KR20220111171A - Method and repeater apparatus for reverse gain automatic level control - Google Patents

Abstract

Disclosed are a method for reverse gain automatic level control (ALC) and a repeater for performing the same. The method for reverse gain automatic level control of a repeater includes the steps of: setting a plurality of reverse gain control zones based on reverse gain of a repeater and path loss between a terminal and the repeater; determining a reverse gain control zone to which a reverse gain state corresponds, from among the plurality of reverse gain control zones, based on a reverse signal output value; and adjusting the reverse gain using automatic level control information set in the determined reverse gain control zone.

Description

Reverse gain automatic level control method and repeater

The present invention relates to a reverse gain automatic level control method and a repeater thereof.

In the case of general closed loop power control (CLPC), the terminal transmit power is controlled so that the base station reception signal-to-interference-plus-noise ratio (SINR) becomes the target SINR. When the base station received SINR is higher than the target SINR, the terminal power is lowered, but when the base station received SINR is lower than the target SINR, the terminal's maximum transmit power is increased. Therefore, when wirelessly interlocked with a base station like an RF repeater and transmit/receive power is limited, the repeater reverse AMP (Amplifier) is saturated even if the terminal transmit power is increased, and the SINR is rather lowered, thereby radiating to the maximum output of the terminal.

In addition, when the reverse AMP is saturated, not only the quality is rather deteriorated, but also the deterioration of the AMP proceeds, thereby shortening the life of the equipment.

In addition, with the introduction of UL (Uplink) 256QAM (Quadrature Amplitude Modulation), the highest speed can be secured only when the received SINR required by the base station is secured by 30 dB or more, which is about 8 dB or more higher than that of the existing UL 64QAM. For this reason, in the past when UL 64QAM was supported, the effect was small, but recently, when UL 256QAM was introduced, the effect is more significant. In order to prevent such over-output, the existing RF repeater applies ALC (Auto Level Control) operation.

ALC operation period, for example, usually detects the output by 200 ~ 500ms and if the output is higher than the upper limit of each ALC, the gain is lowered by the difference between the sensed output and the ALC upper limit at once in the ALC operation period. Increase the gain by several dB per operation period.

If the ALC operation period is too short, the quality deteriorates due to frequent gain fluctuations due to environmental changes and traffic characteristics.

Existing ALC detects the output for each ALC operation period and, if the output is higher than the upper limit for each ALC, lowers the gain by the difference between the detected output and the ALC upper limit at once in the ALC operation period. increase profits. However, by controlling the gain with a detectable output, repeater deterioration and terminal quality deterioration occur for up to several seconds.

As such, in the conventional method, the over-output of the AMP is maintained until ALC is performed, and since the gain is controlled only up to the ALC upper limit based on the output that can be detected, the gain control has to be repeated several times when the reverse input is large. ~ AMP saturation occurs for several seconds, causing equipment deterioration and terminal quality deterioration.

The task to be solved is to divide the reverse gain state into a plurality of reverse gain control zones in consideration of the reverse gain of the repeater and the path loss between the repeater and the terminal, and automatically reverse the gain set in the reverse gain control zone corresponding to the current reverse gain state. A method for performing level control and a repeater thereof are provided.

According to one feature, there is provided a reverse gain automatic level control (ALC) method of a repeater, comprising the steps of setting a plurality of reverse gain control zones based on the reverse gain of the repeater and a path loss between the terminal and the repeater; Determining a reverse gain control zone corresponding to a reverse gain state from among the plurality of reverse gain control zones based on a signal output value, and adjusting the reverse gain using automatic level control information set in the determined reverse gain control zone includes

The plurality of reverse gain control zones include a first zone that maintains a set reverse gain, and a second zone that requires adjustment of the set reverse gain due to reverse over-output, and the adjusting includes: the reverse gain state When ? corresponds to the second zone, preset reverse gain information may be reduced by adding automatic level control attenuation information.

The second zone includes a third zone in which reverse output detection is performed within an accuracy range while having reverse over-output, and the adjusting includes, when the reverse gain state corresponds to the third zone, the second zone Reverse gain can be reduced by adding preset automatic level control attenuation information matched to 3 zones.

The second zone includes a fourth zone in which reverse over-output is present and reverse output detection is performed outside the accuracy range at the same time, and the adjusting includes: when the reverse gain state corresponds to the fourth zone, the current reverse direction The reverse gain can be reduced by adding the gain and automatic level control attenuation information defined in response to the path loss between the terminal and the repeater.

The automatic level control attenuation information defined in the fourth zone may include a plurality of automatic level control attenuation information set stepwise in response to a plurality of reverse gains and path losses between a plurality of terminals and a repeater.

Before the determining step, the steps of collecting output values of the reverse signals measured in units of the reverse period during an automatic level control period, determining whether at least one of the output values is equal to or greater than a predefined threshold value, and the predefined The method further comprising the step of setting an average value of all the collected output values as a reference output when there is no average value of at least one output value equal to or greater than a threshold value or at least one output value equal to or greater than the predefined threshold value, wherein the determining comprises: A zone corresponding to the reverse gain state may be determined using the reference output.

Prior to the determining, the method may further include setting an initial reverse gain to a value obtained by adding an operator offset to a forward gain.

According to another feature, as a repeater for performing reverse gain automatic level control (ALC), a reverse amplifier amplifying and outputting a reverse signal by a reverse gain, detecting the output value of the reverse signal output by the reverse amplifier By comparing the output value of the reverse signal with each threshold condition set in a plurality of reverse gain control zones set based on the detection unit, the reverse gain of the repeater, and the path loss between the terminal and the repeater, the reverse gain state of the reverse amplifier and an automatic level control (ALC) unit that determines a corresponding reverse gain control zone and adjusts the reverse gain based on automatic level control information set in the determined reverse gain control zone.

