KR101150937B1 - Apparatus and method for estimating carrier to interference noise ratio in mobile communication system - Google Patents

Abstract

The present invention relates to an apparatus and method for signal to interference and noise ratio estimation in a mobile communication system. In the mobile communication system according to the present invention, an apparatus for estimating signal-to-interference and noise ratio comprises: generating an i-th operation value T (i) by calculating a difference between an i + 1 th pilot subcarrier value and an i th pilot subcarrier value; A first operation unit, a memory for storing the i th operation value T (i) and an i-1 th operation value T (i-1), and an i th operation value T (i) according to the value of the pilot subcarrier index i; A second operation unit which selects one of 0, selects an i-1 th operation value T (i-1) and 0 according to the i value, and calculates a difference between two selected values according to the i value; A third operation unit that squares a result of the difference between the two values, multiplies the squared value by 1/2 or 1/6 according to the i value, and a pilot subcarrier multiplied by the 1/2 or 1/6 And a fourth calculator configured to add interference result values to estimate interference and noise power of the signal.

CINR, OFDM, DASS, Interference, and Noise Estimators

Description

Apparatus and method for estimating signal-to-interference and noise ratio in mobile communication systems {APPARATUS AND METHOD FOR ESTIMATING CARRIER TO INTERFERENCE NOISE RATIO IN MOBILE COMMUNICATION SYSTEM}

1 is a diagram illustrating a configuration of an OFDM receiver including a CINR estimator according to the present invention;

2 is a diagram illustrating a configuration of a CINR estimator including an interference and noise power estimator according to the present invention;

3 illustrates an implementation of an interference and noise power estimator in accordance with the present invention;

4 is a block diagram implemented by serially processing an interference and noise power estimator according to the present invention;

5 is a block diagram of an interference and noise power estimator according to a first embodiment of the present invention; and

6 is a block diagram of an interference and noise power estimator according to a second embodiment of the present invention.

The present invention relates to a mobile communication system, and more particularly, to an apparatus and method for signal-to-interference and noise ratio estimation.

Orthogonal Frequency Division Multiplexing (OFDM), which is recently used as a useful method for high-speed data transmission in a wired / wireless channel, is a method of transmitting data using a plurality of carriers. A method of converting data in parallel and modulating the data into a plurality of sub-carriers (or sub-channels) having mutual orthogonality to each other is transmitted.

The orthogonal frequency division multiplexing (OFDM) scheme is similar to the conventional frequency division multiplexing (FDM) scheme, but transmits data while maintaining orthogonality between a plurality of subcarriers, thereby providing optimum data transmission at high speed. The transmission efficiency can be obtained, the frequency efficiency is good, and the characteristics are strong against multi-path fading. In addition, by using the frequency spectrum superimposed, it is strong in frequency selective fading, and the inter-symbol interference effect can be reduced by using a guard period. In addition, it is possible to simply design the equalizer structure in hardware and has the advantage of being resistant to impulsive noise.

In addition, the orthogonal frequency division multiplexing (OFDM) method is a hardware complexity due to the development of various digital signal processing technologies including the fast Fourier transform (FFT) and the inverse fast Fourier transform (IFFT). Digital transmission such as digital / audio broadcasting, digital TV, wireless local area network (WLAN), wireless asynchronous transfer mode (WATM), and broadband wireless access (BWA) It is widely applied to the technology.

On the other hand, a wireless communication system based on orthogonal frequency division multiplexing (hereinafter, referred to as OFDM) or orthogonal frequency division multiple access (hereinafter, referred to as OFDMA) (hereinafter referred to as OFDM) In this case, channel signal quality, for example, carrier to interference noise ratio (CINR), which is a parameter required for power control or adaptive modulation and demodulation, needs to be measured. Here, the adaptive power control or the adaptive modulation and demodulation device controls the power and adjusts the demodulation level according to the channel quality using the CINR value. The CINR is defined as a value obtained by dividing the total signal power of each subcarrier by the sum of noise and interference power, and is a measure of transmission / reception channel quality determination in an OFDM system.

