CN115243353A

CN115243353A - Power control method and related base station

Info

Publication number: CN115243353A
Application number: CN202210719340.4A
Authority: CN
Inventors: 苏佳伟; 蒋坤霖
Original assignee: Zhonglei Electronics Suzhou Co ltd; Sercomm Corp
Current assignee: Zhonglei Electronics Suzhou Co ltd; Sercomm Corp
Priority date: 2022-06-23
Filing date: 2022-06-23
Publication date: 2022-10-25

Abstract

The invention provides a power control method and a related base station. The power control method comprises the following steps: receiving a plurality of uplink data of the user equipment, and determining channel situations corresponding to the plurality of uplink data. A plurality of impact differences between channel conditions corresponding to the plurality of uplink data and expected conditions, respectively, are determined. A transmission power command is determined based on a plurality of statistics affecting the difference. Transmitting a transmission power instruction to set an uplink transmission power at which the user equipment transmits subsequent data. Each lane scenario includes the impact that the corresponding uplink data is subjected to via the lane. Therefore, the reliability and stability of the uplink transmission power adjustment can be improved.

Description

Power control method and related base station

Technical Field

The present invention relates to a wireless communication technology, and in particular, to a power control method for wireless communication and a related base station.

Background

In a mobile communication system (e.g., a Fourth Generation (4G), long Term Evolution (LTE), fifth Generation-New Radio (5G-NR), etc.), a conventional closed-loop power control is to measure power of uplink (uplink) data transmitted by a User Equipment (UE) through a base station (e.g., a next Generation node B (gNB)) to determine an uplink power adjustment amount, and to transmit the uplink power adjustment amount to the UE. However, if a certain measured uplink data is wrong or the channel is momentarily severely interfered (e.g. a rapidly changing radio channel, or the ue does not transmit uplink data at a proper transmission time point), the base station may misjudge the adjustment amount. If the adjustment amount of the uplink power does not meet the actual channel condition, the uplink power used by the ue will be too large or too small, and the uplink stability will be affected.

Disclosure of Invention

The present invention is directed to a power control method and a base station, which can determine an adjustment amount according to statistics corresponding to a plurality of uplink data, so as to correspond to a fast changing channel.

According to an embodiment of the present invention, the power control method includes (but is not limited to) the following steps: and determining channel situations corresponding to a plurality of uplink data. A plurality of impact differences between channel conditions corresponding to the plurality of uplink data and expected conditions, respectively, are determined. A transmission power command is determined based on a plurality of statistics affecting the difference. A transmission power command is transmitted. Each channel condition includes an impact on a channel over which corresponding uplink data is to be communicated. The transmission power command is for controlling power for transmitting subsequent data.

According to an embodiment of the present invention, a base station includes, but is not limited to, a transceiver and a processor. The transceiver is used for transmitting or receiving signals. The processor is coupled to the transceiver. The processor is configured to: and determining channel situations corresponding to a plurality of uplink data. A plurality of impact differences between channel conditions corresponding to the plurality of uplink data and expected conditions, respectively, are determined. A transmission power command is determined based on a plurality of statistics affecting the difference. The transmission power command is transmitted by the transceiver. Each channel condition includes an impact on a channel over which corresponding uplink data is to be communicated. The transmission power command is for controlling power for transmitting subsequent data.

Based on the above, according to the power control method and the base station in the embodiments of the present invention, the influence difference between the channel situation corresponding to the plurality of uplink data and the expected situation is counted, and the transmission power command related to the power adjustment amount is determined according to the statistical result of the influence difference. Therefore, the power adjustment amount can be in accordance with the actual situation, and the stability of the uplink is further improved.

Drawings

The accompanying drawings form a part of the specification. The drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification.

FIG. 1 is a schematic diagram of a communication system according to an embodiment of the present invention;

FIG. 2 is a block diagram of the components of a base station in accordance with an embodiment of the present invention;

FIG. 3 is a flow chart of a power control method according to an embodiment of the invention;

fig. 4 is a flow chart of determining a transmission power command according to an embodiment of the present invention.

