WO2014123393A1 - Procédé et appareil de commande de la puissance d'émission d'un réseau de communication de dispositif à dispositif - Google Patents

Procédé et appareil de commande de la puissance d'émission d'un réseau de communication de dispositif à dispositif Download PDF

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WO2014123393A1
WO2014123393A1 PCT/KR2014/001078 KR2014001078W WO2014123393A1 WO 2014123393 A1 WO2014123393 A1 WO 2014123393A1 KR 2014001078 W KR2014001078 W KR 2014001078W WO 2014123393 A1 WO2014123393 A1 WO 2014123393A1
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link
transmission power
terminals
links
yield
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PCT/KR2014/001078
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English (en)
Korean (ko)
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류현석
정민영
김동현
배성재
김경규
김대균
박승훈
임치우
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삼성전자주식회사
성균관대학교산학협력단
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Priority to US14/765,996 priority Critical patent/US9538484B2/en
Priority claimed from KR1020140014472A external-priority patent/KR101908951B1/ko
Publication of WO2014123393A1 publication Critical patent/WO2014123393A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04—TPC
    • H04W52/18—TPC being performed according to specific parameters
    • H04W52/24—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters
    • H04W52/245—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters taking into account received signal strength

Definitions

  • the present invention relates to a D2D communication network, and more particularly to a method and apparatus for controlling transmit power.
  • a device-to-device (or ⁇ D2D '') (or peer-to-peer) communication network is an adjacent network without an infrastructure consisting of centralized access points such as base stations and access points.
  • a wireless terminal identifies geographically adjacent neighbor terminals and, if necessary, establishes a wireless link with a specific neighbor terminal to transmit data. Since this process is based on distributed performance among terminals without the help of other devices, D2D communication has an advantage that a rapid market introduction is possible without a separate infrastructure compared to other wireless communication networks.
  • D2D communication can solve the data overload problem that is currently concentrated in the base station or AP by accepting data traffic locally.
  • terminals In a D2D communication network, terminals (or devices) should be able to form a D2D link with another terminal and perform data communication by themselves without the help of a base station or an AP.
  • a distributed link scheduling method in which each of a plurality of D2D links transmits data over which radio resource is transmitted is very important in terms of performance of a D2D communication network.
  • Qualcomm Co., Ltd. is a distribution that considers Signal to Interference Ratio (SIR) through single-tone detection signal exchange based on Orthogonal Frequency Division Multiplexing (OFDM) signal structure in a synchronized wireless environment.
  • the proposed link scheduling scheme is proposed: X. Wu, S. Tabildar, S. Shakkottai, T. Richardson, J. Li, R. Laroia, and A. Jovicic. FlashLinQ: A synchronous Distributed Scheduler for Peer-to-Peer Ad Hoc Networks, Technical Report, 2010.
  • the FlashLinQ is a wireless communication technology capable of single hop communication with another terminal over a radius of 1 km for each terminal. In determining whether to transmit each link, the FlashLinQ considers an amount of interference instead of carrier sensing, It supports high performance D2D communication over D2D links. However, if each D2D link arbitrarily performs transmit power in the FlashLinQ, since the degree of transmit power control directly affects the distributed link scheduling result based on SIR, the performance of the entire D2D network may be degraded. . Therefore, in the D2D communication network using distributed link scheduling, a method of controlling the transmission power of each D2D link needs to be devised to improve the performance of the entire network.
  • embodiments of the present invention are to provide a method and apparatus for controlling the transmission power of each D2D link in a D2D communication network.
  • embodiments of the present invention to provide a method and apparatus for controlling the transmission power in consideration of not only the effect on the D2D link of the D2D communication network but also the effect on the neighbor link.
  • embodiments of the present invention by controlling the transmission power distributed for each D2D link in consideration of the effect of the degree of transmission power control on the SIR-based distributed link scheduling results in each D2D link of the D2D communication network It is to provide a method and apparatus for improving the performance of the entire D2D network.
  • embodiments of the present invention by centrally controlling the transmission power of each D2D link in consideration of the effect of the degree of transmission power control on the SIR-based distributed link scheduling results in each D2D link of the D2D communication network It is to provide a method and apparatus for improving the performance of the entire D2D network.
  • a processing method at a transmitting terminal of the first link for controlling power includes: measuring an intensity of first detection signals transmitted from receiving terminals of the first link and the second link; And determining a first transmission power adjustment ratio for a transmitting terminal of the first link so that the signal-to-interference ratio of the second link is equal to or greater than a predetermined threshold based on the measured strengths of the first detection signals.
  • a processing method at a receiving terminal of the first link for controlling power includes: measuring an intensity of detection signals transmitted from transmitting terminals of the first link and the second link; And determining a first transmission power adjustment ratio for a transmitting terminal of the first link so that the signal-to-interference ratio of the first link is equal to or greater than a predetermined threshold based on the measured detection signals.
  • a device-to-device direct (D2D) communication network including a plurality of terminals adjacent to each other and a controller
  • the controller for controlling the transmission power of the transmitting terminals of the links
  • the processing method includes: receiving a control message from each transmitting terminal of the links, the control message including a yield indicator for causing a signal-to-interference ratio of its own link and a signal-to-interference ratio of a neighboring link to be equal to or greater than a predetermined threshold value; Selecting a link for adjusting transmission power among the plurality of links; Determining a transmission power adjustment ratio for a transmitting terminal of the selected link by using a yield indicator included in the control message; And transmitting the determined transmission power adjustment ratio to a transmitting terminal of the selected link.
  • D2D device-to-device direct
  • a device-to-device direct (D2D) communication network comprising at least terminals of a first link and terminals of a second link neighboring the first link, transmission of transmitting terminals of the links.
  • the transmitting terminal apparatus of the first link for controlling power includes: a transmitting / receiving unit which measures the intensity of first detection signals transmitted from receiving terminals of the first link and the second link; And a controller configured to determine a first transmission power adjustment ratio for a transmitting terminal of the first link so that the signal-to-interference ratio of the second link is equal to or greater than a predetermined threshold based on the measured strengths of the first detection signals.
  • a device-to-device direct (D2D) communication network comprising at least terminals of a first link and terminals of a second link neighboring the first link, transmission of transmitting terminals of the links.
  • An apparatus at a receiving terminal of the first link for controlling power includes: a transceiver configured to measure the strength of detection signals transmitted from transmitting terminals of the first link and the second link; And a controller configured to determine a first transmission power adjustment ratio for a transmitting terminal of the first link so that the signal to interference ratio of the first link is equal to or greater than a predetermined threshold based on the measured detection signals.
  • a controller device for controlling the transmission power of the transmitting terminals of the links
  • a receiving unit for receiving a control message from the transmitting terminals of the link including a yield indicator for causing the signal-to-interference ratio of its own link and the signal-to-interference ratio of the neighboring link is greater than a predetermined threshold value;
  • a control unit for selecting a link for adjusting transmission power among the plurality of links and determining a transmission power adjustment ratio for a transmitting terminal of the selected link by using a yield indicator included in the control message;
  • a transmitter for transmitting the determined transmission power adjustment ratio to a transmitting terminal of the selected link.
  • the embodiments of the present invention control transmission power by considering not only the effect of the D2D link on the D2D link of the D2D communication network but also the effect on the neighboring link, and thus, compared to the case of using the fixed transmission power. It can improve the performance of the entire D2D network.
  • FIG. 1 shows a basic transmission structure according to a distributed link scheduling scheme to which the present invention is applied.
  • FIG. 2 illustrates a traffic slot structure constituting the traffic section shown in FIG. 1.
  • 3A illustrates the structure of the link scheduling interval shown in FIG. 2.
