KR102052103B1 - Method and device for designing non linear block using adaptive blanker based on binary phase shift keying modulation system - Google Patents

Abstract

The present invention provides a method for estimating a narrowband middleton parameter of impulse noise using a signal received for a predetermined time, calculating a threshold value using the estimated narrowband middleton parameter, and a signal value provided from an SNR meter. Operating a first blanker to remove noise from the received signal by comparing the absolute value of the received signal at an arbitrary time and the threshold when the threshold value is smaller than the threshold value, and the absolute value of the received signal and the A non-linear noise cancellation method using an adaptive blanker based on a PPS modulation system comprising operating a second blanker to remove noise from the received signal by comparing a sum of a threshold value and a signal value.

Description

Nonlinear Noise Reduction Apparatus and Method Using Adaptive Blanker Based on JPPS Modulation System {METHOD AND DEVICE FOR DESIGNING NON LINEAR BLOCK USING ADAPTIVE BLANKER BASED ON BINARY PHASE SHIFT KEYING MODULATION SYSTEM}

The present invention relates to a BPSK modulation system. More particularly, the present invention relates to a BPSK modulation system based adaptive blanker that can remove noise by adaptively using two blankers based on a noise signal value and a threshold value. A nonlinear noise canceling apparatus and method are disclosed.

Recently, due to the increase of electronic devices, radio interference of wireless devices due to impulse noise has increased. In order to improve the performance deterioration of the wireless device against such impulse noise, a nonlinear block has been proposed to increase the output value if it is Gaussian noise and to reduce the value if the impulse noise is large.

At this time, the method of designing the nonlinear block is performed by a method of determining the weight by a blanker. Prior art US 2011-0158369 (published May 30, 2011) discloses a method of reducing the effects of impulsive noise while using respective weights in an OFDM system.

However, in providing a method of designing a nonlinear block, the threshold of the blanker for determining the respective weights is not formulated. In addition, no signal sampling is used and the overall receiver complexity is high.

US 2011-0158369 (published May 30, 2011) discloses a blanking technique for impulse noise mitigation in an SNR-based wireless network.

An embodiment of the present invention provides two blanker structures by using parameter estimates A and Γ of a narrowband middleton model calculated from signals received for a predetermined time in advance, and a signal S obtained from a signal-to-noise ratio meter of a receiver. An apparatus and method for removing a nonlinear noise using an adaptive blanker based on a PPS modulation system which can minimize BER performance deterioration due to impulse noise using a nonlinear block having a nonlinear block can be provided. However, the technical problem to be achieved by the present embodiment is not limited to the technical problem as described above, and other technical problems may exist.

According to an aspect of the present invention, there is provided a method of estimating a narrowband middleton parameter of impulse noise using a signal received for a predetermined time, calculating a threshold using the estimated narrowband middleton parameter, and an SNR meter. Operating a first blanker to remove noise from the received signal by comparing the absolute value of the received signal received at any point and the threshold when the signal value received from the threshold value is smaller than the threshold value; And a second blanker for removing noise from the received signal by comparing an absolute value of the signal with a sum of the threshold value and the signal value, and providing a nonlinear noise canceling method using an adaptive blanker based on a PPS modulation system. .

,

이고, m은 0 또는 1이며, A와 Γ는 협대역 미들턴 파라미터)에 의해 산출되는 것을 특징으로 한다.In the present invention, the threshold is the following equation (

,

, M is 0 or 1, and A and Γ are narrow band middleton parameters).

In the present invention, the operating of the first blanker may include outputting “O” when an absolute value of the received signal is greater than or less than a threshold z, and outputting the received signal otherwise. .

In the present invention, the operating of the second blanker may include outputting a very small positive number close to zero when the sum of the threshold and the signal value is greater than or less than the absolute value of the received signal; It is characterized by outputting.

According to another aspect of the present invention, a parameter estimator estimates a narrowband middleton parameter of impulse noise using a signal received for a predetermined time, and calculates a threshold value using the estimated narrowband middleton parameter before receiving the signal. A control unit providing a switching signal by comparing the measured signal-to-noise ratio signal value based on the received signal and the threshold value, and a first noise removing noise from the received signal by comparing the absolute magnitude value and the threshold value of the received signal. A blanker, a second blanker which removes noise from the received signal by comparing an absolute magnitude value of the received signal with a sum of the threshold value and a signal value, and switching according to the switching signal to convert the received signal into the second signal. ＫPS modulation system based adaptation comprising a switching unit for applying to one blanker or a second blanker Provides a non-linear noise reduction apparatus using a blanker.