Description of the reference numerals

1: a communication system;

10: a base station;

20: a user equipment;

11: an antenna;

12: a transceiver;

13: analog-to-digital/digital-to-analog converter

14: a memory;

15: a processor;

s310 to S350, S410 to S433: and (5) carrying out the following steps.

Detailed Description

Embodiments of the present invention will now be described with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts.

Fig. 1 is a schematic diagram of a communication system 1 according to an embodiment of the present invention. Referring to fig. 1, a communication system 1 includes, but is not limited to, a base station 10 and one or more user equipments 20.

The communication system 1 is, for example, a global system for mobile communications (GSM) system, a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (WCDMA) system, a General Packet Radio Service (GPRS), a Long Term Evolution (LTE) system, an LTE Frequency Division Duplex (FDD) system, an LTE duplex time division (TDD) system, an advanced long term evolution (LTE-a) system, a new radio (new radio, an NR) system, an evolution system of the NR system, an LTE (LTE-based access to unlicensed spectrum, LTE-U) system on an unlicensed frequency band, an NR (NR-based access to unlicensed spectrum, NR-U) system on an unlicensed frequency band, a Universal Mobile Telecommunications System (UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication system, a Wireless Local Area Network (WLAN), a wireless fidelity (WiFi), a next generation communication system, an indoor millimeter wave wireless communication system, or other communication systems.

Fig. 2 is a block diagram of the components of the base station 10 according to an embodiment of the present invention. Referring to fig. 2, the Base station 10 may be an Evolved Node B (eNB), a Home Evolved Node B (HeNB), a generation Node B (gNB), a Base Transceiver System (BTS), a relay, a repeater (repeater), or a WiFi 7 wireless access point.

The base station 10 includes, but is not limited to, one or more antennas 11, a transceiver 12, an Analog to Digital (Analog to Digital)/Digital to Analog (Digital to Analog) converter 13, a memory 14, and a processor 15.

The transceiver 12 is used to wirelessly receive uplink (uplink) signals and transmit downlink (downlink) signals through the antenna 11. Transceiver 12 may also perform analog signal processing operations such as low noise amplification, impedance matching, mixing, up-conversion or down-conversion, filtering, amplification, and the like.

The adc 13 is coupled to the transceiver 12, and the adc 13 is configured to convert from an analog signal format to a digital signal format during uplink signal processing and from a digital signal format to an analog signal format during downlink signal processing.

The Memory 14 may be implemented by any suitable fixed or removable Random Access Memory (RAM), read-Only Memory (ROM), flash Memory (Flash Memory), or the like, or any combination thereof. The memory 14 stores program codes, device configurations, codebooks, buffered or persistent Data, and other various communication Protocol related software modules such as a Radio Resource Control (RRC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Media Access Control (MAC) layer, and a Physical (PHY) layer.

The processor 15 is coupled to the analog-to-digital/digital-to-analog converter 13 and the memory 14, the processor 15 is configured to process the digital signals and execute a program according to an exemplary embodiment of the present invention, and can access or load data and software modules stored in the memory 14. The functions of the processor 15 may be implemented using one or more components such as a Central Processing Unit (CPU), a microprocessor, a microcontroller, a Digital Signal Processing (DSP) chip, a Field Programmable Gate Array (FPGA), and the like. The functions of the processor 15 may also be implemented by a stand-alone electronic device or an Integrated Circuit (IC), and part of the operations of the processor 15 may also be implemented by software.

The User Equipment 20 (UE, or called as a Mobile terminal or a terminal device) may be a Mobile Station (MS), an Advanced Mobile Station (AMS), a telephone device, customer Premises Equipment (CPE), a wireless sensor, a wearable device, an intelligent appliance, or a vehicle-mounted system.

The base station 10 may provide communication coverage for a particular geographic area and may communicate with user equipment 20 located within that coverage area.

For convenience of understanding the operation process of the embodiment of the present invention, the operation process of the communication system 1 in the embodiment of the present invention will be described in detail below with reference to the embodiment. Hereinafter, the method according to the embodiment of the present invention will be described with reference to each device and its components in the communication system 1. The flow of the method according to the embodiment of the present invention may be adjusted according to the implementation situation, and is not limited thereto.

