KR100958300B1 - Methods and apparatuses for selecting modulation and coding level - Google Patents

Abstract

A mobile terminal capable of selecting an optimal modulation and coding level estimates a block size of a received frame and a moving speed of the mobile terminal and based on the block size and the estimated moving speed, selects an optimum among a plurality of modulation and coding levels. Selection information indicating the modulation and coding level is transmitted to the base station. Accordingly, the base station transmits data to the mobile terminal through the modulation and coding level corresponding to the selection information.

Effective CINR, modulation and coding level,

Description

Modulations and apparatus levels for selecting modulation and coding level

The present invention relates to a communication technology, in particular, in an orthogonal frequency division multiple access (OFDMA) wireless communication system, a terminal selects a modulation and coding level through an effective carrier to interface ratio (CINR) value, and When the information is fed back to the base station, the present invention relates to a method and apparatus for transmitting data at a selected modulation and coding level.

An IEEE 802.16 based OFDMA system is adopted for portable Internet services that can be used on the go. In a packet network such as an OFDMA system, a link adaptation method such as rate control is used to improve the throughput of the OFDMA system.

Rate control is a method of changing a modulation method and a code rate according to a channel environment of a mobile station. To this end, the mobile station periodically reports Channel Quality Indicator (CQI) to the base station, thereby improving throughput of the OFDMA system.

The mobile station reports the CQI to the base station through a CQI channel (CQICH) allocated to an uplink (UL) frame. Each mobile station can know the location information and CQI reporting period of its CQICH allocated to the UL frame through compact UL MAP IE and CQICH Allocation IE of UL MAP in downlink (DL) frame.

The mobile station quantizes the average received CINR value of the preamble / a specific zone into 6 bits and reports it to the base station as a CQI. One CQICH consists of a total of six tiles in the form of 4x3 (e.g., frequency x time) (for example, 48 data subcarriers and 12 pilot subcarriers). pilot sub-carrier)) Creates one FAST-FEED BACK message and each FAST-FEED BACK message occupies one UL slot.

The mapping order is mapped to an area indicated by Uplink Interval Usage Code (UIUC) = 0 in UL-MAP with frequency priority. The lower order of modulation and coding reduces the error of the transmission data, but at the same time has the problem of increasing the cost and overhead of the transmission data.

On the other hand, selection of higher orders of modulation and coding can result in data transmission errors. The value of the modulation and coding level depends on the value of the signal-to-interference + noise ratio (SINR) of the communication channel and the SINR value of the individual sub-carriers constituting the channel. One way to select the modulation and coding level is EESM (Exponential effective SIR Mapping).

In IEEE 802.16, the use of this CQICH is used for various purposes such as CINR reporting, ECINR request, and MIMO mode selection (multiple-input and multiple-output mode selection). In EESM, the effective CINR value is determined by the SINR value and the calibration value of each sub-carrier. However, to select the best modulation and coding level, the base station must exchange a large amount of information with the mobile terminal.

It is essential to select an appropriate modulation and coding level for effective transmission of data at the base station or mobile terminal.

Accordingly, a technical problem of the present invention is to select a modulation and coding level through an effective carrier to interface ratio (CINR) value in an OFDMA wireless communication system and feed back the selected modulation and coding level to the base station. A method and apparatus for transmitting data at a modulation and coding level are provided.

Another object of the present invention is to provide a method for selecting an optimal modulation and coding level in response to a change in a moving speed and a channel of a mobile terminal and a mobile terminal capable of performing the method.

Another object of the present invention is to provide a method for accurately calculating a modulation and coding level regardless of the amount of data transmitted from a base station, and a mobile terminal capable of performing the method.

The modulation and coding level selection method of the mobile terminal for achieving the technical problem is calculated from the block size information included in the received frame, and moved from the phase differences of the plurality of pilot signals included in the received frame Estimating a moving speed of the terminal; Selecting a look-up table corresponding to the calculated block size and the estimated moving speed from the plurality of look-up tables; Calculating an effective carrier to interference ratio (CINR) value corresponding to each of a plurality of beta values defined for each modulation and coding level included in the selected look-up table; And comparing the calculated effective CINR value with the effective CINR value included in the selected look-up table for each beta value, and selecting information indicating any one beta value selected based on comparison results among the plurality of beta values. Transmitting to.

