KR100956182B1 - Method and apparatus for allocating wireless resource in wireless telecommunication system - Google Patents

Abstract

The present invention relates to a method and apparatus for allocating a radio resource in a wireless communication system. The present invention relates to a first CQI report for a subchannel zone using a first frequency reuse factor. If the first CQI report satisfies a condition determined according to the first frequency recycling factor, the second CQICH is allocated to the terminal and the second channel reuse factor for the subchannel zone using the second frequency recycling factor is received from the terminal. After receiving the 2 CQI report through the second CQICH, determining whether to allocate a subchannel zone using the second frequency recycling factor for the UE based on the first and second CQI reports. do.

According to the present invention, by appropriately allocating frequency resources to the terminal using the frequency reuse factor, it is possible to optimize the overall capacity of the system.

Description

Method and apparatus for allocating a radio resource in a wireless communication system {Method and apparatus for allocating wireless resource in wireless telecommunication system}

The present invention relates to a wireless communication system, and more particularly, to a radio resource allocation method and apparatus in a wireless communication system.

In general, cellular communication systems use the same frequency resources in two spatially separated areas in order to efficiently use limited frequency resources. 1 schematically illustrates the concept of frequency reuse in a typical cellular communication system. As shown in FIG. 1, the frequency resource F1 used in the first cell 100 having a radius R is another cell having a radius R spaced apart from the center of the first cell 100 by D, that is, the second cell 150. Is used again in frequency, called frequency reuse. On the other hand, the frequency reuse factor (hereinafter referred to as FRF) K is defined as one frequency resource, that is, the frequency band is reused in units of K cells.

In addition, when each cell is composed of three sectors (not shown), when each sector is assigned the same RF frequency, it is called K = 1, and each sector is a set of three subchannels different from the entire RF frequency. K = 3 can be defined.

Therefore, as the frequency FRF increases, the amount of interference due to the use of frequency resources between cells and sectors using frequency resources decreases.

The subchannel reuse pattern algorithm may be configured such that terminals having a high signal to interference and noise ratio (SINR) operate in an all sub-channel zone (hereinafter, referred to as an all subchannel zone) in which all subchannels are available. On the other hand, for terminals with low SINR, each cell or sector operates in a zone where a fraction subchannel is available. With this configuration, full load frequency reuse allows terminals with high SINR to maintain spectral efficiency to the maximum, and fractional frequency reuse allows terminals with low SINR to achieve connection quality. ) And throughput.

However, the above features are not conceptually complicated, but there are practical considerations as follows. First, the frequency allocation for channel quality indicator (CQI) reporting must be updated according to the zone to which the MS belongs. For example, if the MS belongs to an all subchannel zone, a carrier to interference and noise ratio (CINR) is measured based on the FRF-1 configuration, and if the UE belongs to a segmented zone, CINR is measured based on this.

Next, the starting Orthogonal Frequency Division Multiple Access (OFDMA) symbol offset and the size of the segmented zone or all subchannel zone should be synchronized between all neighboring base stations. This means that dynamic zone allocation based on the number of terminals, network load and interference conditions is not possible by a single base station without synchronizing with communication with neighboring base stations.

In the conventional subchannel reuse pattern method, when allocating an all subchannel zone to a UE, a lower limit threshold or threshold is set to change the subchannel zone when the subchannel zone is below a threshold value or a threshold value. When allocating segmented zones (hereinafter referred to as segment zones), an upper boundary or threshold is set to change the sub-channel zone when the boundary or threshold is greater than or equal to each zone. It is to check whether the CINRs of UEs belonging to AT are within the boundary.

If the CINR of the terminal in the all subchannel zone is less than or equal to a predetermined first threshold value, the terminal will be changed to the segment zone. On the contrary, when the CINR of the terminal in the segment zone is equal to or greater than a predetermined second threshold value, the terminal is changed to the all subchannel zone. When the zone to which the terminal belongs is changed, the CINR measurement is also changed according to the zone. If the UE moves from the all subchannel zone to the segment zone, the CINR is measured based on the FRF-3 configuration. Also, when the UE moves from the segment zone to the all subchannel zone, it is measured based on the FRF-1 configuration. To this end, the base station transmits a CQICH Allocation IE message to the terminal.

By applying such a basic subchannel reuse pattern method, the UE can not be serviced in the FRF-1 configuration due to the low CINR can be serviced through the segment zone, so the cell coverage is full (FFR) Although it can be extended more widely than the cell coverage of the -1 configuration, the method has two problems.

