of the communication system, affect the quality of the service, and waste the power consumption of the base station.

[7] Summary of the invention [8] An embodiment of the present invention provides a base station initial power control method, apparatus, and system, so as to implement base station power control in an initial stage, reduce interference to the system, and save power consumption of the base station.

[9] A base station initial power control method, the method comprising:

[10] Calculate the path loss between the mobile station and the base station;

[11] predicting the downlink signal strength received by the mobile station according to the path loss and the transmit power strength of the carrier frequency of the call of the mobile station;

[12] determining, according to the predicted downlink signal strength, a power strength of the base station to perform initial power transmission, and notifying the base station to perform initial power transmission according to the power strength.

[13] A base station initial power control device, the device comprising:

[14] a path loss calculation module, configured to calculate a path loss between the mobile station and the base station;

[15] a signal strength calculation module, configured to predict a downlink signal strength received by the mobile station according to a path loss calculated by the path loss calculation module and a transmit power intensity of a carrier frequency of the call of the mobile station;

[16] The power control module is configured to calculate a downlink signal strength predicted by the module according to the signal strength, determine a power strength of the base station to perform initial power transmission, and notify the base station to perform initial power transmission according to the power strength.

[17] An initial power control system, comprising: a base station controller, a base station, and a mobile station, wherein the base station controller comprises the base station initial power control device described above.

[18] It can be seen from the foregoing solution that, in the embodiment of the present invention, the path loss between the mobile station and the base station is calculated, and the mobile station is predicted according to the calculated path loss and the transmit power strength of the allocated carrier frequency of the call. The received downlink signal strength, that is, in the initial stage of call access and before the cell handover, indirectly obtains the downlink signal strength information received by the more accurate mobile station, and then determines according to the predicted downlink signal strength information received by the mobile station. The base station performs the power intensity of the initial power transmission, and notifies the base station to perform initial power transmission according to the power strength, thereby implementing power control in the initial stage, reducing interference to the system, and saving power consumption of the base station.

[19] BRIEF DESCRIPTION OF THE DRAWINGS

1 is an exemplary flowchart of an initial power control method in Embodiment 1 of the present invention;

2 is a schematic structural diagram of an initial power control device according to Embodiment 1 of the present invention;

FIG. 3 is still another schematic structural diagram of an initial power control apparatus according to Embodiment 1 of the present invention; FIG. 4 is an exemplary flowchart of an initial power control method in Embodiment 2 of the present invention;

FIG. 5 is a schematic structural diagram of an initial power control apparatus according to Embodiment 2 of the present invention.

[25] Specific implementation

[26] In the embodiment of the present invention, in consideration of the initial stage of the call access and the inter-cell handover, the downlink measurement report of the channel where the call reported by the MS is located cannot be obtained (ie, the downlink signal strength received by the mobile station) Information) or the obtained measurement information is not accurate enough, etc., by calculating the path loss between the MS and the base station, and using the calculated path loss and the transmission power intensity of the carrier frequency of the channel on which the call is located (referred to as the carrier frequency of the call) The downlink signal strength information received by the MS is predicted, and according to the predicted result, the power strength of the initial power transmission performed by the base station is determined, and the base station is notified to perform initial power transmission according to the power strength.

[27] Correspondingly, the initial power control system in the embodiment of the present invention includes: a BSC, a base station, and an MS. The BSC is configured to calculate a path loss between the MS and the base station, and predict a downlink signal strength received by the MS according to the calculated path loss and a transmit power strength of a carrier frequency of the channel where the call is located; and receive the downlink according to the MS. Signal strength, determining the power strength of the base station for initial power transmission, and notifying the base station to perform initial power transmission according to the power strength.

[28] In the following, taking the case of cell handover and call access as an example, the embodiments of the present invention are further described in detail in conjunction with the embodiments and the accompanying drawings.

[29] Example 1:

[30] In this embodiment, the case of cell handover is taken as an example. Considering that the MS is in a steady state in the source cell before the cell handover, the signal of the Broadcast Control Channel (BCCH) of the target cell received by the MS is used. The strength information is relatively accurate. Therefore, in this embodiment, the path loss between the MS and the base station where the target cell is located is calculated by using the signal strength of the BCCH of the target cell received by the MS reported by the MS received by the source cell base station controller BS C. FIG. 1 is a flowchart of an initial power control method in Embodiment 1 of the present invention. As shown in FIG. 1, the process includes the following steps:

Step 101: Receive a signal strength of the BCCH of the target cell received by the MS reported by the MS (Rxlev_B)

Before the MS performs cell handover, the MS reports the signal strength of the received BCCH of the target cell to the BSC through the measurement report, so that the BSC decides whether to perform handover according to the measurement report, and the BSC according to the measurement. The quantity report records the signal strength of the BCCH of the target cell received by the MS to facilitate subsequent path loss calculation.