The automatic level control unit, based on the output value of the reverse signal, determines whether the reverse gain state corresponds to a first zone maintaining a set reverse gain or a second zone requiring adjustment of the set reverse gain due to reverse over-output. can

The repeater further includes a reverse attenuation control unit for decreasing a reverse gain of the reverse amplifier through automatic level control attenuation information, and the automatic level control unit, when the reverse gain state corresponds to the second zone, the reverse gain It is possible to output automatic level control attenuation information for reducing , to the reverse attenuation control unit.

The automatic level control unit, when detecting a transition of the reverse gain state from the second zone to the first zone based on the output value of the reverse signal, maintains the reverse gain of the second zone until the terminal call is terminated can do it

When the reverse signal output value is less than or equal to a first threshold or the reverse gain meets a predetermined gain condition, the automatic level control unit determines the reverse gain state as the first zone, and maintains the reverse gain set in the reverse amplifier. can

The second zone includes a third zone in which reverse output detection is performed within an accuracy range while having a reverse over-output, and the automatic level control unit determines the reverse gain state when the reverse signal output value is within a threshold range. It is determined as the third zone and the reverse gain may be reduced using a gain reduction value set in the third zone.

The second zone includes a fourth zone in which reverse output detection is performed outside the accuracy range while having reverse over-output, and the automatic level control unit determines the reverse gain state when the reverse signal output value is greater than or equal to a second threshold. The fourth zone may be determined and the reverse gain may be reduced using a current reverse gain and a gain reduction value determined based on a path loss between the repeater and the UE.

According to the embodiment, when there is a 5G RF repeater in the area of the base station operating as CLPC, even if the terminal output is increased by the CLPC condition of the base station, it is possible to minimize the deterioration of the repeater and provide fast stabilization of the terminal quality through fast gain control.

1 is a diagram for explaining an ALC operation in the related art.
2 is a block diagram illustrating a configuration of a repeater performing reverse ALC control according to an embodiment.
3 shows a reverse gain control zone according to an embodiment.
4 is a diagram illustrating an additional reduction in reverse gain according to a repeater-to-terminal path loss and a repeater reverse gain according to an embodiment.
5 is an example illustrating transition between reverse gain control zones according to an embodiment.
6 is a flowchart illustrating a reverse gain ALC control method according to an embodiment.
7 is a flowchart illustrating a method for determining a reverse power for an ALC operation according to an embodiment.

Hereinafter, with reference to the accompanying drawings, the embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

In addition, terms such as “…unit”, “…group”, “…module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. can

The devices described in the present invention are composed of hardware including at least one processor, a memory device, a communication device, and the like, and a program executed in combination with the hardware is stored in a designated place. The hardware has the configuration and capability to implement the method of the present invention. The program includes instructions for implementing the method of operation of the present invention described with reference to the drawings, and is combined with hardware such as a processor and a memory device to execute the present invention.

As used herein, "transmission or provision" may include not only direct transmission or provision, but also transmission or provision indirectly through another device or using a detour path.

In this specification, expressions described in the singular may be construed as singular or plural unless an explicit expression such as “a” or “single” is used.

In this specification, the same reference numbers refer to the same components regardless of the drawings, and "and/or" includes each and every combination of one or more of the referenced components.

In this specification, terms including an ordinal number such as first, second, etc. may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present disclosure, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component.

In the flowchart described with reference to the drawings in this specification, the order of operations may be changed, several operations may be merged, some operations may be divided, and specific operations may not be performed.

In the specification, a terminal (Terminal/User Equipment) accesses a base station of an Access Network/Radio Access Network (RAN) and uses Network Functions (NFs) of the Core Network. Here, the base station may include an eNB, a gNB, an AP, etc. according to an access network. The terminal may be a terminal of various types and uses, such as a portable terminal, an IoT terminal, a vehicle terminal, a display terminal, a broadcasting terminal, and a game terminal. The devices constituting the network may be implemented by hardware or software or a combination of hardware and software.

It is assumed that the terminal RSRP (Reference Signal Received Power) is at a position of -50dBm in the base station area. Assuming that the 5G base station output is 52dBm/Total (17dBm/RE ^{Resource Element} ), the path loss between the base station and the terminal is 67dB, which is 17dBm/RE - (-50dBm/RE), and the 3.5GHz 5G used in Korea is TDD (Time division duplex), so it is assumed that the DL/UL frequencies are the same and the path loss is also the same. Here, dBm/Total is defined as a total output unit for the 100 MHz band (BW). dBm/RE means output per 1 RE. If there are 273 RBs in 100 MHz BW, and 1 RB = 12 RE, then 3276 RE (=273 RB × 12 RE/RB) in 100 MHz BW, so 52 dBm/Total = 52 dBm/3276RE = (52 - 10*log(3276)) dBm/RE ≒ (52 - 35) dBm/RE = 17 dBm/RE The ^{Resource Element} can be calculated as . The path loss is transmit power per RE - RSRP (receive power per RE at the terminal), that is, 17 dBm/RE - (-50 dBm/RE) = 67 dB.

The terminal initial power, that is, uplink channel (Physical Uplink Shared Channel (PUSCH) power) is determined as -3dBm by Equation 1 below.

=-74,α=0.7,

= 273RB 라고 가정한다.At this time,

=-74,α=0.7,

= 273 RB.

는 단말 최대 출력이다.

는 단말 초기 전력을 계산하는데 사용되는 초기값으로서, α=1로 가정시 RB당 기지국 수신 요구 전력을 의미한다. here,

is the maximum output of the terminal.

As an initial value used to calculate the initial power of the UE, α=1 means the base station reception required power per RB, assuming that α=1.