First, for synchronization in the sub-channel reuse pattern, the starting OFDMA symbol offset and the size of each zone must be fixed for all neighboring base stations, so that one resource is wasted in one zone while the other zone is wasted. ) May suffer from lack of resources.

Secondly, if the base station changes the CINR measurement scheme after leaving the threshold by the CQICH Allocation IE to the terminal, it is too late. Therefore, it may take time to obtain a reliable CINR measurement value from the CQI report. Difficulties arise in determining an initial Modulation and Coding Scheme (MCS) level immediately after switching to an allocated zone.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a technical problem to be achieved by the present invention is to reduce the loss of frequency resources due to synchronization of the frequency reuse pattern, a radio resource allocation method and apparatus in a wireless communication system To provide.

The technical problem to be achieved in the present invention is to provide a radio resource allocation method and apparatus for optimizing the overall capacity of the system to more easily determine the initial MCS level determination.

The technical problem to be achieved in the present invention is to provide a radio resource allocation method and apparatus for allocating a frequency reuse pattern suitable for OFDMA scheme.

For this purpose, the radio resource allocation method in the wireless communication system according to the present invention, the first CQI report on the CQICH channel for the sub-channel zone using the first frequency reuse factor (frequency reuse factor) Receiving a second CQI report for a subchannel zone using a second frequency recycling factor from the terminal if the terminal meets a predetermined condition; And determining whether to allocate a sub-channel zone using the second frequency recycling factor based on the CQI reports. The predetermined condition is that when the first frequency recycling factor is 1, the CINR report value of the first CQI is smaller than the lower limit CINR threshold. The predetermined condition is that when the first frequency recycling factor is 3, the CINR report value of the first CQI is larger than the upper limit CINR threshold. The subchannel zone allocation is preferably applied when the first frequency recycling factor and the second frequency recycling factor are used for each frame or in each frame.

For this purpose, the radio resource allocation method in the wireless communication system according to the present invention, the first CQI through the CQICH channel for the first sub-channel zone using the first frequency reuse factor (frequency reuse factor) Receiving a second CQI report on the CQICH channel for a second subchannel zone using the second frequency recycling factor from the terminal, when the terminal making the report meets a predetermined condition; And determining whether to allocate the second subchannel zone from at least one of spectral efficiency for each subchannel zone and resource utilization rate of each subchannel zone based on the CQI reports. It is characterized by. The radio resource allocation method according to the present invention preferably further comprises the step of determining the change of the current sub-channel zone according to the available resources of the current sub-channel zone (zone) according to the determination. In the radio resource allocation method according to the present invention, when there is no available resource of the current subchannel zone according to the determination and there are available resources of another subchannel zone, the radio resource allocation method is different from the terminal to which the loss of spectrum efficiency is low. Preferably, the method further includes allocating sub-channel zones.

For this purpose, the radio resource allocation support method for frequency redundancy in the wireless communication system according to the present invention, the first CQICH for the sub-channel zone using a first frequency reuse factor (frequency reuse factor) Requesting a UE for reporting a first CQI through a channel to report a second CQI for a subchannel zone using the second frequency recycling factor when the CINR of the first CQI report corresponds to a predetermined condition; ; And reporting the second CQI and the first CQI channel through the second CQICH channel to determine whether to allocate a subchannel zone using a factor using the second frequency recycling factor from the terminal. And receiving the first CQI report together, wherein the terminal supports at least two CQI channels.

For this purpose, the radio resource allocation support method for frequency redundancy in a wireless communication system according to the present invention, the first frequency reuse factor (frequency reuse factor) in a terminal supporting at least two (Current) CQI channels Using a second frequency recycling factor transmitted from the base station when the CINR of the first CQI report corresponds to a predetermined condition while transmitting the first CQI report on the first CQI channel for the subchannel zone to be used. Receiving a request for a second CQI report for a subchannel zone to perform; And reporting the second CQI and the first CQI through a second CQI channel to support a base station in determining whether to change to a subchannel zone using a factor using the second frequency recycling factor. And transmitting the first CQI report together through a channel.

For this purpose, an apparatus for allocating a radio resource in a wireless communication system according to the present invention is reported from a terminal through a CQICH channel for a subchannel zone using a first frequency reuse factor. A condition determination unit that determines whether a CINR value of the first CQI report corresponds to a predetermined condition; A CQI report requesting unit requesting to the terminal to transmit a second CQI report on a subchannel zone using the second frequency recycling factor through the CQICH channel; And a zone determination unit determining whether to allocate a subchannel zone using the second frequency recycling factor based on the CQI reports.

