KR20230030998A - Method for resource allocation and power control in wireless communication system - Google Patents

Abstract

Disclosed is a resource allocation method, which can be applied to a wireless communication system using multiple carriers to improve communication reliability. The resource allocation method is performed in a wireless communication system based on an energy-wireless sensor network (e-WSN) including a gateway and a device. The resource allocation method comprises a step of connecting a main link between a gateway and a device. In addition, a frame structure in the main link includes one frame and the frame includes ten subframes. Also, one of the subframes includes two slots.

Description

Method for resource allocation and power control in wireless communication system

The present invention relates to wireless communication technology, and more particularly, to a method for optimizing resource allocation and power control in a wireless communication system using multiple carriers.

The recently developed e-WSN (energy-Wireless Sensor Network) is a narrowband system developed as part of a self-communication network establishment plan. In the case of this system, wide coverage due to excellent diffraction and transmittance of the 380Hz UHF (Ultra High Frequency) band, QAM (Quadrature Amplitude Modulation) modulation method is used. Therefore, it is possible to provide stable communication performance due to transmission speed 15 times faster than TRS (Trunked Radio Service) technology in the same frequency and no signal interference problem due to the characteristics of the licensed band.

Based on this e-WSN system, it is used not only for power control where stability is important, but also for various IoT (Internet of Things) businesses. It is expected that the problem can be solved.

In general, in the e-WSN communication method, each device must be allocated a channel for data transmission, and in this process, a Schedule Request (SR) channel is used. In addition, the SR channel is a channel shared by several devices, and a different sequence is allocated and used for each device in order for the multiple devices to simultaneously use the channel.

In this case, since signal interference occurs when signals received by the gateway differ in magnitude, power control is performed in a general closed-loop manner in the case of uplink. At this time, the size of the signal received by the gateway is controlled for each device to be -100dBm.

Meanwhile, the current resource allocation and power control scheme has the following problems.

① The e-WSN communication method is a system that uses multiple carriers, and although the amount of interference is different for each carrier, the power measurement result of the closed-loop method using one carrier is applied equally to all carriers.

② Optimized resource allocation is possible when subcarriers are allocated in consideration of the channel condition of each device and a group of devices using the same SR resource, but conventionally, channels are allocated sequentially.

③ There is a maximum and minimum range for the transmission output of a device, and there are cases where power control is impossible due to these restrictions, but this is not considered in the past. When the wireless channel condition is good because the distance between the gateway and the device is close, even if the device transmits a signal with the lowest output, it is received as a very large signal by the gateway, and as a result, power control does not operate normally, causing interference to other devices. Therefore, there is a limit to optimization of resource allocation and power control.

1. Korea Patent Registration No. 10-1813232 (registration date: December 21, 2017)

The present invention has been proposed to solve the problems caused by the above background art, and an object of the present invention is to provide a resource allocation and power control method that can improve communication reliability by being applied to a wireless communication system using multiple carriers.

In order to achieve the above object, the present invention provides a resource allocation method that can improve communication reliability by being applied to a wireless communication system using multiple carriers.

The resource allocation method,

A resource allocation method in an e-WSN (energy-wireless sensor network) based wireless communication system consisting of a gateway and a device, comprising:

and connecting a primary link between the gateway and the device.

At this time, the frame structure in the main link is characterized in that one frame is composed of 10 subframes, and one subframe is composed of 2 slots.

In addition, one frame has a length of 1 sec, the subframe has a length of 100 ms, and the slot consists of 1000 symbols and has a length of 50 ms.

In addition, five resource blocks are allocated to one slot 111-1, and one resource block has a length of 9.9 ms and has a plurality of ( N _sc ) subcarriers.

In addition, one slot is composed of a plurality of shared channels (SCHs) and one control channel (CCH), and one resource block is allocated to one CCH, and four resource blocks are allocated to a plurality of SCHs. In the last part, a guard time is inserted, and the length of the time is 0.5 ms.

In addition, if one slot is a downlink slot of a primary link, one CCH is inserted between SCH 1 among the plurality of SCHs.

In addition, if one slot is an uplink slot of a primary link, one CCH is inserted between SCH 2 among the plurality of SCHs.

In addition, one CCH can transmit up to 2 * N _sc (where N is a natural number) of SR (Schedule Request) information having a length of 99 symbols, and the number of transmissions is set in a higher layer. Characterized in that.

