KR100340198B1 - Narrowband Interference Canceller System and its Method in CDMA System - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a narrowband interference noise control apparatus and method in a code division multiple access system.

2. The technical problem to be solved by the invention

The present invention provides a code division multiple access system for controlling the introduced narrowband interference noise using digital autoregressive and least mean square (LMS) algorithms at baseband before despreading a received signal. An object of the present invention is to provide a narrowband interference noise control apparatus and a method thereof and a computer-readable recording medium recording a program for realizing the method.

3. Summary of Solution to Invention

An interference noise control apparatus applied to a code division multiple access system, comprising: analog-to-digital (A / D) conversion means for converting a received analog signal into a digital signal; Digital downconversion means (DDC) for converting the converted digital signal into a baseband signal; Adaptive interference noise control means for removing narrowband interference noise signal components from the converted baseband signal using an autoregressive and least squares average (LMS) algorithm and controlling a final output within a predetermined reference range; Digital upconverting means (DUC) for converting the digital signal from which the narrowband interference noise is removed into a digital upconverting frequency band signal; And said digital-to-analog (D / A) converting means for converting said converted digital upconverted frequency band signal into an analog signal.

4. Important uses of the invention

Used for interference noise control in code division multiple access system.

Description

Narrowband Interference Canceler System and Its Method in Code Division Multiple Access System

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a narrowband interference noise control apparatus and method therefor in a code division multiple access system, and in particular, digitally autoregressive and least square mean (LMS) at baseband before despreading a received signal. An apparatus and a method for controlling a narrowband interference noise in a code division multiple access system using an algorithm to remove / suppress the introduced narrowband interference noise as much as possible, and a computer readable recording medium recording a program for implementing the method. It is about.

Source technologies related to CDMA, which have been academically researched and used for military purposes, are now generalized and are commercialized to promote breakthroughs in information and communication. In addition, the domestic and overseas wireless communication and mobile communication field is developing CDMA system and PCS system by applying CDMA technology and applied to the mobile communication field, and is preparing for the development progress and early service of IMT-2000 system.

However, the spread spectrum communication method, which is a characteristic of CDMA technology, communicates with a transmission bandwidth (broadband signal) that is much wider than the bandwidth of the information signal to be transmitted. On the receiving side, if the same spreading signal is used to despread, the original information signal is extracted. In other words, the transmitter transmits information and reaches the receiver through the wireless transmission channel to reach the receiver because the noise signal or interference signal is included in the spread spectrum transmitted and reaches the receiver. Can be extracted.

The subscriber capacity of the CDMA system having such characteristics is expressed by the following Equation 1.

Where N is the number of subscribers acceptable, W / R is the processing gain, E _b / N _o is the ratio of noise and interference to signal energy, F is the frequency reuse efficiency, S is the cell split gain, and V is the transmission rate. Adjustment gain.

In the system using CDMA technology, the low data rate code is spread over a wide bandwidth, so that the same performance is maintained by using an error correcting code having a much lower coding rate than that of the FDMA or TDMA method. Required.

In fact, E _b / N _o in Equation 1 is changed by various propagation environment conditions such as multipath fading, moving speed, change of interference signal received from other systems, and the subscriber capacity is determined. It is a major variable, and this value should be minimized to increase subscriber capacity and the noise energy ratio should be reduced.

That is, although the system is very robust against the interference noise signal due to the characteristics of the CDMA technology using the spread spectrum communication method, it becomes difficult to transmit information when the interference noise signal becomes stronger than the spread signal to some extent. In order to avoid noise and interference in the wireless environment, there is a method of performing powerful power control. However, a new method needs to be introduced for an unexpected interference noise signal.

As a countermeasure against such an unexpected interference noise signal, it has been studied to control a narrowband interference noise signal using an adaptive signal processing algorithm before demodulation.

However, antenna diversity technology, interleaving technology, and equalizers as countermeasures for anticipated interference and unexpected interference noises operating in a wireless environment to increase subscriber capacity and improve system efficiency. (Equalization), Correlation, Frequency Hopping Technology, RAKE Receiver Technology, and Power Control Technology are adopted for each field, but there is a problem that the interference cancellation effect is not satisfactory.

In other words, the fading pattern is a combination and antenna diversity technique for processing different received signals, and a PASD method that estimates the signal strength by measuring a radio path signal of the past. Interleaving technology for distributed transmission of frame signals in time slots, Linear equalizer technology for correcting ISI between symbols of received signals, Nonlinear equalizer technology using DFE or MLSE algorithm, GSM Frequency hopping method used for overcoming fading, Rake receiver technology for overcoming delay distortion of received signal due to multipath fading, and Power control method Although it is being utilized, there is a problem that the subscriber capacity calculated using the CDMA source technology is not utilized.