For this purpose, the apparatus for allocating a radio resource in a wireless communication system according to the present invention sets a switching range for setting a zone switching range according to a CINR threshold difference between MCS levels for subchannel zone change. part; On the basis of the first CQI report received from the UE through the CQICH channel for the first sub-channel zone using the first frequency recycling factor, it is determined whether the set range is met; A range determination / CQI report request unit for requesting a second CQI report for a second subchannel zone using a frequency recycling factor; And determining whether to allocate the second subchannel zone from at least one of spectral efficiency for each subchannel zone and resource utilization rate of each subchannel zone based on the CQI reports. And a zone determination unit.

According to the present invention, it is possible to allocate an efficient frequency resource by reducing the loss of the frequency resource according to the synchronization of the frequency reuse pattern. In addition, it is easier to determine the initial MCS level to optimize the overall capacity of the system. In addition, it is possible to implement allocation of frequency reuse patterns suitable for the OFDMA scheme.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments. For reference, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted in the following description.

2 is a block diagram illustrating an embodiment of a configuration of an apparatus for allocating a radio resource according to the present invention. The apparatus for allocating radio resources for frequency reuse according to the present invention includes a condition determining unit 210, a CQI report requesting unit 220, and a zone determining unit 230.

The condition determination unit 210 determines whether the CINR value of the CQI report reported from the terminal corresponds to a predetermined condition. That is, it is determined whether the first CQI report value reported through the CQICH channel for the subchannel zone using the first frequency reuse factor corresponds to a predetermined condition. For example, if the UE is allocated to a subchannel zone using FRF-1, it is determined whether the CINR value of the CQI report reported through the CQICH channel for the FRF-1 corresponds to a preset condition. Here, the predetermined condition is when the first frequency recycling factor is 1, that is, FRF-1, when the CINR value of the first CQI is smaller than the lower limit CINR threshold, and when the first frequency recycling factor is 3, that is, If FRF-3, the CINR value of the first CQI is larger than the upper limit CINR threshold. In addition, the predetermined condition may include a CINR value of the first CQI report within a CINR range set according to a predetermined MCS level table.

If the CQI report requesting unit 220 corresponds to the predetermined condition, the CQI report requesting unit 220 requests the terminal to transmit a second CQI report for a subchannel zone using a second frequency recycling factor through the CQICH channel. . For example, when the UE is in the FRF-1 subchannel zone and the CINR value of the CQI is smaller than the lower limit CINR threshold, the UE is requested to transmit the CQI report for the FRF-3 through the CQICH channel.

The zone determiner 230 determines whether to allocate a subchannel zone that uses the second frequency recycling factor based on the CQI reports. The subchannel zone allocation may be applied when the first frequency recycling factor and the second frequency recycling factor are mixed for each frame or in each frame.

In more detail, whether the CINR of the UE belonging to the FRF-1 zone is within a predetermined range based on the first predetermined threshold value, or if the CINR of the UE belonging to the FRF-3 zone is a predetermined agent. 2 Check if it is within a certain range based on the threshold. As a result of this check, if it is determined that the terminal is within a certain range based on the first threshold value or the second threshold value, an additional CQICH is assigned to the terminal to measure the CINR for FRF-1 and the CINR for FRF-3. Have them report. Then, the frequency reuse factor (FRF) zone is moved when the CINR value reported from the terminal exceeds a predetermined first threshold value or a second threshold value. The movement of the FRF-1 and FRF-3 zones occurs when the CINR of the UE belonging to FRF-1 is smaller than the first threshold or when the CINR of the UE belonging to FRF-3 is larger than the second threshold. .

3 is a flowchart illustrating a radio resource allocation method according to the present invention. An operation of the radio resource allocation apparatus for frequency reuse shown in FIG. 2 will be described with reference to FIG. 3.

First, a first CQI report is received through a CQICH channel for a subchannel zone using a first frequency reuse factor. (Step S310) The terminal reporting the first CQI is determined. (S320) If the predetermined condition is satisfied, a second CQI report is also received from the terminal for the subchannel zone using the second frequency recycling factor. If the CINR value of the CQI report crosses a predetermined threshold based on the 1CQI report and the second CQI report (step S340), a subchannel zone using the second frequency recycling factor is allocated (step S350). )

In more detail, if the UE belongs to the FRF-1 zone, the CINR1 of the UE is received through the condition determination unit 210 (step S310), and the CINR value is the first predetermined value. It is checked whether it is within a predetermined range (Range 1) based on the threshold value (step S320). That is, it is checked whether the CINR1 reaches near the first threshold value. This is to measure the CINR for FRF-3 in advance before changing the zone on the premise that the first threshold is likely to be reached.