( 여기에서 u는 시퀀스의 근(root), N은 수열의 길이를 나타낸다)으로 정의되며, 시퀀스의 근(sequence root)은 수학식

(여기서, ID는 게이트웨이(gateway)의 식별 번호이다)으로 정의되는 것을 특징으로 한다.In addition, the SR information is Equation

(where u is the root of the sequence, and N represents the length of the sequence), and the sequence root is

(Here, the ID is an identification number of a gateway).

On the other hand, another embodiment of the present invention, (a) periodically collecting measurement information in the gateway; (b) classifying a channel according to the measurement information in the gateway; (c) grouping a plurality of devices based on reception sensitivity and transmission output of similar uplink signals according to channel classification in the gateway; (d) allocating SR channels to a plurality of devices in the gateway; (e) limiting the output range of the plurality of devices according to the allocation of the SR channel; provides a power control method in a wireless communication system comprising the.

In addition, in step (a), (a-1) periodically measures the power value of Additive White Gaussian Noise (AWGN) + interference of a wireless channel using an uplink SCH channel that is not in use in the gateway, and not a single channel measuring all channels; (a-2) measuring reception sensitivity of the uplink signal when signals are transmitted from the plurality of devices to the gateway, and measuring an average value of the reception sensitivity without classifying them according to channels; (a-3) calculating a signal-to-noise ratio (SNR) for each channel using the reception sensitivity and the power value of the AWGN+interference in the plurality of devices; and (a-4) managing transmission output values of the devices using a CCH channel in the same manner as before in the plurality of devices.

In addition, the gateway manages a rank using the power value of the AWGN+interference for a plurality of channels, and the rank is utilized when the SR channel is allocated in the device.

In addition, the grouping is managed by dividing into two groups when the transmission power is the maximum or the minimum, and the remaining devices whose transmission power is not the maximum or the minimum are managed as the remaining groups, and each group has the transmission power Characterized in that it is determined according to the level order.

In addition, the step (d) may include (d-1) allocating the group having the maximum transmit power first to a channel having the lowest AWGN + interference among a plurality of channels; (d-2) first allocating the group having the lowest transmit power to the channel having the highest AWGN+interference among the plurality of channels; (d-3) allocating the remaining groups to channels obtained by subtracting 2 from the plurality of channels, and allocating channels with low (AWGN + interference) in order of highest transmit power; and (d-4) performing power control in a closed-loop manner based on the SNR for each channel after allocating the SR channel.

( 여기서, S ₀ 는 수신감도가 가장 낮은 디바이스의 수신감도, l은 디바이스 번호, S _l 은 l번째 디바이스의 수신감도, D _l 은 디바이스 간 수신감도 차, L은 송신출력이 최소인 그룹의 디바이스 총 개수이다)는 것을 특징으로 한다.In addition, the group with the minimum transmission output minimizes interference between the plurality of devices by using the difference in reception sensitivity between the plurality of devices based on the device having the lowest reception sensitivity, and the difference in reception sensitivity is expressed by Equation

(Where S ₀ is the reception sensitivity of the device with the lowest reception sensitivity, l is the device number, S _l is the reception sensitivity of the lth device, D _l is the reception sensitivity difference between devices, and L is the device of the group with the minimum transmission output is the total number).

According to the present invention, it is possible to secure high communication reliability of a system through a resource allocation process in which power control is performed for each carrier used in a wireless communication system using multiple carriers and a radio channel state of devices is considered.

In addition, another effect of the present invention is that it can additionally solve the problems of communication delay and efficiency deterioration.

In addition, another effect of the present invention is that the failure probability of channel allocation using the SR (Schedule Request) channel is reduced even in an environment with a lot of interference, so that the reliability of the system is improved, and it is possible to provide a system that is robust to interference signals. can

In addition, as another effect of the present invention, when channel allocation fails using the SR channel, a delay of at least 100 ms occurs each time it is retried after one failure, and low-latency data transmission is achieved by reducing the failure probability of the SR channel point out that it is possible.

In addition, as another effect of the present invention, when channel allocation and data transmission fail, a retransmission procedure is performed. In this case, additional radio resources are consumed and power consumption occurs due to signal transmission. Due to the proposed technique, efficient device power and radio resource management.

1 is a frame structure of an e-WSN (energy-wireless sensor network) system according to an embodiment of the present invention.
2 is a resource block structure according to an embodiment of the present invention.
3 is a downlink slot structure of a primary link according to an embodiment of the present invention.
4 is an uplink slot structure of a primary link according to an embodiment of the present invention.
5 is a SR (Schedule Request) transmission structure according to an embodiment of the present invention.
6 is a conceptual diagram of a power control method of a resource allocation channel according to an embodiment of the present invention.
7 is a flowchart showing a power control process according to an embodiment of the present invention.
8 is a configuration block diagram of a communication device according to an embodiment of the present invention.