[102] Step 102: The BSC obtains a path loss between the MS and the target base station according to the measurement report of the signal strength of the BCCH of the target cell that is received by the MS and the transmit power strength of the carrier frequency of the BCCH of the target cell.

[34] In this step, for the cell handover in the BSC, since the BSC can know the transmit power strength of the carrier frequency of the BCCH of the target cell to be switched, the path loss between the MS and the target base station can be calculated according to the following formula:

[35] Path loss = transmit power strength of the carrier frequency of the BCCH of the target cell - signal strength of the BCCH of the target cell received by the MS

[36] In addition, if the target cell to be switched is a multi-band cell, and the carrier frequency of the BCCH of the target cell and the carrier frequency of the call are in different frequency bands, there is a path loss between the bands. Therefore, in calculating the path loss, it is necessary to consider the path loss between the carrier frequency of the BCCH and the carrier frequency of the call.

(The specific calculation method can be implemented according to the prior art, which is not mentioned here). The calculation of the path loss can be referred to the following formula:

[37] Path loss = transmit power strength of the carrier frequency of the BCCH of the target cell - Target cell received by the MS

BCCH signal strength + inter-band path loss difference

[38] Step 103: Predict the downlink signal strength received by the mobile station according to the path loss and the transmit power strength of the carrier frequency of the call of the mobile station.

[39] In this step, the BSC can predict the downlink signal strength received by the MS according to the transmit power of the carrier frequency of the channel on which the call is located and the path loss, as shown in the following formula:

[40] Downlink signal strength received by the MS = transmit power strength of the carrier frequency of the call - path loss

[41] Step 104: Determine, according to the downlink signal strength received by the MS, the power strength of the base station to perform initial power transmission, and notify the base station to perform initial power transmission according to the power strength.

[42] The implementation process of this step may be consistent with the implementation process in the prior art, that is, the BSC compares the predicted downlink signal strength received by the MS with the ideal downlink signal strength received by the MS, and uses a power control algorithm. Calculate the power strength that the base station should adjust. For example, the power level that the base station should adjust to can be calculated, and the base station is notified to perform initial power transmission according to the power level. [43] Considering that the MS performs cell handover, the BSC first activates the traffic channel of the target cell to which the MS applies (Traffic

CHannel, TCH), and after receiving the response of the target cell, notify the MS to access the TCH of the target cell, thereby completing the cell handover. Therefore, in this embodiment, the TCH 吋 of the target cell to be applied may be activated, and the initial power control may be performed by using the foregoing method, so that the base station performs transmission according to an appropriate power; or after the MS successfully switches to the target cell, the foregoing method is used. Initial power control allows the base station to transmit at the appropriate power. That is, after calculating the power strength that the base station should adjust to, the TCH吋 of the target cell that the MS applies for is activated, and the base station is notified to transmit according to the power strength to be adjusted; or the MS can successfully switch to the target cell. The base station is notified to transmit according to the power strength to be adjusted as described above.

[44] In this embodiment, power control is performed by switching after the BSC, so that the base station does not need to transmit according to the maximum power, but only needs to transmit with appropriate power, thereby reducing system interference and improving service quality. And reduce the power consumption of the BTS. In addition, since the measurement report before convergence is convergent, the signal strength is relatively stable, so the power control is more accurate.

[45] The method for initial power control in the first embodiment is described in detail above. The initial power control device in the first embodiment will be described in detail below.

FIG. 2 is a schematic structural diagram of an initial power control device according to Embodiment 1 of the present invention. As shown in FIG. 2, the apparatus may include: a path loss calculation module 201, a signal strength calculation module 202, and a power control module 203.

[47] The road loss calculation module 201 is configured to calculate a path loss between the mobile station and the base station.

[48] The signal strength calculation module 202 is configured to predict the downlink signal strength received by the MS according to the path loss calculated by the path loss calculation module 201 and the transmission power intensity of the carrier frequency of the call. The downlink signal strength received by the MS can be predicted by determining the difference between the transmit power strength and the path loss of the carrier frequency at which the call is located. The path loss calculation module 201 may send the calculated path loss to the signal strength calculation module 202; or the signal strength calculation module 202 actively acquires the path loss calculated by the path loss calculation module 201 from the path loss calculation module 201.

