WO2009054604A1 - Procédé pour effectuer la programmation de liaisons montantes - Google Patents

Procédé pour effectuer la programmation de liaisons montantes Download PDF

Info

Publication number
WO2009054604A1
WO2009054604A1 PCT/KR2008/004547 KR2008004547W WO2009054604A1 WO 2009054604 A1 WO2009054604 A1 WO 2009054604A1 KR 2008004547 W KR2008004547 W KR 2008004547W WO 2009054604 A1 WO2009054604 A1 WO 2009054604A1
Authority
WO
WIPO (PCT)
Prior art keywords
interference
frequency band
mobile station
frequency bands
value
Prior art date
Application number
PCT/KR2008/004547
Other languages
English (en)
Inventor
Kwang Jae Lim
Chul Sik Yoon
Original Assignee
Electronics And Telecommunications Research Institute
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020080022613A external-priority patent/KR20090042128A/ko
Application filed by Electronics And Telecommunications Research Institute filed Critical Electronics And Telecommunications Research Institute
Priority to US12/738,740 priority Critical patent/US8798073B2/en
Publication of WO2009054604A1 publication Critical patent/WO2009054604A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/50—Allocation or scheduling criteria for wireless resources
    • H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
    • H04W72/542—Allocation or scheduling criteria for wireless resources based on quality criteria using measured or perceived quality
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/20—Control channels or signalling for resource management
    • H04W72/23—Control channels or signalling for resource management in the downlink direction of a wireless link, i.e. towards a terminal