Fig. 3 is a flow chart of a power control method according to an embodiment of the present invention. Referring to fig. 3, the processor 15 of the base station 10 receives uplink data from the user equipment 20 through the transceiver 12 (step S310). For example, the Uplink data may be one or a combination of more of a Physical Uplink Shared Channel (PUSCH), a Physical Uplink Control Channel (PUCCH), a Sounding Reference Signal (SRS), and other data from the user equipment 20.

The processor 15 determines the channel conditions corresponding to the plurality of uplink data (step S320). In particular, each channel condition includes the impact that the corresponding uplink data is subjected to via the channel. The channel may be affected by noise, interference, movement, etc., thereby changing the amplitude and/or phase of the wireless signal transmitting the uplink data. For example, the Channel condition may be calculated based on a Signal-to-Interference-plus-Noise Ratio (SINR), a Signal-to-Noise Ratio (SNR), channel State Information (CSI), a received Signal strength, a received Signal quality, and one or more other metrics to determine the Channel condition

The processor 15 determines a plurality of influence differences between the channel situations corresponding to the plurality of uplink data and the expected situations, respectively (step S330). Specifically, the processor 15 performs a physical layer (physical layer) operation to calculate a pointer of a corresponding channel status from the received uplink data, and then performs a medium access control layer (MAC layer) operation on the channel status to determine the influence difference. The desired situation includes the impact on the channel over which the base station 10 expects uplink data. Similarly, the desired situation may be represented by SINR, SNR, CSI, received signal strength, received signal quality, or other indicator or indicators to learn the channel situation. In addition, each influence difference is the difference of the (quantized) expected case minus the channel case, and thus how much and which larger/smaller influence difference is. For example, if the SINR of the current channel is 22 decibels (dB) and the desired SINR is 20dB, the difference between the two is-2 dB, i.e., the SINR of the current channel is 2dB greater than the desired SINR. It should be noted that in other embodiments, it is also possible that the channel condition is the subtrahend and the desired condition is the subtrahend. In addition, the difference between the two values can be directly used as the difference, and the difference can be further quantized into a metric (metric) value, so as to represent the influence difference. For example, a metric of 0 for SINR differences less than-3 dB, a metric of 1 for SINR differences between-3 and 0, and so on for the remainder of the process.

The processor 15 determines a transmission power instruction from the statistics of the plurality of impact differences (step S340). Specifically, for each user equipment 20, the processor 15 counts a plurality of influence differences to obtain a statistical amount, and sets the adjustment amount or the designated power indicated by the transmission power instruction according to the statistical amount. In addition, the transmission power instruction is for controlling power with which the user equipment 20 transmits subsequent uplink data. That is, the user equipment 20 sets uplink transmission power based on the transmission power command, and transmits subsequent uplink data accordingly.

The transmission power instruction may indicate an amount of adjustment of the uplink transmission power. For example, the base station 10 may employ a Transmission Power Control (TPC) command as the TPC command, and the ue 20 may set the uplink Transmission Power according to the TPC command transmitted by the base station 10. Table (1) illustrates an embodiment of the correspondence between TPC commands and adjustment amounts:

watch (1)

TPC command value	Adjustment [ dB ]]
		0	-1
1	0
		2	1
3	3

Wherein a positive value of the adjustment amount represents that the user equipment 20 increases the uplink transmission power, a negative value represents that the user equipment 20 decreases the uplink transmission power, and an adjustment amount of zero represents that the user equipment 20 maintains the existing uplink transmission power. For another example, table (2) illustrates another embodiment of the correspondence between the TPC command and the adjustment amount:

watch (2)

TPC command value	Adjustment [ dB ]]
		First command value	First power adjustment value
Second command value	Second power adjustment value
		Third command value	Third power adjustment value
Fourth command value	Fourth power adjustment value
		The fifth command value	Fifth power adjustment value
The sixth command value	Sixth power adjustment value
		The seventh command value	Seventh power adjustment value
Eighth command value	Eighth power adjustment value

Wherein the command value and the adjustment value can be determined according to actual requirements. As another example, the transmission power command may indicate a desired uplink transmission power.