If the terminal belongs to the FRF-3, the CINR (CINR2) of the terminal is received through the condition determination unit 210 (step S310), and the CINR value is in a predetermined range (Range2 based on a predetermined second threshold value). In step S320, it is checked whether the CINR2 reaches the second threshold. This is also to measure the CINR for FRF-1 in advance before changing the zone on the premise that the second threshold is likely to be reached.

The CQICH is allocated to the UE within the Range1 or Range2, and the CQI report requester 220 measures the CINR (CINR1) for the FRF-1 and the CINR (CINR2) for the FRF-3 to be reported to the base station. (Step S330) The CINR1 and CINR2 measurement may be performed by allocating one more CQICH to the terminal.

If the CINR value reported from the terminal exceeds a predetermined threshold (step S340), the frequency determining factor zone currently included is changed to another frequency reuse factor zone through the zone determination unit 230 (step S350). If the CINR (CINR1) of the UE belonging to FRF-1 is smaller than the first threshold, the UE moves to the FRF-3 zone, and the CINR (CINR2) of the UE belonging to FRF-3 is the second threshold. If larger, move to FRF-1 zone.

As a result, when the CINR approaches the threshold for changing the zone, it is highly likely to change the zone of the terminal, so that the terminal temporarily measures both CQICHs. This reduces the time it takes to set the MCS level to an appropriate value even if the zone changes, and avoids wasting CQICH resources compared to always assigning two because of temporary assignment.

The subchannel zone allocation may be applied when the first frequency recycling factor and the second frequency recycling factor are mixed for each frame or in each frame. In addition, based on the CQI reports, the frequency efficiency for each subchannel region can be estimated. In addition, the predetermined condition may include a CINR value of the first CQI report within a CINR range set according to a predetermined MCS level table.

4 is a block diagram showing another embodiment of the configuration of the radio resource allocation apparatus according to the present invention. The radio resource allocation apparatus for frequency reuse includes a switching range setting unit 410 and a range determination / CQI report requesting unit. 420 and the zone determination unit 430.

The switching range setting unit 410 sets a zone switching range according to the CINR threshold difference between MCS levels for subchannel zone change. In more detail, when the terminal moves from the FRF-1 zone to the FRF-3 zone, the switching range setting unit 410 switches a section in which the difference in the CINR threshold between MCS levels is small. switching region). On the contrary, when the UE moves from the FRF-3 zone to the FRF-1 zone, a section having a large CINR threshold difference between MCS levels is set as a switching range. This means that when moving from the FRF-1 zone to the FRF-3 zone, there is a CINR gain of about 8 dB on average, so there are many MCS level gains when the CINR thresholds for each MCS are close, and vice versa. This is because the loss due to the MCS level is small.

The range determination / CQI report request unit 420 corresponds to the set range based on the first CQI report reported from the UE through the CQICH channel for the first subchannel zone using the first frequency recycling factor. The second CQI report is requested for the second subchannel zone using the second frequency recycling factor if it corresponds to the set switching range. For example, if the UE belongs to the FRF-1 zone, it is determined whether the CINR value of the CQI report for the channel from the UE belongs to the switching range through the CQICH channel for the zone. As a result of determination, the CQICH for the FRF-3 zone is allocated by requesting the CQI report of the FRF-3 zone if it belongs to the switching range.

The zone determiner 430 may determine from at least one of spectral efficiency for each subchannel zone and resource utilization of each subchannel zone based on the CQI reports. It is determined whether to allocate the second subchannel zone. For example, when a zone is determined based on spectral efficiency for each subchannel zone, if the terminal is allocated to the FRF-1 zone, the zone determination unit (430) calculates and compares spectral efficiencies for FRF-1 and FRF-3. As a result of the comparison, if the terminal has higher spectral efficiency of the FRF-3 zone than the FRF-1 zone, the terminal is moved to the FRF-3 zone.

If a zone is determined based on the resource utilization rate of each subchannel zone, even if a zone other than the zone to which the zone belongs currently has higher spectral efficiency, When resources are scarce and resources in other zones are left, they are allocated to the other zones in the order of terminals with the least loss of spectrum efficiency. That is, if the spectrum efficiency is high only in the terminals in the FRF-3 zone, and thus the terminals are allocated only in the FRF-3 zone and the terminals are not assigned in the FRF-1 zone, the FRF-3 zone is deficient in resources, and the FRF-1 zone appears. Is a waste of resources. To prevent this, even though the spectral efficiency is high in the FRF-3 zone, the terminal is allocated to the FRF-1 zone to prevent resource waste. In this case, terminals are allocated to the FRF-1 zone in order of low spectral efficiency. The reverse is also true.