Conventional carrier to interference and noise ratio (CINR) estimation technique estimates the noise level using a guard band, thereby estimating the CINR. However, the number of subcarriers used for estimating the noise level is not sufficient, and thus, the accuracy of the CINR may be degraded, and the noise level may be estimated to be higher than actual due to the ACLR (Adjacent Channel Leakage Ratio). Accordingly, there is a need for an apparatus for more accurately estimating the CINR in the OFDM system.

Accordingly, an object of the present invention is to provide an apparatus and method for estimating signal-to-interference and noise ratio in a mobile communication system.

Another object of the present invention is to estimate the noise power of a signal using similar characteristics of a channel experienced by each adjacent subcarrier in subcarriers of a received signal in a mobile communication system, thereby providing a more accurate signal to interference and noise ratio (CINR). An apparatus and method for estimation are provided.

Another object of the present invention is to provide an apparatus and method for interference and noise power estimation using an optimized DASS algorithm in a mobile communication system.

According to a first embodiment of the present invention, an apparatus for estimating a signal-to-interference and noise ratio in a mobile communication system includes calculating a difference between an i + 1 th pilot subcarrier value and an i th pilot subcarrier value a first operation unit generating an i th operation value T (i), a memory for storing the i th operation value T (i) and an i-1 th operation value T (i-1), and a pilot subcarrier index i Select one of the i th operation value T (i) and 0 according to the value, select one of the i-1 th operation value T (i-1) and 0 according to the i value, and select the value according to the i value A second operation unit for calculating a difference between two values, a third operation unit for squaring a result of the difference between the two values, and multiplying the squared value by 1/2 or 1/6 according to the i value, and A method for estimating the interference and noise power of a signal by adding the pilot subcarriers multiplied by 1/2 or 1/6 It characterized in that it comprises a calculation unit.

According to a second embodiment of the present invention, an apparatus for estimating a signal-to-interference and noise ratio in a mobile communication system includes calculating a difference between an i th pilot subcarrier value and an i + 1 th pilot subcarrier value A first operation unit for generating a first operation value, a second operation unit for generating a second operation value by calculating a difference between the i-th pilot subcarrier value and the i-1 th pilot subcarrier value, and a value of the pilot subcarrier index i A third operation unit which selects one of the first operation value and 0, selects one of the second operation value and 0 according to the i value, and calculates a sum of two selected values according to the i value; A fourth operation unit that squares a result of the sum of two values, multiplies 1/2 or 1/6 according to the i value with respect to the squared value, and a pilot subcarrier result obtained by multiplying the 1/2 or 1/6 Interference of Signals by Adding Values It characterized by a fifth calculation unit for estimating the noise power.
According to a third embodiment of the present invention, a method for estimating a signal-to-interference and noise ratio in a mobile communication system includes calculating a difference between an i + 1 th pilot subcarrier value and an i th pilot subcarrier value generating an i th operation value T (i) and selecting one of the i th operation value T (i) and 0 according to the value of the pilot subcarrier index i, and the i-1 th operation value T according to the i value selecting one of (i-1) and 0, calculating a difference between two selected values according to the i value, squares a result of the difference between the two values, and calculates the i value with respect to the squared value And multiplying 1/2 or 1/6 according to the method, and estimating interference and noise power of the signal by adding result values for each pilot subcarrier multiplied by 1/2 or 1/6. .
According to a fourth exemplary embodiment of the present invention, a method for estimating signal-to-interference and noise ratio in a mobile communication system includes calculating a difference between an i th pilot subcarrier value and an i + 1 th pilot subcarrier value. Generating a first operation value, calculating a difference between an i th pilot subcarrier value and an i-1 th pilot subcarrier value, and generating a second operation value, and performing the first operation according to a value of a pilot subcarrier index i Selecting one of a value and 0, selecting one of the second operation value and 0 according to the value of i, calculating a sum of two selected values according to the value of i, and a result value of sum of the two values Squared, multiplying the squared value by 1/2 or 1/6 according to the value of i, and adding the resultant values of the pilot subcarriers multiplied by the 1/2 or 1/6 to add the interference and To estimate noise power It is characterized by including a tablet.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Hereinafter, an interference and noise power estimation method for estimating noise power of a signal using similar characteristics of a channel experienced by each adjacent subcarrier in subcarriers of a received signal in a mobile communication system will be described.