  • FIG. 3B shows the structure of the paging segment shown in FIG. 1.
  • FIG. 4 shows an example of a D2D communication network for describing an SIR based link scheduling operation.
  • FIG. 5 is a diagram for explaining the need for new transmission power control in each D2D link of a D2D communication network according to an SIR based link scheduling operation.
  • FIG. 6 illustrates an example of a D2D communication network for explaining an operation of calculating concession relation indicators as a reference for transmission power control in a D2D link according to embodiments of the present invention.
  • FIG. 7 shows an example of a communication network for the centralized power control operation according to the first embodiment of the present invention.
  • FIG. 8 shows a detailed configuration of the devices shown in FIG. 7.
  • FIG. 9 shows a detailed configuration of the base station shown in FIG. 7.
  • FIG. 10 shows a processing flow of the centralized power control operation according to the first embodiment of the present invention.
  • FIG. 11 shows the processing flow of the centralized power control operation according to the first embodiment of the present invention by the components of the communication network shown in FIG.
  • FIG. 12A illustrates an example of values stored in a table of a base station shown in FIG. 9 in a centralized power control operation according to an embodiment of the present invention.
  • FIG. 12B illustrates an example of calculating a power adjustment ratio from values stored in a table of a base station shown in FIG. 9 in a centralized power control operation according to an embodiment of the present invention.
  • FIG. 13 shows an example of a communication network for distributed power control operation according to an embodiment of the invention.
  • FIG. 14 shows a detailed configuration of the devices shown in FIG. 13.
  • FIG. 15 illustrates a processing flow of distributed power control operation according to an embodiment of the present invention.
  • FIG. 16 shows the processing flow of the distributed power control operation according to the second embodiment of the present invention by the components of the communication network shown in FIG.
  • 17A shows an example of values stored in a table of the devices shown in FIG. 14 during a power control operation according to the second embodiment of the present invention.
  • 17B illustrates an example in which a power adjustment ratio is calculated from values stored in a table of the devices shown in FIG. 14 during a power control operation according to the second embodiment of the present invention.
  • FIG. 18 illustrates a processing flow of distributed power control operation according to another embodiment of the present invention.
  • 19A-19C contrast the performance of a power control operation in accordance with embodiments of the present invention.
  • Embodiments of the present invention to be described below are to provide a method for effectively adjusting the transmission power of each D2D link in a D2D communication network composed of wireless communication devices.
  • two indicators are defined in which each D2D link indicates the transmit (Tx) and receive (Rx) yield impact and degree from neighboring links.
  • Embodiments of the present invention propose a method and apparatus that can adjust the transmission power of D2D links centrally through each link based on two indicators or by a controller such as a mobile communication base station.
  • the power control method proposed by the embodiments of the present invention can improve the performance of the D2D network by efficiently controlling the transmission power of each link in consideration of the geographical and propagation relationship and the link scheduling effect between the D2D links.
  • the terminals form and maintain a D2D communication network by allowing the use of distributed limited radio resources without the help of a base station.
  • the basic transmission structure for performing such a function may have a function structure that is periodically repeated as shown in FIG. 1.
  • Each cycle consists of a synchronization section 10, a peer search section 20, a paging section 30, and a traffic section 40.
  • synchronization section 10 basic time and frequency synchronization is performed between terminals through a global positioning system (GPS).
  • GPS global positioning system
  • peer search section 20 neighboring terminals that are geographically adjacent are identified through terminal information broadcasted by each terminal.
  • a D2D link is formed for unidirectional transmission between terminals to perform communication. Based on the link formed through this process, link scheduling and accompanying data transmission are performed in the traffic section 40.
  • the traffic interval consists of a plurality of traffic slots, and independent link scheduling and data transmission are performed for each traffic slot.
  • the traffic slot has a basic structure as shown in FIG. 2, which is divided into four sections: link scheduling section 42, rate scheduling section 44, data transmission section 46, and acknowledgment transmission section 48 by function. do.
  • link scheduling interval 42 a single-tone detection signal using an OFDM signal structure is transmitted for each D2D link for unidirectional communication to measure a signal interference relationship between links and determine whether data can be transmitted in a corresponding traffic slot.
  • the rate scheduling interval 44 the detailed rate is adjusted for links determined to transmit data in the corresponding traffic slot.
  • the transmitting terminals perform data transmission to the peer receiving terminal, and an acknowledgment message thereof is transmitted in the acknowledgment transmission interval 48.
  • an OFDM signal in which radio resources orthogonal in time and frequency planes are defined in order to determine link scheduling, that is, whether to use a link, for single-hop unidirectional D2D links.
  • a structure is defined, through which a plurality of D2D terminals transmit single-tone detection signals simultaneously without signal interference with each other.
  • signal-to-interference ratio SIR is calculated for self and neighboring D2D links measured and link scheduling is performed based on this.
  • the number of D2D links that can use the same radio resources at a specific time is limited due to the nature of radio resources. For this reason, in a centralized wireless communication technology such as mobile communication, the use of radio resources of terminals is limited by a central controller such as a base station.
  • a method capable of limiting the occupation of a radio resource of a link in consideration of signal interference is required.
  • the distributed link scheduling scheme allocates a link identifier (CID), which is an identifier uniquely assigned locally for each link, and assigns a unique priority to the link in every traffic slot using the link identifier.
  • CID link identifier
  • each link determines whether to perform communication in the current traffic slot by considering the SIRs of links having a higher priority with itself. At this time, the priority is changed evenly in each traffic slot by using a hash, pseudo noise (PN) code, etc. in order to ensure fairness between links.
  • PN pseudo noise
  • the distributed link scheduling scheme defines a single-tone detection signal transmission method based on an OFDM signal structure (block) as shown in FIG. 3A.
  • the link scheduling interval 42 consists of a Tx OFDM block 42A for transmitting terminals and an Rx OFDM block 42B for receiving terminals.
  • Each OFDM block consists of N subcarriers in the frequency plane and M OFDM symbols in the time plane and includes a total of N ⁇ M transmission units.
  • N ⁇ M transmission units are assigned priorities from 1 to N ⁇ M in order from top to bottom and from left to right, as shown in FIG. 3A, and each link has a resource corresponding to its priority. Units are used to transmit and receive single-tone detection signals. In this case, the priority is 1 and N ⁇ M is the lowest.
  • the single-tone signal refers to a tone signal having only one subcarrier in the frequency plane.
  • the signal occupies a narrow frequency bandwidth, allowing for higher power transmission compared to multi-tone signals.
  • By utilizing such a single-tone signal can have a wide communication range of 1km radius.
  • Scheduling for D2D links based on priorities assigned locally uniquely is performed as follows.
  • a transmitting terminal having data to be sent to a peer receiving terminal transmits a single-tone signal through a transmission unit corresponding to its link priority in a Tx OFDM block.
  • the receiving terminal observes the corresponding transmission unit in every traffic slot to receive data. If a single-tone signal from the transmitting terminal is received, the receiving terminal compares the signal strength from the peer transmitting terminal with the interference signal strength from the link having the higher priority and determines whether the corresponding link can be communicated. If it is determined that communication of the link is possible, the receiving terminal transmits a single-tone signal in a corresponding transmission unit in the Rx OFDM block.
  • a transmitting terminal that receives single-tone signals from a peer receiving terminal and a receiving terminal having a higher priority may determine that the receiving terminal has a certain level of signal interference below the receiving terminal having a higher priority. If it is decided to perform communication on the link.
  • link scheduling An example of link scheduling will be described with reference to FIG. 4.