5 is a flowchart illustrating a radio resource allocation method according to the present invention. An operation of the radio resource allocation apparatus for frequency reuse shown in FIG. 4 will be described with reference to FIG. 5.

In order to provide a method for frequency allocation, the present invention first sets the switching range through the switching range setting unit 410 (step S500). For example, FRF, which is a high frequency recycling factor in the FRF-1 zone, is set. When the terminal moves to the -3 zone, the section in which the difference in the CINR threshold between MCS levels is small is set as the switching range. On the contrary, when the UE moves from the FRF-3 zone to the FRF-1 zone, a section having a large CINR threshold difference between MCS levels is set as a switching range.

The UE receives a first CQI report through a CQICH channel for a first subchannel zone using a first frequency reuse factor from the UE (step S505). For example, the UE receives a FRF-1 zone. When belonging to the zone, the CQI for the zone is received through the CQICH channel. Then, the range determination / CQI report request unit 420 checks whether the received CQI report value, that is, the CINR value, falls within a predetermined condition, for example, the set switching range (step S510).

If the CINR value of the terminal belongs to the set switching range, the terminal allocates a CQICH channel for a second subchannel zone using the second frequency recycling factor to request a second CQI report and the CQICH The channel receives the second CQI report (step S515).

Then, the spectral efficiency is compared with respect to the MCS levels of the two zones (step S520). That is, the spectral efficiency Sppff1 of the currently-used frequency reuse factor zone is different from the frequency reuse factor zone. Compare spectral efficiency (SpEff2).

It is determined whether to allocate the second subchannel zone from at least one of spectral efficiency for each subchannel zone and resource utilization rate of each subchannel zone based on the CQI reports. As a result of the comparison, when the spectral efficiency (SpEff2) of another frequency reuse factor zone is higher than the specter efficiency (SpEff1) of the current frequency reuse factor zone, the terminal may move to a zone having high frequency spectrum efficiency. have.

On the other hand, if the consideration of resources is also considered, it is checked whether resources of one zone are insufficient and resources of another zone remain (step S525), that is, the current subchannel zone. If there are no available resources and there are available resources in other subchannel zones, the allocated spectrums are allocated in the order of the UEs with the smallest SpEff loss in the zone in which the available resources exist (step S530). If there is no bias or severe resource in the step, the UE moves to the high frequency reuse factor zone with high frequency spectrum efficiency SpEff2 (step S535). By doing so, it is possible to optimize the overall capacity of the system.

Meanwhile, FIG. 6 is a flowchart illustrating a method in which a base station supports radio resource allocation for frequency reuse. In the method for supporting radio resource allocation for frequency reuse, a first CQI report is received through a first CQICH channel for a subchannel zone using a frequency reuse factor (step S610). If the CINR value of the received CQI report corresponds to a predetermined condition (step S620), the UE requests a second CQI report on a subchannel zone using a second frequency recycling factor (step S630). The second CQI report through the second CQICH channel and the second CQI channel through the first CQI channel to determine whether to allocate a subchannel zone using a factor using the second frequency recycling factor from the terminal. The first CQI report is received together (step S640). The UE supports at least two CQI channels.

7 is a flowchart illustrating a method in which a terminal supports radio resource allocation for frequency reuse. The method for supporting radio resource allocation for frequency reuse includes: a first CQI for a subchannel zone using a first frequency reuse factor in a terminal supporting at least two CQI channels; The first CQI report is transmitted through the channel (step S710). If the CINR of the first CQI report corresponds to a predetermined condition (step S720), the subchannel zone using the second frequency recycling factor transmitted from the base station is transmitted. Receive a request for a second CQI report for a zone (step S730).

The second CQI report and the first CQI channel through a second CQI channel to support a base station to determine whether to change to a sub-channel zone using a factor using the second frequency recycling factor. The first CQI report is transmitted together through the process (S740).

The above-described embodiments will be described in more detail. The present invention dynamically allocates a frequency, that is, a user or a terminal, in which the terminals temporarily receive two separate CQI reports to obtain information of both zones. Depending on their spectral efficiency, zones are alternatively determined on a frame-by-frame basis.