Definitions

  • the present invention relates to a method of performing uplink scheduling. More particularly, the present invention relates to a method of performing uplink scheduling including uplink power control so as to reduce interference in an orthogonal frequency multiplex division access (OFMDA) system.
  • OFDMDA orthogonal frequency multiplex division access
  • An orthogonal frequency division multiplex access (referred to as OFDMA or OFDM-FDMA) scheme is one of multiple access schemes.
  • OFDMA orthogonal frequency division multiplex access
  • a base station forms one service cell and allocates at least one of subcarriers, which are different from each other, to at least one mobile station included in the service cell. Accordingly, the OFDMA communication system can minimize interference in the cell.
  • the mobile station transmits signals in uplink with restricted power. Therefore, when the mobile station is located at the edge of a cell, the mobile station cannot transmit packets in uplink because of a lack of sufficient power. For this reason, in order for the base station to properly receive packets from the mobile station located in the service cell, it is necessary to restrict interference generated from an adjacent cell to be less than a specific level.
  • a mobile communication system of a general OFDMA scheme when the mobile station is located in a cell, path loss between the mobile station and the service cell is smaller than that between the mobile station and an adjacent cell. In this case, the mobile station experiences little restriction on transmission power and transmits packets using comparatively high power in the uplink.
  • the mobile station when the mobile station is located at the edge of a cell, since the mobile station is close to an adjacent cell, interference by the adjacent cell due to the transmission power of the mobile station can occur. Therefore, the mobile station reduces the amount of uplink interference power that interacts with the adjacent cell by restricting the transmission power, and transmits the packets by using a comparatively low power in the uplink. However, the mobile station requires recognition of an interference situation of the adjacent cell so as to control the transmission power.
  • the interference influence of the cell is divided into three stages, and the base station broadcasts the interference stage of the service cell into the stage of a mobile station located in the service cell and an adjacent cell with a very low encoding rate over a specific broadcasting channel (OSICH).
  • the mobile station receives the interference stage of the adjacent cell through the specified broadcasting channel (OSICH), and controls the transmission power in consideration of the interference stage of the adjacent cell.
  • the base station transmits the interference stage of the service cell with a 2 bit OSI value such that the mobile station can control the transmission power according to the interference stage of the adjacent cell. For this reason, since only some mobile stations are capable of receiving the OSI value and can recognize the interference stage of the adjacent cell, it is difficult for the control of transmission power to be commonly applied to all mobile stations that bring about the interference of the adjacent cell.
  • the mobile station should periodically receive the OSI value corresponding to the interference stage of the adjacent cell from the base station of the adjacent cell so as to recognize the interference stage of the adjacent cell.
  • the base station utilizes one OFDM (orthogonal frequency division multiplex) symbol so as to transmit the 2 bit OSI value corresponding to the interference of the service cell, radio resources can be unnecessarily wasted.
  • the mobile station sets the transmission power in consideration of the interference stage of the adjacent cell and sets the transmission power by using a power control report message.
  • the mobile station should carry out processes such as, for example, an uplink band request for the transmission power report message, band allocation through a control channel, and transmission of the power control report message. Accordingly, the mobile station cannot quickly report the transmission power to the base station.
  • the base station When the base station is not able to receive the power control report message from the mobile station, the base station carries out uplink scheduling by using incorrect information. Accordingly, there is a problem in that the reception success rate of an uplink traffic burst is decreased.
  • the present invention has been made in an effort to provide a method of performing uplink scheduling, which controls transmission power of a mobile station, in a base station, so as to reduce interference influence of an adjacent cell.
  • An exemplary embodiment of the present invention provides a method of performing uplink scheduling of a mobile station in a base station, the mobile station being located in a service cell of the base station.
  • the uplink includes a plurality of frequency bands that are different from one another.
  • the method of performing the uplink scheduling includes: receiving interference amounts of the plurality of frequency bands corresponding to the at least one adjacent cell, respectively; calculating a plurality of interference values each corresponding to the plurality of frequency bands by using the plurality of interference amounts corresponding to the at least one adjacent cell, respectively; obtaining scheduling control information corresponding to the mobile station by using the plurality of interference values; and transmitting the scheduling control information to the mobile station.
  • the plurality of frequency bands may include: a first frequency band that is commonly used in all of cells; a second frequency band that is commonly used in the service ceil and the at least one adjacent cell and is allocated to a mobile station located at an edge of the service cell; and a third frequency band that is commonly used in the service cell and the at least one adjacent cell and is allocated to a mobile station located at an edge of the adjacent cell.
  • the calculating of the plurality of interference values may include: receiving a path gain corresponding to the service cell from the mobile station; receiving path gains corresponding to the at least one adjacent cell from the mobile station, respectively; recognizing a difference in at least one path gain each corresponding to the at least one adjacent cell by using the path gain corresponding to the service cell and the path gains each corresponding to at least one adjacent cell; and calculating the plurality of interference values by using the difference in the plurality of interference amounts and the path gain each corresponding to the at least one adjacent cell.
  • the obtaining of the scheduling control information corresponding to the mobile station may include: calculating a plurality of transmission powers each corresponding to the plurality of frequency bands by using the plurality of interference values; calculating a plurality of signal to interference and noise ratios corresponding to the plurality of frequency bands by using the plurality of transmission powers; searching one frequency band corresponding to a maximum signal to interference and noise ratio among the plurality of frequency bands; recognizing a modulation and coding scheme control level corresponding to the maximum signal to interference and noise ratio; and generating scheduling control information including information on the one frequency band, a bandwidth corresponding to the one frequency band, and the modulation and coding scheme control level.
  • the obtaining of the scheduling control information corresponding to the mobile station may include: generating a plurality of signal to interference and noise ratios each corresponding to the plurality of frequency bands by using the plurality of interference values; calculating a plurality of transmission power densities each corresponding to the plurality of frequency bands by using the plurality of signal to interference and noise ratios; calculating a plurality of bandwidths each corresponding to the plurality of frequency bands by using the plurality of transmission power densities; searching one frequency band corresponding to a maximum bandwidth among the plurality of frequency bands; recognizing a modulation and coding scheme control level corresponding to a signal to interference and noise ratio of the one frequency band; and generating scheduling control information including information on the one frequency band, the maximum bandwidth, and the modulation and coding scheme control level.
  • the signal to interference and noise ratio may correspond to signals that are capable of being received from the mobile station.