The main cause of the problem is that it is impossible to completely eliminate the interference noise signal being mixed in the radio path and the noise signal generated in the system, and also because of the technical shortcomings used above.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a narrowband interference noise control apparatus for controlling narrowband interference noise in a code division multiple access system, a method thereof, and a computer recording a program for realizing the method. The purpose is to provide a recording medium that can be read by.

In other words, the present invention is a code division multiple access system for controlling the introduced narrowband interference noise signal using digital autoregressive and least squares average (LMS) algorithm in the baseband before despreading the received signal An object of the present invention is to provide a narrowband interference noise control apparatus and a method thereof and a computer-readable recording medium recording a program for realizing the method.

1 is an explanatory diagram for the generation of interference noise of a radio channel to which the present invention is applied.

2 is an explanatory diagram for a CDMA signal and a narrowband interference noise signal applied to the present invention.

3 is a block diagram of an embodiment of a narrowband interference noise control apparatus in a code division multiple access system according to the present invention;

4 is a diagram illustrating an embodiment of the adaptive interference noise controller of FIG. 3 according to the present invention;

Figure 5 is a configuration diagram of an embodiment of the first comparative analysis of Figure 4 according to the present invention.

Figure 6 is a block diagram of one embodiment of the interference noise controller of Figure 4 in accordance with the present invention.

Figure 7 is a configuration diagram of an embodiment of a second comparative analysis of Figure 4 according to the present invention.

8 is an explanatory diagram of an output level adjusting function compared to a reference level applied to the present invention.

9 is a block diagram of an embodiment of the adaptive interference cancellation filter of FIG. 6 according to the present invention;

10 is a flowchart illustrating a narrowband interference noise control method in a code division multiple access system according to the present invention.

* Explanation of symbols on the main parts of the drawing

300: analog to digital (A / D) converter 302: digital down converter (DDC)

304: adaptive interference noise control unit 306: digital upconverter (DUC)

308: digital-to-analog (D / A) converter 400: the first comparative analysis unit

402: interference noise controller 404: second comparison and analysis unit

In order to achieve the above object, the present invention provides an interference noise control apparatus applied to a code division multiple access system, comprising: analog-to-digital (A / D) conversion means for converting a received analog signal into a digital signal; Digital downconversion means (DDC) for converting the converted digital signal into a baseband signal; Adaptive interference noise control means for removing narrowband interference noise signal components from the converted baseband signal using an autoregressive and least squares average (LMS) algorithm and controlling a final output within a predetermined reference range; Digital upconverting means (DUC) for converting the digital signal from which the narrowband interference noise is removed into a digital upconverting frequency band signal; And the digital-to-analog (D / A) converting means for converting the converted digital upconverted frequency band signal into an analog signal.

The present invention provides an interference noise control method applied to a narrowband interference noise control apparatus in a code division multiple access system, comprising: a first step of converting a received analog signal into a digital signal; Converting the converted digital signal into a baseband signal; A third step of controlling narrowband interference noise signal components from the transformed baseband signal using an autoregressive and least squares average (LMS) algorithm and controlling a final output within a predetermined reference range; Converting the digital signal from which the narrowband interference noise has been removed into a digital upconversion frequency band signal; And a fifth step of converting the converted digital upconverted frequency band signal into an analog signal.

The present invention also provides a narrowband interference noise control device having a processor for controlling narrowband interference noise in a code division multiple access system, comprising: a first function of converting a received analog signal into a digital signal; A second function of converting the converted digital signal into a baseband signal; A third function for controlling narrowband interference noise signal components from the converted baseband signal using an autoregressive and least squares average (LMS) algorithm and controlling a final output within a predetermined reference range; A fourth function of converting the digital signal from which the narrowband interference noise is removed into a digital upconversion frequency band signal; And a computer readable recording medium having recorded thereon a program for realizing a fifth function of converting the converted digital upconverted frequency band signal into an analog signal.

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

1 is an explanatory diagram for the generation of interference noise of a radio channel to which the present invention is applied.

As the base stations and repeaters of other companies are in close proximity and the installed number thereof increases, the degree of interference noise increases and the quality of communication decreases.

2 is an explanatory diagram for a CDMA signal and a narrowband interference noise signal applied to the present invention.