Allows the UE to report multiple CQIs for dynamic frequency allocation. For example, as shown in Table 1, the WiMAX forum mobile system profile can perform two CINR measurements and CQI reporting that are simultaneously generated by the requirements of the terminal.

TABLE 1

The base station may also know whether the terminal supports two concurrent CQI channels by OFDMA Subscribe Station (SS) CINR capability TLV in SS Basic Capability (REC) -REQ message. Table 2 shows "Draft IEEE Standard for Local and metropolitan area networks-Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems, Amendment 2: Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bnads and Corrigendum 1," IEEE P802. 16e-2005 Fbruary 2006.

The base station may obtain CQI report of FRF-3 based on CINR measurement simultaneously with FRF-1 based on CINR measurement by allocating two CQICH or sharing CQICH time division scheme through two CQICH allocation IEs.

TABLE 2

Dynamic frequency allocation is described in more detail. First, network entry is performed as follows. 8 is a flowchart illustrating a dynamic frequency allocation method for network entry, which will be briefly described as to network entry. First, if the UE is the same as the MAC address in the RNG-REQ message (step S800), the base station allocates a basic CID (BCID) and a primary management CID (PMCID) (step S810).

After allocating the BCID, the base station may allocate the CQICH to the CQICH assignment IE. (Step S820) In step S820, Frame offset = 0b001, Duration = 0b111 (up to explicit deallocation), Feedback type = 0b00 (PCINR), Report typ = 0b1 (zone), Zone permutation = 0b001 (PUSC with use all SC = 1).

The terminal measures the CINR based on the FRF-1 configuration. The basis for the FRF-1 configuration is that the expected spectral efficiency is higher in the all sub-channel zone than the segmented zone. The UE periodically sends a CQI report based on the FRF-1 configuration. (Step S830) It is recommended that the reporting period be in units of frames.

The base station compares the reported CQI with a predefined FRF-1 exit threshold (step S840). The FRF-1 exit threshold is a threshold in an all sub-channel zone. If the reported CQI is lower than the FRF-1 threshold for N consecutive reports, or the spectral utility of the segmented zone is higher than the spectral utility of the all sub-channel zone. If it is expected, the base station updates the current CQICH allocation information to measure and report the CINR based on the FRF-3 configuration (step S850), and measures and reports the CINR based on the FRF-3 configuration. In step S850, Frame offset = 0b001, Duration = 0b111 (up to explicit deallocation), Feedback type = 0b00 (PCINR), Report typ = 0b1 (preamble), and CINR preamble report type = 0b1 (FRF-3 configuration).

The base station allocates a data grant for the SBC-REQ message before the T9 timer expires so that the terminal transmits the SBC-REQ message, and restores the OFDMA SS CINR measurement capability information to check whether the terminal supports two concurrent CQICHs. .

If the steps S830 to S860 is completed, the base station sends the SBC-RSP message through the selected zone (step S870). That is, if the current CQI report is based on the FRF-1 configuration, the base station transmits all the subchannel zones. Send an SBC-RSP message and, if the current CQI report is based on the FRF-3 configuration, send an SBC-RSP message through the segment zone.

9 to 11 show a flowchart of a radio resource allocation method in a normal operation after network entry. The radio resource allocation method according to the present invention for the sub-channel reuse pattern after network entry is as follows.

Receiving the first CQI report from the terminal (steps S900 and S950), the terminal restores OFDMA SS CINR measurement capability (step S915) and confirms whether the terminal supports two concurrent CQICHs (step S920). If the UE supports two concurrent CQICHs, if the reported CQI crosses the FRF-1 Exit candidate boundary downward or the FRF-3 Exit candidate boundary upward (steps S905 and S955), the base station uses a new CQICH allocation IE. To make the second CQI report. (Step S910, S960)

Meanwhile, as another embodiment for radio resource allocation, a radio resource may be allocated by receiving two CQI reports by checking whether the CINR value of the CQI reported from the UE belongs to a certain range. In more detail, the UE restores OFDMA SS CINR measurement capability (step S915), and after confirming whether the terminal supports two concurrent CQICHs (step S920), if the terminal supports two CQICHs, If the CINR value of the CQI reported from the UE is in the switch region based on the threshold value and is in the switch region (step S930), the CQICH allocation IE for another zone is allocated (S940). step)

In this way, if the CQI report for both FRF-1 and FRF-3 is obtained (step S945), the spectral efficiency is compared based on the two CQI reports (step S1010). FRF-3)) is three times more than the spectral efficiency (SpEff (FRF-1)) of the all subchannel zone, and moves to the segment zone (step S1020), otherwise it is in the all subchannel zone (step S1045). When the terminal whose zone is changed is far from the candidate boundary (steps S1025 and S1050), the CQICH allocation based on another zone is canceled (steps S1030 and S1055).