[49] The power control module 203 is configured to determine, according to the downlink signal strength received by the MS predicted by the signal strength calculation module 202, the power strength of the initial power transmission performed by the base station, and notify the base station according to the power strength. Perform initial power transmission. The signal strength calculation module 202 may send the downlink signal strength received by the predicted MS to the power control module 203. Alternatively, the power control module 203 actively obtains the MS received by the signal strength calculation module 202 and the MS received by the signal strength calculation module 202. Downstream signal strength.

Specifically, in order to calculate the path loss between the mobile station and the base station, the device in this embodiment may be as shown in FIG. 3, and may further include: a broadcast control channel signal strength receiving module 301, The signal strength of the BCCH of the target cell received by the MS reported by the MS before the cell handover is received, and the signal strength of the target cell BCCH received by the received MS is provided (can be provided actively, or can be obtained in the path loss calculation module 201) Further provided) to the path loss calculation module 201.

Correspondingly, the path loss calculation module 201 calculates the MS and the signal strength of the BCCH of the target cell received by the MS received by the broadcast control channel signal strength receiving module 301 and the transmission power strength of the carrier frequency of the BCCH of the target cell. Path loss between the target base stations, which may be the difference between the transmit power strength of the carrier frequency of the BC CH of the target cell and the signal strength of the BCCH of the target cell received by the MS.

[52] In addition, if the target cell to be switched is a multi-band cell, and the carrier frequency of the BCCH in the target cell and the carrier frequency of the call belong to different frequency bands, the apparatus in this embodiment may further include: The loss calculation module 302 is configured to calculate a path loss difference between the carrier frequency of the BCCH and the carrier frequency of the call. The path loss calculation module 201 may be configured according to the signal strength of the target cell BCCH received by the MS from the broadcast control channel signal strength receiving module 301, the transmit power strength of the carrier frequency of the BCCH of the target cell, and the inter-band path loss difference calculation module 302. Calculating the path loss between the inter-bands, calculating the path loss between the mobile station and the target base station, the path loss = the transmit power strength of the carrier frequency of the BCCH of the target cell - the signal strength of the target cell BCCH received by the MS + frequency band The path loss is poor.

[53] Example 2:

In the embodiment, the case of the MS call access is taken as an example. Considering that the uplink path loss and the downlink path loss are the same, in this embodiment, the uplink path loss is used instead of the downlink path loss. FIG. 4 is a flowchart showing an exemplary power control method for the initial access port of the MS in the second embodiment of the present invention. As shown in FIG. 4, the process may include the following steps:

[55] Step 401, obtaining the actual transmit power of the MS.

BSC is available under the Third Generation Partnership Project (Third Generation Partnership) Project, 3GPP) TS

The specification in 05.05 calculates the actual transmit power of the MS. For example, after the call is accessed, the MS sends a class update to the BSC (Classmark

Update the message to inform the BSC of the relevant information, and the BSC can calculate the actual transmit power of the MS according to the power class and other information in the class update message reported by the MS.

[57] Step 402: Receive an uplink signal strength measured by the base station reported by the base station.

[58] In general, the base station can measure the received uplink signal and report the measurement result to the BSC. After initial call access, the base station can be carried on a separate dedicated control channel (Standalone Dedicated Control)

The signal on the CHannel, SDCCH) is measured, and the signal carried on the TCH after the access is completed is measured, and the uplink signal strength received by the base station is obtained and reported to the BSC. The BSC can record the received uplink signal strength of the received base station for subsequent path loss calculation.

[59] The order of execution of the actions described in 401 and 402 in this embodiment is not limited, and the order in which they occur does not affect the implementation of the method.

[60] Step 403: Obtain a path loss between the MS and the base station according to the uplink signal strength measured by the base station and the actual transmit power strength of the MS.

[61] In this step, the path loss between the MS and the base station can be calculated according to the following formula:

[62] Path loss Actual transmit power strength of MS - Uplink signal strength measured by the base station

[63] Step 404: Predict the downlink signal strength received by the mobile station according to the calculated path loss and the transmit power strength of the carrier frequency of the call.