은 PUSCH로 할당하는 RB 수로서, 대역폭은 100㎒ 주파수 간격 30㎑ 기준으로 최대 273이다. α는 경로손실의 반영치이다. 그리고 PL(Path Loss)은 경로 손실로서, 기지국에서 받은 SSB(Synchronization Signal Block)에 대한 RE(Resource Element) 당 전송 출력과 단말이 측정한 SSB의 RSRP 차이로 계산된다. f(i)는 CLPC(Closed Loop Power Control)에 따른 단말 전력 제어를 위한 파라미터이다.

is the number of RBs allocated to the PUSCH, and the bandwidth is up to 273 based on a 100 MHz frequency interval of 30 kHz. α is a reflection of the path loss. And PL (Path Loss) is a path loss and is calculated as the difference between the transmission output per resource element (RE) for the synchronization signal block (SSB) received from the base station and the RSRP difference of the SSB measured by the terminal. f(i) is a parameter for terminal power control according to Closed Loop Power Control (CLPC).

When the UE transmits the initial power at -3 dBm, the base station receives power of -70 dBm due to the 67 dB path loss from the base station to the UE equal to the DL. In this case, the UL SINR measured by the base station becomes 20 dB by Equation 2 below. In this case, it is assumed that I = 0 and the base station NF is 4 dB.

Here, P _{base station reception} denotes the power received by the base station for the signal transmitted by the terminal. N is the base station noise level (kTB + base station noise figure). The unit of thermal noise is kTB. B is the bandwidth, which can be defined as 100MHz = 10^8 Hz. As N = kTB + NF, N=-174dBm/Hz + 10*log(B) + 4dB(Assumption)= -174dBm/Hz + 10*log(10^8Hz) + 4dB= (-174 + 80 + 4 )dBm = -90dBm, and UL SINR@base station = -70dBm - (-90dBm) = 20Db.

), T는 절대온도(K), B는 대역폭이며, 상온에서의 kT를 계산하면 -174dBm/Hz의 값이 도출된다.I stands for interference. In thermal noise, k is the Boltzmann constant (

), T is the absolute temperature (K), and B is the bandwidth. When kT is calculated at room temperature, a value of -174dBm/Hz is derived.

Assuming that the target SINR of UL 64QAM (Quadrature Amplitude Modulation) is 22 dB and the target SINR of 256QAM is 32 dB, in the case of a terminal supporting only UL 64QAM, -1 dBm in which the terminal power is increased by 2 dB is emitted to satisfy the target SINR, whereas In the case of a terminal supporting UL 256QAM, it is necessary to increase the value by 12 dB, so the value of f(i) is transmitted to the terminal as 12, and the terminal transmits it at 9 dBm, so that the base station secures a UL SINR of 32 dB. Since the base station reception UL SINR = 20dB, the terminal power must be transmitted 2dB higher to match the target SINR@UL 64QAM = 22dB, and the terminal power must be raised by 12dB to match the target SINR@UL 256QAM.

However, in the RF repeater area, there is a repeater whose output is limited between the base station and the terminal even if the terminal is in a position where the RSRP is -50dBm in the same way.

It is assumed that the repeater's DL input is -40dBm/Total(-75dBm/RE), the repeater's DL output is 30dBm/Total(-5dBm/RE), UL maximum output 30dBm/Total, and DL/UL gain is 70dB. The output, UL target SINR, base station noise figure (NF), etc. are assumed to be the same as the previously assumed values and described. That is, it is assumed that the terminal electric field and the target SINR are the same when it is assumed that the above-described base station is in the base station service area without the repeater.

The path loss from the base station to the repeater becomes 92dB which is 17dBm/RE - (-75dBm/RE), and the pathloss from the repeater to the terminal becomes 45dB which is -5dBm/RE - (-50dBm/RE). Path loss is calculated as the difference between the output of the transmitter and the input of the receiver.

However, the terminal cannot know whether there is a repeater between the base station and the terminal. Since only the base station transmission output can be known on the signaling received from the base station, it is assumed that there is a terminal in the same electric field, so the terminal recognizes the base station to the terminal path loss as 67 dB, and the same as when there is no repeater, that is, calculated in Equation 1 - It transmits an output of 3dBm.

The repeater reverse input is calculated as terminal output-(repeater to terminal path loss), that is, -3dBm - 45dB=-48dBm. The repeater reverse output is amplified with a repeater reverse gain of 70dB. Therefore, since the repeater reverse output is the sum of the repeater reverse input and the repeater reverse gain, it is transmitted to the base station as -48dBm+70dBm=22dBm. Since this signal (22 dBm) is attenuated by 92 dB of path loss from the base station to the repeater, the base station reverse input is received by the base station at 22 dBm - 92 dB = -70 dBm. This is the same as the reception level in the base station area, and the base station calculates the UL SINR as 20 dB.

Similarly, in the case of a UE supporting up to UL 64QAM in the repeater area, a target SINR of 22 dB is assumed. Since the UL SINR received from the base station is 20 dB, the f(i) value is transmitted to the terminal to raise the output by 2 dB. The repeater reverse input receives -46dBm (= -1dBm - 45dB), and the repeater reverse output is transmitted to the base station at 24dBm (= -46dBm + 70dB) amplified by 70dB. The base station reverse input may receive -68 dBm (= 24 dBm - 92 dB) to satisfy the target SINR. That is, the UL SINR of the base station is -68 dBm - (-90 dBm) = 22 dB, so that the target SINR can be satisfied.

