A method and a base station for uplink open loop power control on the base station side

Abstract

Embodiments of the present application disclose a method and a base station for uplink open loop power control on the side of the base station. The method comprises: determining a power compensation coefficient β of a nominal power of each user terminal (UE) based on a link state between each UE and the base station when the UE initially accesses; and determining the nominal power of each UE currently used in a cell by using a calculation expression, comprising: wherein, P O_UE_PUSCH,b,f,c (j) is the nominal power of the UE, β is the power compensation coefficient, Pmax is a maximum value of the nominal power of the UE, and j is a configuration index.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of mobile communications, and in particular to a method for uplink open-loop power control at a base station and a base station. BACKGROUND

[0002] Wireless network is the foundation and guarantee of mobile communication, and is of great significance to the promotion of mobile services, user experience and customer perception. Power control has a great impact on ensuring link quality and reducing interference. The key objects involved in uplink power control in 5G wireless systems include PUCCH (Physical Uplink Control Channel), PUSCH (Physical Uplink Shared Channel) and SRS (Sounding Reference Signal). Through reasonable and effective power control optimization, channel quality can be improved, thereby effectively improving the rate experience. Generally speaking, when the uplink channel quality decreases, the system will instruct the UE (User Equipment) to raise the transmission power as needed, and when the uplink channel quality increases, the system will instruct the UE to reduce the transmission power as needed.

[0003] Uplink open-loop power adjustment is a main uplink power control method in 5G wireless systems. The base station sets a rough working point for the UE's transmission power spectral density, and the UE determines the adjustment of its uplink transmission power based on the measured path loss information, without feeding back any information to the base station or involving the base station.

[0004] In 3GPP (3rd Generation Partnership Project), when the UE only transmits the PUSCH channel at time slot i, the power control calculation expression of the UE at time slot i on the PUSCH channel is as follows:

[0005]

[0006] Wherein:

[0007] P CMAX,f,c (i) is the maximum transmission power configured for the UE;

[0008] Open-loop power adjustment is mainly reflected in the adjustment of the nominal power P O_PUSCH,b,f,c (j). The nominal power P O_PUSCH,b,f,c (j) is composed of two parts: the cell nominal power P O_NOMINAL_PUSCH,f,c (j) and the UE nominal power P O_UE_PUSCH,b,f,c (j). The cell nominal power P O_NOMINAL_PUSCH,f,c(j) is configured to UE by base station, which is common configuration in cell, broadcasted to all UE in cell through SIB1 message, and the value range is [-126, 24] dB. UE nominal power P O_UE_PUSCH,b,f,c (j) is specific uplink transmit power budget compensation of each UE, and the value range is [-8, 7] dB, which is delivered to UE through dedicated RRC signaling (Uplink PowerControl Dedicated: p0-PUSCH-AlphaSet), wherein j is configuration index, which is used to indicate UE to use which configuration.

[0009] In prior art, base station sets nominal power P O_PUSCH,b,f,c (j) to UE, and then does not participate in adjustment of the value, and UE determines nominal power P O_PUSCH,b,f,c (j) according to the value. O_NOMINAL_PUSCH,f,c (j) is common configuration value, but UE nominal power P O_UE_PUSCH,b,f,c (j) is adjustable for each UE, and in prior art, UE nominal power P O_UE_PUSCH,b,f,c (j) is also preset value configured according to power level of UE when system is deployed, further, no matter UE at cell edge or UE at cell center, as long as their power levels are same, UE nominal power P O_UE_PUSCH,b,f,c (j) of the UEs are same; and the actual position of UE in cell will lead to different distances from base station, and if UE close to base station also uses larger uplink open loop power, energy consumption and energy waste will be caused. SUMMARY

[0010] In order to solve any of the above technical problems, the embodiment of the present application provides a method and a base station for uplink open loop power control on base station side.

[0011] In order to achieve the purpose of the embodiment of the present application, the embodiment of the present application provides a method for uplink open loop power control on base station side, which comprises:

[0012] When each UE initially accesses, respectively determine power compensation coefficient β of nominal power of each UE based on link state between each UE and base station;

[0013] Determine UE nominal power currently used by each UE in cell by using following calculation expression, comprising:

[0014] P O_UE_PUSCH,b,f,c (j) = β * maxP O_UE_PUSCH,b,f,c (j);

[0015] (j) = β * maxP O_UE_PUSCH,b,f,c (j) is UE nominal power, and β is power compensation coefficient, and maxPO_UE_PUSCH,b,f,c (j) is a UE nominal power maximum value, j is a configuration index.