  • Another embodiment of the present invention provides a method of performing uplink scheduling of a mobile station in a base station, the mobile station being located in a service cell of the base station.
  • the method at least one of adjacent cells that are influenced by power of the mobile station exists, and the uplink includes a plurality of frequency bands that are different from one another.
  • the method of performing the uplink scheduling includes: receiving interference amounts of the plurality of frequency bands corresponding to the at least one adjacent cell, respectively; calculating a plurality of interference values each corresponding to the plurality of frequency bands by using the plurality of interference amounts each corresponding to the at least one adjacent cell; calculating a plurality of transmission powers corresponding to the plurality of frequency bands by using the plurality of interference values; generating scheduling control information corresponding to the mobile station by using the plurality of transmission powers; and transmitting the scheduling control information to the mobile station.
  • the plurality of frequency bands may include: a first frequency band that is commonly used in all of cells; a second frequency band that is commonly used in the service cell and the at least one adjacent cell and is allocated to a mobile station located at an edge of the service cell; and a third frequency band that is commonly used in the service cell and the at least one adjacent cell and is allocated to a mobile station located at an edge of the adjacent cell.
  • the calculating of the plurality of transmission powers may include: in correspondence with the plurality of frequency bands, respectively, setting a power correction value of the related frequency band as a rising value when an interference value of the related frequency band is less than a first reference value, setting a power correction value of the related frequency band as a falling value when an interference value of the related frequency band is larger than a second reference value that is larger than the first reference value, and setting a power correction value of the related frequency band as a basic value when an interference value of the related frequency band is in the range of between the first reference value and the second reference value; and calculating the plurality of transmission powers by using a plurality of power correction values each corresponding to the plurality of frequency bands, respectively.
  • the generating of the scheduling control information may include: calculating a plurality of signal to interference and noise ratios each corresponding to the plurality of frequency bands by using the plurality of transmission powers; selecting one frequency band among the plurality of frequency bands by using the plurality of signal to interference and noise ratios; recognizing a bandwidth corresponding to the one frequency band; selecting a modulation and coding scheme control level corresponding to a signal to interference and noise ratio of the one frequency band; and generating scheduling control information including information on the one frequency band, the bandwidth, and the modulation and coding scheme control level.
  • the calculating of the plurality of signal to interference and noise ratios may include: measuring a plurality of interference levels each corresponding to the plurality of frequency bands in the service cell, respectively; and calculating the plurality of signal to interference and noise ratios by using a path gain corresponding to the service cell, the plurality of interference levels, and the plurality of transmission powers, respectively.
  • the selecting of the one frequency band may include: searching a maximum value among a signal to interference and noise ratio of the first frequency band, a signal to interference and noise ratio of the second frequency band multiplied by a predetermined weight value, and a signal to interference and noise ratio of the third frequency band; and selecting one frequency band corresponding to the maximum value.
  • the predetermined weight value may be below 1.
  • Yet another embodiment of the present invention provides a method of performing uplink scheduling of a mobile station in a base station, the mobile station being located in a service cell of the base station.
  • the uplink includes a plurality of frequency bands that are different from one another.
  • the method of performing the uplink scheduling includes: receiving a plurality of interference amounts each corresponding to the plurality of frequency bands in at least one adjacent cell corresponding to the mobile station from the base station of the at least one adjacent cell, respectively; recognizing a plurality of interference values each corresponding to the plurality of frequency bands by using the plurality of interference amounts each corresponding to the at least one adjacent cell; generating a plurality of signal to noise and interference ratios each corresponding to the plurality of frequency bands by using the plurality of interference values; generating scheduling control information corresponding to the mobile station by using the plurality of signal to noise and interference ratios; and transmitting the scheduling control information to the mobile station.
  • the signal to interference and noise ratio is a factor with respect to signals that are capable of being received from the mobile station.
  • the plurality of frequency bands may include: a first frequency band that is commonly used in all of cells; a second frequency band that is commonly used in the service cell and the at least one adjacent cell and is allocated to a mobile station located at an edge of the service cell; and a third frequency band that is commonly used in the service cell and the at least one adjacent cell and is allocated to a mobile station located at an edge of the adjacent cell.
  • the generating of the plurality of signal to noise and interference ratios may include: in correspondence with the plurality of frequency bands, respectively, setting a correction value of the related frequency band as a rising value when an interference value of the related frequency band is less than a first reference value, setting a correction value of the related frequency band as a falling value when an interference value of the related frequency band is larger than a second reference value that is larger than the first reference value, and setting a correction value of the related frequency band as a basic value when an interference value of the related frequency band is in the range of between the first reference value and the second reference value; and generating the plurality of signal to interference and noise ratios by using a plurality of correction values each corresponding to the plurality of frequency bands.
  • the generating of the scheduling control information may include: calculating a plurality of transmission power densities each corresponding to the plurality of frequency bands by using the plurality of signal to interference and noise ratios; calculating a plurality of bandwidths each corresponding to the plurality of frequency bands by using the plurality of transmission power densities; selecting one frequency band among the plurality of frequency bands by the plurality of bandwidths; selecting a modulation and coding scheme control level by using a signal to interference and noise ratio of the one frequency band; and generating scheduling control information including information on the one frequency band, a bandwidth corresponding to the one frequency band, and the modulation and coding scheme control level.
  • the calculating of the plurality of transmission power densities may include: measuring a plurality of interference levels each corresponding to the plurality of frequency bands in the service cell, respectively; and calculating the plurality of transmission power densities by using a path gain corresponding to the service cell, the plurality of interference levels, and the plurality of signal to interference and noise ratios, respectively.
  • the selecting of the one frequency band may include: selecting a maximum value among a bandwidth of the first frequency band, a bandwidth of the second frequency band multiplied by a predetermined weight value, and a bandwidth of the third frequency band; and selecting one frequency band corresponding to the maximum bandwidth. At this time, the predetermined weight value is below 1.
  • FIG. 1 is a view schematically illustrating cells according to an exemplary embodiment of the present invention.
  • FIG. 2 is a flowchart illustrating a method of controlling uplink power according to an exemplary embodiment of the present invention.
  • FIG. 3 is a flowchart illustrating a method of allocating modulation, coding schedule, and radio resources to a mobile station according to a first exemplary embodiment of the present invention.