1 is a diagram illustrating a configuration of an OFDM receiver including a CINR estimator according to the present invention.

Referring to FIG. 1, an OFDM receiver includes an antenna 101, an RF processor 103, a guard interval remover 105, a serial / parallel converter 107, an FFT 109, an equalizer 111, and a channel estimator ( 113 and CINR estimator 115.

The RF processor 103 outputs the channel data from the wireless channel received through the antenna 101 to the guard interval remover 105. The guard interval remover 105 removes the guard interval from the received channel data. The serial / parallel converter 107 converts the serial data and the redundant data from which the guard interval has been removed into a plurality of parallel data and outputs the data to the fast Fourier transformer (FFT) 109. The fast Fourier transformer 109 performs Fourier transform on the parallel data and the surplus data at high speed, and outputs the Fourier transformed data to the equalizer 111.

The equalizer 111 removes signal distortion due to Fourier transformed information data and excess data channels, and outputs data from which signal distortion has been removed. The channel estimator 113 estimates the channel state according to the distortion of the phase and amplitude in the frequency domain due to the channel degradation occurring during transmission and reception, and compensates for the distortion of the phase amplitude in the frequency domain. The CINR estimator 115 then measures the channel quality, i. E. CINR.

As described above, a transmitter of an OFDM system transmits a modulated signal by performing a fast Fourier Inverse Transform (IFFT) and then attaches a guard interval. In contrast, the receiver first removes the guard interval and then performs a Fast Fourier Transform (FFT). Demodulate to obtain the transmitted signal. In this case, when a transmitter of the OFDM system transmits a digital signal of a known pattern such as a pilot signal or a preamble signal, the OFDM receiver receiving the estimated signal estimates the CINR using the received signal.

2 is a diagram illustrating a configuration of a CINR estimator including an interference and noise power estimator according to the present invention.

Referring to FIG. 2, a carrier to interference and noise ratio (CINR) estimator 115 includes a signal power estimator 201 for estimating total received signal power, interference and noise power of a received preamble or pilot signal. And an interference and noise power estimator 203 for estimating a noise level, a noise level estimator 205 for estimating a noise level of a received signal, and a CINR calculator 207 for estimating a CINR in a data interval. Here, the CINR estimator 115 outputs the signal output from the FFT 109 to the signal power estimator 201, the interference and noise power estimator 203, and the noise level estimator 205.

The signal power estimator 201 estimates the power of the received signal. In detail, the signal power estimator 201 obtains the power of each subcarrier of the signal received from the FFT unit 109, and then adds the power of each subcarrier to estimate the power of the signal and uses the CINR calculator ( 207).

The interference and noise power estimator 203 estimates the noise power of the received signal and outputs the estimated noise power information to the CINR calculator 207. The interference and noise power estimator 203 according to an embodiment of the present invention estimates the noise power of a signal by using similar characteristics of a channel experienced by each adjacent subcarrier in the subcarriers of the received signal.

The noise level estimator 205 estimates the noise level of the received signal and provides the estimated noise level information to the CINR calculator 207. Here, the noise level estimator 205 may estimate the noise level using signal powers of a plurality of subcarriers on which no signal is carried.

The CINR calculator 207 receives power information of the entire received signal from the signal power estimator 201 and noise power information of the received signal from the interference and noise power estimator 203. The CINR calculator 207 also receives noise level information from the noise level estimator 205. In this case, the CINR calculator 207 estimates the CINR in the data interval by using the provided information.