Advantages and features of the present invention, and methods for achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only the present embodiments make the disclosure of the present invention complete, and those skilled in the art in the art to which the present invention belongs It is provided to fully inform the person of the scope of the invention, and the invention is only defined by the scope of the claims. The sizes and relative sizes of components shown in the drawings may be exaggerated for clarity of explanation.

Like reference numbers throughout the specification indicate like elements, and “and/or” includes each and every combination of one or more of the recited items.

Terms used in this specification are for describing embodiments and are not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. The referenced elements, steps, operations and/or elements that “comprise” and/or “comprise” as used in the specification do not exclude the presence or addition of one or more other elements, steps, operations and/or elements. .

Although used to describe various components such as first and second, these components are not limited to these terms, of course. These terms are only used to distinguish one component from another. Accordingly, it goes without saying that the first component mentioned below may also be the second component within the technical spirit of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless explicitly specifically defined.

Hereinafter, a resource allocation and power control method in a wireless communication system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a frame structure of an e-WSN (energy-wireless sensor network) system according to an embodiment of the present invention. In particular, FIG. 1 shows a frame structure in a main link connected between a gateway and a device (ie, a terminal). Referring to FIG. 1 , a frame structure 100 is composed of 1 frame 110 and has a length of about 1 sec, and 1 frame 110 includes 10 sub-frames 111 . One subframe 111 has a length of about 100ms and consists of two slots 111-1. One slot 111-1 consists of 1000 symbols and has a length of about 50 ms.

N _sc의 자원블록(200)이 할당된다. 도 2를 참조하면, 하나의 자원 블록(200)은 9.9ms의 길이를 가지며 N _sc는 부반송파(210)의 개수를 나타낸다. 2 is a resource block structure according to an embodiment of the present invention. Resources are allocated in units of resource blocks, and five resource blocks 200 are allocated to one slot based on one subcarrier. Therefore, considering the number N _sc of subcarriers 210, 5

A resource block 200 of N _sc is allocated. Referring to FIG. 2, one resource block 200 has a length of 9.9 ms and N _sc represents the number of subcarriers 210.

3 is a downlink slot structure of a primary link according to an embodiment of the present invention. The slot 111-1 is composed of a shared channel (SCH) 310 and a CCH 320. One resource block is allocated to the control channel (CCH), four resource blocks are allocated to the SCH, and the last part of the slot A guard time 330 is inserted in , and the length of time is 0.5 ms. CCH is inserted in the center of SCH resource block 1. That is, it is inserted between SCH 1 and SCH 1.

4 is an uplink slot structure of a primary link according to an embodiment of the present invention. The uplink slot configuration and the amount of resource blocks allocated to the SCH 410 and CCH 420 are the same as those of the downlink. However, in the uplink, the insertion position of the CCH 420 is inserted in the center of SCH #2 resource block and is inserted at a position delayed by 9.9 ms compared to the CCH in the downlink. In the last part of the slot, a guard time 430 of 0.5 ms is inserted like the downlink.

5 is a SR (Schedule Request) transmission structure according to an embodiment of the present invention. That is, FIG. 5 is an SR channel structure of CCH. Referring to FIG. 5, the SR transmits information on one bit in an on-off keying (OOK) method. That is, a signal is transmitted when a scheduling request is made, and no signal is transmitted otherwise. SR information is generated using the Zadoff-Chu (ZC) sequence shown below.

Here, u is the root of the sequence and N is the length of the sequence. At this time, the length of the sequence is 99 symbols, and the sequence root is given as follows.

Here, ID is the identification number of the gateway.

The ZC sequence generated through the above process is circularly shifted and transmitted, and an even number in the range of 0 to 98 is used for the circular shift index 510, and the circular shift index is set in the upper layer.

Referring to FIG. 5, it shows an example in which SR is transmitted in one UL (Uplink)-CCH resource block, and up to 2 * N _sc of SR information having a length of 99 symbols (521 + 522 = 520) can be transmitted. The number is set in the upper layer.