However, in the case of a UE supporting up to UL 256QAM, it is assumed that the target SINR is 32 dB. Since the UL SINR received from the base station is 20 dB, the base station transmits an f(i) value to the terminal to raise the output by 12 dB. The terminal transmits the output of -3dBm transmission as 9dBm, which is increased by 12dB. Then, the repeater reverse input is received at -36dBm (= 9dBm - 45dB), and the repeater reverse output is radiated with 34dBm (= -36dBm + 70dB) amplified by 70dB. Since the base station reverse input is subtracted by the path loss between the base station and the repeater from the repeater's reverse output of 34dBm, it is received as -58dBm (= 34dBm - 92dB). At this time, the output exceeds the rated output of the AMP (Amplifier) of 30 dBm and the AMP is saturated, so the SINR of the signal radiated from the repeater to the base station is lower than 32 dB. That is, although the output is increased, it is radiated with a higher output than the reverse AMP, resulting in a decrease in SINR due to saturation of the AMP.

Even if this signal arrives at the base station, the SINR of the input signal is lower than 32 dB, and the base station received UL SINR is lower than the target SINR, so the base station informs the terminal to increase the output again. However, as the terminal output increases, the repeater reverse AMP saturation becomes more severe, so the UL SINR received from the base station continues to decrease, and the terminal raises the terminal output to P _max , which can no longer increase the terminal output. .

To prevent such over-output, the RF (Radio Frequency) repeater applies ALC (Auto Level Control) operation.

1 is a diagram for explaining an ALC operation in the related art.

Referring to FIG. 1 , the repeater detects the output for each ALC operation period, usually 200ms to 500ms, and when the output is higher than the upper limit for each ALC, lowers the gain by the difference between the sensed output and the ALC upper limit at once in the ALC operation period. In addition, if the output of the repeater is lower than the lower limit of each ALC and the gain is lowered, the gain is increased by several dB per ALC operation period.

However, when the ALC is operated with an operation period that is too short, the quality may be rather deteriorated due to frequent gain fluctuations due to environmental changes and traffic characteristics.

In addition, the over-output of the AMP is maintained until ALC is performed, and the gain is controlled only up to the ALC upper limit based on the output that can be detected. During AMP saturation, equipment deterioration and terminal quality deterioration may occur. In order to solve this problem, according to the embodiment, the repeater divides zones according to the path loss between the repeater and the terminal, and the repeater reverse gain, and performs reverse ALC according to each zone, which will be described below with reference to the drawings.

2 is a block diagram showing the configuration of a repeater performing reverse ALC control according to an embodiment, FIG. 3 shows a reverse gain control zone according to the embodiment, and FIG. 4 is a repeater-terminal path loss and repeater according to the embodiment It is a view showing a further reduction in the reverse gain according to the reverse gain, and FIG. 5 is an example showing the transition between the reverse gain control zones according to the embodiment.

Referring to FIG. 2 , the repeater 100 includes an antenna #1(101), a filter #1(102), a circulator #1(103), and a low noise amplifier (hereinafter, collectively referred to as 'LNA')# 1 (104), forward attenuator (Attenuator, hereinafter collectively called 'ATT') control unit 105, forward amplifier (Amplifier, hereinafter collectively called 'AMP') 106, circulator #2 (107), Filter #2 (108), antenna #2 (109), switch 110, LNA #2 (111), reverse ATT control unit 112, reverse AMP 113, ALC control unit 114, detection unit 115 and and a repeater control unit 116 .

The forward signal received from the base station 200 is antenna #1 (101) → filter #1 (102) → circulator #1 (103) → LNA #1 (104) → forward ATT controller 105 → forward AMP (106) ) → circulator #2 (107) → filter #2 (108) → is transmitted to the terminal 300 through a forward path consisting of antenna #2 (109).

The reverse signal received from the terminal 300 is antenna #2 (109) → filter #2 (108) → circulator #2 (107) → switch 110 → LNA #2 (111) → reverse ATT control unit 112 → Reverse AMP (113) → Circulator #1 (103) → Filter #1 (102) → It is transmitted to the base station 200 through the reverse path consisting of the antenna #1 (101).

Antenna #1 101 transmits and receives a reverse signal and a forward signal to and from the base station 200 .

Filter #1 (102) is a band-pass filter, and filters a signal of a predetermined frequency band among signals received by the antenna #1 (101) so as to transmit/receive forward/reverse signals of a predetermined frequency band with the base station 200. do.

The circulator #1 (103) outputs the forward signal introduced through the filter #1 (102) to the LNA #1 (104) and prevents the signal output from the reverse path from flowing into the forward path.

The LNA #1 (104) amplifies the forward signal passing through the circulator #1 (103) to a predetermined gain level.

The forward ATT control unit 105 controls the output of the forward AMP 106 with the forward ATT value output from the ALC control unit 114 . The forward ATT control unit 105 checks the output of the forward AMP 106 and when the output of the forward AMP 106 is high compared to the ALC upper limit, the forward ATT value received from the ALC control unit 114 is added to the forward AMP 106. lower the output of When the output of the forward AMP 106 is lower than the ALC lower limit, the forward ATT control unit 105 decreases the forward ATT value to increase the output of the forward AMP 106 .

The forward AMP 106 amplifies and outputs the forward signal whose output has been adjusted by the forward ATT control unit 105 by the gain characteristic of the forward AMP 106 , that is, a fixed gain.

The circulator #2(107) outputs the forward signal introduced from the forward AMP(106) to the filter #1(108) and prevents the forward signal from flowing into the reverse path, that is, the LNA #2(111).

Filter #2(108) is a bandpass filter, and filters a signal of a frequency band agreed with the terminal 300 among the forward signals passing through circulator #2(107).

Antenna #2 (109) transmits the forward signal passing through filter #2 (108) to the terminal (300).

The switch 110 serves to block the forward signal passing through the forward AMP 106 in the forward transmission section, that is, the DL (DownLink) section, from flowing into the reverse path after passing through the circulator #2 (107). and a reverse signal is introduced into LNA #2 (111) in the reverse transmission section.

LNA #2 (111) amplifies the reverse signal passing through antenna #2 (109) to a predetermined gain level.