If narrowband interference noise of a signal far greater than the power strength of the CDMA signal is applied within the bandwidth of a CDMA system using a wideband frequency, the narrowband interference noise signal serves to damage the CDMA signal. In the case of transmitting the information by applying the system, the transmission of the desired information becomes impossible.

The bandwidth of the narrowband interference noise signal is a signal having a bandwidth within 30% of the bandwidth of the CDMA information signal and is an interference noise signal that causes a fatal error in the transmission of the CDMA information signal.

3 is a configuration diagram of an apparatus for controlling narrowband interference noise in a code division multiple access system according to the present invention.

Digital signal processing is performed to select only the desired information from the received CDMA and PCS system's RF / IF signals with large narrowband interference noise to deliver only the desired information without interruption of information. Is as follows.

The narrowband interference noise control device includes an analog-to-digital (A / D) converter 300, a digital down converter (DDC) 302, an adaptive interference noise controller 304, and a digital up converter (DUC). Converter 306, and Digital-to-Analog (D / A) Converter 308.

The A / D converter 300 converts an RF / IF analog signal including CDMA information into a digital signal.

A digital down converter (DDC) 302 selects a desired FA from an A / D converted signal which is converted to an appropriate sampling rate in the IF band and quantized, and selects a digital signal of the selected IF band. Decimation is performed from 1/4 to 1/8 to convert to baseband and facilitate digital processing of oversampled signals.

The interference noise controller 304 performs autoregressive and adaptive algorithms to remove and suppress narrowband interference noise included in a signal input from the DDC 302.

Digital up converter (DUC) 306 is converted to baseband by digital downconverter 302 and decited to 1/4 to 1/8, and then narrowband interference noise by interference noise control unit 304. The removed or suppressed output signal is restored to the state before conversion by the digital down converter 302 and interpolated.

The D / A converter 308 converts the digital signal upconverted and interpolated by the digital upconverter 306 into an initially received analog RF / IF signal.

In more detail, it is as follows.

The A / D converter 300 divides a FA of a line divided / allocated into a constant frequency band according to the frequency allocation of the CDMA system at an intermediate frequency of the received RF / IF band for all bands or divided unit FAs. Convert analog signals to digital signals.

That is, the analog signal is sampled using a sample-and-hold amplifier according to a predetermined sampling rate, and the sampled data is quantized to a predetermined bit.

The analog IF power level input to the A / D converter 300 does not exceed the dynamic range of the A / D converter 300 so that a signal of a predetermined level or more is adjusted to a reference level in the RF / IF part to A / D converter 300. It must be delivered to the input of the D converter 300, and if the set reference level of the A / D converter is exceeded, overflow or saturation may occur, and A / D conversion may be performed. It will be recognized as a maximum or no constant level.

Therefore, level adjustment is required in the RF / IF part, and the level adjustment method uses Total AGC or FA unit AGC, and Total ALC or FA unit ALC method.

However, AGC aims to ensure that the received signal has the desired power level, and that stability problems must be kept within the dynamic range of the receiving device (A / D converter) by ensuring that the amplitude of the information signal is within a certain reference level. Consideration should be given.

In addition, AGC adjusts the gain to a certain amount regardless of the interference noise signal coming from the surroundings, and therefore, it is not possible to immediately respond to a change in the power level of the interference noise for interference noise such as a large amplitude impulse signal. Errors caused by sudden ingress or destruction cannot be handled.

For example, if only an information signal source comes in during system initialization, the AGC adjusts the gain based on the received information signal. At this time, if an interference noise signal having power equivalent to that of the original signal is suddenly introduced, the power of the entire signal is doubled, and thus the original signal is clipped during the A / D conversion of the signal, resulting in quantization error. ) Will occur.

In addition, when the receiver receives strong narrowband interference noise, such as impulse interference noise, to the wireless transmission line, the performance of the system may be degraded. Therefore, the receiver may not meet the originally designed system performance. The operation of the receiver becomes unstable and the transmission data cannot be detected.

Even more problematic is that large-band interference noise can not be adaptively eliminated because it is impossible to predict when and at which frequency band narrow-band interference noise will be applied. Adjust the level carefully so that it becomes the input of the A / D converter by adjusting the level to the appropriate level.

The interference noise controller 304 is composed of a CPU, an MPU or a Digital Signaling Processor (DSP), and various peripheral circuits. The interference noise control unit 304 performs autoregressive and real-time adaptation of the received narrowband interference noise signal. Digital signal processing technique using Real Time Adaptive algorithm removes and suppresses narrowband interference noise signal components included in CDMA information signals.