The method of selecting a modulation and coding level of the mobile terminal further includes the mobile terminal receiving data transmitted at a modulation and coding level selected by the base station according to the selection information among a plurality of modulation and coding levels.

A mobile terminal for achieving the technical problem includes a storage device and a processor for storing a plurality of look-up tables.

The processor calculates a block size from block size information included in a received frame, estimates a moving speed of the mobile terminal from phase differences of a plurality of pilot signals included in the received frame, and the plurality of look-ups. Selecting a look-up table corresponding to the calculated block size and estimated movement speed from the tables, and each validity corresponding to each of a plurality of beta values defined for each modulation and coding level included in the selected look-up table. Compute a CINR value, compare the calculated effective CINR value with the effective CINR value included in the selected look-up table for each beta value, and select any one beta value based on comparison results among the plurality of beta values. The selection information indicated is transmitted to the base station.

The method for selecting a modulation and coding level of a mobile terminal to achieve the technical problem comprises the steps of receiving a frame transmitted from the base station to a first modulation and coding level of a plurality of modulation and coding levels from the base station; Calculating a block size from block size information included in the received frame by the mobile terminal; Selecting, by the mobile terminal, any one look-up table corresponding to the calculated block size among a plurality of look-up tables stored in its storage device; Calculating, by the mobile terminal, respective effective CINR values corresponding to each of a plurality of beta values defined for each modulation and coding level included in the selected look-up table; And comparing the effective CINR value calculated by the mobile terminal with the effective CINR value included in the selected look-up table for each beta value and selecting one of the plurality of beta values based on the results of comparison by the beta value. And transmitting selection information indicating a beta value of the to the base station.

The method of selecting a modulation and coding level of the mobile terminal further includes the mobile terminal receiving data transmitted at a second modulation and coding level selected by the base station among the plurality of modulation and coding levels according to the selection information. do.

A mobile terminal for achieving the technical problem includes a storage device and a processor for storing a plurality of look-up tables.

The processor receives a frame transmitted from a base station at a first modulation and coding level among a plurality of modulation and coding levels, calculates a block size from block size information included in the received frame, and stores the plurality of frames stored in the storage device. Select one look-up table corresponding to the calculated block size among the look-up tables, and each validity corresponding to each of a plurality of beta values defined for each modulation and coding level included in the selected look-up table. Compute a CINR value, compare the calculated effective CINR value with the effective CINR value included in the selected look-up table for each beta value, and select any one based on the results of the beta comparison among the plurality of beta values. Selection information indicating one beta value is transmitted to the base station.

The processor further receives data transmitted at a second modulation and coding level selected by the base station among the plurality of modulation and coding levels according to the selection information.

Modulation and coding level selection methods and apparatuses according to an embodiment of the present invention, the modulation and coding level that the terminal can achieve the optimal performance through the effective carrier to interface ratio (CINR) value in the OFDMA wireless communication system There is an effect to choose from.

In addition, modulation and coding level selection methods and apparatuses according to an embodiment of the present invention have an effect of selecting a modulation and coding level in response to a change in a moving speed and a channel thereof.

In addition, modulation and coding level selection methods and apparatuses according to an embodiment of the present invention have the effect of accurately calculating the modulation and coding level regardless of the amount of data transmitted from the base station. Therefore, the call quality of the mobile terminal is maintained optimally.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

1 is a flowchart illustrating a decoding order of downlink frames. Referring to FIG. 1, a mobile terminal such as a mobile phone or a PDA acquires synchronization through a preamble of a frame, obtains an ID of a base station, and estimates a channel (S10).

Since the ID of the base station used to distinguish the base station, described in IEEE 802.16e, is used as a seed value for subcarrier permutation and scrambling, obtaining the ID of the base station is downlink (Down Link (DL)). ) Is necessary for decoding of data bursts.