In one embodiment, the statistics include a sum of a plurality of impact differences. For example, each time the base station 10 receives uplink data for a certain user equipment, the impact differences are accumulated to give a sum of these impact differences (desired situation minus channel situation). The processor 15 may determine a first comparison result that affects the sum of differences and the difference threshold. The first comparison result includes the sum of the impact differences being greater than, less than, and/or equal to the difference threshold. The channel condition is, for example, SINR, and the difference threshold is, for example, 0, but not limited thereto. In addition, the processor 15 may determine a second comparison of the last difference to the difference threshold. This last difference is the difference in influence between the channel situation for the last received uplink data of those uplink data and the expected situation (expected situation minus the channel situation for the last received data). For example, the base station 10 receives 25 uplink data from a certain user equipment 20 during a certain period. The last received data may be uplink data according to the 25 th or other order of the order. That is, the last received data is received later than the other data and can also represent the current channel situation. Additionally, the second comparison result includes the last difference being greater than, less than, and/or equal to the difference threshold.

The processor 15 may then determine a transmission power command based on the first comparison and the second comparison. The first comparison result may reflect the channel condition at a plurality of time points within the statistical period or a period before the current time point, and the second comparison result may reflect the channel condition at the current time point.

In one embodiment, each impact difference is a difference obtained by subtracting each channel condition from the expected condition, and the processor 15 may send a transmission power command to set the ue 20 to increase the uplink transmission power for transmitting the subsequent data, corresponding to the first comparison result and the second comparison result both being greater than the difference threshold. That is, the quantized values of the channel situation during statistics and the current channel situation are approximately lower than the expected situation. Thus, a desired situation may be reached by increasing the uplink transmission power. Taking table (1) as an example, a TPC command of 2 represents the user equipment 20 increasing the uplink transmission power by 1dB. In response to the first comparison result and the second comparison result both being less than the difference threshold, the processor 15 may transmit a transmission power command to set the ue 20 to decrease the uplink transmission power for transmitting the subsequent data. That is, the quantized values of the channel situation during statistics and the current channel situation are approximately higher than expected. Thus, the desired situation can be reached by reducing the uplink transmission power. Taking table (1) as an example, a TPC command of 0 represents a 1dB reduction.

In addition, the processor 15 may maintain the existing uplink transmission power to transmit subsequent data corresponding to one of the first comparison result and the second comparison result being less than the difference threshold and the other being greater than the difference threshold. That is, the first comparison result is less than the difference threshold but the second comparison result is greater than the difference threshold, or the second comparison result is less than the difference threshold but the first comparison result is greater than the difference threshold. In addition, such comparison results represent that the channel conditions during the statistics may vary repeatedly between higher and lower than expected. Thus, fast changing channel conditions can be combated by maintaining the uplink transmission power. Taking table (1) as an example, a TPC command of 1 represents neither increasing nor decreasing the uplink transmission power.

Referring to fig. 4, fig. 4 is a flowchart illustrating an embodiment of determining a transmission power command (step S340), wherein the channel condition is represented by SINR in this embodiment. Each time the receiving base station 10 receives uplink data of one of the user equipments 20, the processor 15 calculates SINR corresponding to the uplink data and an influence difference between the SINR and a desired SINR, and accumulates the influence differences (step S410). The processor 15 determines whether the number of times of receiving uplink data or accumulation within the counting period reaches a number threshold (e.g., 20, 50, or 80) (step S420).

Corresponding to the number or accumulated number of the plurality of uplink data not being equal to the number threshold, the processor 15 does not adjust the existing uplink transmission power of the ue 20 or transmits the transmission power command to allow the ue 20 to maintain the existing uplink transmission power, and returns to step S410 to continue accumulating the impact difference. For example, during the counting period, if there is a demand for the base station 10 to transmit the transmission power command but the number does not reach the number threshold, the base station 10 transmits the transmission power command to the ue 20 and sets the adjustment amount of the uplink transmission power to zero. For another example, if the base station 10 has no need to transmit the transmission power command, the base station 10 disables/stops/does not transmit the transmission power command to the ue 20.

The processor 15 is configured to determine a number or an accumulated number of times corresponding to a plurality of uplink data being equal to or greater than a number threshold according to a plurality of shadowsThe statistics of the response differences determine the transmission power commands. The mathematical expression of the accumulated difference is

Wherein the SINR _i,target To the desired SINR, SINR _i,received P is a predetermined number threshold, which is the SINR corresponding to the ith uplink data.