  • FIG. 4 is a flowchart illustrating a method of allocating modulation, coding schedule, and radio resources to a mobile station according to a second exemplary embodiment of the present invention.
  • a mobile station may designate a terminal, a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS) 1 user equipment (UE), an access terminal (AT), and so on.
  • the mobile station may include all or a part of functions of the terminal, the mobile terminal, the subscriber station, the portable subscriber station, the user equipment, and so on.
  • a base station may designate an access point (AP), a radio access station (RAS), a node B, an ENB (evolved node B), a base transceiver station (BTS), a mobile multihop relay (MMR)-BS and so on.
  • the base station may include all or a part of functions of the access point, the radio access station, the node B, the base transceiver station, the MMR-BS, and so on.
  • FIG. 1 is a view schematically illustrating cells according to the exemplary embodiment of the present invention.
  • FIG. 1 illustrates three cells corresponding to three base stations.
  • each of three cells may include a plurality of sectors (shown as "Sectori",
  • one cell includes three sectors, but one cell may include one or more sectors. Furthermore, since sectors in the cell are used as one cell, the cell represents a sector or cell, hereinafter. In addition, hereinafter, a cell where the mobile station is located is designated as a service cell, and a cell adjacent to the service cell is designated as an adjacent cell.
  • an uplink of a system to be operated in one cell may be classified into a plurality of frequency bands according to a service.
  • the plurality of frequency bands includes a reuse frequency band (RBW, hereinafter referred to as an "RBW”), a cell edge frequency band (EBW, hereinafter referred to as an "EBW”), and a suppressed frequency band (SBW, hereinafter referred to as an "SBW”).
  • RBW reuse frequency band
  • EBW cell edge frequency band
  • SBW suppressed frequency band
  • the RBW represents a general frequency band for applying a frequency reuse factor (FFR, hereinafter referred to as an "FFR") of 1.
  • FFR frequency reuse factor
  • the FFR represents the number of frequencies to be reused in the cell. That is, in order to reduce interference applied to an adjacent cell due to the power of the mobile station, the power of the mobile station is determined by a control of interference over thermal noise (loT, hereinafter referred to as "amount of interference" in the RBW.
  • the EBW represents a frequency band for applying a soft fractional frequency reuse (soft FFR, hereinafter referred to as a "soft FFR"). That is, the EBW is a frequency band that the service cell and the adjacent cell commonly used, and the EBW is a frequency band for controlling the power of the mobile station so as to ensure the interference of the adjacent cell to below a predetermined reference by the power of the mobile station that is located at an edge of the service cell.
  • soft FFR soft fractional frequency reuse
  • the SBW represents a frequency band that applies the Soft FFR in the service cell and is used as the EBW in the adjacent cell. That is, it is possible to set the power of the mobile station to zero so as to minimize the interference of the adjacent cell due to the power of the mobile station in the SBW.
  • a frequency band BW 0 is a frequency band ("non-FFR BW" in FIG. 1) to which the FFR is not applied, and the frequency band BW 0 is used as RBW in sector 1 , sector 2, and sector 3, respectively.
  • frequency bands BW 1 , BW 2 , and BW 3 are frequency bands ("Soft FFR BW" in FIG. 1) to which the Soft FFR is applied. That is, the frequency band BWi is used as the EBW in sector 1 and is used as the SBW in sector 2 and sector 3.
  • the frequency band BW 2 is used as the EBW in sector 2 and is used as the SBW in sector 1 and sector 3.
  • the frequency band BW 3 is used as the EBW in sector 3 and is used as the SBW in sector 1 and sector 2.
  • FIG. 1 also illustrates three frequency bands to which the soft FFR is applied.
  • the reuse factor is 7, it is possible to set seven frequency bands to which the soft FFR is applied.
  • uplink resources include a plurality of frequency bands.
  • the base station controls the power of the plurality of frequency bands, thereby searching scheduling control information to be suitable to the mobile station.
  • FIG. 2 is a flowchart illustrating a method of controlling uplink power according to an exemplary embodiment of the present invention.
  • a plurality of base stations 200 and 300 forming cells periodically inform each other of their interference amount ("reception interference amount" in FIG. 2) through a backbone network (indicated as a dotted line in FIG. 2) (S110). That is, the base station 200 of the service cell receives a plurality of interference amounts corresponding to a plurality of frequency bands from each base station 300 of at least one adjacent cell. That is, one of the plurality of base stations 200 and 300 transmits a plurality of interference amounts, which includes the interference amount in the RBW, the interference amount in the EBW, and the interference amount in the SBW, to the other base station.
  • the mobile station 100 located in the service cell transmits a path gain associated with the base station 200 of the service cell and a path gain associated with at least one adjacent cell to the base station 200 by periods or according to the request of the base station (S120).
  • the base station 200 of the service cell can receive the interference amount of the adjacent cell after receiving the path gain.
  • the base station 200 When receiving uplink request information from the mobile station 100, the base station 200 calculates a difference in the plurality of interference amounts corresponding to at least one adjacent cell (S130). That is, the base station 200 calculates ⁇ IOTRBWJ, ⁇ IOTEBWJ, and ⁇ IOT S BW,J corresponding to at least one adjacent cell(j), respectively.
  • Equation 1 is a formula for calculating the difference in the interference amounts.
  • the loT Xj represents the interference amount corresponding to the frequency band x in the adjacent cell j
  • the loT x ,target represents a reference interference amount corresponding to the frequency band x
  • the ⁇ loT X j indicates the difference in the interference amounts corresponding to the frequency band x in the adjacent cell j.
  • the reference interference amount indicates a target value that is necessary to control the interference amount.
  • the reference interference amount may be set to a value that varies in each frequency band. For example, since the SBW is a band to be used as the EBW in the adjacent cell, the interference amount corresponding to the SBW may be set to a low value so as to show the adjacent cell having a low interference amount in the related band. On the contrary, since the EBW is a band to be used as the SBW in the adjacent cell, the interference amount corresponding to the EBW may be set to a high value so as to ensure the service of the service cell in the related band.
  • the difference ⁇ loT x ,j of the interference amount may be obtained by the difference between the reference interference amount loT x, target and the interference amount loT X j. That is, when the difference ⁇ loT XJ - of the interference amount is larger than 1 , it implies that the interference amount corresponding to frequency band x in the adjacent cell j is larger than the reference interference amount. Further, when the difference ⁇ loT x ,j of the interference amount is smaller than 1 , it implies that the interference amount corresponding to frequency band x in the adjacent cell j is smaller than the reference interference amount.
  • the difference ⁇ loT Xj of the interference amount may be obtained by the difference between the reference interference amount loT Xi target and the interference amount loT X ⁇ j .
  • the base station 200 receives the path gain between the mobile station 100 and the service cell and the path gain between the mobile station 100 and each at least one adjacent cell from the mobile station 200, thereby calculating the difference in at least one path gain each corresponding to at least one adjacent cell (S140).
  • the following Equation 2 is a formula for calculating the difference in a path gain.
  • the PGj represents a path gain between the mobile station 100 and the service cell i
  • the PGj represents a path gain between the mobile station 100 and the adjacent cell j
  • the ⁇ PGg represents the difference in a path gain of the service cell i and the adjacent cell j.
  • the path gains PGi and PGj each corresponding to the service cell i or at least one adjacent cell j are to indicate an average path loss on the mobile station, and include shadow fading.
  • the path gains PGi and PGj are to indicate an average channel loss on the frequency band or time.