The frame control header (FCH) transmitted after the preamble transmits information required for DL-MAP decoding. That is, the FCH is transmitted as 1/2 code rate QPSK data of 4 repetitions and includes information on the DL-MAP length of the DL-MAP, a coding method, and information on repetitive transmission (S20).

The DL-MAP which is then transmitted has information necessary for decoding of DL data bursts in the current frame (S30). That is, information about the position and magnitude of each burst, and the modulation and coding scheme. Therefore, in order to decode DL-MAP data bursts, a signal processing procedure as shown in Fig. 1 must be performed.

2 illustrates a method of calculating a beta value of an effective carrier to interference ratio (CIINR). Here, each beta value β0 to β21 is a CINR value (for example, expressed in dB) or an ECINR value (for example, expressed in dB) in a pedestrian reference channel (PedBn, n is an integer, for example, n is 0 to 21). ) Is a calibration parameter for mapping or fitting each AWGN (Additive White Gaussian Noise).

Each beta value (e.g., beta 0 to beta 21) used in this specification represents a correction parameter when the data reception packet error rate (PER) is 10%.

For example, the CINR value or ECINR value of the pedestrian reference channel PedB0 at modulation and coding level 0 (MCS0) is adjusted to AWGN by the beta value β0. In addition, the CINR value or ECINR value of the pedestrian reference channel PedB21 at the modulation and coding level 21 (MCS21) is adjusted to AWGN by the beta value β21.

For example, each calibration parameter, i.e., each beta value (e.g., beta 0 to beta 21) may be determined (or calculated) by equation (1).

[Equation 1]

Here, γ i denotes the i-th PCINR value, that is, the pilot-based CINR value.

By Equation 1, a beta value β0 for modulation and coding level 0 (MCS0) is determined and each modulation and coding level (e.g., MCS0 to MCS21 shown in FIG. 5B). Each of the beta values (eg, β 0 to β 21) may also be determined or calculated through Equation 1.

3 shows a graph of effective CINR (ECINR) versus beta value.

The xxdB shown in FIG. 2 matches the effective CINR, which matches βxx. For example, a quadratic curve can be obtained by connecting an equivalent CINR value with each beta value (eg, β0 to β21) and AWGN having a PER (Packet Error Rate) of 10%. .

In addition, as shown in FIG. 5B, a table of beta value-to-ECINR values (eg, a look-up table) may be generated for each modulation and coding level (MCS0 to MCS21). For example, the ECINR value measured by the mobile terminal is selected by the mobile terminal through the following procedure to select an optimal modulation and coding level, and to encode information about the selected modulation and coding level to transmit the encoded information to the base station. do.

1. The mobile station measures the CINR (γ _i ) for each subcarrier. Since the beta value is already defined for each modulation and coding level, the calculated (or measured) effective CINR value ECINR 'can be obtained through Equation 2.

[Equation 2]

ECINR '=

2. The mobile terminal compares each calculated or measured ECINR value (ECINR ') with the AWGN equivalent CINR (ie, effective CINR) at all modulation and coding levels defined in the selected look-up table. Then, the modulation and coding level corresponding to the beta value satisfying Equation 3 is found.

&Quot; (3) "

ECINR '(dB)> AWGN Equivalent CINR (MCS)

3. The mobile station encodes the modulation and coding level corresponding to the beta value as 0b00xxxx according to the standard and transmits the encoded signal to the base station.

However, since the modulation and coding level selection method according to the conventional scheme does not consider the moving speed and the block size of the mobile terminal, it is difficult for the mobile terminal to request an accurate modulation and coding level from the base station.

However, in the embodiment of the present invention, the mobile terminal selects an optimal modulation and coding level (or a beta value corresponding to the optimal modulation and coding level) in consideration of the following two methods and selects the selected modulation and coding. Information about the level (or beta value) is transmitted to the base station. Accordingly, the base station transmits data including the at least one frame to the mobile terminal at the optimal modulation and coding level selected based on the information on the received modulation and coding level (or beta value). Thus, the call quality of the mobile terminal is improved.