The reverse ATT control unit 112 controls the output of the reverse AMP 113 with the reverse ATT value output from the ALC control unit 114 . The reverse ATT control unit 112 checks the output of the reverse AMP 113, and when the output of the reverse AMP 113 is high compared to the upper limit of the ALC, the reverse ATT value received from the ALC control unit 114 is added to the reverse AMP 113. lower the output of When the output of the reverse ATT control unit 112 is lower than the ALC lower limit, the reverse ATT control unit 112 decreases the reverse ATT value to increase the output of the reverse AMP 113 .

The reverse AMP 113 amplifies the signal passing through the reverse ATT control unit 112 to a predetermined gain level. The amplified reverse signal is output to the filter #1 (102) through the circulator #1 (103). Filter #1 (102) filters the amplified reverse signal with respect to a service band.

In a state in which the forward AMP 106 and the reverse AMP 113 are turned off, the forward signal is not emitted. The ALC control unit 114 sets the forward ATT value for forward ATT control to 0 and outputs it to the forward ATT control unit 105, thereby controlling the forward gain of the forward AMP 106 to operate at the maximum gain.

The repeater control unit 116 turns on the forward AMP 106 and the reverse AMP 113 by obtaining TDD (Time Division Duplex) switching synchronization.

At this time, since the output that can be radiated through the repeater 100 is limited, the ALC control unit 114 performs forward gain control to radiate within the rated output of the repeater. The forward output detects a value coupled to the signal output from the forward AMP 106 and utilizes this value for the forward ALC function.

The ALC controller 114 sets the reverse initial gain to a value obtained by adding an operator offset to the forward gain. The ALC control unit 114 detects a value obtained by coupling the signal output from the reverse AMP 113 and utilizes this value for the reverse ALC function.

Here, the reason why the reverse gain is set in conjunction with the forward gain is a method that has been used to keep the bidirectional link budget difference constant because the forward input value of the repeater changes due to fading between the base station and the repeater. The reason for setting the operator offset is to prevent the base station coverage from being reduced by the repeater 100 .

At this time, the ALC control unit 114 divides the zone corresponding to the reverse signal detected by the detection unit 115 from the reverse AMP 113 and the reverse gain set in the reverse AMP 113, and controls the reverse gain set in the zone. 3, the reverse gain control zone is three zones divided according to the repeater reverse gain and the repeater-to-terminal path loss, that is, a green zone (hereinafter, collectively referred to as a 'G' zone). ), a yellow zone (hereinafter, collectively referred to as a 'Y' zone), and a red zone (hereinafter, collectively referred to as an 'R' zone).

The G zone is a region in which the reverse gain set in the reverse AMP 113 is maintained without additionally controlling the reverse gain, and the ALC control unit 114 maintains the same forward ATT value in the G zone. When the base station-repeater loss is small and the repeater reverse gain is low, the base station reception target SINR may be satisfied even if the output of the terminal 300 is increased by the CLPC operation.

In addition, if the distance between the base station and the repeater is large and the terminal (3) radiates at its maximum output, but the repeater does not have reverse over-output, it is not necessary to additionally control the reverse gain. The loss region is defined as the G zone. In the G zone, the ALC controller 114 operates as the original gain without additionally controlling the reverse gain, where the original gain refers to the gain defined in the ALC operation. According to , when the output is detected for each ALC operation period and the output is higher than the ALC upper limit, the gain is lowered by the difference between the sensed output and the ALC upper limit at once in the ALC operation period, and when the output is lower than the upper limit, that is, when the gain is lowered Increase the gain by several dB per ALC operation period.

Zone Y radiates excess output in the reverse direction of the repeater, but when output detection is made within the range of accuracy, the amount of gain reduction to be applied can be known. Add y(dB) to lower the reverse gain by y(dB). The reverse gain of the repeater and the path loss region between the repeater and the terminal are defined as the Y zone. However, in the Y zone, the ALC control unit 114 may maintain a stable reverse gain through an additional margin, that is, an additional gain reduction parameter offsetΔ, in order to prevent a large gain change.

In addition, if the repeater radiates excessive power in the reverse direction, but the output detection is out of accuracy and it is not known how much to reduce the gain, the reverse gain of the repeater and the path loss region between the repeater and the terminal is defined as an R zone. In the R zone, the ALC control unit 114 considers the MCL (Minimum Coupling Loss, minimum coupling loss) and assuming that the terminal 300 is at the closest position from the antenna, for example, by adding the reverse ATT value x (dB) to the reverse gain x(dB) is lowered and the repeater gain is maintained until the terminal call is terminated. Referring to FIG. 4, unlike in the G zone and the Y zone, where the gain reduction amount is one, the gain reduction amount in the R zone depends on the repeater reverse gain. change step by step

For example, when the repeater to terminal path loss is P1, if the repeater reverse gain is G2-G1, the amount of further reduction in reverse gain (offsetΔ) is 10 (dB), and when the repeater to terminal path loss is P2, the repeater reverse gain If this is G3-G2, the amount of further reduction in the reverse gain (offsetΔ) is 14 (dB), and when the repeater-terminal path loss is P3, if the repeater reverse gain is G4-G3, the amount of additional reduction in the reverse gain (offsetΔ) is 18 ( dB), when the repeater to terminal path loss is P4, if the repeater reverse gain is G5-G4, the amount of further reduction in reverse gain (offsetΔ) is 22(dB), when the repeater to terminal path loss is P5, the repeater reverse gain is If G6-G5, the amount of additional reduction in the reverse gain (offsetΔ) is 26 (dB), when the repeater-terminal path loss is P6, if the repeater reverse gain is G7-G6, the amount of additional reduction in the reverse gain (offsetΔ) is 30 (dB) ) can be applied step by step.