[0016] A base station, performing the method described above.

[0017] One of the above technical solutions has the following advantages or beneficial effects:

[0018] Based on the link state between each UE and the base station, the power compensation coefficient β of the UE nominal power of each UE is determined, and the transmission power compensation is performed through different power compensation coefficients β, which not only meets the link connection requirements of each UE and the base station, but also reduces the total system power and effectively saves energy.

[0019] Other features and advantages of the embodiments of the present application will be described in the subsequent description, and some will become apparent from the description, or will be understood by those skilled in the art. The purpose and other advantages of the embodiments of the present application can be achieved and obtained by the structure specifically pointed out in the specification, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the technical solutions of the embodiments of the present application, and constitute a part of the specification, and are used to explain the technical solutions of the embodiments of the present application together with the embodiments of the embodiments of the present application, and do not constitute a limitation of the technical solutions of the embodiments of the present application.

[0021] Figure 1 The flowchart of the uplink open-loop power control method provided for the first embodiment of the present application;

[0022] Figure 2 The flowchart of the uplink open-loop power control method provided for the second embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the embodiments of the present application will be described in detail below with reference to the drawings. It should be noted that, in the case of no conflict, the embodiments in the embodiments of the present application and the features in the embodiments can be combined with each other at will.

[0024] In order to solve the above problems, the present application provides a base station side uplink open-loop power control method. In the initial access, based on the link state between each UE and the base station, the UE nominal power P O_UE_PUSCH,b,f,c (j) of each UE is determined, and the power compensation coefficient β of P O_UE_PUSCH,b,f,c (j) is determined. O_UE_PUSCH,b,f,c (j) is determined. O_UE_PUSCH,b,f,c (j).

[0025] Example 1:

[0026] like Figure 1 As shown, the present invention provides an uplink open-loop power control method, which is applied to the initial access of UE. The link status between UE and base station includes: the distance between UE and base station, and different UE nominal power P is configured for different UEs according to the different distances between UE and base station. O_UE_PUSCH,b,f,c (j). Through UE nominal power P O_UE_PUSCH,b,f,c (j) changes, thereby changing the nominal power P O_PUSCH,b,f,c (j) In this way, after the UE access process, the base station configures different uplink open-loop powers for different UEs. The specific method is as follows:

[0027] S1: The base station obtains the TA (Time Alignment) value of each UE in the cell and determines the coverage factor β based on the obtained TA value, which represents the influence of distance. TA ;

[0028] In conventional wireless communication systems, when a UE establishes a connection with a base station and performs random access, the UE sends a message 1 (message 1) carrying a random access preamble to the base station; the base station calculates the uplink TA based on the received random access preamble. However, in an embodiment of the present application, the UE's TA is preferably calculated based on information carried in a message 3 (message 3) sent by the UE. Because Msg3 is the last uplink message in the contention access process, it is closer to a stable access state than the Msg1 commonly used in conventional technologies, and the TA value is more accurate.

[0029] In this step, once the base station determines the TA value of each UE, the distance between each UE and the base station can be determined based on the determined TA value. The larger the TA value, the farther the UE is from the base station, and the UE is currently in a weak coverage position; the smaller the TA value, the closer the UE is to the base station, and the UE is currently in a strong coverage position. Typically, when the base station and UE establish a connection, the TA value is: 0-63:

[0030] In this step, the cover factor β TA Characterizes the distance and is used to compensate for the change in required power due to the distance between the UE and the base station. When the UE is far away from the base station, there are fewer useful signals, the SNR is lower, and a larger transmission power is required. Therefore, the coverage factor β TA Larger; when the UE is closer to the base station, there are more useful signals, the SNR is higher, and a smaller transmission power is required, so the coverage coefficient β TA Small. So the coverage factor β TAAccording to the distance between the UE and the base station from far to near, the synchronization is reduced.