According to any one of the above-described means for solving the problem of the present invention, it is possible to lower the BER when using less blanker-based nonlinear blocks than the BER using only the conventional receiver in the impulse noise environment, and obtain a good BER even at a low signal-to-noise ratio Can be.

1 is a block diagram illustrating a BPSK modulation system to which a nonlinear noise processing device according to an embodiment of the present invention is applied;
2 is a flowchart illustrating a process of processing a received signal using a nonlinear noise canceller according to an embodiment of the present invention;
Figure 3 is a graph showing the results of the experiment using the PSPS modulation system to which the nonlinear noise canceller according to an embodiment of the present invention.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims.

In describing the embodiments of the present disclosure, when it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present disclosure, the detailed description thereof will be omitted. Terms to be described below are terms defined in consideration of functions in the embodiments of the present invention, and may vary according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a block diagram illustrating a BPSK modulation system to which a nonlinear noise processing device according to an embodiment of the present invention is applied.

As shown therein, the BPSK modulation system includes a receiver 110 having an SNR measurer 112, a parameter estimator 120, a controller 130, a nonlinear noise processor 140, a sampler 150, and the like. It may include.

The reception device 110 may extract a signal-to-noise value (hereinafter, referred to as a signal value) through the SNR measuring unit 112 based on a previously measured reception signal.

In addition, the receiver 110 may demodulate a signal output through the sampler 150 and output a demodulated signal.

The parameter estimator 120 may estimate the narrowband middleton parameter of the impulse noise from previously measured received signals.

The signal value output from the SNR measuring unit 112 of the receiving device 110 and the narrowband middleton parameter estimated from the parameter estimator 120 are provided to the controller 130.

The controller 130 calculates the threshold z by applying the narrowband middleton parameter to Equation 1 below, and outputs a switching signal to the nonlinear noise processing apparatus 140 by comparing the calculated threshold with a signal value. have.

이고, m은 0 또는 1을 가진다. 또한, A와 Γ는 협대역 미들턴 파라미터를 의미한다.In Equation 1 above,

And m has 0 or 1. Also, A and Γ refer to narrowband middleton parameters.

When the signal value is smaller than the threshold z, the controller 130 outputs a first switching signal to the switching unit 142 for applying the received signal, which is applied at a predetermined time, to the first blanker 144. If the value is larger than the threshold value, the second switching signal for applying the received signal to the second blanker 146 may be output to the switching unit 142.

The switching unit 142 may operate according to the first and second switching signals of the controller 130 to apply the received signal to the first blanker 144 or the second blanker 144.

The first blanker 144 may operate based on Equation 2 below, that is, the noise is received from the received signal x _k through a comparison between the absolute magnitude value of the received signal x _k and the threshold z. Can be removed.

Referring to the first blanker 144 based on Equation 2, when the absolute value of the received signal x _k is greater than or less than the threshold z, “O” is output. Outputs a received signal x _k .

Meanwhile, the second blanker 146 may operate based on Equation 3 below, that is, the sum of the threshold z and the signal value S and the absolute value of the received signal x _k are received. Noise can be removed from the signal x _k .

In Equation 3 above, ε is a very small positive number near zero.

Referring to the second blanker 146 based on Equation 2, if the sum of the threshold z and the signal value S is greater than or less than the absolute value of the received signal x _k , it is zero. It outputs a very small positive integer "ε", otherwise it outputs the received signal x _k .

The signal output by the first blanker 144 or the second blanker 146 may be input to the sampler 150.

The sampler 150 over-samples the signals input from the first blanker 144 or the second blanker 146 to the receiving device 110 compared to the sampling of the symbols.

The receiving device 110 may demodulate the oversampled signal and output a demodulated signal.

The operation of the BPSK modulation system having the above configuration will be described with reference to FIG.

2 is a flowchart illustrating a process of processing a received signal using a nonlinear noise canceller according to an exemplary embodiment of the present invention.

The start of an embodiment of the present invention (step 200) estimates narrowband middleton parameters A and Γ of impulse noise from the previously measured received signals (step 202) and calculates the calculated (A, Γ) estimates. Is substituted into Equation 1 above to calculate the threshold z (step 204).