When the terminal 300 transmits with the maximum output at a position where the path loss between the repeater and the terminal is MCL, the maximum output flows into the reverse input of the repeater regardless of the reverse gain of the repeater. Therefore, since the repeater reverse gain to be controlled according to the repeater reverse gain is different, the amount of gain reduction can be subdivided for stable quality of the terminal or set in several groups. If it occurs frequently, the gain may fluctuate a lot, and the quality may be deteriorated. In consideration of this, a state transition is made between zones as shown in FIG. 5 .

Referring to FIG. 5 , the state transition between zones is from G zone to Y zone, G zone to R zone entry, Y zone to R zone entry, Y zone to G zone entry, and R zone to G zone entry. includes In this case, the entry from the Y zone or the R zone to the G zone may be referred to as Y zone release or R zone release.

At this time, in order to prevent quality degradation due to frequent gain fluctuations, after the reverse gain state enters the R or Y zone, the repeater maintains the reverse gain until the terminal call is terminated, and enters the G zone when it is determined that the terminal call is terminated. can do.

In addition, when the reverse gain state enters the Y zone and the reverse output value is greater than X ₁ due to the increase in the reverse output of the additional terminal 300 or the existing terminal 300 causing reverse over-output, the reverse gain state is in the Y zone. to the R zone, even in this case, the reverse gain of the Y zone may be maintained and the terminal 300 may transition to the R zone after the call is terminated.

The ALC controller 114 determines a zone corresponding to the reverse gain state based on the reverse signal detected by the detector 115 and performs ALC control set in the zone as described with reference to FIGS. 3 and 4 . The ALC control unit 114 outputs the reverse gain control value set in the zone to the reverse ATT control unit 112 .

The detection unit 115 is connected to the front end of the reverse AMP 113 to detect a forward signal output from the reverse AMP 113 and outputs a forward output value to the ALC control unit 114 .

The ALC control unit 114 operates using the reverse ALC control parameters defined as shown in Table 1. Table 1 is stored in the memory of the ALC control unit 114 .

variable parameter unit Contents Zone classification red zone X ₁ dBm Entry condition: Reverse output ≥ X ₁ yellow zone Entry condition: X ₂ < Reverse output < X ₁ Green zone x ₂ dBm Entry condition: Reverse output ≤ X ₂ offsetΔ
Initialization condition UL Out Pwr X ₃ dBm When holding X ₃ level or less for X ₄ ms
R zone/Y zone release and transition to G zone holding time X ₄ ms UL output detection condition
(average application conditions) X ₅ dBm Whether to take the overall average when output is detected,
Threshold to decide whether to average only values greater than X ₅ Threshold@Green zone X ₆ dB Reverse gain condition that exists only in G zone UL ATT@ Yellow zone X ₇ dB Gain reduction value in Y zone (fixed-operator) ALC cycle X ₈ episode ALC period: 2.5ms×X ₈

The ALC control unit 114 determines the zone where the output value of the reverse AMP 113 and the reverse gain of the reverse AMP 113 correspond to the repeater reverse gain vs. the gain control parameter according to the path loss between the repeater and the terminal defined in Table 1. decide

The ALC control unit 114 initializes the offsetΔ used in the ALC algorithm. The offsetΔ is a parameter indicating an additional gain reduction and is output to the reverse ATT control unit 112 .

The ALC control unit 114 detects the reverse output value of the reverse AMP 113 through the detection unit 115 several times for each UL slot, in this case, every 2.5 ms period. The reason for detecting every 2.5ms cycle is that the forward (DL, DownLink)/reverse direction (UL, UpLink) signals used in the domestic 3.5GHz 5G TDD are repeated at a 2.5ms cycle.

The ALC control unit 114 collects the reverse output value sensed at 2.5 ms period during the ALC period (X ₈ times). When there is an output value greater than the average application condition (X ₅ ) among the collected reverse output values, the ALC control unit 114 takes an average of the output values greater than the average application condition (X ₅ ). When there is no signal greater than the average application condition (X ₅ ), the ALC control unit 114 takes an average of all output values collected during the ALC period (X ₈ times).

The ALC controller 114 uses the calculated average output value as a reference output for operating the reverse ALC. This is to detect that the terminal 300 located in the short distance and the terminal 300 located in the far distance are mixed or the terminal 300 having little traffic transmits a reverse signal in the short distance.

The ALC control unit 114 determines the zone to which the reverse gain state belongs, based on the reference output value, and then sets the path loss (PL) for each zone and the reverse ATT value according to the current repeater reverse gain.

At this time, when the reverse gain is less than or equal to the reverse gain condition (X ₆ ), the ALC control unit 114 determines the reverse gain state as the G zone. Also, when the reverse reference output value is equal to or less than the G zone threshold (X ₂ ), the ALC control unit 114 determines the reverse gain state as the G zone. When the reverse gain state is determined to be the G zone, the ALC control unit 114 sets offsetΔ to 0.

When the reverse reference output value exceeds the G zone threshold (X ₂ ) and is less than the R zone threshold (X ₁ ), the ALC control unit 114 determines the reverse gain state as the Y zone. At this time, the ALC control unit 114 sets the offsetΔ to -X ₇ (dB). -X ₇ (dB) is the value stored in Table 1 and is a fixed value set by the operator, but may be changed by the operator in some cases.

When the reverse reference output value is equal to or greater than the R zone threshold (X ₁ ), the ALC control unit 114 determines the reverse gain state as the R zone. At this time, as shown in Table 4, the ALC control unit 114 sets the corresponding offsetΔ based on the repeater-terminal path loss and the repeater reverse gain. For example, referring to FIG. 4 , the ALC controller 114 may set offsetΔ=14 (dB) if the current reverse gain is included in the G2-G3 section and the repeater-terminal path loss is P2.