  • the base station applies a value (hereinafter referred to as "average path gain”) that takes an average of the path gain PGj between the mobile station and the service cell (i) during a predetermined time to Equation 2, and can thereby allow the difference in the path gain to not be sensitively varied by high fading.
  • average path gain a value that takes an average of the path gain PGj between the mobile station and the service cell (i) during a predetermined time to Equation 2, and can thereby allow the difference in the path gain to not be sensitively varied by high fading.
  • the base station 200 calculates a plurality of considered interference amounts (hereinafter also referred to as "interference values"), that are necessary for the power control of the related mobile station, by using the difference in the plurality of interference amounts and the difference in the path gain each corresponding to at least one adjacent cell (S 150).
  • the plurality of considered interference amounts correspond to a plurality of frequency bands, respectively. That is, the base station 200 calculates a considered interference amount corresponding to the RBW, a considered interference amount corresponding to the EBW, and a considered interference amount corresponding to the SBW, respectively.
  • Equation 3 is a formula for calculating the considered interference amount.
  • a IoT x represents the considered interference amount corresponding to the frequency band x.
  • the considered interference amount ⁇ loT x can be obtained by the sum of at least
  • the W Xj represents weight value corresponding to the adjacent cell j in the frequency band x. That is, the weight value W x ,j is set according to each characteristic of the plurality of frequency bands or each characteristic of at least one adjacent cell.
  • a weight value W RB w ,j each corresponding to at least one adjacent cell j in the RBW is as indicated in the following Equation 4. (Equation 4)
  • Equation 5 the weight value corresponding to the RBW is set to the same parameter W nO rmai regardless of the adjacent cell.
  • the parameter W nor mai is determined by the following Equation 5. (Equation 5)
  • Equation 6 Equation 6
  • the ⁇ W nO rmai is determined by a first resulting value that is a sum of the difference in the interference amounts, each of which corresponds to at least one adjacent cell in the RBW, during a predetermined time t.
  • the first resulting value is not less than a basic value (represented as "0" in Equation 6)
  • the ⁇ W nO rm a i is determined as a rising value ⁇ W, and thereby the parameter W noriT1a i rises.
  • the ⁇ W n0 rmai is determined as a falling value - ⁇ W, thereby the parameter W n0 ⁇ nai falls.
  • a weight value W E BW,J corresponds to at least one adjacent cell j in the EBW, respectively, is as indicated in the following Equation 7.
  • the weight value corresponding to the EBW is set to the same parameter W sma ⁇ regardless of the adjacent cell.
  • the parameter W sm ai ⁇ is smaller than the parameter W nO rmai- Therefore, the weight value WEBWJ corresponding to the EBW is set to a smaller value than the weight value WRBWJ corresponding to the RBW so as to not be sensitive to the interference amount of the adjacent cell in the EBW.
  • the parameter W sma i ⁇ is as indicated in the following Equation 8.
  • Equation 9 the ⁇ W S mai ⁇ is as indicated in the following Equation 9.
  • the ⁇ W sma i ⁇ is determined by a second resulting value that is the sum of the difference in the interference amounts, each of which corresponds to at least one adjacent cell in the EBW, during a predetermined time (t). That is, when the second resulting value is not less than a basic value (represented as "0" in Equation 9), the ⁇ W sma ⁇ is determined as a rising value ⁇ W, and thereby the parameter W sm ai ⁇ rises. Further, when the second resulting value is less than the basic value 0, the ⁇ W sma ⁇ is determined as a falling value - ⁇ W, and thereby the parameter W sma ⁇ falls.
  • a weight value WSBWJ corresponding to a portion of at least one adjacent cell, which uses the related frequency band as the EBW, in the SBW, is as indicated in the following Equation 10.
  • the weight value WSBWJ corresponding to the SBW is set to a parameter W
  • Equation 11 a weight value W S BW,J corresponding to the rest of at the least one adjacent cell, which does not use the related frequency band as the EBW 1 in the SBW, is as indicated in the following Equation 11. (Equation 11)
  • the weight value W S BW,J corresponding to the SBW is set to the parameter W nO rmai like the weight value W RB w,j corresponding to the RBW.
  • M ,_ U- 1 U can be expressed by the sum of a previously used parameter A ' ⁇ f ⁇ "' and a ⁇ W
  • Equation 13 AloTm j V ⁇ O [ ⁇ B] ⁇ for ⁇ BJFJ (0 ⁇ 0 [dB]
  • ar ge is determined by a third resulting value is a sum of the difference in the interference amounts, each of which corresponds to at least one adjacent cell in the SBW, during a predetermined time t. That is, when the third resulting value is not less than a basic value (represented as "0" in Equation 13), the ⁇ W
  • FIG. 2 will now be described.
  • the base station 200 generates scheduling control information corresponding to the mobile station 100 by using the plurality of considered interference amounts (S160). Furthermore, the base station 200 transmits the scheduling control information to the mobile station 100 (S 170). A method of generating the scheduling control information in the base station 200 will now be described in detail.
  • the mobile station 100 receives the scheduling control information from the base station to control the power of an uplink transmission signal by using the scheduling control information (S180).
  • the base station 200 receives the plurality of interference amounts each corresponding to the plurality of frequency bands from the base station 300 of at least one adjacent cell, respectively.
  • the base station 200 generates the scheduling control information of the mobile station 100 by using the path gain transmitted from the mobile station 100 and the plurality of interference amounts each corresponding to at least one adjacent cell.
  • FIG. 3 is a flowchart illustrating the method of generating the scheduling control information according to the first exemplary embodiment of the present invention.
  • the base station 200 receives the plurality of interference amounts each corresponding to the plurality of frequency bands from the base station 300 of at least one adjacent cell (S310).
  • the base station 200 recognizes the difference ⁇ PGg in at least one path gain each corresponding to the base station of at least one adjacent cell by using Equation 2 (S320).
  • the base station 200 calculates a plurality of considered interference amounts each corresponding to a plurality of frequency bands through the plurality of interference amounts and the difference in the path gain each corresponding to at least one adjacent cell by using Equation 3 (S330). According to the first exemplary embodiment of the present invention, the base station 200 calculates a plurality of transmission powers each corresponding to the plurality of frequency bands at the current time (S340).
  • the base station 200 determines a transmission power corresponding to the RBW, a transmission power corresponding to the EBW, and a transmission power corresponding to the SBW at the current time, respectively.
  • Equation 14 is a formula for obtaining the transmission power at the current time.
  • Equation 14 the P x (t) represents the transmission power corresponding to the frequency band(x) at the current time t, the Px(H) represents the transmission power corresponding to the frequency band(x) at the previous time t-1 , and the ⁇ P X represents a power correction value corresponding to the frequency band x.
  • Equation 15 is a formula for obtaining the power correction value ⁇ P x .
  • the power correction value ⁇ P X corresponding to the frequency band x is determined by the considered interference amount ⁇ loT x corresponding to the frequency band x. That is, when the considered interference amount ⁇ loT x is not more than the ⁇ loT
  • the power correction value ⁇ P x is determined as a falling value ⁇ P d own-
  • the power correction value ⁇ P x is determined as a basic value (represented as "0" in Equation 15).
  • the base station 200 measures interference levels of the service cell in the plurality of frequency bands, respectively (S350).
  • the base station 200 calculates a plurality of SINRs (hereinafter also referred to as "signal to interference-plus-noise ratio") corresponding to the plurality of frequency bands by using the plurality of interference levels and the plurality of transmission powers corresponding to the plurality of frequency bands (S360).
  • the following Equation 16 is a formula for obtaining the SINR.
  • SINR x represents a SINR corresponding to the frequency band x