Then, after comparing the threshold value z with the signal S value obtained from the SNR meter 112 of the reception apparatus 110 (step 206), for the received signal x _k for the time point k, S is equal to or greater than z. If small, the first blanker 144 operating as Equation 2 above is executed (step 208), and if the symbol S is greater than z, then the second blanker 146 having the function of Equation 3 above is Is performed (step 210). The sampler 150 samples and adds the signals input from the selected blanker of the first blanker 144 or the second blanker 146 with N over samplings compared to the sampling of the symbols (step 210). .

The output value of the sampler 150 is input to the receiving device 110, and the receiving device 110 demodulates the output value output from the sampler 150 to output a demodulation signal (step 212). Since the subsequent operation is the same as the operation of the general receiving apparatus, it will be omitted.

As described above, in the present invention, selecting one of the two blankers according to the comparison result of the signal value S and z output from the SNR measuring unit 112 is called an adaptive blanker.

Experimental effects according to an embodiment of the present invention can be shown through computer simulations of the BER of the BPSK modulation system. When A is 035, Γ is 0.0005, and the sampling number N is 10, the present invention is improved as shown in FIG. 3. As shown in FIG. 3, it can be seen that the BER using the adaptive blanker based nonlinear noise processing device 140 is much lower than the BER using only the conventional receiving device 110 in the impulse noise environment. In particular, a good BER can be obtained even at a signal-to-noise ratio lower than 0dB.

According to the embodiment of the present invention, the BER in the case of using the adaptive blanker-based nonlinear block can be lowered than the BER using only the receiver in the impulse noise environment, and a good BER can be obtained even at a low signal-to-noise ratio.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

110: receiving device 112: SNR meter
120: parameter estimation unit 130: control unit
140: nonlinear noise canceller 142: switching unit
144: First Blanker 146: Second Blanker
150: sampler

Claims (8)

Estimating a narrowband middleton parameter of impulse noise using a signal received for a predetermined time;
Calculating a threshold value using the estimated narrowband middleton parameter;
Operating a first blanker to remove noise from the received signal by comparing the absolute value of the received signal at any time and the threshold when the signal value received from the SNR meter is smaller than the threshold value;
Operating a second blanker to remove noise from the received signal by comparing an absolute value of the received signal with a sum of the threshold value and the signal value;
Nonlinear Noise Reduction Method Using Adaptive Blanker Based on JPPS Modulation System.
The method of claim 1,
The threshold is the following equation (

,

M is 0 or 1, and A and Γ are calculated by a narrow band middleton parameter).
Nonlinear Noise Reduction Method Using Adaptive Blanker Based on JPPS Modulation System.

The method of claim 1,
Operating the first blanker,
If the absolute value of the received signal is greater than or less than the threshold z, "O" is output, otherwise the received signal is output.
Nonlinear Noise Reduction Method Using Adaptive Blanker Based on JPPS Modulation System.
The method of claim 1,
Operating the second blanker,
When the sum of the threshold and the signal value is greater than or less than the absolute value of the received signal, a very small positive number close to zero is output, otherwise the received signal is output.
Nonlinear Noise Reduction Method Using Adaptive Blanker Based on JPPS Modulation System.
A parameter estimator for estimating a narrowband middleton parameter of impulse noise using a signal received for a predetermined time;
A controller which calculates a threshold value using the estimated narrowband middleton parameter and provides a switching signal by comparing a signal-to-noise ratio signal value measured based on a previously received signal and the threshold value;
A first blanker for removing noise from the received signal by comparing between an absolute magnitude value and a threshold of the received signal received at an arbitrary time point;
A second blanker for removing noise from the received signal by comparing an absolute magnitude value of the received signal with a sum of the threshold value and the signal value;
And a switching unit configured to switch according to the switching signal to apply the received signal to the first blanker or the second blanker.
Nonlinear Noise Reduction Device Using Adaptive Blanker Based on JPPS Modulation System.
The method of claim 5,
The control unit is a mathematical formula (

,

M is 0 or 1, and A and Γ are calculated by a narrow band middleton parameter).
Nonlinear Noise Reduction Device Using Adaptive Blanker Based on JPPS Modulation System.
The method of claim 5,
The first blanker,
If the absolute value of the received signal is greater than or less than the threshold value "O", otherwise output the received signal, characterized in that
Nonlinear Noise Reduction Device Using Adaptive Blanker Based on JPPS Modulation System.
The method of claim 5,
The second blanker,
When the sum of the threshold and the signal value is greater than or less than the absolute value of the received signal, a very small positive number close to zero is output, otherwise the received signal is output.
Nonlinear Noise Reduction Device Using Adaptive Blanker Based on JPPS Modulation System.

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