The ALC control unit 114 monitors whether the output value of the reverse direction group in the Y zone satisfies the zone release condition, and when the zone release condition is satisfied, the ALC control unit 114 transitions to the G zone. That is, the ALC controller 114 determines that the zone release condition is satisfied when the backward reference output value is maintained for the initialization threshold time X4 in a state that is less than the initialization threshold value X ₃ . The ALC control unit 114 corrects the offsetΔ in consideration of belonging to the Y zone and continuously checks whether it belongs to the R zone.

When the ALC control unit 114 corresponds to the R zone, it adjusts the gain according to the reverse gain vs. path loss table, and maintains the reverse gain as fixed until released from the R zone. If the backward reference output value in the R zone is maintained for the initialization threshold time X4 in a state that is less than the initialization threshold value X ₃ , it is determined that the zone release condition is satisfied and transitions to the G zone.

At this time, even if the zone release condition is satisfied in the Y zone or the R zone, the ALC control unit 114 does not immediately transition to the G zone, maintains the current reverse gain, and then transitions to the G zone after the terminal call is terminated.

When determining the R zone entry condition, the ALC control unit 114 determines whether the 'reverse output value-offsetΔ' is equal to or greater than the R zone threshold (X ₁ ). If the state before the R zone is the G zone, offsetΔ=0, and if the state before the R zone is the Y zone, the offsetΔ becomes an additional gain reduction parameter set in the Y zone. Accordingly, it is possible to determine whether to enter the R zone by excluding the reverse gain already reduced in the Y zone, and determining whether the reverse gain is in an over-output state.

6 is a flowchart illustrating a reverse gain ALC control method according to an embodiment, and the same reference numerals are used to describe the same components in connection with the components of FIG. 2 .

6, when the forward AMP 106 and the reverse AMP 113 are turned on (S101), the ALC control unit 114 sets the forward gain to the maximum gain, and the reverse gain is obtained by adding the operator offset to the forward gain. set (S102).

The ALC controller 114 initializes offsetΔ, which is a parameter indicating an additional gain reduction used in the ALC algorithm (S103).

The ALC control unit 114 checks the reverse output value of the reverse AMP 113 through the detection unit 115 ( S104 ). Here, the reference output is calculated through the reverse output value, and the reference output refers to the reverse output value used to continuously update for transition between zones after determining the reverse gain control zone. The reverse output value will be described in detail later with reference to FIG. 7 .

The ALC control unit 114 determines whether the reverse gain of the reverse AMP 113 is equal to or less than the reverse gain condition (X ₆ ) ( S105 ).

If it is determined in S105 that the reverse gain condition (X ₆ ) is not or less, the ALC control unit 114 determines whether the reverse output value is equal to or less than the G zone threshold (X ₂ ) (S106).

The ALC control unit 114 determines that the reverse gain is equal to or less than the reverse gain condition (X ₆ ) in S105, or the reverse output value is less than or equal to the G zone threshold (X ₂ ) in S106, and determines the reverse gain state as the G zone and , the reverse gain control defined in the G zone is performed (S107). That is, the offsetΔ is set to 0 (S107).

If it is determined that the reverse output value is not less than or equal to the G zone threshold (X ₂ ) in S106, the ALC control unit 114 determines whether the reverse output value exceeds the G zone threshold (X ₂ ) and is less than the R zone threshold (X ₁ ) (S108) ).

If the reverse output value exceeds the G zone threshold (X ₂ ) and is less than the R zone threshold (X ₁ ), the ALC control unit 114 determines the reverse gain state as the Y zone and performs reverse gain control defined in the Y zone ( S109). That is, the ALC control unit 114 sets the offsetΔ to a predetermined gain reduction value in the Y zone to -X ₇ ( S109 ).

If the reverse output value exceeds the G zone threshold (X ₂ ) and is not less than the R zone threshold (X ₁ ) in S108, the ALC control unit 114 determines the reverse gain state as the R zone, and controls the reverse gain defined in the R zone do (S110). At this time, the ALC control unit 114 maintains the reverse gain fixed until it is released from the R zone.

On the other hand, the ALC control unit 114 checks the reverse output value in the Y zone ( S111 ), and maintains the reverse output value under the zone release condition, that is, the initialization threshold value (X ₃ ) for the initialization threshold time (X4) or R It is determined whether the zone entry condition is satisfied (S112).

If the zone release condition is satisfied in S112, the reverse gain state is determined as the G zone and the offsetΔ is initialized (S113), and then the reverse gain control defined in the G zone, that is, S107 is performed. At this time, after the terminal call is terminated, the transition is from the Y zone to the G zone.

If the 'reverse output value-offsetΔ' in S112 is equal to or greater than the R zone threshold (X ₁ ), the ALC control unit 114 determines a transition to the R zone and performs S110. In this case, the transition from the Y zone to the R zone is also made after the terminal call is terminated.

In addition, the ALC control unit 114 checks the reverse output value in the R zone (S114), and determines whether the reverse output value is maintained for the initialization threshold time (X ₄ ) under the zone release condition, that is, less than the initialization threshold (X ₃ ). (S115).

If the zone release condition is satisfied in S115, the ALC control unit 114 determines the reverse gain state as the G zone, initializes the offsetΔ (S113), and then performs the reverse gain control defined in the G zone (S107). At this time, after the terminal call is terminated, it transitions to the G zone.

Meanwhile, steps S104, S111, and S114 are procedures for checking the reverse output value, which will be described in detail with reference to FIG. 7 .

7 is a flowchart illustrating a method for determining a reverse output for an ALC operation according to an embodiment. In connection with the components of FIG. 2 , the same reference numerals are used to describe the same components.

Referring to FIG. 7 , when the reverse output value checking procedure starts ( S201 ), the ALC control unit 114 determines whether a 2.5 ms period, which is a reverse period, arrives ( S202 ).