  • Nl x represents an interference level of the service cell in the frequency band x
  • P x represents a transmission power corresponding to the frequency band x
  • Gj represents a path gain between the mobile station 100 and the base station 200 of the service cell.
  • the base station 200 applies the latest path gain Gj to the path gain between the mobile station 100 and base station 200 of the service cell in Equation 16 such that a SINR x that is suitable for a current uplink channel can be calculated.
  • the base station 200 selects one frequency band applied to the mobile station 100 among a plurality of frequency bands through a plurality of SINRs using Equation 17.
  • the base station 200 searches a maximum value among a SINR (SINRRBW) corresponding to RBW, a SINR (SINRSBW) corresponding to SBW, and a SINR ( ⁇ SINR EB w) corresponding to EBW and multiplied by a weight value ⁇ .
  • SINR SINR
  • SINR SINR
  • SBW SINR
  • ⁇ SINR EB w SINR
  • EBW can be prevented from being applied to most mobile stations.
  • the weight value ⁇ is less than 1 , and thereby a ratio of EBW applied to a mobile station located at the edge of service cells in accordance with the weight value ⁇ can be controlled.
  • the base station 200 selects the frequency band X corresponding to the maximum SINR as one frequency band that is applied to the mobile station 100.
  • the base station 200 selects a frequency band X using Equation 17 and recognizes a bandwidth corresponding to the frequency band X (S370).
  • a plurality of bandwidths each corresponding to a plurality of frequency bands are predetermined in accordance with the difference in interference amounts.
  • Equation 18 is a formula for determining a bandwidth corresponding to an arbitrary frequency band x at the current time. (Equation 18)
  • the bandwidth ' t X J corresponding to the frequency band x at the current time corresponds to the sum of ⁇ L x and the
  • ⁇ L x is determined by a value that is a sum of the difference in interference amounts each corresponding to at least one adjacent cell in the frequency band x during a predetermined time t. That is, when the sum is not less than a basic value (represented as "0" in Equation 19),
  • ⁇ L X is determined as a falling value - ⁇ L step , thereby decreasing the
  • the base station 200 selects an MCS level corresponding to the frequency band X such that Equation 20 is satisfied, and generates scheduling control information including information on the bandwidth and MCS level (S380).
  • Equation 20 Nl o , x represents power density per subcarrier in the frequency band X, and N SUb represents the number of subcarriers corresponding to a bandwidth ( L ⁇ I ⁇ i) J ) of the frequency band X. Px represents transmission power corresponding to the frequency band X.
  • the base station 200 calculates a plurality of transmission powers using a plurality of considered interference amounts, calculates a plurality of SINRs using a plurality of transmission powers, selects a maximum value among a plurality of SINRs, and selects the bandwidth and MCS level corresponding to the selected SINR.
  • the base station 200 generates the scheduling control information including information of the frequency band corresponding to the maximum SINR, the transmission power of the selected frequency band, the bandwidth corresponding to the selected frequency band, and the MCS level corresponding to the maximum SINR.
  • the scheduling control information is transmitted to the mobile station 100 through the downlink.
  • FIG. 4 is a flowchart illustrating a method of generating scheduling control information according to a second exemplary embodiment of the present invention.
  • the base station 200 receives a plurality of interference amounts each corresponding to the plurality of frequency bands from the base station 300 of at least one adjacent cell (S410).
  • the base station 200 recognizes a difference
  • Equation 2 Equation 2 (S420).
  • the base station 200 calculates a plurality of interference amounts each corresponding to at least one adjacent cell, and a plurality of considered interference amounts corresponding to a plurality of frequency bands through the difference in path gain (S430).
  • the base station 200 calculates a plurality of SINRs (hereinafter referred to as "allowed SINRs") that can be allowably received from the mobile station 100 by using a plurality of interference amounts each corresponding to at least one adjacent cell, respectively (S440).
  • the plurality of allowed SINRs corresponds to a plurality of frequency bands, respectively.
  • Equation 21 is a formula for calculating the allowed SINR.
  • Equation 21 ' r * ⁇ (t) / represents the allowed SINR corresponding to
  • the allowed SINR correction value A / 7 ⁇ ? f> is expressed as below in Equation 22.
  • the allowed SINR correction value A&. corresponding to the frequency band x is determined in accordance with the considered interference amount ⁇ loT x corresponding to the frequency band x. That is, when the considered interference amount A IoT x is not more than
  • correction value y £ is determined as a basic value (represented as "0" in Equation 22).
  • the base station 200 measures interference levels of the service cell in the plurality of frequency bands, respectively (S450).
  • the base station 200 calculates a plurality of transmission power densities corresponding to a plurality of frequency bands, respectively.
  • Equation 23 is a formula for calculating the transmission power density.
  • Equation 23 P' x represents the transmission power density corresponding to the frequency band x, and Nl x represents the interference level
  • the base station 200 can obtain a transmission power density P'RBW corresponding to RBW, a transmission power density P'EBW corresponding to EBW, and a transmission power density P'SBW corresponding to EBW.
  • the base station 200 calculates bandwidths each corresponding to the plurality of frequency bands (S470).
  • Equation 24 is a formula for calculating the bandwidth. (Equation 24)
  • BW x represents the bandwidth corresponding to the frequency band x
  • P max represents the physical maximum transmission power in the mobile station 100
  • P x represents the transmission power density corresponding to the frequency band x.
  • the bandwidth BW x can be obtained from a magnitude of the physical maximum transmission power P max in the mobile station 100 with respect to the transmission power density P' x .
  • the base station 200 selects one frequency band applied to the mobile station 100 among a plurality of frequency bands through a plurality of bandwidths.
  • the base station 200 searches a maximum value among the bandwidth BW'RBW corresponding to RBW, the bandwidth
  • the weight value ⁇ is set to be less than 1 , and thereby a ratio of EBW applied to a mobile station located at the edge of service cells in accordance with the weight value ⁇ can be controlled.
  • the base station 200 selects the frequency band X corresponding to the maximum bandwidth as the frequency band that is applied to the mobile station 100.
  • the base station 200 selects an MCS level corresponding to the frequency band X so as to satisfy the following Equation 26, and generates the scheduling control information including information on the bandwidth and MCS level (S480).
  • Equation 26 Nl o , x represents power density per subcarrier in the frequency band X 1 and N sub represents a number of subcarriers corresponding to the bandwidth BW'x of the frequency band X.
  • the MCS level m corresponding to the allowed SINR (SINRx) of one frequency band
  • the base station 200 calculates a plurality of allowed SINRs using a plurality of considered interference amounts, calculates a plurality of transmission power densities using a plurality of allowed SINRs, and calculates a plurality of bandwidths using a plurality of transmission power densities, respectively. Then, the base station 200 selects a maximum value among a plurality of bandwidths to select a frequency band corresponding to the selected bandwidth and MCS level corresponding to the allowed SINR. In addition, the base station 200 generates the scheduling control information including information on each of the selected bandwidth and MCS level, and transmits the scheduling control information to the mobile station 100 through the downlink.
  • the uplink scheduling in the mobile station can be performed such that the interference of adjacent cells is minimized.
  • the exemplary embodiment of the present invention can not only be implemented by the above-described apparatus and/or method, but can be implemented by, for example, a program that achieves the functions corresponding to the configuration of the exemplary embodiments of the present invention and a recording medium in which the program is recorded. This will be easily implemented from the above-described exemplary embodiments of the present invention by those skilled in the related art.