Here, the CINR is defined as a value obtained by dividing the sum of signal power of each subcarrier by the sum of noise and interference power, and is generally defined as Equation 1 below.

P (i) denotes the i-th pilot subcarrier value, I (i) denotes the interference and noise power corresponding to the i-th pilot, and i denotes the index of the pilot subcarrier.

The sum of noise and interference power for calculating the CINR, that is, I (i), is generally calculated through a DIF (Difference of Adjacent Subcarrier Signal) method. In this case, the calculation for the interference and noise power estimation is performed using Equation 2.

여기서, 상기 M은 주파수 영역에서 유사한 채널 특성을 보이는 인접한 파일럿 부반송파의 개수를 의미한다.

Here, M denotes the number of adjacent pilot subcarriers having similar channel characteristics in the frequency domain.

FIG. 3 is a diagram illustrating the hardware implementation of the interference and noise power estimator of the CINR estimator using the DASS technique. Here, the interference and noise power estimator 203 includes M-2 multipliers 301-2 to 301-M-1, M adders 302-1 to 302-M, and M calculators 303. -1 to 303-M) and a summer 304.

Referring to FIG. 3, the first adder 302-1 calculates and outputs a difference between the first pilot subcarrier value P (1) and the second pilot subcarrier value P (2), and outputs the Mth adder 302-. M) calculates and outputs a difference between the Mth pilot subcarrier value P (M) and the M-1st pilot subcarrier value P (M-1). The second adder 302-2 to the M-1 adder 302-M-1 multiply the corresponding i-th pilot subcarrier value P (i) by 2, and then double P (i). ) Subtracts the i-1 th pilot subcarrier value P (i-1) and the i + 1 th pilot subcarrier value P (i + 1). Here, M denotes the number of adjacent pilot subcarriers having similar channel characteristics in the frequency domain.

Thereafter, the first calculator 303-1 and the M-th calculator 303 -M square the result values output from the corresponding first adder 302-1 and the M-th adder 302 -M, respectively. , Dividing by 2 to print. The second calculator 303-2 to the M-1 calculator 303-M-1 respectively square the result of the corresponding adder, divide the result by 6, and output the result to the summer 304. The summer 304 adds all the values output from the M calculators 303-1 to 303-M to obtain the total interference and noise signal power.

Here, when there are a lot of parallel processing as shown in FIG. 3, since there are various side effects such as the size of the circuit is increased and thus the power consumption is increased, there is an actual implementation.

Referring to FIG. 4, the first delay unit 401 delays and outputs the input pilot subcarriers by one time. The second delay unit 402 delays and outputs the pilot subcarriers from the first delay unit by a predetermined time, and the third delay unit 403 delays and outputs the pilot subcarriers from the second delay unit by a predetermined time. Herein, the output from the first delay unit is assumed to be an i + 1th pilot subcarrier value, the output from the second delay unit is assumed to be an i-th pilot subcarrier value, and the output from the third delay unit is i Assume the -1th pilot subcarrier value.

Thereafter, the first adder 404 subtracts the output P (i + 1) of the first delay unit 401 from the output P (i) of the second delay unit 402 and then uses the fourth delay unit ( 409, and the second adder 405 calculates a difference between the pilot subcarrier values output from the second delay unit 402 and the third delay unit 403 and outputs the difference to the sixth delay unit 411. do. The shifter 406 shifts the value from the second delay unit 402, that is, doubles the calculation and outputs the result to the third adder 407. At this time, the third adder 407 subtracts the output P (i + 1) of the first delay unit 401 from the output 2P (i) of the shifter 406 and then adds the result value to the fourth adder. 408, and the fourth adder 408 outputs P (of the third delay unit 403 from an output 2P (i) -P (i + 1) of the third adder 407. i-1) is subtracted and then output to the fifth delay unit 410.