When the reverse cycle arrives, the ALC control unit 114 detects and stores the output value of the reverse signal output from the reverse AMP 113 (S203).

The ALC control unit 114 repeats steps S202 and S203 until the ALC cycle arrives.

When the ALC period arrives (S204), the ALC control unit 114 determines whether there are backward output values equal to or greater than the average application condition (X ₅ ) (S205).

If there are reverse output values equal to or greater than the average application condition (X ₅ ) in S205 , the ALC control unit 114 calculates an average value of the reverse output values equal to or greater than the average application condition (X ₅ ) ( S206 ).

When there is no reverse output value equal to or greater than the average application condition (X ₅ ) in S205, the ALC control unit 114 calculates an average value of all reverse output values stored in S203 (S207).

The ALC control unit 114 determines the average value of the reverse output values calculated in S206 or S207, that is, the average reverse output value, as a reference output for determining the zone. At this time, when there is only one reverse output value equal to or greater than the average application condition (X ₅ ), the ALC control unit 114 uses one reverse output value as a reference output for determining the zone.

The embodiment of the present invention described above is not implemented only through the apparatus and method, and may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium in which the program is recorded.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improved forms of the present invention are also provided by those skilled in the art using the basic concept of the present invention as defined in the following claims. is within the scope of the right.

Claims (14)

A method for reverse gain automatic level control (ALC) of a repeater, comprising:
Based on the reverse gain of the repeater and the path loss between the terminal and the repeater, setting a plurality of reverse gain control zones;
determining a reverse gain control zone corresponding to a reverse gain state from among the plurality of reverse gain control zones based on the reverse signal output value; and
Adjusting the reverse gain by using the automatic level control information set in the determined reverse gain control zone
A method comprising In claim 1,
The plurality of reverse gain control zones,
A first zone maintaining a set reverse gain, and a second zone requiring adjustment of the set reverse gain due to reverse over-output,
The adjusting step is
When the reverse gain state corresponds to the second zone, the method of reducing preset reverse gain information by adding automatic level control attenuation information. In claim 2,
The second zone,
and a third zone in which reverse over-output is present and at the same time, reverse-output detection is made within the accuracy range;
The adjusting step is
When the reverse gain state corresponds to the third zone, the method for reducing the reverse gain by adding preset automatic level control attenuation information matched to the third zone. In claim 2,
The second zone,
and a fourth zone in which reverse over-output is present and at the same time reverse-output detection is made outside the accuracy range;
The adjusting step is
When the reverse gain state corresponds to the fourth zone, a method of reducing a reverse gain by adding automatic level control attenuation information defined in response to a current reverse gain and a path loss between a terminal and a repeater. In claim 4,
Automatic level control attenuation information defined in the fourth zone,
A method comprising a plurality of automatic level control attenuation information set step by step in response to a plurality of reverse gains and a plurality of terminal and relay path losses. In claim 1,
Prior to the determining step,
Collecting the output values of the reverse signals measured in units of the reverse period during the automatic level control period;
determining whether at least one of the output values is greater than or equal to a predefined threshold, and
If there is no average value of at least one output value equal to or greater than the predefined threshold value or at least one output value equal to or greater than the predefined threshold value, setting an average value of all collected output values as a reference output, further comprising:
The determining step is
determining the zone to which the reverse gain state corresponds using the reference output. In claim 1,
Prior to the determining step,
Setting the initial reverse gain to a value obtained by adding the operator offset to the forward gain
A method further comprising: As a repeater performing reverse gain automatic level control (ALC, Auto Level Control),
a reverse amplifier for amplifying and outputting a reverse signal by a reverse gain;
a detector for detecting an output value of a reverse signal output from the reverse amplifier; and
By comparing the output value of the reverse signal with each threshold condition set in a plurality of reverse gain control zones set based on the reverse gain of the repeater and the path loss between the terminal and the repeater, the reverse direction corresponding to the reverse gain state of the reverse amplifier An automatic level control (ALC) unit that determines a gain control zone and adjusts the reverse gain based on automatic level control information set in the determined reverse gain control zone
Including, repeater. In claim 8,
The automatic level control unit,
Based on the output value of the reverse signal, determining whether the reverse gain state corresponds to a first zone maintaining a set reverse gain or a second zone requiring adjustment of the set reverse gain due to reverse over-output, a repeater. In claim 9,
Further comprising a reverse attenuation control unit for reducing the reverse gain of the reverse amplifier through the automatic level control attenuation information,
The automatic level control unit,
When the reverse gain state corresponds to the second zone, automatic level control attenuation information for reducing the reverse gain is output to the reverse attenuation control unit, a repeater. In claim 9,
The automatic level control unit,
When a transition of the reverse gain state from the second zone to the first zone is detected based on the output value of the reverse signal, the reverse gain of the second zone is maintained until the terminal call is terminated. In claim 9,
The automatic level control unit,
When the reverse signal output value is equal to or less than a first threshold or the reverse gain meets a predetermined gain condition, the reverse gain state is determined as the first zone, and the reverse gain set in the reverse amplifier is maintained. In claim 9,
The second zone,
and a third zone in which reverse over-output is present and at the same time, reverse-output detection is made within the accuracy range;
The automatic level control unit,
When the reverse signal output value is within a threshold range, the reverse gain state is determined as the third zone and the reverse gain is reduced by using the gain reduction value set in the third zone. In claim 9,
The second zone,
and a fourth zone in which reverse over-output is present and at the same time reverse-output detection is made outside the accuracy range;
The automatic level control unit,
When the reverse signal output value is equal to or greater than the second threshold, the reverse gain state is determined as the fourth zone, and the reverse gain is reduced using a current reverse gain and a gain reduction value determined based on the path loss between the repeater and the terminal. , repeater.

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