Meanwhile, each device (not shown) uses an SR channel in a channel assignment process, and the corresponding channel is a channel shared by several devices. When several devices simultaneously transmit signals on the SR channel for resource allocation and the signal sizes received by the gateway (not shown) are different, the device with a relatively small signal size causes significant interference, which causes channel allocation to fail. It is very likely to do

Therefore, in the eWSN, closed-loop power control is performed for the uplink in order to equalize the amplitude of the signal received through the SR channel. The gateway compares the difference between the reception sensitivity of each device and the required reception sensitivity at regular intervals and controls power so that reception is received with the reception sensitivity required for each device.

On the other hand, the TRS frequency uses the existing TETRA method to establish a telecommunication network nationwide, and uses a low frequency band, so various interference signals are generated from the existing TETRA system and electronic devices. As a result, each channel has a different spectrum show characteristics

In the case of an e-WSN that combines and uses multiple TRS channels, interference signals of different sizes are received for each channel, so sophisticated control is limited when using a general closed-loop power control method. In addition, since the range of transmission output is determined in the device, a region in which power control is not possible occurs. Therefore, a method for sophisticated power control is required.

Therefore, an embodiment of the present invention proposes a method for overcoming interference and transmit power range restrictions that are different for each channel in the power control process of the SR channel.

6 is a conceptual diagram of a power control method of a resource allocation channel according to an embodiment of the present invention. Referring to FIG. 6 , the horizontal axis represents frequency (Freq.), and the vertical axis represents Power Spectrum Density (PSD). At this time, each signal 620 and additive white gaussian noise (AWGN) & interference 610 are shown.

7 is a flowchart showing a power control process according to an embodiment of the present invention. Referring to FIG. 7 , first, the gateway periodically collects measurement information (step S710). In other words, eWSN gateways have previously periodically measured and managed upstream link noise and interference signal power, reception sensitivity, signal-to-noise ratio, and transmit power information for each device, and channel information for some information for sophisticated power control. It is measured separately.

The measurement information collection process is as follows.

①. (AWGN + Interference) The gateway periodically measures the power of AWGN (Additive White Gaussian Noise) and interference of the wireless channel using an unused uplink SCH channel, and measures all channels, not just a single channel.

②. (Reception sensitivity) When transmitting signals from the device to the gateway, the reception sensitivity of the uplink signal is measured. In the case of reception sensitivity, the average value is measured without classifying by channel (differences in reception sensitivity by channel due to use of narrowband frequency and non-mobility environment) is Mimi)

③. (Signal-to-noise ratio) Calculate the signal-to-noise ratio for each channel using the measured reception sensitivity and the power value of AWGN + interference

④. (Transmission output) Manages the transmission output value of the device using the CCH channel as before

Still referring to FIG. 7 , after step S710, channels according to AWGN+interference are classified (step S720). In a wireless channel, it is divided into AWGN and an interference signal. AWGN is theoretically about -174dBm/Hz, and since the TRS channel bandwidth is about 25kHz and the effective bandwidth is about 20kHz, the power of AWGN is about -131dBm.

In addition, when checking the power of the received signal, the remaining signals except for about -131 dBm are interference signals. Since these interference signals are affected by various electronic devices, other systems, or the same system, they are unpredictable, have various values according to channel conditions, and are different for each TRS channel.

In addition, the gateway manages the rank using the power value of AWGN + interference for N _sc channels, and the rank is used when allocating the SR channel to the device.

Still referring to FIG. 7 , after step S720, devices are grouped according to similar reception sensitivity and transmission power (step S730). In order to minimize the influence of the interference signal between devices using the SR channel, the gateway establishes and manages groups for each device having similar uplink reception sensitivity and transmit power, and the criteria for grouping are as follows.

①. If the transmission output of the device is maximum or minimum, it is divided into two groups and managed.

②. Devices with not the maximum or minimum transmit power are managed as a group of N _sc -2, and the group is determined according to the level order of the transmit power.

)의 이득을 갖는다. 따라서 수신 모듈 검출기의 임계값 및 마진을 고려하여 약 10dB 내로 그룹화할 수 있다.The length of the sequence transmitted through the SR channel is 99, and after cross-correlation at the receiver, about 20 dB (

) has a gain of Therefore, it is possible to group within about 10 dB in consideration of the threshold and margin of the receiving module detector.

After step S730, an SR channel is allocated (step S740). The SR channel is allocated to the device using the information presented above, and the allocation procedure is as follows.

①. Among the device groups, the group with the maximum transmit power is assigned priority to the channel with the lowest (AWGN+interference) among N _sc channels.

②. Among the device groups, the group with the lowest transmit power is assigned first to the channel with the highest (AWGN+interference) among the N _sc channels.