Meanwhile, the terminal may be forcibly allocated to a specific zone according to the utilization rate of the zone. That is, when resources in one zone are insufficient and resources in another zone remain, that is, when resource utilization in all subchannel zones is 100% and the resource utilization in segment zone is less than 100%. (Step S1100) or when resource utilization rate of the segment zone is 100% and resource utilization rate of all subchannel zones is less than 100% (step S1125), the other zones are ordered in the order of the terminal with the least loss of spectrum efficiency. If the terminal whose zone is changed is far from the candidate boundary (steps S1115 and S1140), the CQICH allocation based on another zone is canceled. (Step S1120, Step S1145)

For this purpose, the base station knows the required CINR for each MCS level as shown in Table 3.

[Table 3]

Assuming that the CINR gain of FRF-3 over FRF-1 is about 8 dB, it can be considered as follows. If the CINR of UE 1 in the all subchannel zone is 20 dB, the highest MCS level applicable is 16 QAM 1/2. If this terminal is assigned to the segment zone, the CINR will be approximately 28 dB and 64QAM 3/4 will be applied. In this case, the spectral efficiency of the UE in all subchannel zones is 2 bps / sub-carrier, whereas in the segment zone, it is 4.5 bps / sub-carrier.

If the CINR of UE 2 is 2 dB in all subchannel zones, the highest MCS level applicable is QPSK 1/2 repetition 6. If the terminal is assigned to the segment zone, the CINR will be approximately 10 dB and QPSK 1/2 repetition 4 will be applied. In this case, the spectral efficiency in all subchannel zones is 1/6 bps / sub-carrier while in the segment zone it is 1/4 bps / sub-carrier. In this case, the spectral efficiency of the segment zone corresponds to a value reduced to 1/3 by assuming that the subchannel zone corresponds to 1/3 of the all subchannel zone.

Accordingly, the spectral efficiency reduced by the terminal 2 moving from the all subchannel zone to the segment zone will be smaller than the terminal 1. In the above example, the larger the spectral efficiency from the segment zone to the all subchannel zone, that is, the smaller the spectral efficiency loss from the segment zone to the all subchannel zone, the lower the current MCS level and the lower MCS level. The CINR difference will be larger.

Conversely, the larger the spectral efficiency from the all subchannel zone to the segment zone, the smaller the spectral efficiency from the all subchannel zone to the segment zone, the smaller the CINR difference between the current MCS level and the lower MCS level. Will lose.

As a result, the base station can set a specific CINR range to the recommended switch region for each segment zone and all subchannel zones.If the UE's CINR belongs to the switch region, the base station measures the CINR of another zone. A CQICH for may be allocated.

As a result, there is a section that is far from the CINR threshold for each MCS is close to the distance, the case that the sub-zone from the sub-channel zone to the segment zone is more advantageous to attach the threshold, the opposite case is advantageous when the far away. This section is set and the UE belonging to it raises the CQICH for another zone. Compare SpEff for the appropriate MCS level for the two zones and switch zones if another zone is advantageous over the current zone. In the case where one zone lacks resources and the other zones remain, it is a method of optimizing the overall capacity of the system to allocate the zones to other zones in the order of the terminal with the least SpEff loss.

On the other hand, the present invention described above can also be embodied as computer readable codes on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disks, hard disks, optical data storage devices, and also in the form of carrier waves (e.g., transmission over the Internet). It includes what is implemented. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. And functional programs, codes and code segments for implementing the present invention can be easily inferred by programmers in the art to which the present invention belongs.

Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art to which the present invention pertains can implement the present invention in other specific forms without changing the technical spirit or essential features, The examples are to be understood in all respects as illustrative and not restrictive.

In addition, the scope of the present invention is specified by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention. Should be interpreted as

1 schematically illustrates the concept of frequency reuse in a typical cellular communication system.

2 is a block diagram illustrating an embodiment of a radio resource allocation apparatus configuration according to the present invention.

3 is a flowchart illustrating a radio resource allocation method according to the present invention.

4 is a block diagram showing another embodiment of the configuration of the apparatus for allocating a radio resource according to the present invention.

5 is a flowchart illustrating a radio resource allocation method according to the present invention.

6 is a flowchart illustrating a radio resource allocation support method according to the present invention by a base station.

7 is a flowchart illustrating a radio resource allocation support method according to the present invention.