[64] In this step, the BSC can predict the downlink signal strength received by the MS according to the transmit power of the carrier at the call and the path loss, as shown in the following equation:

[65] Downstream signal strength received by the MS = Transmit power strength of the carrier where the call is located - Path loss

[66] Step 405: Determine, according to the predicted downlink signal strength received by the MS, the power strength of the base station to perform initial power transmission, and notify the base station to perform initial power transmission according to the power strength.

[67] The implementation process of this step may be consistent with the implementation process in the prior art, that is, the BSC compares the predicted downlink signal strength received by the MS with the ideal downlink signal strength received by the MS, and uses a power control algorithm. Calculate the power level that the base station should adjust to, and inform the base station to perform the initial according to the power level. Power transmission.

[68] Considering the initial call access, the BSC first activates the TCH of the current cell requested by the MS, and after receiving the response of the current cell, notifies the MS to access the TCH, thereby completing the call access. Therefore, in this embodiment, the TCH吋 applied by the MS may be activated, and the power control may be performed by using the foregoing method, so that the base station performs transmission according to an appropriate power; or after the MS successfully accesses, the power control is performed by using the foregoing method, so that the base station is used. Emit at the appropriate power. That is, after calculating the power strength that the base station should adjust to, the TCH吋 of the current cell requested by the MS may be activated, and the base station may be notified to transmit according to the power strength to be adjusted; or the MS may successfully access the network, The base station transmits according to the power intensity to be adjusted as described above.

[69] In this embodiment, power control is performed after the call is accessed, so that the base station does not need to transmit according to the maximum power, but only needs to transmit with appropriate power, thereby reducing system interference and improving services. Quality, and reduced power consumption of the BTS.

[70] The method for initial power control in the second embodiment is described in detail above. The composition and connection relationship of the initial power control device in the second embodiment are basically the same as those in the device shown in FIG. The difference is that, in order to calculate the path loss between the mobile station and the base station, the initial power control device in the second embodiment may further be as shown in FIG. 5. On the basis of the device shown in FIG. 2, the mobile power station may further include: The transmit power acquisition module 501 and the uplink signal strength receiving module 502.

[71] The mobile station transmit power acquisition module 501 is configured to obtain the actual transmit power of the MS call access 吋MS, and provide the acquired actual transmit power of the MS to the path loss calculation module 201. Wherein the specific implementation and may be implemented as shown in FIG. ₄ described 401 consistent process.

[72] The uplink signal strength receiving module 502 is configured to receive the uplink signal strength measured by the base station reported by the base station, and provide the uplink signal strength measured by the received base station to the path loss calculation module 201.

Correspondingly, the path loss calculation module 201 is configured to calculate the MS according to the uplink signal strength measured by the base station received by the uplink signal strength receiving module 502 and the actual transmit power strength of the MS acquired by the mobile station transmit power acquiring module 501. Path loss between the base station and the base station. That is, the path loss may be the difference between the actual transmit power strength of the MS and the uplink signal strength measured by the base station. The mobile station transmit power acquisition module 501 and the uplink signal strength receiving module 502 can respectively send the respective obtained information to the path loss calculation module 201. Alternatively, the path loss calculation module 201 actively acquires the above information from the two modules. [74] The initial power control device in each of the above embodiments may be disposed in the BSC.

[75] The initial power control system in the embodiment of the present invention includes: a BSC, a base station, and an MS. The device in the first embodiment or the second embodiment may be provided in the BSC.

[76] The above describes only the initial power control of the initial call or just switched to the target cell.

The subsequent power control is not limited, and the existing power control algorithm can be used in the subsequent power control.

[77] The above description is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of within the technical scope disclosed by the present invention. Changes or substitutions are intended to be included within the scope of the invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

Claim

[1] A method for initial power control of a base station, the method comprising:

Calculating path loss between the mobile station and the base station;

Predicting the downlink signal strength received by the mobile station according to the path loss and the transmit power strength of the carrier frequency of the call of the mobile station;

And determining, according to the predicted downlink signal strength, a power strength of the base station to perform initial power transmission, and notifying the base station to perform initial power transmission according to the power strength.

[2] The method according to claim 1, wherein before the calculating the path loss between the mobile station and the base station, the method further includes: receiving a target cell received by the mobile station reported by the mobile station before the cell handover Signal strength of the broadcast control channel BCCH;

The calculating the path loss between the mobile station and the base station comprises: calculating a path loss between the mobile station and the base station where the target cell is located according to the received signal strength of the target cell BCCH received by the mobile station.