[0031] Typically, the coverage coefficient β TA The TA value can be determined by the following way:

[0032] The TA value is divided into multiple TA value intervals according to a set rule, and each TA value interval corresponds to a coverage coefficient β TA The rule is that the different location attributes of the UE from the base station are determined by the application scenario. In fact, because the location attributes of the UE from the base station are different, the same transmission power has different experiences for the UE user. Because the TA directly represents the distance between the UE and the base station, different intervals can be directly determined according to the TA value. Typically, the TA can be divided into five intervals as shown in Table 1, which correspond to the location attributes of the UE relative to the base station: excellent point, good point, medium point, poor point, and very poor point. A coverage coefficient β TA is determined for each of the five intervals. TA The coverage coefficient β

[0033] Location properties of a UE TA Coverage coefficient β TA ]] Very good point [0,30] -1 Good point (30,40] -0.5 Medium point (40,50] 0 Bad point (50,60] 0.5 Very bad point (60,63] 1

[0034] Table 1

[0035] The different intervals of the TA value can be based on the analysis of the corresponding relationship between the SNR and the TA value in the field log, and the TA value corresponding to the different SNR value intervals and the location attribute of the UE are determined according to the interval of the SNR value: Specifically:

[0036] SNR∈[25,40], TA∈[0,30], and the location attribute of the UE is an excellent point.

[0037] SNR∈[15,25), TA∈(30,40], and the location attribute of the UE is a good point.

[0038] SNR∈[10,15), TA∈(40,50], and the location attribute of the UE is a medium point.

[0039] SNR∈[5,10), TA∈(50,60], and the location attribute of the UE is a poor point.

[0040] Among them, the interval division of the SNR value is determined according to the number of intervals required and the SNR influence generally considered in the art. SNR∈[5,40] is the SNR value that the UE usually receives in the existing application scenario. The SNR value outside this interval is generally considered that the UE cannot be normally used, and as a typical value, it is not introduced.

[0041] Of course, in the embodiment of the present application, the location attributes of the UE are not necessarily the excellent point, good point, middle point, poor point, good point, and poor point listed in the above example, and may be only good point, middle point, and poor point. It can be determined by a person of ordinary skill in the art according to the system scenario.

[0042] Furthermore, due to the coverage factor β TA It is a compensation for the maximum nominal power of the UE, so its interval is usually selected as [-1,1]. Of course, in other embodiments, a sub-interval in [-1,1] may also be used. This is not specifically limited here and can be selected by ordinary technicians in this field. At the same time, due to the coverage coefficient β TA The distance between the UE and the base station decreases from far to near, so the reduction can be evenly divided according to the number of intervals between the extreme values ​​of the interval. For example, the step size in Table 1 is 0.5; of course, other methods are also possible, but the above typical values ​​can be applied to most scenarios without special settings.

[0043] S2: Base station based on coverage coefficient β TA Determine the UE nominal power P currently used by each UE in the cell O_UE_PUSCH,b,f,c (j);

[0044] Specifically, according to formula P O_UE_PUSCH,b,f,c (j) = β*maxP O_UE_PUSCH,b,f,c (j) Determine the P of each UE in the cell O_UE_PUSCH,b,f,c (j), where β is the power compensation coefficient, β = β TA ;

[0045] In the prior art, P O_UE_PUSCH,b,f,c The value range of (j) is [-8,7]dB, so the maximum value of UE nominal power maxP O_UE_PUSCH,b,f,c (j) = 7 dB;

[0046] In this step, the power compensation coefficient β is taken as the coverage coefficient β TA , since the coverage coefficient βTA actually represents the distance between the UE and the base station, the farther the UE is from the base station, the greater the required transmission power is, and the coverage coefficient β TA Adapting to this trend change, the power compensation coefficient β also increases with increasing distance.

[0047] S3: The base station sends the determined UE nominal power to the UE;

[0048] Specifically, in Msg4 (Message 4), the field dedicated RRCUplinkPowerControl:p0-PUSCH-AlphaSet carries the determined UE nominal power P O_UE_PUSCH,b,f,c(j) is issued to the corresponding UE, so that the UE can transmit according to the UE nominal power P O_UE_PUSCH,b,f,c (j) is issued to the corresponding UE, so that the UE can transmit according to the UE nominal power P

[0049] Through the above method, it can be seen that for the UE in the cell at different positions from the base station, that is, the UE in different coverage ranges of the base station, the transmission power compensation is performed through different power compensation coefficients β according to the distance from the base station, which not only meets the link connection requirements of each UE and the base station, but also reduces the total system power and effectively saves energy.