8 is a flowchart illustrating a dynamic user allocation method for network entry.

9, 10, and 11 show flowcharts of a radio resource allocation method in normal operation.

Claims (17)

Receiving a first CQI report on a subchannel zone using a first frequency reuse factor from a terminal through a first CQICH; If the first CQI report satisfies a condition determined according to the first frequency recycling factor, the second CQI report is allocated from the terminal to the second CQI report for the subchannel zone using the second frequency recycling factor. Receiving through the second CQICH; And And determining whether to allocate a subchannel zone using the second frequency recycling factor for the terminal based on the first and second CQI reports. The method of claim 1, wherein the predetermined condition is And wherein the first frequency recycling factor is 1 and the CINR value of the first CQI report corresponds to a zone switching range set based on a lower limit CINR threshold for the first frequency recycling factor. . The method of claim 1, wherein the predetermined condition is Wherein the first frequency recycling factor is 3 and the CINR value of the first CQI report corresponds to a zone switching range set based on an upper limit CINR threshold for the first frequency recycling factor. . delete The method of claim 1, wherein the subchannel zone allocation is And the first frequency recycling factor and the second frequency recycling factor are mixed or used for each frame or within individual frames. The method of claim 1, Estimating frequency efficiency for each subchannel zone based on the first and second CQI reports. The method of claim 1, wherein the predetermined condition is And the CINR value of the first CQI report corresponds to a CINR range set according to a predetermined MCS level table. Receiving a first CQI report on a first subchannel zone using a first frequency reuse factor from a terminal through a first CQICH; If the first CQI report satisfies a condition determined according to the first frequency recycling factor, the second CQI for the second subchannel zone using the second frequency recycling factor from the terminal by assigning a second CQICH to the terminal. Receiving a report on the second CQICH; And Determining whether to allocate the second subchannel zone to the terminal using at least one of spectral efficiency for each subchannel zone and resource utilization rate of each subchannel zone based on the first and second CQI reports. Radio resource allocation method comprising a. delete The method of claim 8, And determining a change of the current subchannel zone according to whether the current subchannel zone is available resource according to the determination. The method of claim 10, If there is no available resource of the current subchannel zone according to the determination and there are available resources of another subchannel zone, allocating the other subchannel zone to a terminal having a relatively low loss of spectral efficiency. Radio resource allocation method comprising a. Receiving a first CQI report on a subchannel zone using a first frequency reuse factor from a terminal supporting at least two CQICHs through a first CQICH; When the CINR of the first CQI report satisfies a predetermined condition, a second CQI report is allocated to the terminal through a second CQI report for a subchannel zone using a second frequency recycling factor from the terminal. Receiving; And And determining whether to allocate a subchannel zone using the second frequency recycling factor for the terminal based on the first and second CQI reports. Transmitting, by a terminal supporting at least two CQICHs, a first CQI report for a subchannel zone using a first frequency reuse factor to a base station through the first CQICH; When the first CQI report satisfies a condition determined according to the first frequency recycling factor, the terminal is allocated a second CQICH from the base station and reports a second CQI report for a subchannel zone using a second frequency recycling factor. Receiving a request; And A first CQI report for a subchannel zone in which the terminal uses the first frequency recycling factor to support whether the base station allocates a subchannel zone using the second frequency recycling factor to the terminal; And transmitting a second CQI report for the subchannel zone using the second frequency recycling factor to the base station. A condition determination unit determining whether a CINR value of a first CQI report for a subchannel zone using a first frequency reuse factor transmitted from a terminal through a first CQICH corresponds to a predetermined condition; A CQI report requesting unit requesting to transmit a second CQI report for a subchannel zone using a second frequency recycling factor through the second CQICH by allocating a second CQICH to the terminal if the predetermined condition is met; And And a zone determination unit configured to determine whether to allocate a subchannel zone using the second frequency recycling factor for the terminal based on the first and second CQI reports. delete A switching range setting unit configured to set a zone switching range according to a CINR threshold difference between MCS levels for subchannel zone change; It is determined whether the CINR value of the first CQI report for the first subchannel zone using the first frequency recycling factor transmitted from the terminal through the first CQICH corresponds to the set zone switching range, and corresponds to the set zone switching range. A CQI report requesting unit for requesting a second CQI report for a second subchannel zone using a second frequency recycling factor by allocating a second CQICH to the terminal; And By using at least one of spectral efficiency for each subchannel zone and resource utilization rate of each subchannel zone based on the first and second CQI reports, And a zone determination unit for determining whether to allocate. delete

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