In the first method used in the embodiment of the present invention, the mobile station selects an optimal modulation and coding level (or beta value) in consideration of the moving speed and block size of the mobile terminal and selects the selected modulation and coding level (or beta value). When the selection information corresponding to) is transmitted to the base station, the base station transmits data at the modulation and coding level corresponding to the selection information.

4 shows a schematic block diagram of a system 10 including a base station 20 and a mobile terminal 30 according to an embodiment of the invention, and FIG. 7 shows a mobile terminal 30 according to an embodiment of the invention. A flowchart for explaining a modulation and coding level selection method of s) is shown.

3 to 7, the mobile terminal 30 considers an optimal modulation and coding level (or the modulation and coding level) in consideration of the moving speed and the block size (eg, N bytes, N is a natural number) of the mobile terminal 30. A method of selecting a beta value corresponding to a coding level) and transmitting selection information corresponding to the selected modulation and coding level (or beta value) to the base station 20 will be described below.

First, the base station 20 and the mobile terminal 30 is a storage device 33 for storing a plurality of look-up tables (eg, LUT1 ~ LUT9) as shown in (a) and (b) of FIG. Each look-up table includes a beta value (β0, β1, ..., β21) and an effective CINR value (ECINR0, ECINR1, ..., ECINR21) for each modulation and coding level (MCS0 to MCS21). Suppose you are saving.

For example, FIG. 5A shows the look-up tables LUT1 to LUT9 according to the block size BS and the estimated speed EV, and FIG. 5B shows the calculated block size (eg, BS2). ) And a look-up table LUT5 corresponding to the estimated speed (eg, EV2). Referring to FIG. 5B, the look-up table LUT5 selected by the processor 31 of the mobile terminal 30 is a beta for each modulation and coding level MCS0, MCS1, ..., MCS21. Values β0, β1, ..., β21 and respective effective CINR values ECINR0, ECINR1, ..., ECINR21.

The base station 20 transmits data including the at least one frame to the mobile terminal 30 at any one of a plurality of modulation and coding levels (eg, MCS0, MCS1, ..., MCS21). .

Therefore, the processor 31 of the mobile terminal 30 receives a frame input through an antenna (not shown) and a low noise amplifier (not shown) (S110), and block size information included in the received frame, for example, DL- The block size is calculated (or obtained) from the information included in the MAP IE, and the moving speed of the mobile terminal 30 is estimated from phase differences of the plurality of pilot signals included in the received frame (S120).

For example, the processor 31 of the mobile terminal 30 may estimate its moving speed φ _n using the scheme proposed by Yang Baogue. That is, φ _n = φ (nTs), where φ (t) is the phase of the received signal (or received frame), n is the discrete time index of the pilot signal, and Ts is the pilot symbol period.

이고, N은 관찰 벡터(observation vector)의 길이이고, 도플러 쉬프트(fd)는 다음과 같이 추정될 수 있다.α =

, N is the length of the observation vector, and the Doppler shift fd can be estimated as follows.

fd = (0.012 + 0.21α) / Ts, 0≤0.0619

fd = (0.066 + 0.097α) / Ts, 0.619 ≦ α ≦ 0.328

As illustrated in FIG. 5A, the storage device 33 may include a plurality of look-up tables LUT1 to LUT9 classified according to the block size BS and the estimated speed EV. The storage device 33 may be implemented as a volatile memory device (eg, DRAM or SDRAM) or a nonvolatile memory device (or flash EEPROM, or ROM).

The processor 31 of the mobile terminal 30 may include a look-up table (eg, LUT5) corresponding to a block size (eg, BS2) and a moving speed (eg, EV2) among the plurality of look-up tables LUT1 to LUT9. Select (S130).

The processor 31 of the mobile terminal 30 includes a plurality of defined by the modulation and coding levels (MCS0, MCS1, ..., MCS21) included in the selected look-up table (eg, LUT5 of FIG. 5B). Each of the effective carrier to interference ration values CIINR0 ', ECINR1', ..., ECINR21 'corresponding to each of the beta values β0, β1, ..., β21 of Eq. It calculates using Formula 2 (S140).