[0050] Embodiment two:

[0051] Because in the use of the existing network, the base station will usually be disturbed by external radio frequency interference sources, and the result of uplink interference will also cause the reduction of the coverage of the base station. Specifically, if the UE is at the same transmission power, when the UE is in the case without uplink interference, the base station can receive the signal of the UE far away, and when the uplink interference occurs, the UE signal must be stronger than the interference signal, so that the base station can establish a stable connection with the UE, and therefore the UE must be closer to the base station. Based on this, embodiment two of the present application continues to improve on the basis of embodiment one, and the uplink level interference NI value is also taken as a factor affecting the power compensation coefficient β, so that the current use of the UE nominal power P O_UE_PUSCH,b,f,c (j) not only considers the distance but also considers the interference, so that the transmission power of the UE is more robust and the energy saving effect is better.

[0052] The embodiment proposes an uplink open loop power control method. This method is applied when the UE initially accesses, and the link state between the UE and the base station includes the distance between the UE and the base station, and the uplink level interference NI received by the base station for each UE. According to the different distances between different UEs and the base station, and the NI of the base station for each UE, different UE nominal powers P O_UE_PUSCH,b,f,c (j) are configured for different UEs. The specific method is as follows: O_UE_PUSCH,b,f,c (j) is changed, and then the nominal power P O_PUSCH,b,f,c (j) is changed. In this way, after the UE accesses, the base station configures different uplink open loop powers for different UEs.

[0053] S11: The base station obtains the TA value of each UE in the cell, and determines the coverage coefficient β representing the distance influence according to the obtained TA value TA ;

[0054] This step S11 is similar to step S1 in embodiment one, and the same implementation process will not be described here;

[0055] S12: The base station acquires the current uplink level interference NI value of each UE in the cell, and determines the interference coefficient β NI ;

[0056] In the prior art wireless communication system, the NI is acquired when the uplink data is demodulated by the physical layer, and its range is usually [-130, 0] dB. The larger the NI value, the greater the interference, and the smaller the NI value, the smaller the interference.

[0057] In this step, the interference coefficient β NI characterizes the interference size and compensates for the required power change due to interference; it can be reduced synchronously from large to small according to the interference brought to the base station; typically, it can be determined as follows:

[0058] The NI value is divided into multiple NI value intervals according to a set rule. The rule is that different interference levels of NI are divided by ordinary technical personnel in the application scenario. In the embodiments of the present application, different intervals can be directly divided according to the NI value. Typically, as shown in Table 2, NI is divided into five intervals corresponding to different interference levels, i.e. excellent, good, medium, poor and very poor. Each NI value interval corresponds to an interference coefficient β NI ;

[0059]

[0060] Table 2

[0061] In this step, since the interference coefficient β NI compensates for the maximum value of the UE nominal power, its interval is usually selected as [-1, 1]. Of course, in other embodiments, a sub-interval of [-1, 1] can also be used. Here, it is not specifically limited and can be selected by ordinary technical personnel in the art. Further, for the interference coefficient β NI corresponding to each NI interval, since the smaller the interference value, the larger the coverage, the interference coefficient β NI can be smaller, therefore, the interference coefficient β NI decreases synchronously as the interference value decreases, so it can be evenly divided and reduced according to the number of intervals between the interval extremes, for example, the step of Table 2 is 0.5. Of course, other ways can also be used, but the typical values described above can be applied to most scenarios without special settings.

[0062] S13: The base station determines the UE nominal power currently used by each UE in the cell according to the coverage coefficient β TA and the interference coefficient β NI ;

[0063] Specifically, according to the formula P O_UE_PUSCH,b,f,c (j) = β * maxP O_UE_PUSCH,b,f,c (j) determines the current UE nominal power P O_UE_PUSCH,b,f,c (j) of each UE in the cell, wherein β is a power compensation coefficient, β = β TA + β NI ;

[0064] In the prior art, the value range of P O_UE_PUSCH,b,f,c (j) is [-8, 7] dB, so the maximum value maxP O_UE_PUSCH,b,f,c (j) of the UE nominal power is 7 dB.

[0065] In this step, the value of the power compensation coefficient β takes into account the coverage coefficient β TA and the interference coefficient β NI , that is, both the distance between the UE and the base station and the radio frequency interference received by the base station are considered when calculating the transmission power budget compensation, so that the uplink transmission power of the UE does not need to be always maintained at the maximum to meet the access requirements.

[0066] S14: The base station sends the determined UE nominal power to the UE.

[0067] Specifically, the base station determines the UE nominal power P O_UE_PUSCH,b,f,c (j) and carries it to the corresponding UE in the Msg4 message through the field dedicated RRC UplinkPowerControl: p0-PUSCH-AlphaSet, so that the UE can perform uplink power configuration according to the UE nominal power P O_UE_PUSCH,b,f,c (j) determined by the base station.