In step S430, the processor 15 determines a transmission power command according to the first comparison result and the second comparison result. If the first comparison result and the second comparison result are both greater than the difference threshold, the processor 15 may send a transmission power command to the ue 20 to increase the uplink transmission power for transmitting the subsequent data (step S431). Taking table (1) as an example, the final difference is 2dB and is between the adjustments 1 and 3 in table (1), then the TPC command is 2 and represents an increase of 1dB; the final difference is 3.5dB and greater than the adjustment 3 in table (1), then the TPC command is 3 and represents a 3dB increase. That is, the larger the final difference, the larger the increase amount; conversely, the less the increase; however, the present invention is not limited thereto.

If the first comparison result and the second comparison result are both greater than the difference threshold, the processor 15 may send a transmission power command to the ue 20 to reduce the uplink transmission power for transmitting the subsequent data (step S432). Taking table (1) as an example, the TPC command is 0 and represents a 1dB reduction. In addition, if the first comparison result is smaller than the difference threshold but the second comparison result is larger than the difference threshold, or the second comparison result is smaller than the difference threshold but the first comparison result is larger than the difference threshold, the processor 15 allows the ue 20 to maintain the existing uplink transmission power for transmitting the subsequent data (step S433). Taking table (1) as an example, the TPC command is 1.

In one embodiment, the statistics include an average or weighted operation of the plurality of impact differences. The average value may be a moving average (also referred to as rolling average, moving average), such as a simple moving average, an exponential moving average, a weighted moving average, or a cumulative moving average, to determine an average value of a subset formed by a plurality of influence differences and accordingly trend the influence differences over time. At this time, the first comparison result may be a comparison result of the moving average value with the difference threshold value. On the other hand, the weighted operation value may be obtained by giving the same or different weights to those influence differences (e.g., having a larger weight closer to the current time point and a smaller weight farther from the current time), multiplying each influence difference by the corresponding weight, and summing all the products. At this time, the first comparison result may be a comparison result of the weighted operation value and the difference threshold value.

It should be noted that other variations of the statistics are possible, such as how many and/or how many times the quantized values of those channel cases are greater or less than the desired case during the statistical period.

In one embodiment, the uplink data used to determine the statistics passes error checking. The error Check is, for example, a Cyclic Redundancy Check (CRC), a parity Check, or a Hamming code Check, and the processor 15 performs the error Check on the uplink data through a physical layer operation. When the uplink data passes the error check, the processor 15 may retain the impact difference corresponding to the uplink data and determine the statistics based thereon. Uplink data that fails the error check is not used to determine the transmission power command. For example, when the uplink data fails to pass the error check, the processor 15 may ignore/delete the impact difference corresponding to the uplink data, and disable/stop/not use the impact difference to determine the statistics.

Referring to fig. 3, the processor 15 may transmit a transmission power command through the transceiver 12 to set an uplink transmission power for the ue 20 to transmit subsequent data (step S350). Specifically, the base station 10 transmits a transmission power instruction to the user equipment 20, so that the user equipment 20 can adjust the uplink transmission power for transmitting subsequent uplink data according to the transmission power instruction. In one embodiment, the transmission power command is transmitted through Downlink Control Information (DCI). The DCI may be DCI format 0_0, DCI format 0_1, DCI format 1_0, DCI format 1_1, DCI format 2_, u 2with CRC coded by TPC-PUSCH-RNTI, DCI format 2_, u 2with CRC coded by TPC-PUCCH-RNTI, or DCI format 2_3/3/3A. As another example, the transmission power command is transmitted via other control signaling.