The selecting unit 412 outputs the outputs of the fourth delay unit 409, the fifth delay unit 410, and the sixth delay unit 411 according to the i value representing the index of the subcarrier, that is, P (i). Select one of -P (i + 1) and 2P (i) -P (i-1) -P (i + 1) and P (i) -P (i-1) to the first calculator 413. Output Here, as shown in Equation 2, if i is 1, the output P (i) -P (i + 1) of the fourth delay unit 409 is output to the first calculation unit 413, and If i is M, the outputs P (i) -P (i-1) of the sixth delay unit 411 are output to the first calculation unit 413. If i is not 1 or M, the outputs 2P (i) -P (i-1) -P (i + 1) of the fifth delay unit 410 are output to the first calculator 413. Here, the selector 412 may use a 3x1 multiplexer.

Thereafter, the first calculator 413 squares the value output from the selector 412, multiplies 1/2 or 1/6 according to the i value, and outputs the result to the summer 304. Here, if i is 1 or M, the value output from the selector 412 is multiplied by 1/2, and if i is not 1 or M, the value output from the selector 412 is 1 / m. Multiply by 6.

Here, the implementation of Equation 2 and FIGS. 3 and 4 is a simple implementation of an algorithm, and uses a method of separately calculating and selecting each case. In this case, by properly modifying Equation 2, the hardware implementation may be optimized.

In order to optimize the hardware implementation, Equation 2 may be modified as in Equation 3 below.

5 is a block diagram of an interference and noise power estimator according to the first embodiment of the present invention using Equation 3 above.

 Referring to FIG. 5, the first delay unit 501 delays and outputs input pilot subcarriers by one time. The second delay unit 502 delays and outputs pilot subcarriers from the first delay unit for a predetermined time, and the third delay unit 503 outputs the pilot subcarriers from the second delay unit for a predetermined time. Herein, the output from the first delay unit is assumed to be an i + 1th pilot subcarrier value, the output from the second delay unit is assumed to be an i-th pilot subcarrier value, and the output from the third delay unit is i Assume the -1th pilot subcarrier value.

Thereafter, the first adder 504 subtracts the output P (i + 1) of the first delay unit 501 from the output P (i) of the second delay unit 502 and then uses the fourth delay unit ( 506, and the second adder 505 calculates a difference between the pilot subcarrier values output from the second delay unit 502 and the third delay unit 503, and outputs the difference to the fifth delay unit 507. do.

The first selector 508 selects one of the output P (i) -P (i + 1) and 0 of the fourth delay unit 506 according to the i value representing the index of the subcarrier and adds the third adder ( 510). Here, as shown in Equation 3, if i is M, 0 is output to the third adder 510. If i is not M, P (i) -P (i + 1) 3 is output to the adder 510. The second selector 509 selects one of the outputs P (i) -P (i-1) and 0 of the fifth delay unit 507 and 0 according to the i value representing the index of the subcarrier and adds the third adder ( 510). Here, as shown in Equation 3, if i is 1, 0 is output to the third adder 510, and if i is not 1, P (i) -P (i-1) is removed. 3 is output to the adder 510. Here, the first selector 508 and the second selector 509 may use a 2 × 1 multiplexer, and select and output one of the two input signals.

Thereafter, the third adder 510 adds the output values of the first selector 508 and the second selector 509 and outputs the output values to the first calculator 511. Here, as shown in Equation 3, if i is 1, the output P (i) -P (i + 1) of the first selector 508 and the output 0 of the second selector 509 are zero. Is added and output to the first calculation unit 511. If i is M, output 0 of the first selection unit 508 and output P (i) -P (i-) of the second selection unit 509. 1) is added and output to the first calculation unit 511. In addition, when i is any other value, the third adder 510 is configured to output the output P (i) -P (i + 1) of the first selector 508 and the second selector 509. The outputs P (i) -P (i-1) are added and output to the first calculation unit 511.