  • a procedure of performing a link scheduling for data transmission from a terminal C 100C to a terminal D 100D in a D2D communication network in which two links coexist as shown in FIG. 4 is considered.
  • the terminal A 100A has data to be transmitted to the terminal B 100B (link 1)
  • the terminal C 100C has data to be transmitted to the terminal D 100D (link 2)
  • the priority of the link 1 is higher than the link 2.
  • Hxy also represents the channel gain between terminal X and terminal Y.
  • UE A 100A and UE C 100C transmit a single-tone signal (Direct Power Signal, hereinafter referred to as 'DPS') having transmission powers of P A and P C through transmission units according to their priorities. do.
  • the receiving terminal D 100D receives the DPS received from its peer terminal (terminal C 100C) (P C ⁇
  • the expected signal-to-interference ratio (SIR link_2 ) of link 2 according to the signal interference from the higher priority link is calculated as follows.
  • SIR link_2 is a predefined threshold ( Less than), the UE D 100D determines that communication of the link 2 cannot be performed due to strong interference from an upper transmitting terminal, and performs Rx yielding. Whereas SIR If greater, the terminal D 100D determines that communication of the link 2 is possible.
  • the terminal D 100D and the terminal B 100B which have determined that communication is possible, transmit a single-tone signal called an inverse power echo (IPE) signal through a transmission unit corresponding to priorities of links 2 and 1, respectively, in the subsequent Rx OFDM block. Transmit with strength.
  • IPE inverse power echo
  • K is a constant defined in the system
  • P Tx represents the transmit power strength of the peer transmitting terminal
  • h Tx, Rx represents the channel gain between itself and the transmitting terminal.
  • the strengths of the IPE signals transmitted by the terminal B 100B and the terminal D 100D are K / (P A ⁇
  • the terminal C 100C Upon receiving the IPE signal from the terminal D 100D through the transmission unit for the link 2, the terminal C 100C receives the strength ((K ⁇
  • the transmitting terminal 100C starts transmission of link 2 by transmitting a pilot signal in a subsequent rate scheduling interval. Whereas the calculated SIR link_1 has a threshold If smaller, the transmitting terminal 100C determines that its data transmission has a great influence on the SIR of link 1, and abandons the transmission of link 2, thereby yielding Tx.
  • a transmitting terminal and a receiving terminal constituting each D2D link use a resource unit given locally locally according to the CID of the link in the Tx and Rx OFDM blocks to determine whether to access the medium.
  • the transmitting and receiving terminals each calculate the expected SIRs based on the degree of signal interference expected to reach the receiving terminals of the D2D links having higher priority and the signal interference from the transmitting terminals of the links. And the corresponding SIRs each have a certain threshold ( And Above), it is decided to perform data transmission through the medium.
  • Such SIR-based link scheduling is greatly influenced by the strength of the single-tone signal that the transmitting and receiving terminals exchange.
  • Table 1 shows the effects of the transmission terminal adjusting the transmission power of a specific D2D link j.
  • D2D links adjacent to link j increase the likelihood of performing Rx concessions because the effect of signal interference from link j increases, while they increase the likelihood of guaranteeing the SIR of link j, so that they yield Tx The likelihood of carrying out is reduced.
  • link j adjusts the transmission power down.
  • the adjustment of transmit power on a specific D2D link has the opposite effect when the link performs Rx yield and Tx yield.
  • adjusting the transmit power of the link can change the probability of Tx and Rx concessions of adjacent D2D links. Therefore, transmission power adjustment of the D2D link needs to be performed carefully by considering not only the effect of the D2D link but also the effect on the neighboring link. Nevertheless, effective power control cannot be considered considering only the method of performing the transmission power considering only the state of the D2D link without considering the effect of the transmission power on the SIR based link scheduling. If the transmission power of the link is adjusted without considering the effect on the link scheduling result, the performance of certain links may be degraded.
  • FIG. 5 is a diagram for explaining the need for new transmission power control in each D2D link of a D2D communication network according to an SIR based link scheduling operation.
  • a D2D communication network an environment in which all links use the same transmission power is mainly considered.
  • certain D2D links (links between Tx1 100T1 and Rx1 100R1) cause Tx / Rx concessions to multiple other links (links between Tx1 100T1 and Rx2-Rx5 100R2-100R5), and also SINR
  • the channel capacity is reduced due to the decrease. Therefore, a new power control scheme for the D2D link is required.
  • power control it is necessary to consider the problem that the link quality is deteriorated due to power reduction, and that the capacity of the network increases with transmission of another link.
  • embodiments of the present invention provide a method for effectively adjusting the transmission power of each D2D link in a D2D communication network composed of wireless communication devices.
  • two indicators are defined in which each D2D link indicates the transmit (Tx) and receive (Rx) yield impact and degree from neighboring links.
  • Embodiments of the present invention propose a method and apparatus that can adjust the transmission power of D2D links centrally through each link based on two indicators or by a controller such as a mobile communication base station.
  • the power control method proposed by the embodiments of the present invention can improve the performance of the D2D network by efficiently controlling the transmission power of each link in consideration of the geographical and propagation relationship and the link scheduling effect between the D2D links.
  • Embodiments of the present invention to be described below are applicable to a wireless communication terminal device capable of performing D2D communication.
  • Embodiments of the present invention are indicative of the reception (Rx) yield relationship between each other based on single-tone signal information in which D2D links are interchanged for link scheduling.
  • Indicative of concession relations And calculating the transmission power to be used by each of the D2D links in a distributed manner or determining the transmission power to be used by the D2D links centrally based on the central controller.
  • Assumed matters in the embodiments of the present invention are as follows. First, it is assumed that time and frequency synchronization between all terminals is performed in a synchronization period as shown in FIG. 1. In addition, the D2D links consider an environment for performing SIR-based link scheduling based on the traffic slot structure shown in FIG. 2.
  • the concession relationship index is an index indicating whether and how much Tx and Rx concessions are generated by neighboring D2D links.
  • Concession indicators Denotes the Rx concession relationship that link X results from neighboring link Y.
  • Concession indicators Denotes the Tx concession relationship that link X results from neighboring link Y.
  • These concession relation indicators are used as a criterion for determining whether a specific D2D link generates Tx yield and Rx yield by each neighboring D2D link. For example, concession indicators Is less than 1 ( ⁇ 1), link X performs Rx yield by link Y, and yield relation index Is greater than 1 ( > 1), link X performs Tx yield by link Y.
  • the yield relationship indicators are also used in the calculation of the power adjustment range of the neighboring D2D link where a particular D2D link is required to not yield Tx and Rx yields. For example, P Y new / P Y current Less than (P Y new / P Y current ⁇ ) Is the condition that link X does not yield Rx by link Y, and P Y new / P Y current Greater than (P Y new / P Y current > ) Is a condition for link X not to yield Tx by link Y.
  • FIG. 6 illustrates an example of a D2D communication network for explaining an operation of calculating concession relation indicators as a reference for transmission power control in a D2D link according to embodiments of the present invention.
  • the configuration shown in FIG. 6 is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.
  • FIG. 6 illustrates a D2D communication network including a D2D link X for calculating concession relation indexes and a D2D link Y for influencing the determination of Tx / Rx yield on the link X.
  • the D2D link Y consists of a transmitting terminal A 100A and a receiving terminal B 100B
  • the D2D link X consists of a transmitting terminal C 100C and a receiving terminal D 100D.
  • the signal strengths transmitted by the transmitting terminal A 100A and the transmitting terminal C 100C are P A [Watt] and P C [Watt], respectively. It is written as.
  • Concession indicators Indicates whether an arbitrary D2D link X performs Rx yield by the D2D link Y located adjacent to it, and how much the transmit power of the D2D link X or link Y can be adjusted so as not to perform the Rx yield. It is an indicator.