In summary, in the power control method and the base station according to the embodiments of the present invention, the statistics of the difference in influence between the channel situation and the expected situation are used to confirm the channel variation during the statistics, and accordingly, the transmission power command is determined. In addition, the correctness of uplink data is confirmed. Therefore, the power adjustment is in accordance with the actual channel situation, the reliability of the power adjustment in the wireless channel with high-speed change can be improved, the situation of excessive adjustment or wrong adjustment of the uplink power caused by the traditional TPC mode determination is solved, and the use experience of a terminal user is further reduced.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of power control, comprising:

receiving a plurality of uplink data of a user equipment;

determining channel conditions corresponding to the plurality of uplink data, wherein each channel condition comprises an influence on the corresponding uplink data through a channel;

determining a plurality of influence differences between channel situations corresponding to the plurality of uplink data and expected situations respectively;

determining a transmission power command based on statistics of the plurality of impact differences; and

transmitting the transmission power instruction to set an uplink transmission power at which the user equipment transmits subsequent data.

2. The power control method of claim 1, wherein the statistics comprise a sum of the plurality of impact differences, and wherein determining the transmission power command based on the statistics of the plurality of impact differences comprises:

determining a first comparison of the sum to a difference threshold;

determining a second comparison result of a last difference and the difference threshold, wherein the last difference is an influence difference between a channel situation corresponding to a last received uplink data in the plurality of uplink data and the expected situation; and

determining the transmission power command according to the first comparison result and the second comparison result.

3. The power control method of claim 2, wherein each of the impact differences is a difference of the expected case minus each of the channel cases, and wherein determining the transmit power command based on the first comparison and the second comparison comprises:

setting the transmission power command to set the UE to increase the uplink transmission power for transmitting the subsequent data, corresponding to the first comparison result and the second comparison result both being greater than the difference threshold; and

setting the transmission power command to set the UE to reduce uplink transmission power for transmitting the subsequent data, in response to the first comparison result and the second comparison result both being less than the difference threshold.

4. The power control method of claim 2 or 3, wherein the step of determining the transmission power command according to the first comparison result and the second comparison result comprises:

setting an uplink transmission power at which the user equipment maintains transmitting the subsequent data, corresponding to one of the first comparison result and the second comparison result being less than the difference threshold and the other being greater than the difference threshold.

5. The power control method of claim 1, further comprising:

determining the transmission power instruction based on statistics of the plurality of impact differences corresponding to a number of the plurality of uplink data equaling a number threshold; and

setting an uplink transmission power at which the user equipment maintains transmitting the subsequent data, corresponding to the number of the plurality of uplink data not being equal to the number threshold.

6. The power control method of claim 1, wherein the plurality of uplink data passes error checking, and wherein uplink data that fails the error checking is not used to determine the transmission power command.

7. The power control method of claim 1, wherein the channel condition and the desired condition are calculated according to a signal-to-interference-plus-noise ratio, wherein any one of the plurality of uplink data is a physical uplink shared channel, a physical uplink control channel or a sounding reference signal, and wherein the transmission power command is transmitted via downlink control information.

8. The power control method of claim 1, wherein the statistic comprises an average or a weighted operation of the plurality of impact differences.

9. A base station, comprising:

a transceiver to receive a plurality of uplink data of a user equipment; and

a processor coupled to the transceiver and configured to:

transmitting, by the transceiver, the transmission power instruction to set an uplink transmission power at which the user equipment transmits subsequent data.

10. The base station of claim 9, wherein the statistics comprise a sum of the plurality of impact differences, and wherein the processor is further configured to:

determining a first comparison of the sum to a difference threshold;

11. The base station of claim 10, wherein each of the impact differences is a difference of the desired case minus each of the channel cases, the processor further configured to:

setting the transmission power command to set the UE to reduce the uplink transmission power for transmitting the subsequent data, corresponding to the first comparison result and the second comparison result both being smaller than the difference threshold.

12. The base station of claim 10 or 11, wherein the processor is further configured to:

13. The base station of claim 9, wherein the processor is further configured to:

14. The base station of claim 9, wherein the plurality of uplink data passes error checking and uplink data that fails the error checking is not used to determine the transmission power command.

15. The base station of claim 9, wherein the channel condition and the desired condition are calculated according to a signal-to-interference-plus-noise ratio, wherein any of the plurality of uplink data is a physical uplink shared channel, a physical uplink control channel, or a sounding reference signal, and wherein the transmission power command is transmitted via downlink control information.

16. The base station of claim 9, wherein the statistics comprise an average or weighted operation of the plurality of impact differences.