Thereafter, the first calculator 511 squares the value output from the third adder 510, multiplies 1/2 or 1/6 according to the i value, and outputs the result to the summer 304. do. Here, if i is 1 or M, the value output from the third adder 510 is multiplied by 1/2, and if i is not 1 or M, the value is output from the third adder 510. Multiply by 1/6. In this case, it can be seen that the hardware structure is much simpler than the case of FIG. 4 in which hardware is implemented using Equation 2.

If the Equation 3 is partially modified again, the Equation 3 is transformed into the same Equation 4.

Here, it may be confirmed that the following Equation 5 is repeated, and Equation 4 may be modified to the same as Equation 6 using Equation 5.

FIG. 6 is a block diagram of an interference and noise power estimator using Equation 6 according to the second embodiment of the present invention.

Referring to FIG. 6, the first delay unit 601 delays the input pilot subcarriers by one time and outputs the result, and the second delay unit 602 outputs the pilot subcarriers from the first delay unit by a predetermined time. Delayed output. Here, it is assumed that the output from the first delay unit is an i + 1th pilot subcarrier value, and the output from the second delay unit is assumed to be an i-th pilot subcarrier value.

Thereafter, the first adder 603 subtracts the output P (i + 1) of the first delay unit 601 from the output P (i) of the second delay unit 602 and subtracts the result value T. After storing as (i), it outputs to the 3rd delay part 604.

The third delay unit 604 outputs the delayed output T (i) of the first adder 603 by one time, and the fourth delay unit 605 of the third delay unit 604 The output value is delayed for a predetermined time and output. Here, if the output from the third delay unit 604 is assumed to be T (i), the output from the second delay unit may be assumed to be T (i-1).

The first selector 606 selects one of the output T (i) and zero of the third delay unit 604 and outputs it to the second adder 608 according to an i value representing the index of the subcarrier. Here, as shown in Equation 6, if i is M, 0 is output to the second adder 608, and if i is not M, T (i) is transmitted to the second adder 608. Output The second selector 607 selects one of the output T (i-1) and 0 of the fourth delay unit 605 and outputs it to the second adder 608 according to the i value indicating the index of the subcarrier. . Here, as shown in Equation 6, if i is 1, 0 is output to the second adder 608, and if i is not 1, T (i-1) is added to the second adder 608. ) The first selector 606 and the second selector 607 may use a 2 × 1 multiplexer, and select and output one of the two input signals.

Thereafter, the second adder 608 subtracts the output values of the first selector 606 and the second selector 607 and outputs them to the first calculator 609. Here, as shown in Equation 6, if i is 1, the output T (i) of the first selector 606 and the output 0 of the second selector 607 are subtracted and the first calculator ( 609, and when i is M, the output 0 of the first selector 606 and the output T (i-1) of the second selector 607 are subtracted to the first calculator 609. Output Further, when i is any other value, the second adder 608 outputs T (i) of the first selector 606 and output T (i-1) of the second selector 607. Is subtracted and output to the first calculator 609.

Thereafter, the first calculator 609 squares the value output from the second adder 608 and multiplies 1/2 or 1/6 according to the value of i to output the result to the summer 304. do. Here, if i is 1 or M, the value output from the second adder 608 is multiplied by 1/2, and if i is not 1 or M, the value is output from the second adder 608. Multiply by 1/6. Here, FIG. 6 may share one adder in the entire calculation by storing the calculation for T (i).

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, the present invention optimizes the implementation of the DASS algorithm for measuring interference and noise in a mobile communication system, which simplifies the overall hardware structure, improves the computational speed, and furthermore has a kind of pipeline structure to operate. There is an advantage that can contribute to improvement.