The functions of the digital up-converter 306 and the D / A converter 308 perform the inverse functions of the digital down-converter 302 and the A / D converter 300, and the sampling rate of the D / A converter 308. ) Is set higher than the sampling rate of the A / D converter 300 to improve conversion efficiency.

In this case, the A / D converter 300 converts an analog signal to a digital signal for a divided unit FA by converting a series of FAs divided / allocated into a constant frequency band according to the frequency allocation rule of the CDMA system to a narrow band. In case of eliminating and suppressing the interference noise signal component, in order to convert the processed digital signal into the original analog signal, the FA sequence according to the frequency allocation is added by adding an ADD or MUX function for synthesizing the processed signal in each FA unit. Must be rearranged.

The A / D converter 300, the DDC 302, the interference noise controller 304, the DUC 306, and the D / A converter 308 to perform unique functions as described above are applied to each functional single component. It can be developed and integrated into FPGA or ASIC by integrating some or all of them.

In addition, the light and short functional module can be applied to various fields and can be applied to all systems to which future CDMA technology is applied as well as existing CDMA and PCS systems.

4 is a diagram illustrating an embodiment of the adaptive interference noise controller of FIG. 3 according to the present invention.

The adaptive interference noise controller 304 includes a first comparison analyzer 400 (FIG. 5), an interference noise controller 402 (FIG. 7), and a second comparison analyzer 404 (FIG. 6). The description will be made with reference to FIGS. 5 to 7.

5 is a configuration diagram of an embodiment of the first comparative analysis of FIG. 4 according to the present invention.

The first comparison analyzer 400 includes an absolute value and average value calculator 500, a signal detection and control signal generator 502, and main functions and functions are performed by a CPU, an MPU, or a digital signal processor (DSP). It is centralized at, and the behavior is as follows.

In the digital output signals of the A / D converter 300 and the DDC 302, the absolute value calculator 500 obtains the absolute value of the digitally converted signal. The reason for obtaining the absolute value is that the output values of the A / D converter 300 and the DDC 302 should be within a constant amplitude level rather than having a constant power level. For example, if the square value is used to have a constant power level, it is advantageous to use an absolute value since a value greater than 1 becomes larger and a value smaller than 1 becomes smaller.

The average calculator 500 is located at the rear end of the absolute value calculator 500, sets a predetermined window for the output of the absolute value calculator, obtains a peak value from the samples in each window, and then obtains a predetermined number of windows in each window. Average the peaks. The reason for obtaining the peak value is to ensure a stable output that operates within a constant amplitude level, and is for general information processing for adjusting the final output level of the narrowband interference noise control device. The size of the window is adjustable and the average of the peaks is intended to be insensitive to noise.

The signal detection and control signal generator 502 detects the level of the output of the average calculator 500 to adjust the final output level of the narrowband interference noise control device, and stores a reference level, an upper limit threshold, and a lower limit threshold previously stored therein. After analyzing the predicted value which needs to adjust the current gain and the final output level in comparison with the maximum value and the minimum value, the output of the average value calculator 500 sensed through the first output is sent to the interference noise controller 402. 2 outputs a control signal for adjusting the final output level of the narrowband interference noise control device according to the comparison / analysis result and outputs it to the second comparison analysis unit (404).

6 is a block diagram of an embodiment of the interference noise controller of FIG. 4 according to the present invention. The interference noise controller 402 includes a combiner 606, 608, a divider 610, 612, an adaptive interference cancellation filter 602, And LMS algorithm 604.

The adaptive algorithm applied to the interference noise controller 402 is an adaptive weighting factor function as an algorithm for real-time adapting the adaptive interference cancellation filter 602.

The adaptive weighting coefficient function uses a generalized and well-established least mean square (LMS) algorithm, which minimizes the estimated error signal of the output, eliminating interference noise signals and outputting only the desired information signal.

The main functions of the first combiner 606 are the input signal Z _k of the interference noise controller 402 (that is, the output signal of the first comparison analyzer) and the estimated output value of the adaptive interference cancellation filter 602 ( And combines the backward feedback signal of) to generate the output error value ε _k .

The output error value of the first combiner 606 is adapted to be the minimum mean square value by the LMS algorithm. The second coupler 608 also estimates the output error value ε _k of the first coupler 606 ( ) And the output estimate of the adaptive interference cancellation filter ( Of the feedback feedback signal of the ).