  • Concession indicators The procedure for calculating is as follows.
  • the transmitting terminal A 100A and the transmitting terminal C 100C of each link having data to be transmitted in the D2D communication network select one of the plurality of resource units constituting the Tx OFDM block 42A as shown in FIG. And transmits a single-tone DPS signal through the corresponding resource unit.
  • a single resource unit consists of one carrier in the frequency domain and one OFDM symbol in the time domain.
  • Receiving terminal D 100D of the D2D link X to be measured measures the strength of the DPS (Direct Power Signal) transmitted by transmitting terminals of adjacent links through different resource units by listening to the entire Tx OFDM block 42A.
  • the receiving terminal can check which CID the linking terminal having the CID transmits by using the inverse function of a function (hash function, etc.) that converts the CID to the resource unit position (priority). have.
  • the receiving terminal D 100D of the link X indicates the yield relationship with the link Y.
  • the method of calculating is divided into (1) a method of calculating from the power control point of the link (additional link) Y and (2) a method of calculating from a power control point of the link (damage link) X.
  • Equation 4 instead of A' P A ⁇ P A / P A Substituting, the link Y the transmitting terminal A 100A receives the terminal the sending terminal A 100A to D does not cause Rx yield at 100D of the transmit power
  • the upper limit of the adjustment ratio P ' A // P A can be obtained as shown in Equation 5 below.
  • Equation 5 which defines the upper limit of the transmission power adjustment ratio P ' A / P A of the transmitting terminal A, as shown in Equation 6 below, is a concession relation index in the embodiments of the present invention. Is defined as
  • Yield index in terms of power of transmitting terminal C of link X How to calculate is as follows. Suppose that the transmitting terminal C 100C changes its transmit power from P C [Watt] to P ' C [Watt] in order not to cause Rx yield in the receiving terminal D 100D due to signal interference from the link Y. The SIR of X must satisfy the following condition.
  • Equation (7) instead of C P 'P in C ⁇ P C / P Substituting C receiving terminal transmit power adjustment of the transmission terminal C 100C for D does not cause Rx yield at 100D ratio P "C / P C
  • the lower limit can be found as follows, which is obtained from Has the inverse form.
  • the receiving terminal D of the link X obtained in the above procedure is obtained from the acknowledgment message transmitted to the transmitting terminal C 100C in the acknowledgment transmission section 48 shown in FIG. Send it with the value.
  • the receiving terminal C 100C performs the power control considering the value (distributed power control) or reports the value to the central controller (centralized power control).
  • Tx yield indicator Calculates the transmitting terminal through the strength of the IPE signals detected by the Rx OFDM block 42B. Transmit terminal C 100C of link X In order to calculate, the strength of the IPE signal received from the receiving terminal B in Rx OFDM block 42B ( Measure Watt. Based on this The method of calculating is divided into (1) the method of calculating from the power control point of the link (additional link) Y and (2) the method of calculating from the power control point of the link (damage link) X.
  • Equation 9 instead of A' P A ⁇ P A / P A Substituting, link Y the transmitting terminal A 100A the transmit power of the transmitting station A 100A for does not cause the Tx yield in the transmission terminal C 100C of
  • the lower limit of the adjustment ratio P ' A / P A can be obtained as shown in Equation 10 below.
  • Equation 10 Is the strength of the IPE signal Can be obtained by dividing by the system parameter K.
  • the lower limit of the power adjustment ratio of the transmitting terminal A 100A for the transmitting terminal C 100C of the link X not to perform Tx yield by the link Y is expressed by Equation 11 below. Defined as
  • Equation 12 ' instead of C P' P C ⁇ P C / P C Substituting the receiving terminal D transmit power adjustment of the transmitting terminal C 100C for not cause Rx yield in a non-P, the upper limit of the C / P C Can be obtained as in Equation 13, which is obtained from Equation 11. Has the inverse form.
  • the transmitting terminal of each D2D link in each traffic slot is reported from the receiving terminal. And measured by yourself On the basis of this, the concession table shown in Table 2 is formed and updated.
  • the receiving terminal of the damaged link X is the strength of the DPS signals transmitted from neighboring transmitting terminals through the Tx OFDM block (42A in FIG. 3A) of each traffic slot ( Figure 2). Yield relationship indicator And the transmitting terminal measures the strength of IPE signals transmitted from neighboring receiving terminals through the Rx OFDM block (42B of FIG. 3A) of each traffic slot ( Figure 2) Calculate As such, each terminal has a yield relationship index for all neighbor links. Wow Since it is necessary to observe a large number of traffic slots in the calculation, the delay time and power consumption according to the calculation of concession relation index may be increased.
  • Another embodiment of the present invention calculates concession relation index using the DP / IPE broadcast interval 36 shown in FIG. 3B.
  • the paging segment 30 includes a quick paging segment 32, a CID broadcast segment 34, a DP / IPE broadcast segment 36, and a paging request segment 38.
  • the DP / IPE broadcast interval 36 includes a DP broadcasting OFDM block 36A and an IPE broadcasting OFDM block 36B.
  • each OFDM block 36A, 36B includes 28 subchannels in the frequency plane and 4 OFDM symbols in the time plane.
  • All transmitting terminals forming the D2D link use the transmission power of the transmission power (for example, 20 dBm) basically set in the DP broadcasting OFDM block 36A, and the transmission unit corresponding to the CID (1 to 112) for the own link. Transmits DP single-tone signal through Receiving terminals observe the DP broadcasting OFDM block 36A to yield concession relations for all neighboring links. Can be calculated.
  • the transmission power for example, 20 dBm
  • All receiving terminals forming the D2D link transmit the IPE single-tone signal through the transmission unit corresponding to the CID (1 to 112) for its link in the IPE broadcasting OFDM block 36B.
  • the strength of the IPE single-tone signal is determined as shown in Equation 2 above. Transmitting terminals look at IPE broadcasting OFDM block 36B to yield concession indicators for all neighboring links. Can be calculated.
  • yield relationship index collected by a transmitting terminal of each D2D link can be largely divided into a distributed power control method and a centralized power control method.
  • Distributed power control is performed by the transmitting terminal of each D2D link.
  • It is a method of adjusting its own transmission power within a certain criterion based on information, and centralized power control uses a central controller such as a mobile communication base station and a repeater to power a specific D2D link based on concession relations collected at each terminal. It is a way to instruct control.
  • FIG. 7 illustrates an example of a D2D communication network for centralized power control operation according to an embodiment of the present invention.
  • the configuration shown in FIG. 7 is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.
  • the D2D communication network includes device 1 101 and device 2 102, which are terminals connected through a D2D link.
  • the devices 101 and 102 may be a transmitting terminal or a receiving terminal, and the devices 101 and 102 may include a transmitting terminal and a receiving terminal (not shown) of a neighboring link.
  • the devices 101 and 102 each include a PHY layer part L12, a MAC layer part L22 and a higher layer part L30 for D2D communication.
  • the devices 101 and 102 are connected to a mobile communication base station (eNB) 200 as a controller for a centralized transmission power control operation according to an embodiment of the present invention.
  • the devices 101 and 102 are connected to the base station 200 via a cellular link.
  • the devices 101 and 102 each include a PHY layer part L11, a MAC layer part L21, and a higher layer part L30 to access the base station 200.
  • the mobile communication base station 200 may be an LTE base station.
  • the mobile communication base station 103 may be connected to the Internet 300 through a core network.
  • FIG. 8 shows a detailed configuration of the devices 101, 102 shown in FIG. 7.
  • the configuration shown in FIG. 8 is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.