For example, the processor 31 of the mobile terminal 30 calculates the effective CINR value ECINR0 'by substituting the beta value β0 corresponding to the modulation and coding level MCS0 into Equation 1 or Equation 2, The effective CINR value (ECINR1 ') is calculated by substituting the beta value (β1) corresponding to the modulation and coding level (MCS1), and the effective CINR value by substituting the beta value (β21) corresponding to the modulation and coding level (MCS21). ECINR21 'is calculated (S140).

The processor 31 of the mobile terminal 30 includes the calculated effective CINR values (ECINR0 ', ECINR1', ..., ECINR21 ') and the selected look-up table (e.g., LUT5 of FIG. 5 (b)). Effective CINR values (ECINR0, ECINR1, ..., ECINR21) are compared by beta values (β0, β1, ..., β21), and among a plurality of beta values (β0, β1, ..., β21). Based on the comparison results, one beta value (βx, eg, x = 10) is selected (S150), and selection information indicating the selected beta value (eg, β10) is transmitted to the base station 20.

FIG. 6 shows a graph A of effective CINRs (ECINRs) according to beta values included in the selected look-up table and a graph B of effective CINRs (ECINR ′) calculated for each beta value.

As shown in FIG. 6, the processor 31 of the mobile terminal 30 performs a look-up table (for example, LUT5 of FIG. 5B) by beta values (β0, β1, ..., β21). Compares the effective CINR value already stored in the mobile terminal 20 with the effective CINR value calculated by the processor 31 of the mobile terminal 20, and stores the effective CINR value already stored in the look-up table (e.g., LUT5 of FIG. 5 (b)). The beta value (e.g., beta 10) is selected when it is larger than the effective CINR value calculated by the processor 31 of this mobile terminal 30.

The base station 20 selects a modulation and coding level (eg, MCS10 corresponding to β10) corresponding to the received selection information among a plurality of modulation and coding levels based on the selection information output from the mobile terminal 30, and selects the selected information. Transmit data comprising at least one frame at a modulation and coding level. Accordingly, the mobile terminal 30 may receive data including at least one frame at the selected modulation and coding level (S160), and perform steps S110 to S160 again.

As described above, the mobile terminal 30 according to an embodiment of the present invention is a modulation and coding level selected for the block size and the moving speed of the mobile terminal 30 or a beta value corresponding to the modulation and coding level. After transmitting the information to the base station 20, there is an effect that can receive data including at least one frame transmitted at the selected modulation and coding level.

8 is a flowchart illustrating a method of selecting a modulation and coding level of a mobile terminal according to another embodiment of the present invention. A method of selecting a modulation and coding level of a mobile terminal according to another embodiment of the present invention will be described with reference to FIGS. 4, 5, 6, and 8 as follows.

That is, the mobile terminal 30 selects an optimal modulation and coding level (or beta value) in consideration of the block size, and transmits selection information corresponding to the selected modulation and coding level (or beta value) to the base station 20. The method is as follows.

First, the base station 20 and the mobile terminal 30 for storing a plurality of look-up tables (LUT11, LUT12, LUT13, ...) as shown in (b) or (c) of FIG. Since it contains a storage device such as a memory, the beta values (β0, β1, ..., β21) and effective CINR values (ECINR0, ECINR1) for each modulation and coding level (MCS0, MCS1, ..., MCS21), respectively. , ..., ECINR21).

FIG. 5C shows the look-up tables LUT11, LUT12, LUT13, ... according to the calculated block size BS, and FIG. 5B shows the calculated block size (e.g., BS2). ) Shows a look-up table (LUT12). Referring to FIG. 5B, the selected look-up table LUT12 is valid with beta values β0, β1, ..., β21 for each modulation and coding level MCS0, MCS1, ..., MCS21. CINR values (ECINR0, ECINR1, ..., ECINR21) are included.

The base station 20 transmits data including at least one frame at any one of a plurality of modulation and coding levels (eg, MCS0, MCS1, ..., MCS21).