Landscapes

  • Engineering & Computer Science (AREA)
  • Quality & Reliability (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

La présente invention vise à effectuer la programmation de liaison montante d'une station mobile. Afin d'effectuer la programmation de liaison montante de la station mobile située dans une cellule de service, une station de base reçoit une pluralité de quantités d'interférence correspondant chacune à une pluralité de bandes de fréquence associées à une liaison montante dans au moins une cellule adjacente correspondant à la station mobile provenant de la station de base d'au moins une cellule adjacente, respectivement, et calcule une pluralité de valeurs d'interférence correspondant chacune à la pluralité de bandes de fréquence en utilisant la pluralité de quantités d'interférence correspondant chacune à au moins une cellule adjacente. De plus, la station mobile génère des informations de contrôle de programmation correspondant à la station mobile en utilisant la pluralité de valeurs d'interférence et transmet les informations de contrôle de programmation à la station mobile.
PCT/KR2008/004547 2007-10-24 2008-08-05 Procédé pour effectuer la programmation de liaisons montantes WO2009054604A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US12/738,740 US8798073B2 (en) 2007-10-24 2008-08-05 Method of performing uplink scheduling

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR20070107239 2007-10-24
KR10-2007-0107239 2007-10-24
KR1020080022613A KR20090042128A (ko) 2007-10-24 2008-03-11 상향링크 스케줄링 방법
KR10-2008-0022613 2008-03-11

Publications (1)

Publication Number Publication Date
WO2009054604A1 true WO2009054604A1 (fr) 2009-04-30