  • the devices 101 and 102 include a first transceiver 110, a controller 120, and a second transceiver 130.
  • the first transceiver 110 is for signal transmission and reception through the D2D link.
  • the second transceiver 130 is for signal transmission and reception through the cellular link.
  • the controller 120 controls the overall operations of the devices 101 and 102.
  • the control unit 120 includes a yield indicator calculation unit 122 and a transmission power adjustment unit 124 for the operation according to an embodiment of the present invention.
  • the first transceiver 110 receives first detection signals (eg, IPE) transmitted from a receiving terminal of a first link (its link) and a receiving terminal of a second link (neighbor link), and receives the received detection signals. Measure their strength.
  • the yield indicator calculator 122 of the controller 120 adjusts the first transmit power for the transmitting terminal of the first link so that the signal-to-interference ratio of the second link is greater than or equal to a predetermined threshold based on the measured strengths of the first detection signals. Determine concession indicators as ratios.
  • the first transmission power adjustment ratio may be an upper limit of the first transmission power adjustment ratio.
  • the transmission power adjusting unit 124 controls the transmission power within a range including an upper limit value of the first transmission power adjustment ratio.
  • the yield indicator calculator 122 adjusts the second transmission power for the transmitting terminal of the second link so that the signal-to-interference ratio of the second link is greater than or equal to a predetermined threshold based on the measured strengths of the first detection signals. Determine concession indicators as ratios.
  • the second transmission power adjustment ratio may be a lower limit of the second transmission power adjustment ratio.
  • the first transceiver 110 receives a control message including a third transmission power adjustment ratio for the transmitting terminal of the first link so that the signal-to-interference ratio of the first link is equal to or greater than a predetermined threshold. Can be received from.
  • the third transmission power adjustment ratio is determined based on the measurement result of the strength of the second detection signals transmitted from the transmitting terminals of the first link and the second link.
  • the third transmission power adjustment ratio may be a lower limit of the third transmission power adjustment ratio.
  • the transmission power adjusting unit 124 may control the transmission power within a range including a lower limit value of the third transmission power adjustment ratio.
  • the first transceiver 110 receives detection signals (eg, DPS) transmitted from transmitting terminals of the first link (its link) and the second link (neighbor link), and measures the strength of the received detection signals. do.
  • the yield indicator calculation unit 122 of the control unit 120 is a first transmission power adjustment ratio for the transmitting terminal of the first link so that the signal-to-interference ratio of the first link is greater than or equal to a predetermined threshold based on the measured strengths of the detection signals. Determine yield indicators.
  • the first transmission power adjustment ratio may be a lower limit of the first transmission power adjustment ratio.
  • the first transceiver 110 transmits the lower limit value of the first transmission power adjustment ratio to the transmission terminal of the first link so that the transmission terminal of the first link controls the transmission power within a range including the lower limit value of the first transmission power adjustment ratio. do.
  • the yield indicator calculation unit 122 adjusts the second transmission power adjustment ratio for the transmitting terminal of the second link so that the signal-to-interference ratio of the first link is greater than or equal to a predetermined threshold based on the measured detection signals.
  • the second transmission power adjustment ratio may be an upper limit of the second transmission power adjustment ratio.
  • the base station 200 includes a first transceiver 210, a controller 220, and a second transceiver 230.
  • the first transceiver 210 is for transmitting and receiving signals with the D2D devices 101 and 102.
  • the second transceiver 230 is for signal transmission and reception with the core network 300.
  • the controller 220 controls the overall operation of the base station 200.
  • the controller 220 includes a table 222 and a power adjustment ratio calculator 224 for the operation according to the embodiment of the present invention.
  • the first transceiver 210 receives, from each transmitting terminal of the D2D links, a control message including a yield indicator for causing the signal-to-interference ratio of its link and the signal-to-interference ratio of the neighboring link to be equal to or greater than a predetermined threshold value.
  • the controller 220 selects a link for adjusting transmission power among a plurality of links, and determines a transmission power adjustment ratio for a transmitting terminal of the selected link by using a yield indicator included in the control message.
  • the first transceiver 210 transmits the determined transmission power adjustment ratio to the transmitting terminal of the selected link.
  • the concession indicator included in the control message includes a reception yield indicator for causing the signal-to-interference ratio of its link to be equal to or higher than a predetermined threshold value, and a transmission yield indicator index for causing the signal-to-interference ratio of the neighboring link to be equal to or higher than a predetermined threshold value. do.
  • the controller 220 includes a table 222 and a power adjustment ratio calculator 224.
  • Table 222 is for storing the transmission and reception yield relationship indicators included in the control message received from each transmitting terminal of the D2D links.
  • the power adjustment ratio calculation unit 224 determines the number of neighbor links causing transmission yield and reception yield for each link by using the transmission and reception yield relation indicators stored in the table 222, and transmits a lot of transmission yields or reception yields to the neighbor links. Select the link you expect to trigger.
  • the power adjustment ratio calculator 224 selects a link that is expected to cause a lot of transmission yield or reception yield to neighboring links by using the link quality between the transmitting terminal and the receiving terminal on each link.
  • the power adjustment ratio calculator 224 determines the transmission power adjustment ratio for the transmitting terminal of the selected link in consideration of the transmission yield and the reception yield of the selected link and the transmission yield and the reception yield of the selected link.
  • step 310 the UE of the D2D link grasps the concession correlation between the D2D links and expresses it as indicators. Specifically, the transmitting terminal and the receiving terminal of the D2D link, based on the reception strength of the scheduling signals (DPS, IPE) received in the Tx / Rx block, the indicators indicating the Tx / Rx yield relationship and the power adjustment range with the adjacent links Calculate In step 320, the transmitting terminal reports necessary information among the calculated indicators to the eNB 200. In step 330, the eNB 200 calculates a power adjustment ratio of a specific D2D link.
  • DPS scheduling signals
  • the eNB 200 determines a transmission power control range for the links having a great impact on performance based on the reported indicators.
  • the eNB 200 transmits the determined transmission power control range to a corresponding link.
  • the D2D link adjusts the transmission power according to the received transmission power control range.
  • FIG. 11 shows a processing flow of a centralized power control operation according to an embodiment of the present invention by the components of the communication network shown in FIG. In this embodiment, it is assumed that a mobile communication base station supports transmission power control for D2D links belonging to its own communication area.
  • step 412 the transmitting terminals of each of the D2D links X and Y having data to be transmitted transmit a DPS signal through a transmission unit according to a given CID in the Tx OFDM block of the nth traffic slot.
  • step 414 the receiving terminal of the link X based on the strength of the received DPS signals. Calculate the information.
  • step 422 receiving terminals of each of the two links transmit an IPE signal through a given OFDM transmission unit in a subsequent Rx OFDM block.
  • step 424 the transmitting terminal of the link X is based on the received IPE signal strength. Calculate the information.
  • step 432 and 434 the transmission and reception terminals of the link X to perform the medium access through the exchange of the DPS signal and the IPE signal exchange the pilot and channel quality indicator signals in the data transmission process. Determine the modulation technique and coding rate to use. Thereafter, in step 442, the transmitting terminal of the link X transmits data to the receiving terminal, and in step 444, the receiving terminal measures previously. Send an acknowledgment message containing the information. Based on these processes, the sending terminal organizes the table shown in Table 2. In steps 452 and 454, the transmitting terminal periodically reports a control message to the mobile communication base station (eg, a cellular paging period).
  • the mobile communication base station eg, a cellular paging period
  • the control message is the corresponding table information , ) And your link status (your CID, service information in use, link signal quality ( ), Etc.).