Claims (24)

An apparatus for estimating signal to interference and noise ratio in a mobile communication system, A first calculating unit for calculating the difference between the i + 1th pilot subcarrier value and the i th pilot subcarrier value from the pilot subcarrier input first and generating an i th operation value T (i); A memory for storing the i th operation value T (i) and the i-1 th operation value T (i-1); Select one of the i th operation value T (i) and 0 according to the value of the pilot subcarrier index i, and select one of the i-1 th operation value T (i-1) and 0 according to the i value, and a second calculating unit calculating a difference between two selected values according to the i value; A third operation unit which squares a result value of the difference between the two values and multiplies the squared value by 1/2 or 1/6 according to the i value; And a fourth calculator configured to estimate interference and noise power of the signal by adding the pilot subcarrier multiplied by 1/2 or 1/6. The method of claim 1, wherein the second operation unit, When i is M, 0 is selected from T (i) and 0 and T (i-1) is selected from T (i-1) and 0, When i is 1, select T (i) of T (i) and 0 and select 0 of T (i-1) and 0, If i is any other value, select T (i) of T (i) and 0 and select T (i-1) of T (i-1) and 0, In this case, the M means the number of adjacent pilot subcarriers in the frequency domain. The method of claim 1, wherein the third operation unit, If i is 1 or M, multiply the result of square the difference between the two values and multiply by 1/2, If i has any other value, multiply the result of the difference between the two values and multiply by 1/6, In this case, the M means the number of adjacent pilot subcarriers in the frequency domain. The method of claim 1, A signal power estimator for estimating the total received signal power, A noise level estimator for estimating a noise level of a received signal; And a signal-to-interference and noise ratio (CINR) calculator for estimating a signal to interference and noise ratio (CINR) in the data interval. The method of claim 4, wherein And the noise level estimator estimates a signal noise level by using signal powers of some subcarriers in which no signal is loaded among all received subcarriers. The method of claim 4, wherein And a signal-to-interference and noise ratio (CINR) calculator calculates a difference between power of an entire received signal and interference and noise power and calculates a CINR based on the difference. An apparatus for estimating signal to interference and noise ratio in a mobile communication system, A first calculating unit configured to calculate a difference between an i-th pilot subcarrier value and an i + 1th pilot subcarrier value from a pilot subcarrier input first, and to generate a first operation value; A second calculator configured to calculate a difference between an i-th pilot subcarrier value and an i-1 th pilot subcarrier value from the first pilot subcarrier inputted to generate a second operation value; Select one of the first operation value and 0 according to the value of the pilot subcarrier index i, select one of the second operation value and 0 according to the value of i, and add the sum of the two values selected according to the value of i A third calculation unit for calculating, A fourth operation unit which squares a result of the sum of the two values and multiplies the squared value by 1/2 or 1/6 according to the i value; And a fifth calculator configured to estimate the interference and noise power of the signal by adding the pilot subcarrier multiplied by 1/2 or 1/6. The method of claim 7, wherein the third operation unit, When i is 1, a first operation value is selected from the first operation value and 0, and 0 is selected from the second operation value and 0, When i is M, 0 is selected from the first operation value and 0, and a second operation value is selected from the second operation value and 0, If i has any other value, select a first operation value among the first operation value and 0, and select a second operation value among the second operation value and 0, In this case, the M means the number of adjacent pilot subcarriers in the frequency domain. The method of claim 7, wherein the fourth operation unit, If i is 1 or M, multiply 1/2 by multiplying the result of the sum of the two values, If i has any other value, multiply the result of the sum of the two values and multiply by 1/6,  In this case, the M means the number of adjacent pilot subcarriers in the frequency domain. The method of claim 7, wherein A signal power estimator for estimating the total received signal power, A noise level estimator for estimating a noise level of a received signal; And a signal-to-interference and noise ratio (CINR) calculator for estimating a signal to interference and noise ratio (CINR) in the data interval. 11. The method of claim 10, And the noise level estimator estimates a signal noise level by using signal powers of some subcarriers in which no signal is loaded among all received subcarriers. 