Family

ID=40579688

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2008/004547 WO2009054604A1 (fr) 2007-10-24 2008-08-05 Procédé pour effectuer la programmation de liaisons montantes

Country Status (1)

Country Link
WO (1) WO2009054604A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010108142A1 (fr) * 2009-03-19 2010-09-23 Qualcomm Incorporated Partage de ressources sur une liaison montante dans un réseau de communication sans fil
WO2010135090A3 (fr) * 2009-05-22 2011-06-30 Qualcomm Incorporated Systèmes, appareils et procédés de gestion d'interférences sur des canaux de liaison montante dans des systèmes de communication sans fil

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007112547A1 (fr) * 2006-03-20 2007-10-11 Nortel Networks Limited Procédé et système de réutilisation des fréquences des canaux à demi-débit

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007112547A1 (fr) * 2006-03-20 2007-10-11 Nortel Networks Limited Procédé et système de réutilisation des fréquences des canaux à demi-débit

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
"Mobile WiMAX Symposium, 2007. IEEE 25-29 March 2007", article JAE-HEUNG YEOM ET AL.: "Mitigation of inter-cell interference in the WiMAX system", pages: 26 - 31 *
"Wireless Communication Systems, 2007. ISWCS 2007. 4th International Symposium on 17-19 Oct. 2007", article RIATO N. ET AL.: "Interference Mitigation Strategies for WiMAX Networks", pages: 175 - 179 *
"Wireless Communications, Networking and Mobile Computing, 2007. WiCom 2007. International Conference on, 21-25 Sept. 2007", article CHUNWEI HE ET AL.: "Co-Channel Interference Mitigation in MIMO-OFDM System", pages: 204 - 208 *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010108142A1 (fr) * 2009-03-19 2010-09-23 Qualcomm Incorporated Partage de ressources sur une liaison montante dans un réseau de communication sans fil
US8553575B2 (en) 2009-03-19 2013-10-08 Qualcomm Incorporated Resource partitioning for uplink in a wireless communication network
US8804568B2 (en) 2009-03-19 2014-08-12 Qualcomm Incorporated Resource partitioning for uplink in a wireless communication network
WO2010135090A3 (fr) * 2009-05-22 2011-06-30 Qualcomm Incorporated Systèmes, appareils et procédés de gestion d'interférences sur des canaux de liaison montante dans des systèmes de communication sans fil
CN102440052A (zh) * 2009-05-22 2012-05-02 高通股份有限公司 用于在无线通信系统中的上行链路信道上进行干扰管理的系统、装置和方法
JP2012527828A (ja) * 2009-05-22 2012-11-08 クゥアルコム・インコーポレイテッド ワイヤレス通信システムにおけるアップリンクチャネル上での干渉管理のためのシステム、装置および方法
KR101389818B1 (ko) * 2009-05-22 2014-04-29 퀄컴 인코포레이티드 무선 통신 시스템들에서 업링크 채널들에 대한 간섭 관리를 위한 시스템들, 장치 및 방법들
US8958833B2 (en) 2009-05-22 2015-02-17 Qualcomm Incorporated Systems, apparatus and methods for interference management on downlink channels in wireless communication systems

Similar Documents

Publication Publication Date Title
US8798073B2 (en) Method of performing uplink scheduling
US8565778B2 (en) Apparatus and method for uplink scheduling in a broadband wireless communication system
CN101473685B (zh) 频分多址通信系统中的上行链路功率控制的方法和装置
US8126495B2 (en) Communication apparatus
CN101371597B (zh) 无线通信网络调度
US8295241B2 (en) Apparatus and method for supporting peer to peer communication in a broadband wireless communication system
EP1657945B1 (fr) Procédé et système de transfert dans un système de communication sans fil d'accès à bande large
US8565161B2 (en) Adaptive frequency reuse scheme
EP2338311B1 (fr) Attribution de ressource radio pour réduire une interférence de liaison montante
CN101835161B (zh) 多小区无线通信系统的动态资源分配方法和设备
US7962131B2 (en) Channel mode converting method of a wireless portable internet system
EP1919231A1 (fr) Méthode de communication radio pouvant réduire les interférences inter-cellules, système et sa station mobile et sa station de base
EP1746776A2 (fr) Système et procédé pour la planification de liaison montante dans un réseau de communication
US8412243B2 (en) Power control method and apparatus for inter-cell interference removal
WO2008130156A1 (fr) Méthode d'attribution de ressources basées sur le groupage, méthode de transmission de signaux l'utilisant et contrôleur d'attribution de ressources basées sur le groupage
WO2008097792A2 (fr) Procédé et appareil pour la commande de puissance sur une liaison montante dans un système de communication
JP2010206794A (ja) 基地局のセットを含むマルチセル直交周波数分割多元接続ネットワークの性能を最適化する方法
US20110222496A1 (en) Method for operating a multi-cell radio system and a multi-cell radio system
US8374211B2 (en) Method for data transmission and communication system
US9161333B2 (en) Systems and methods for wireless communication system channel allocation using intentional delay distortion
WO2010096946A1 (fr) Procédé de planification de ressources, programmateur et station de base
US8055198B2 (en) Uplink interference control in a wiMAX communication system
Mühleisen et al. Evaluation and improvement of VoIP capacity for LTE
US8867459B2 (en) Mobile subscriber information transmission over multiple uplink frames
WO2009054604A1 (fr) Procédé pour effectuer la programmation de liaisons montantes

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08793061

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 12738740

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 08793061

Country of ref document: EP

Kind code of ref document: A1