[0068] Through the above method, it can be seen that for the UEs in different positions in the cell from the base station, that is, the UEs in different coverage ranges of the base station, different transmission power budget compensations are adopted according to the distance from the base station and the uplink interference received by the base station, which can further reduce the total system power and effectively save energy while ensuring the link connection requirements of the UE and the base station.

[0069] The embodiment of the application also provides a base station for executing the method described above.

[0070] The scheme provided by the embodiment of the application can adopt different transmission power budget compensations according to the connection state of each UE with the base station for the UEs in different coverage ranges of the base station, which can further reduce the total system power and effectively save energy while ensuring the link connection requirements of the UE and the base station.

[0071] Those of ordinary skill in the art will realize and understand that all or some of the steps in the methods disclosed above and the functional modules / units in the systems and devices can be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementation, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component can have multiple functions, or one function or step can be performed by several physical components in cooperation. Some or all of the components can be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on computer-readable media, which can include computer storage media (or non-transitory media) and communication media (or transitory media). As is well known to those of ordinary skill in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. Furthermore, it is common and well understood by those of ordinary skill in the art that communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and can include any information delivery media.

Claims

1. A method of base station side uplink open loop power control, comprising: determining a power compensation coefficient β of a UE nominal power of each UE based on a link state between the UE and a base station when the UE initially accesses; determining a UE nominal power currently used by each UE in a cell by using a calculation expression, comprising: = β * max ; wherein, Pnominal is the UE nominal power, β is the power compensation factor, max Pnominal is the UE nominal power maximum, j is the configuration index; wherein the link state between the UE and the base station comprises a distance between the UE and the base station, and a received uplink level interference NI of the base station for each UE; the determination of the power compensation coefficient β of the UE nominal power of each UE based on the link state between the UE and the base station comprises: Obtaining TA values of UEs in a cell, and determining a coverage coefficient β representing distance influence according to the obtained TA values TA ; Obtaining current uplink level interference (NI) values of each UE in the cell, and determining an interference coefficient β representing the interference size according to the obtained NI values NI ; determining the power compensation factor β according to the coverage factor β TA and the interference factor β NI determining the power compensation factor β.

2. The method of claim 1, wherein, The UE nominal power maximum max is 7 dB.

3. The method of claim 1, wherein, calculating a TA value of the UE according to information carried in a message 3 sent by the UE.

4. The method of claim 1, said coverage factor β TA is determined by: The TA values are divided into a plurality of TA value intervals according to a set rule, and each TA value interval corresponds to a coverage coefficient β TA ; the coverage coefficient β TA increases with the increase of the maximum value of the TA value interval.

5. The method of claim 4, wherein, the setting of rules for different location attributes of the UE from the base station.

6. The method of claim 4, wherein, The TA values are divided into a plurality of TA value intervals according to a set rule, and each TA value interval corresponds to a coverage coefficient β TA Specifically: The TA value interval is [0, 30], the coverage coefficient β TA is -1; The TA value interval is (30, 40], the coverage coefficient β TA is -0.5; The TA value interval is (40, 50], the coverage coefficient β TA is 0; The TA value interval is (50, 60], the coverage coefficient β TA is 0.5 The TA value interval is (60, 63], the coverage coefficient β TA is 1.

7. The method of claim 1, wherein, The interference coefficient β NI is determined by The NI values are divided into a plurality of NI value intervals corresponding to different interference levels according to a set rule; each NI value interval corresponds to an interference coefficient β NI ; the interference coefficient β NI increases with the maximum value of the NI value interval.

8. The method of claim 7, wherein, The NI values are divided into a plurality of NI value intervals corresponding to different interference levels according to a set rule; each NI value interval corresponds to an interference coefficient β NI Specifically: The interval of the NI values is [-130, -120], the covering coefficient β NI is -1. The interval of the NI value is (-120, -110], and the covering coefficient β NI is -0.

5. The interval of the NI value is (-110, -100], and the covering coefficient β NI is 0. The NI value interval is (-100, -90], and the covering coefficient β NI is 0.5 The interval of the NI value is (-90, 0], and the covering coefficient β NI is 1. 9.A base station comprising an apparatus of base station side uplink open loop power control, the apparatus being configured to perform the method of any one of claims 1 to 8.

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