Therefore, the processor 31 of the mobile terminal 30 receives a frame input through an antenna (not shown) and a low noise amplifier (not shown) (S210), and block size information included in the received frame, for example, DL- The block size is calculated (or obtained) from the information included in the MAP IE (S220).

The storage device 33 of the mobile terminal 30 includes a plurality of look-up tables LUT11, classified according to block sizes BS1, BS2, BS3, ..., as shown in FIG. LUT12, LUT13, ...).

The processor 31 of the mobile terminal 30 may include a look-up table (eg, BS2) corresponding to a block size (eg, BS2) calculated among the plurality of look-up tables LUT11, LUT12, LUT13,... LUT12) is selected (S230).

The processor 31 of the mobile terminal 30 includes a plurality of beta values β0 and β1 defined for each modulation and coding level MCS0, MCS1, ..., MCS21 included in the selected look-up table (eg, LUT12). Each of the effective CINR values ECINR0 ', ECINR1', ..., ECINR21 'corresponding to each of ..., ..., β21) is calculated using Equation 1 or Equation 2 (S240).

For example, the processor 31 of the mobile terminal 30 calculates the effective CINR value ECINR0 'by substituting the beta value β0 corresponding to the modulation and coding level MCS0 into Equation 1 or 2, The effective CINR value (ECINR1 ') is calculated by substituting the beta value (β1) corresponding to the modulation and coding level (MCS1), and the effective CINR value by substituting the beta value (β21) corresponding to the modulation and coding level (MCS21). ECINR21 'is calculated (S240).

The processor 31 of the mobile terminal 30 includes the calculated effective CINR values ECINR0 ', ECINR1', ..., ECINR21 'and the selected look-up table (e.g., LUT12 of FIG. 5 (b)). The calculated effective CINR values (ECINR0, ECINR1, ..., ECINR21) by beta values (β0, β1, ..., β21), and among a plurality of beta values (β0, β1, ..., β21). Based on the results, one beta value (βx, eg, x = 10) is selected (S250), and selection information indicating the selected beta value (eg, β10) is transmitted to the base station 20.

As illustrated in FIG. 6, the processor 31 of the mobile terminal 30 may be configured in the look-up table (eg, LUT12 of FIG. 5B) for each of beta values β0, β1, ..., β21. The effective CINR value already stored is compared with the effective CINR value calculated by the processor 31 of the mobile terminal 30, and the effective CINR value already stored in the look-up table (eg, LUT12 of FIG. A beta value (eg, β 10) is selected when the effective CINR value calculated by the processor 31 of the mobile terminal 20 is larger (S250).

The base station 20 selects a modulation and coding level (eg, MCS10 corresponding to β10) corresponding to the received selection information among a plurality of modulation and coding levels based on the selection information output from the mobile terminal 30, and selects the selected information. Transmit data comprising at least one frame at a modulation and coding level. Accordingly, the mobile terminal 30 may receive data including at least one frame at the selected modulation and coding level (eg, MCS10) (S260), and perform steps S210 to S260 again.

As described above, the mobile terminal 30 according to the embodiment of the present invention transmits information on the modulation and coding level or the beta value corresponding to the modulation and coding level selected according to the block size to the base station 20. Thereafter, there is an effect of receiving data including at least one frame transmitted at the selected modulation and coding level.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

The detailed description of each drawing is provided in order to provide a thorough understanding of the drawings cited in the detailed description of the invention.

1 is a flowchart illustrating a decoding order of a downlink (DL) frame.

Figure 2 shows a method for calculating the beta (beta) value of ECINR.

3 shows a graph of Beta Effective CINR.

4 is a block diagram of a system including a base station and a mobile terminal according to an embodiment of the present invention.

FIG. 5 illustrates an embodiment of a look-up table stored in the storage illustrated in FIG. 4.

6 shows a graph of the effective CINR according to the beta value included in the selected look-up table and a graph of the effective CINR calculated for each beta value.

7 is a flowchart illustrating a method of selecting a modulation and coding level of a mobile terminal according to an embodiment of the present invention.