11. The method of claim 10, And a signal-to-interference and noise ratio (CINR) calculator calculates a difference between power of an entire received signal and interference and noise power and calculates a CINR based on the difference. A method for estimating signal to interference and noise ratio in a mobile communication system, Generating an i th operation value T (i) by calculating a difference between an i + 1 th pilot subcarrier value and an i th pilot subcarrier value from a pilot subcarrier input first; Select one of the i th operation value T (i) and 0 according to the value of the pilot subcarrier index i, and select one of the i-1 th operation value T (i-1) and 0 according to the i value, and calculating the difference between the two selected values based on the value of i, Squaring a result of the difference between the two values, multiplying the squared value by 1/2 or 1/6 according to the i value, and Estimating interference and noise power of the signal by adding the pilot subcarriers multiplied by 1/2 or 1/6. The method of claim 13, wherein the calculating of the difference between the two values comprises: When i is M, selecting 0 of T (i) and 0 and selecting T (i-1) of T (i-1) and 0; When i is 1, selecting T (i) among T (i) and 0 and selecting 0 out of T (i-1) and 0; If i is any other value, selecting T (i) of T (i) and 0 and selecting T (i-1) of T (i-1) and 0, Here, the M means the number of adjacent pilot subcarriers in the frequency domain. The method of claim 13, wherein the multiplying by 1/2 or 1/6 is performed. When i is 1 or M, multiplying the result of the difference between the two values and multiplying the squared value by 1/2; If i has any other value, square the resulting value of the difference between the two values, and multiplying the squared value by 1/6, Here, the M means the number of adjacent pilot subcarriers in the frequency domain. The method of claim 13, Estimating the total received signal power; Estimating the noise level of the received signal; And estimating a signal to interference and noise ratio (CINR) in the data interval. The method of claim 16, wherein estimating the noise level of the received signal comprises: And estimating a signal noise level by using signal powers of some subcarriers in which no signals are carried among all received subcarriers. The method of claim 16, wherein estimating the CINR comprises: A method for calculating the difference between the power of the entire received signal and the interference and noise power and calculating the CINR based on the difference. A method for estimating signal to interference and noise ratio in a mobile communication system, Generating a first operation value by calculating a difference between an i-th pilot subcarrier value and an i + 1th pilot subcarrier value from a pilot subcarrier input first; Generating a second operation value by calculating a difference between an i-th pilot subcarrier value and an i-1 th pilot subcarrier value from the first pilot subcarrier input; Select one of the first operation value and 0 according to the value of the pilot subcarrier index i, select one of the second operation value and 0 according to the value of i, and add the sum of the two values selected according to the value of i Calculation process, Squaring the resultant of the sum of the two values, multiplying the squared value by 1/2 or 1/6 according to the i value, and Estimating interference and noise power of the signal by adding the pilot subcarriers multiplied by 1/2 or 1/6. The method of claim 19, wherein the calculating of the sum of the two values comprises: When i is 1, selecting a first operation value among the first operation value and 0 and selecting 0 of the second operation value and 0; When i is M, selecting 0 of the first operation value and 0 and selecting a second operation value of the second operation value and 0; If i has other values, selecting a first operation value among the first operation value and 0 and selecting a second operation value among the second operation value and 0, Here, the M means the number of adjacent pilot subcarriers in the frequency domain. The method of claim 19, wherein the multiplying by 1/2 or 1/6 is performed. When i is 1 or M, multiplying the result of the sum of the two values and multiplying the squared value by 1/2; If i has any other value, square the result of the sum of the two values, and multiplying the squared value by 1/6,  Here, the M means the number of adjacent pilot subcarriers in the frequency domain. The method of claim 19, Estimating the total received signal power; Estimating the noise level of the received signal; And estimating a signal to interference and noise ratio (CINR) in the data interval. The method of claim 22, wherein estimating the noise level of the received signal comprises: And estimating a signal noise level by using signal powers of some subcarriers in which no signals are carried among all received subcarriers. The method of claim 22, wherein estimating the CINR comprises: A method for calculating the difference between the power of the entire received signal and the interference and noise power and calculating the CINR based on the difference.

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