  • the transmitting terminal has a value to be used for actual power control , Since only the c) is reported, congestion of the radio channel due to the report to the base station by a plurality of transmitting terminals can be prevented.
  • the transmitting terminal may transmit the mobile terminal by including the information of the control message in the paging response message.
  • step 462 the mobile communication base station receiving the yield relationship information from the transmission terminal of each link selects a specific link (eg, link Y) for power adjustment based on the given information and network operator information, and transmits the selected link. Determine the power adjustment ratio. Thereafter, in step 464, the base station transmits the determined transmission power adjustment ratio P '/ P to the transmitting terminal of the corresponding D2D link Y through a control message (paging message, etc.). In step 470, the transmitting terminal of the link Y that receives it adjusts its transmission power at the recommended adjustment ratio.
  • a specific link eg, link Y
  • the base station transmits the determined transmission power adjustment ratio P '/ P to the transmitting terminal of the corresponding D2D link Y through a control message (paging message, etc.).
  • step 470 the transmitting terminal of the link Y that receives it adjusts its transmission power at the recommended adjustment ratio.
  • a method of determining a transmission power adjustment ratio of a specific D2D link by a mobile communication base station is as follows.
  • a method of performing transmission power control in advance from D2D links having a large yield effect on other D2D links is considered.
  • the base station preferentially adjusts the transmission power of the D2D link, which causes a large number of Tx yields to other links due to a long distance between the transmitting and receiving terminals, that is, poor link quality.
  • the transmission power adjustment ratio (P '/ P) is calculated based on the table reported from the D2D links for the link selected based on the above criteria.
  • the selected link j does not receive additional Rx yields from other neighbor links, or lowers its transmission power within the range that does not cause additional Tx yields to other links, thereby yielding Tx / Rx yields to neighbor links.
  • the transmission power ratio is determined with the aim of minimizing the impact.
  • the base station determines that the selected power j reduces power of transmission so that no additional Rx concessions are received from neighboring links. ) Is calculated as shown in Equation 14 below.
  • Equation 14 Is the set of D2D links that do not cause Rx yield to the current link j.
  • the base station calculates the power control ratio (link j) by reducing the transmission power so that no additional Tx concessions are made to neighboring links. ) Is calculated as shown in Equation 15 below.
  • Equation 15 Is the set of D2D links that do not cause Rx yield to the current link j.
  • the base station determines a transmission power ratio such that link j does not receive additional Rx yield from other adjacent links or causes additional Tx yield to another link as shown in Equation 16 below. That is, the base station is the power adjustment ratio obtained in the equation (14) and (15) Wow The transmission power ratio is determined by having a small value.
  • the base station updates the ⁇ and ⁇ management tables for the D2D links it manages.
  • An example of an updated table is shown in FIG. 12A.
  • the values reported by link 4 are stored.
  • the base station selects a power adjustment target link based on the contents of the updated table 222.
  • the offending link that has the most influence on the other link is selected. For example, a longer link length causes Tx or Rx concessions to neighboring terminals, and since such a link has a large impact on overall network performance, it is necessary to perform power control first.
  • the power adjustment ratio calculation unit 224 of the base station calculates the power adjustment ratio Pnew / Pcurrent for the selected link using 1 / ⁇ and ⁇ management tables according to various conditions and purposes.
  • This power adjustment ratio aims to reduce the influence on the other link by lowering power within a range in which the selected link j does not receive additional Rx yield from another link or does not cause additional Tx yield to another link.
  • the power adjustment ratio of any link j that does not receive additional Rx yield is calculated as shown in Equation 14 described above.
  • the power regulation ratio of any link j that does not cause additional Tx yield is calculated as shown in equation (15).
  • the final power adjustment ratio of the selected link is determined as in Equation 16 below.
  • FIG. 12B An example of power adjustment ratio calculation is shown in FIG. 12B.
  • 12B shows an example of performing power adjustment for link 2.
  • the power regulation ratio 0.32 of link 2 which does not receive additional Rx yield and the power regulation ratio of 0.02 of link 2 which does not cause additional Tx yield are derived.
  • a small power adjustment ratio of 0.038 (-14.2 dB) is determined as the final power adjustment ratio.
  • the first transceiver 210 of the base station delivers the power adjustment ratio determined for the selected link to the corresponding link.
  • the determined power adjustment ratio is delivered using a periodic cellular paging message or the like.
  • the controller 220 updates the table 222 managed by the controller 220 based on the reports from the D2D links received after the power adjustment, and continuously performs power control on the links that meet the criteria.
  • the transmitting terminal of the D2D link receiving the power adjustment ratio from the base station changes the transmission power of single-tone and multi-tone at the corresponding adjustment ratio. After changing the transmission power, the transmitting terminal reports the updated yield correlation information (indicator) to the base station.
  • FIG. 13 illustrates an example of a D2D communication network for distributed power control operation according to an embodiment of the present invention.
  • the configuration shown in FIG. 13 is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.
  • the D2D communication network includes device 1 101 and device 2 102, which are terminals connected through a D2D link.
  • the devices 101 and 102 may be a transmitting terminal or a receiving terminal, and the devices 101 and 102 may include a transmitting terminal and a receiving terminal (not shown) of a neighboring link.
  • the devices 101 and 102 each include a PHY layer part L12, a MAC layer part L22 and an upper layer part L30 for DD2 communication.
  • FIG. 14 shows a detailed configuration of the devices 101 and 102 shown in FIG. 13.
  • the configuration shown in FIG. 14 is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.
  • the devices 101 and 102 include a transceiver 110 and a controller 120.
  • the first transceiver 110 is for signal transmission and reception through the D2D link.
  • the controller 120 controls the overall operations of the devices 101 and 102.
  • the controller 120 includes a yield indicator calculator 122, a table 126, a power adjustment ratio calculator 128 and a transmission power adjuster 124 for operation according to an embodiment of the present invention.
  • the first transceiver 110 receives first detection signals (eg, IPE) transmitted from a receiving terminal of a first link (its link) and a receiving terminal of a second link (neighbor link), and receives the received detection signals. Measure their strength.
  • the yield indicator calculator 122 and the power adjustment ratio calculator 128 of the control unit 120 allow the signal-to-interference ratio of the second link to be equal to or greater than a predetermined threshold value based on the measured intensity of the first detection signals.
  • a yield indicator is determined as the first transmission power adjustment ratio for the.
  • the first transmission power adjustment ratio may be an upper limit of the first transmission power adjustment ratio.
  • the transmission power adjusting unit 124 controls the transmission power within a range including an upper limit value of the first transmission power adjustment ratio.
  • the concession indicator calculation unit 122 and the power adjustment ratio calculation unit 128 is for transmitting the signal to the interference ratio of the second link based on the measured intensity of the first detection signal to be above a predetermined threshold, the transmission terminal of the second link.
  • a yield indicator is determined as a second transmission power adjustment ratio for the.
  • the second transmission power adjustment ratio may be a lower limit of the second transmission power adjustment ratio.
  • the first transceiver 110 receives a control message including a third transmission power adjustment ratio for the transmitting terminal of the first link so that the signal-to-interference ratio of the first link is equal to or greater than a predetermined threshold. Can be received from.
  • the third transmission power adjustment ratio is determined based on the measurement result of the strength of the second detection signals transmitted from the transmitting terminals of the first link and the second link.
  • the third transmission power adjustment ratio may be a lower limit of the third transmission power adjustment ratio.
  • the transmission power adjusting unit 124 may control the transmission power within a range including a lower limit value of the third transmission power adjustment ratio.
  • the first transceiver 110 receives detection signals (eg, DPS) transmitted from transmitting terminals of the first link (its link) and the second link (neighbor link), and measures the strength of the received detection signals. do.