[3] The method according to claim 2, wherein the calculating a path loss between the mobile station and a base station where the target cell is located according to a signal strength of the target cell BCCH received by the received mobile station includes: And subtracting the signal strength of the target cell BCCH received by the received mobile station from the transmit power strength of the carrier frequency of the BCCH of the target cell, and obtaining the path loss between the mobile station and the base station where the target cell is located.

[4] The method according to claim 2, wherein: the carrier frequency of the BCCH in the target cell and the carrier frequency of the call belong to different frequency bands, and the method further includes: calculating a carrier frequency and a call location of the BCCH The path loss between the frequency bands of the carrier frequency is poor;

Calculating the path loss between the mobile station and the target base station according to the signal strength of the BCCH of the target cell received by the received mobile station, including: subtracting the transmit power strength of the carrier frequency of the BCCH of the target cell by the After the signal strength of the target cell BCCH received by the mobile station, plus the path loss between the bands, the path loss between the mobile station and the target base station is obtained.

[5] The method according to any one of claims 2 to 4, wherein the notifying the base station to perform initial power transmission according to the power strength comprises:: a target cell in activating a cell handover procedure The traffic channel TCH吋, or the mobile station successfully switches to the target cell in the cell handover process, notifying the base station to perform initial power transmission according to the power strength.

[6] The method according to claim 1, wherein before the calculating the path loss between the mobile station and the base station, the method further comprises: acquiring an actual transmit power of the mobile station call access and the mobile station; The uplink signal strength measured by the base station;

Calculating the path loss between the mobile station and the base station includes: calculating a path loss between the mobile station and the base station according to the uplink signal strength measured by the base station and the actual transmit power strength of the mobile station .

[7] The method according to claim 6, wherein: calculating, according to the uplink signal strength measured by the base station and the actual transmit power strength of the mobile station, calculating between the mobile station and the base station The path loss includes: subtracting the actual transmit power strength of the mobile station from the uplink signal strength measured by the base station to obtain a path loss between the mobile station and the base station.

[8] The method according to claim 6 or 7, wherein the notifying the base station to perform initial power transmission according to the power strength comprises: activating a TCH of a current cell applied by the mobile station, or the mobile station succeeds After the access, the base station is notified to perform initial power transmission according to the power strength.

[9] A base station initial power control device, the device comprising:

a path loss calculation module, configured to calculate a path loss between the mobile station and the base station;

a signal strength calculation module, configured to predict a downlink signal strength received by the mobile station according to a path loss calculated by the path loss calculation module and a transmission power intensity of a carrier frequency of the mobile station call;

a power control module, configured to calculate a downlink signal strength predicted by the module according to the signal strength

And determining, by the base station, the power strength of the initial power transmission, and notifying the base station to perform initial power transmission according to the power strength.

[10] The device of claim 9, wherein the device further comprises:

a broadcast control channel signal strength receiving module, configured to receive a signal strength of a broadcast control channel BCCH of the target cell received by the mobile station reported by the mobile station before the cell handover; and the path loss calculation module receives the data according to the mobile station Calculating the signal strength of the BCCH of the target cell and the transmit power strength of the carrier frequency of the BCCH of the target cell, and calculating the mobile station and the target Path loss between base stations where the cell is located.

[11] The device according to claim 9, wherein the device further comprises: an inter-band path loss calculation module, configured to calculate a path loss difference between a carrier frequency of the BCCH and a carrier frequency of the call;

The path loss calculation module is configured to: according to the signal strength of the target cell BCCH received by the mobile station received by the broadcast control channel signal strength receiving module, the transmit power strength of the carrier frequency of the BCCH of the target cell, and the path loss between the frequency bands Calculating the path loss between the inter-bands calculated by the sub-module, and calculating the path loss between the mobile station and the base station where the target cell is located.

[12] The apparatus of claim 9, wherein the apparatus further comprises:

a mobile station transmit power acquisition module, configured to acquire an actual transmit power of the mobile station call access 吋 mobile station;

An uplink signal strength receiving module, configured to receive the uplink signal strength measured by the base station, and the path loss calculation module, according to the uplink signal strength measured by the base station received by the uplink signal strength receiving module, and the mobile station transmitting The actual transmit power strength of the mobile station acquired by the power acquisition module calculates a path loss between the mobile station and the base station.

[13] An initial power control system, characterized in that the system comprises: a base station controller, a base station and a mobile station, wherein the base station controller comprises the base station initial power according to any one of claims 9 to 12. Control device.