③. The remaining device groups are allocated to channels of N _sc -2, and channels with low (AWGN + interference) are allocated in the order of high transmit power.

④. After allocating the SR channel as above, power control is performed based on the signal-to-noise ratio for each channel and the closed-loop method to optimize power control for each channel and minimize interference between devices.

Still referring to FIG. 7 , after step S740, the output range of the device is set (step S750). In other words, even when set as in the previous step, precise power control is not possible for the group with the minimum or maximum transmission output due to the device output range. If the transmit power is maximum and SR channel assignment is impossible due to interference, data transmission using the SCH channel is also impossible, so that case is not considered.

The group with the lowest transmit power minimizes interference between devices by puncturing the sequence transmitted through the SR channel based on the device with the lowest reception sensitivity, and the sequence puncturing method is as follows.

①. Calculate the difference in reception sensitivity between devices based on the device with the lowest reception sensitivity

Here, S ₀ is the reception sensitivity of the device with the lowest reception sensitivity, l is the device number, S _l is the reception sensitivity of the lth device, D _l is the reception sensitivity difference between devices, and L is the total number of devices in the group with the minimum transmission output is the number

②. Each device punctures the sequence of (Equation 1) transmitted through the SR channel according to the value of D _l , and performs the SR process using the punctured sequence. The puncturing method is as follows.

ⓐ In the lth device, check m that satisfies D _l ≤ 3m dB

ⓑ (Formula 1) Among the index k of the sequence, only the symbol corresponding to the index of the equation below is transmitted, and the remaining symbols transmit a value of 0.

ⓒ The sequence puncturing method uses the characteristic that the energy of the sequence is reduced by 1/2 ^m , that is, the interference is reduced by 3 m dB when only symbols corresponding to 1/2 ^m are transmitted in the sequence.

In other words, closed-loop power control is applied to all used carriers. In addition, the SR resource is allocated to the device in consideration of the channel condition of each device and a group of devices using the same SR resource. In addition, when a device transmits a signal with the lowest power, but the wireless channel between the gateway and the device is good and the gateway receives the signal as a very large signal, the device uses the SR resource based on the punctured sequence.

8 is a configuration block diagram of a communication device according to an embodiment of the present invention. A communication device can be a gateway or a device. Referring to FIG. 8 , a receiving module 810 , a transmitting module 820 , a processor 830 and a memory 840 may be included. The receiving module 810 may receive various types of data information. The transmission module 820 may transmit various signals, data, information, and the like. The communication device according to the present embodiment may perform carrier management in a communication system supporting multi-carrier.

The processor 830 may control the receiving module 810 to receive a signal indicating control channel allocation for a carrier from a gateway or a device. In addition, the processor 830 performs a function of calculating and processing information received by the communication device, information to be transmitted, and the like, and the memory 840 may store the calculated information for a predetermined time, buffer (not shown), etc. can be replaced by components of

The memory 840 may include a flash memory disk (SSD: Solid State Disk), a hard disk drive, flash memory, electrically erasable programmable read-only memory (EEPROM), static RAM (SRAM), ferro-electric RAM (FRAM), PRAM ( Non-volatile memory such as phase-change RAM), magnetic RAM (MRAM) and/or volatile memory such as dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate-SDRAM (DDR-SDRAM) It can be composed of a combination of

In addition, the steps of a method or algorithm described in connection with the embodiments disclosed herein are implemented in the form of program instructions that can be executed through various computer means such as a microprocessor, processor, CPU (Central Processing Unit), etc. It can be recorded on any available medium. The computer readable medium may include program (instruction) codes, data files, data structures, etc. alone or in combination.

The program (command) code recorded on the medium may be specially designed and configured for the present invention, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs, DVDs, and Blu-rays, and ROMs and RAMs ( A semiconductor storage element specially configured to store and execute program (instruction) codes such as RAM), flash memory, or the like may be included.

Here, examples of the program (command) code include high-level language codes that can be executed by a computer using an interpreter, as well as machine language codes such as those produced by a compiler. The hardware devices described above may be configured to act as one or more software modules to perform the operations of the present invention, and vice versa.