  • the yield indicator calculator 122 and the power adjustment ratio calculator 128 of the controller 120 are configured to transmit the signal-to-interference ratio of the first link to be equal to or greater than a predetermined threshold value based on the measured detection signals.
  • the yield index is determined as the first transmission power adjustment ratio for the second transmission power.
  • the first transmission power adjustment ratio may be a lower limit of the first transmission power adjustment ratio.
  • the first transceiver 110 transmits the lower limit value of the first transmission power adjustment ratio to the transmission terminal of the first link so that the transmission terminal of the first link controls the transmission power within a range including the lower limit value of the first transmission power adjustment ratio. do.
  • the concession indicator calculation unit 122 and the power adjustment ratio calculation unit 128 may be configured to transmit to the transmitting terminal of the second link a signal-to-interference ratio of the first link to be equal to or greater than a predetermined threshold value based on the measured detection signals.
  • the second transmission power adjustment ratio is determined.
  • the second transmission power adjustment ratio may be an upper limit of the second transmission power adjustment ratio.
  • step 510 the terminal of the D2D link grasps the concession correlation between the D2D links and expresses it as indicators. Specifically, the transmitting terminal and the receiving terminal of the D2D link calculate the indicators indicating the Rx and Tx concession relations and the power adjustment range with the neighboring links based on the reception strengths of the signals (DPS, IPE) received from the neighboring links. do. Since power control must be performed in the link itself that has determined the yield relationship, the Rx and Tx yield relationship indexes are calculated as in Equations 2 and 4 above. In step 520, the terminal calculates the transmission power adjustment ratio for its link.
  • the link according to the Tx and Rx concessions identified above calculates the transmission power adjustment ratio.
  • the terminal adjusts the transmission power of the transmitting terminal with the calculated adjustment ratio. For example, the single-tone and multi-tone transmit powers of the transmitting terminal are adjusted with the calculated adjustment ratio.
  • FIG. 16 illustrates a processing flow of a distributed power control operation according to an embodiment of the present invention by the components of the communication network shown in FIG. In this embodiment, it is assumed that a mobile communication base station supports transmission power control for D2D links belonging to its own communication area.
  • step 412 the transmitting terminals of each of the D2D links X and Y having data to be transmitted transmit a DPS signal through a transmission unit according to a given CID in the Tx OFDM block of the nth traffic slot.
  • step 414 the receiving terminal of the link X based on the strength of the received DPS signals. Calculate the information.
  • step 422 receiving terminals of each of the two links transmit an IPE signal through a given OFDM transmission unit in a subsequent Rx OFDM block.
  • step 424 the transmitting terminal of the link X is based on the received IPE signal strength. Calculate the information.
  • step 432 and 434 the transmission and reception terminals of the link X to perform the medium access through the exchange of the DPS signal and the IPE signal exchange the pilot and channel quality indicator signals in the data transmission process. Determine the modulation technique and coding rate to use. Thereafter, in step 442, the transmitting terminal of the link X transmits data to the receiving terminal, and in step 444, the receiving terminal measures previously. Send an acknowledgment message containing the information.
  • step 480 the transmitting terminal acquires the concession relation indicators ( , Calculate the transmission power adjustment ratio using Thereafter, in step 490, the transmitting terminal adjusts its own transmission power based on the calculated transmission power adjustment ratio.
  • the transmission power of the specific D2D link X may increase the transmission power in order to improve the signal quality of its own link within the range of not experiencing additional Tx yield by neighboring D2D links.
  • Increase The transmitting terminal of the D2D link which has established a yield table for neighboring D2D links, identifies and aggregates the neighboring D2D links that are not currently causing Tx yield to itself. Separate by. In other words Is a set of D2D links that do not yield Tx to D2D link X.
  • Equation 13 In order to adjust the transmission power while maintaining the relationship between links that are not currently causing Tx concessions, the power control method shown in Equation 13 And its own transmission power adjustment Relationship between Consider. In other words, in order not to perform additional Tx concessions, the transmitting terminal of link X must not be able to It should have a low transmission power adjustment ratio. To this end, the transmitting terminal of the link X has its own transmission power adjustment ratio (Equation 17). Is determined.
  • Concession indicators Is calculated by the receiving terminal based on the DPS signal received through the Tx OFDM block from the neighbor links.
  • the transmission terminal of the neighboring link causing Rx yield is identified. That is, the indicator > 1, link X is yielded Rx by link Y.
  • Calculated Metric Is transmitted to the transmitting terminal when transmitting the ACK frame.
  • the calculated yield relationship index identifies the receiving terminal of the neighboring link causing the Tx yield. That is, the indicator If ⁇ 1, link X is yielded by link Y T x .
  • FIG. 17A illustrates an example of values stored in a table of the devices shown in FIG. 14 in a distributed power control operation according to an embodiment of the present invention.
  • Link 9 is Rx yielded by link 3, link 4 and link 5, and Tx yielded by link 1, link 4 and link 7.
  • FIG. 17B illustrates an example in which a power adjustment ratio is calculated from values stored in a table of devices shown in FIG. 14 in a distributed power control operation according to an embodiment of the present invention.
  • the purpose of calculating the power adjustment ratio based on the calculated concession relation indicator is to improve the link capacity by adjusting the power within a range that does not cause additional Tx yield from neighboring D2D links.
  • the transmission power adjustment ratio of the link X is calculated as shown in Equation 17.
  • the transmission terminal directly measures and calculates a concession relationship
  • the power control method supports distributed power control in each D2D link within a range that does not break the Tx concession relationship formed by the conventional D2D links, power control is performed using fixed transmission power or considering only link quality. You can achieve higher performance than you did.
  • FIG. 18 illustrates a processing flow of distributed power control operation according to another embodiment of the present invention.
  • This embodiment differs from the embodiment of the above-described distributed power control operation in which the transmission power is adjusted in consideration of concession relation indicators for all neighboring links regardless of whether the neighboring links have medium access. By adjusting the transmission power only by considering the yield relationship indicators for the links to perform the higher performance can be improved.
  • the distributed power control method identifies links in which a transmission terminal that attempts to access a medium simultaneously with the highest priority in a current traffic slot is expected to simultaneously perform a medium access.
  • a process 610 a process of identifying a range in which the transmitting terminal can adjust the transmission power without affecting the yield relation of another link, and a process 630 of adjusting the transmission power adjustment ratio and transmitting the pilot and data accordingly.
  • the transmitting terminal that has the highest priority in each traffic slot and attempts to access the medium adjusts the transmission power.
  • the reason is that in the SIR-based distributed media approach, it is difficult to exchange control information between links. Therefore, when the transmission power control is performed on two or more links, an effect different from the intention may occur.
  • a process 610 of identifying the links that have the highest priority and is expected to simultaneously perform the medium access by the transmitting terminal that attempts the medium access is performed as follows.
  • Receiving terminal Transmits its IPE signal through the highest priority transmission unit, ) Has the highest priority. Yield indicator for each neighbor link j that sent the IPE signal Is less than 1 (see Table 3), the transmitting terminal Determines that the neighboring link j is a link that can simultaneously access the medium. Transmitting terminal by repeating the above process for all neighbor links Is a collection of neighboring links likely to conduct media access simultaneously with itself. Calculate
  • a process 620 of checking a range in which the transmitting terminal can adjust the transmission power without affecting the yield relationship of the other link is performed as follows.
  • the process 630 of adjusting the transmission power adjustment ratio and transmitting the pilot and data accordingly is performed as follows.
  • a transmitting terminal In order to use the highest possible transmission power, the transmission power adjustment ratio is determined as shown in Equation 19 below.