8 is a flowchart illustrating a method of selecting a modulation and coding level of a mobile terminal according to another embodiment of the present invention.

Claims (9)

Calculating a block size from block size information included in a received frame and estimating a moving speed of the mobile terminal from phase differences of a plurality of pilot signals included in the received frame; Selecting, from the plurality of look-up tables, a look-up table corresponding to the calculated block size and the estimated moving speed; Calculating an effective carrier to interference ratio (CINR) value corresponding to each of a plurality of beta values defined for each modulation and coding level included in the selected look-up table; And The calculated effective CINR value and the effective CINR value included in the selected look-up table are compared for each beta value, and selection information indicating one beta value selected based on comparison results among the plurality of beta values is transmitted to the base station. Method for selecting a modulation and coding level of a mobile terminal comprising the step of transmitting. The method of claim 1, wherein the modulation and coding level selection method of the mobile terminal, And receiving, by the mobile terminal, data transmitted at a modulation and coding level selected by the base station according to the selection information among a plurality of modulation and coding levels. The method of claim 1, wherein calculating each effective CINR value comprises: The following equation, ECINR '=

Calculate the respective effective CINR values corresponding to the respective beta values defined by the modulation and coding levels, where ECINR 'represents the calculated effective CINR, and β is defined by the modulation and coding levels. A method of selecting a modulation and coding level of a mobile terminal, wherein each beta value represents γ _i and _i represents an i (i is a natural number) pilot-based CINR value. A computer-readable recording medium having recorded thereon a computer program for executing the modulation and coding level selection method of the mobile terminal according to any one of claims 1 to 3. A storage device for storing a plurality of look-up tables; And Includes a processor, The processor calculates a block size from block size information included in a received frame, estimates a moving speed of the mobile terminal from phase differences of a plurality of pilot signals included in the received frame, and the plurality of look-ups. Select a look-up table that corresponds to the calculated block size and estimated movement speed from the tables, and each effective CINR corresponding to each of a plurality of beta values defined for each modulation and coding level included in the selected look-up table. calculate an effective carrier to interference ratio, compare the calculated effective CINR value with the effective CINR value included in the selected look-up table for each beta value, and select among the plurality of beta values based on comparison results. A mobile terminal controlling the transmission of selection information indicating any one beta value to the base station. Receiving, by the mobile terminal, a frame transmitted at a first modulation and coding level among a plurality of modulation and coding levels; Calculating a block size from block size information included in the received frame by the mobile terminal; Selecting, by the mobile terminal, any one look-up table corresponding to the calculated block size among a plurality of look-up tables stored in its storage device; Calculating, by the mobile terminal, an effective carrier to interference ratio (CINR) value corresponding to each of a plurality of beta values defined for each modulation and coding level included in the selected look-up table; And The mobile terminal compares the calculated effective CINR value with the effective CINR value included in the selected look-up table for each beta value and selects any one selected based on the results of comparison of the beta values among the plurality of beta values. And transmitting selection information indicating a beta value to the base station. The method of claim 6, wherein the modulation and coding level selection method of the mobile terminal comprises: And receiving, by the mobile terminal, data transmitted at a second modulation and coding level selected by the base station among the plurality of modulation and coding levels according to the selection information. A storage device for storing a plurality of look-up tables; And Includes a processor, The processor receives a frame transmitted from a base station at a first modulation and coding level among a plurality of modulation and coding levels, calculates a block size from block size information included in the received frame, and stores the plurality of frames stored in the storage device. Select one look-up table corresponding to the calculated block size among the look-up tables, and each validity corresponding to each of a plurality of beta values defined for each modulation and coding level included in the selected look-up table. Compute a CINR value, compare the calculated effective CINR value with the effective CINR value included in the selected look-up table for each beta value, and select any one based on the results of the beta comparison among the plurality of beta values. A mobile terminal controlling the transmission of selection information indicating one beta value to the base station. The method of claim 8, wherein the processor, And control to further receive data transmitted at the second modulation and coding level selected by the base station among the plurality of modulation and coding levels according to the selection information.

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