100: frame structure
110: one frame
111: sub frame
111-1: slot
200: resource block
310,410: Shared Channel (SCH)
320,420: (Control Channel)
330,430: protection time
810: receiving module
820: transmission module
830: processor
840: memory

Claims (14)

A resource allocation method in a wireless communication system based on an energy-wireless sensor network (e-WSN) consisting of a gateway and a device,
Including; connecting the main link between the gateway and the device,
The frame structure in the main link consists of one frame, one frame consists of 10 subframes, and one subframe consists of two slots. Resource allocation in a wireless communication system, characterized in that method.
According to claim 1,
One frame has a length of 1 sec, the subframe has a length of 100 ms, and the slot consists of 1000 symbols and has a length of 50 ms. Resource allocation method in a wireless communication system.
According to claim 2,
5 resource blocks are allocated to one slot 111-1, and one resource block has a length of 9.9 ms and has a plurality of (N _sc ) subcarriers. Resources in a wireless communication system, characterized in that allocation method.
According to claim 3,
One slot consists of a plurality of shared channels (SCHs) and one control channel (CCH), one resource block is allocated to one CCH, four resource blocks are allocated to a plurality of SCHs, and the last part A resource allocation method in a wireless communication system, characterized in that a guard time is inserted and the time length is 0.5 ms.
According to claim 4,
If one of the slots is a downlink slot of a primary link, one CCH is inserted between two first SCHs among a plurality of SCHs.
According to claim 4,
If one of the slots is an uplink slot of a primary link, one CCH is inserted between two second SCHs among the plurality of SCHs.
According to claim 4,
One CCH (is a maximum of 2*N _sc (where N is a natural number) of SR (Schedule Request) information having a length of 99 symbols can be transmitted, and the number of transmissions is set in an upper layer. Wireless communication system, characterized in that How to allocate resources in .
According to claim 7,
The SR information is Equation

(where u is the root of the sequence, N represents the length of the sequence), and the sequence root is

(Here, the ID is an identification number of a gateway) A method of allocating resources in a wireless communication system, characterized in that defined.
(a) periodically collecting measurement information in a gateway;
(b) classifying a channel according to the measurement information in the gateway;
(c) grouping a plurality of devices based on reception sensitivity and transmission output of similar uplink signals according to channel classification in the gateway;
(d) allocating SR channels to a plurality of devices in the gateway;
(e) limiting the output range of the plurality of devices according to the allocation of the SR channel;
A power control method in a wireless communication system comprising a.
According to claim 9,
In step (a),
(a-1) periodically measuring the power value of Additive White Gaussian Noise (AWGN) + interference of a wireless channel using an uplink SCH channel that is not in use in the gateway and measuring all channels instead of a single channel;
(a-2) measuring reception sensitivity of the uplink signal when signals are transmitted from the plurality of devices to the gateway, and measuring an average value of the reception sensitivity without classifying them according to channels;
(a-3) calculating a signal-to-noise ratio (SNR) for each channel using the reception sensitivity and the power value of the AWGN+interference in the plurality of devices; and
(a-4) managing the transmission output values of the devices using the CCH channel in the same manner as before in the plurality of devices; A power control method in a wireless communication system comprising the.
According to claim 10,
The power control method in a wireless communication system, characterized in that the gateway manages a rank using the power value of the AWGN + interference for a plurality of channels, and the rank is utilized when an SR channel is allocated in the device.
According to claim 10,
The grouping is managed by dividing into two groups when the transmission power is the maximum or the minimum, and the remaining devices whose transmission power is not the maximum or the minimum are managed as the remaining groups, and each group is in order of the level of the transmission power. Power control method in a wireless communication system, characterized in that determined according to.
According to claim 12,
In step (d),
(d-1) first allocating the group having the maximum transmit power to a channel having the lowest AWGN+interference among a plurality of channels;
(d-2) first allocating the group having the lowest transmit power to a channel having the highest transmit power (between AWGN+) among the plurality of channels;
(d-3) allocating the remaining groups to channels obtained by subtracting 2 from the plurality of channels, and allocating channels with low (AWGN + interference) in order of highest transmit power; and
(d-4) performing power control in a closed-loop manner based on the signal-to-noise ratio for each channel after SR channel allocation; A power control method in a wireless communication system comprising the.
According to claim 12,
The group with the minimum transmission output minimizes interference between the plurality of devices by using the difference in reception sensitivity between the plurality of devices based on the device having the lowest reception sensitivity, and the difference in reception sensitivity is expressed by Equation

(Where S ₀ is the reception sensitivity of the device with the lowest reception sensitivity, l is the device number, S _l is the reception sensitivity of the lth device, D _l is the reception sensitivity difference between devices, and L is the device of the group with the minimum transmission output A power control method in a wireless communication system, characterized in that the total number).

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