  • the new transmission power strength according to the transmission power adjustment ratio [Watt] the maximum transmit power of this terminal If less than [Watt], the transmitting terminal silver The pilot and data signal transmissions are performed with the signal strength of [Watt].
  • the new transmit power strength [Watt] the maximum transmit power of this terminal If greater than [Watt], the transmitting terminal silver The pilot and data signal transmissions are performed with the signal strength of [Watt].
  • the transmitting terminal Is the transmit power of Set to Watt,
  • the pilot and data signal transmissions are performed with the signal strength of [Watt]. Which links Since this is the only terminal that performs media access, it is to maximize the utilization of the radio channel.
  • FIG. 19A-19C contrast the performance of a power control operation in accordance with embodiments of the present invention.
  • the performance is contrasted with the existing technology using fixed transmission power, the centralized power control operation according to the embodiment of the present invention, and the distributed power control operation according to the embodiment of the present invention. Is shown.
  • FIG. 19A shows the performance in terms of network total yield (bps)
  • FIG. 19B shows the performance in terms of average concurrent transmission links
  • FIG. 19C shows the performance in terms of fairness between terminals.
  • the network type assumes a network area of 1Km x 1Km square. Terminals are placed in the network area with equal probability, and all terminals are rearranged every 10 seconds. The distance between the pair of terminals in each link was determined with equal probability within [0, 500] m. The roles of the transmitting terminal and the receiving terminal have been determined, and one-way communication from the transmitting terminal to the receiving terminal is considered. Shading and multipath fading were not considered.
  • the transmission power per link uses the transmission power of 20dBm for the first links, and the centralized technique performs power control for D2D links having the lower 30% link quality, and the distributed scheme is used for all terminals. Power distribution by means of distributed control. And performance evaluation was performed for 1000 seconds.
  • the concession relations indicator according to the embodiments of the present invention as described above can be utilized in various ways. For example, it is possible to know various information related to performing Tx / Rx concessions on a specific D2D link in an entity (base station) or a neighboring D2D link that performs central control. It is also used to determine the transmission power adjustment ratio of a particular link required to maintain / improve the corresponding Tx / Rx yield relationship.
  • the centralized power control scheme according to an embodiment of the present invention enables systematic power control and link management in consideration of concession relations between D2D links. In addition, it can be extended to various power control techniques using concession relations indicators according to operator / manager policies.
  • the distributed power control scheme according to an embodiment of the present invention can perform power control that can maintain / improve the current yield relationship without a separate coordinator.
  • the embodiments of the present invention use fixed transmission power because the transmission power is controlled by comprehensively considering not only the effect of the D2D link in the D2D communication network but also the effect on the neighboring link. Compared to the case, the performance of the entire D2D network can be improved.
  • program instructions for performing various computer-implemented operations may be recorded on a computer-readable medium.
  • the computer-determinable medium may include program instructions, data files, data structures, and the like, alone or in combination.
  • the program instructions may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those skilled in the art.
  • Examples of computer readable recording media include magnetic media such as hard disks, floppy disks and magnetic tape, optical recording media such as CD-ROMs or DVDs, magnetic-optical media such as floppy disks and ROMs.
  • Hardware devices specifically configured to store and execute program instructions such as memory, RAM, flash memory, and the like.
  • Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like.
  • a computer readable recording medium storing the computer program is also included in the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below but also by the equivalents of the claims.

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Abstract

La présente invention concerne un procédé et un appareil de commande de la puissance d'émission tenant compte simultanément de l'influence subie par chaque liaison de dispositif à dispositif (D2D) d'un réseau de communication D2D du fait de liaisons voisines et de l'influence exercée sur les liaisons voisines. Conformément à un mode de réalisation de la présente invention, un procédé de traitement permettant à des terminaux de transmission d'une première liaison de commander la puissance d'émission des terminaux d'émission des liaisons du réseau de communication D2D, qui comprend au moins deux terminaux de la première liaison et des terminaux d'une seconde liaison voisine de la première liaison, comprend les étapes consistant à : mesurer l'intensité de premiers signaux de détection émis par des terminaux de réception de la première liaison et de la seconde liaison ; et déterminer un premier rapport d'ajustement de puissance d'émission des terminaux d'émission de la première liaison de manière à ce qu'un rapport signal à brouillage de la seconde liaison soit supérieur ou égal à une valeur de seuil prédéterminée sur la base de l'intensité mesurée des premiers signaux de détection.
PCT/KR2014/001078 2013-02-07 2014-02-07 Procédé et appareil de commande de la puissance d'émission d'un réseau de communication de dispositif à dispositif WO2014123393A1 (fr)

Priority Applications (1)

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US14/765,996 US9538484B2 (en) 2013-02-07 2014-02-07 Method and apparatus for controlling transmission power of device-to-device communication network

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104135759A (zh) * 2014-08-19 2014-11-05 哈尔滨工业大学 用于近场通信或d2d通信的二级用户动态功率控制方法
WO2020032764A1 (fr) * 2018-08-10 2020-02-13 엘지전자 주식회사 Procédé et appareil destinés à transmettre une pluralité de paquets par un terminal à liaison latérale dans un système de communication sans fil
CN113508623A (zh) * 2019-08-02 2021-10-15 Oppo广东移动通信有限公司 调整功率的方法和终端设备

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100261469A1 (en) * 2009-04-08 2010-10-14 Nokia Corporation Apparatus and method for mode selection for device-to-device communications
US20100329186A1 (en) * 2009-06-26 2010-12-30 Samsung Electronics Co. Ltd. Apparatus and method for transmitting preamble in a wireless communication system
US20120028672A1 (en) * 2010-07-30 2012-02-02 Tao Chen Apparatus and Method for Transmitter Power Control for Device-to-Device Communications in a Communication System
US20120163252A1 (en) * 2010-12-27 2012-06-28 Electronics And Telecommunications Research Institute Method for harq and link adaptation of device to device link in direct communication between user equipments and relaying by user equipment

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100261469A1 (en) * 2009-04-08 2010-10-14 Nokia Corporation Apparatus and method for mode selection for device-to-device communications
US20100329186A1 (en) * 2009-06-26 2010-12-30 Samsung Electronics Co. Ltd. Apparatus and method for transmitting preamble in a wireless communication system
US20120028672A1 (en) * 2010-07-30 2012-02-02 Tao Chen Apparatus and Method for Transmitter Power Control for Device-to-Device Communications in a Communication System
US20120163252A1 (en) * 2010-12-27 2012-06-28 Electronics And Telecommunications Research Institute Method for harq and link adaptation of device to device link in direct communication between user equipments and relaying by user equipment

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104135759A (zh) * 2014-08-19 2014-11-05 哈尔滨工业大学 用于近场通信或d2d通信的二级用户动态功率控制方法
CN104135759B (zh) * 2014-08-19 2017-09-08 哈尔滨工业大学 用于近场通信或d2d通信的二级用户动态功率控制方法
WO2020032764A1 (fr) * 2018-08-10 2020-02-13 엘지전자 주식회사 Procédé et appareil destinés à transmettre une pluralité de paquets par un terminal à liaison latérale dans un système de communication sans fil
US11272461B2 (en) 2018-08-10 2022-03-08 Lg Electronics Inc. Method and apparatus for transmitting plurality of packets by sidelink terminal in wireless communication system
CN113508623A (zh) * 2019-08-02 2021-10-15 Oppo广东移动通信有限公司 调整功率的方法和终端设备
CN113508623B (zh) * 2019-08-02 2023-08-22 Oppo广东移动通信有限公司 调整功率的方法和终端设备

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