In addition, the output error value ε _k of the first combiner 606 serves as a component of the adaptive transfer function [ρ (ε _k )] of the LMS algorithm 604, and the adaptive weighting coefficient of the adaptive interference cancellation filter By inducing, the value of the adaptive interference cancellation filter 602 is adapted at each sampling instant.

Accordingly, the output of the adaptive interference cancellation filter is adaptively changed and output at every sampling moment, and the output value is backward feedback coupled to the first combiner 606 to be adaptively operated to minimize the minimum mean square value.

The detailed design of the adaptive noise canceling filter (ANF) 602 in the interference noise controller 402 can be described in detail in the design method of the adaptive interference canceling filter (see FIG. 9), and the input signal of the adaptive interference canceling filter is shown. time adaptive weighting coefficients to the delayed signal functions by groups of time delay of T _c size (a _{i, k)} are finite impulse response filter which is multiplied by (FIR filter: finite impulse response) or an infinite impulse response filter (IIR: Infinite impulse response filter The model is modeled through the digital adaptive filter in the form of), and the entire modeled output is added and output. The adaptive weighting coefficient algorithm is represented by Equation 2 below.

Where a _k is an adaptive weighting factor function, μ is an adaptive weighting factor, γ _k is an input power estimation function of an adaptive interference cancellation filter, ρ (ε _k ) is an adaptive transfer function, and X _k is an estimated input of an adaptive interference cancellation filter. It is a function.

The adaptive weighting coefficient function of Equation (2) is corrected and supplemented at the instant of sampling, and the adaptive weighting coefficient is added to reduce the difference (error) between the received signal and the output value. To satisfy the LMS algorithm. That is, the purpose of the weight function is to minimize the final output error and minimize the mean square value of the error.

In addition, the input signal of the adaptive interference cancellation filter 602 is a finite impulse response (FIR filter) or infinite impulse response filter (TIR) multiplied by the adaptive weighting coefficient of the adaptive interference cancellation filter with a time delay of T _c size. IIR Filter: This is modeled through digital adaptive filter in the form of Infinite Impulse Response. As such, the output signal via the interference noise controller of FIG. 6 including the adaptive interference cancellation filter 602 and the adaptive algorithm removes and suppresses the narrowband interference noise signal component received by the above-described process. Output only the signal.

7 is a diagram illustrating an embodiment of a second comparative analysis unit of FIG. 4 according to the present invention.

The second comparison analyzer 404 includes a gain analyzer 700 and a gain controller 702, and main functions and functions are centralized in a CPU, an MPU, or a digital signal processor (DSP). The detailed functional operation of 404 is as follows.

The input of the gain analyzer 700 is composed of the output of the interference noise controller of FIG. 6 and the output of the signal detection and control signal generator 502 of the first comparison analyzer 400.

The function and operation of the gain analyzer 600 and the gain regulator 602 are not clearly separated, but mutual functions and operations are mixed, and the main functions are controls for gain adjustment of the first comparison analyzer 400. Gain is adjusted to output an output value according to the final output level set in FIG. 8 using the signal and the output of the interference noise controller 402.

In other words, the signal level between the upper limit threshold and the maximum value is lowered below the upper limit threshold, and the signal level between the lower limit threshold and the minimum value is adjusted to the upper limit of the gain above the lower limit threshold, and the final output level is shown in FIG. Adjust the gain appropriately so that it exists within the upper and lower thresholds with respect to the reference level.

8 is an explanatory diagram of an output level adjustment function compared to a reference level applied to the present invention, and shows a final output model of a narrowband interference noise control device.

The final output of the narrowband interference noise control device is gain adjusted to output the output value according to the final output level set in the CDMA system to which it is mounted. In other words, for the signal level between the upper and lower thresholds, the gain is lowered below the upper threshold.The signal level between the lower and minimum thresholds adjusts the upper and lower gains above the lower threshold and adjusts the final output level to the reference level. Adjust the gain appropriately so that it is centered and within the upper and lower thresholds.

A / D converter when an input signal level is input that exceeds the maximum value (A / D conversion dynamic range of the A / D converter) set by the CDMA system in which the adaptive narrowband interference noise control device is mounted. This causes saturation errors, which tends to degrade the performance of the entire system.

Therefore, in order to stabilize the system, the overflow level of the input signal needs to be adjusted so that the level of the signal may exist within the dynamic range of the A / D converter.

In general, the signal level in the CDMA system can be set to the system output level or system connection level in each connection point, module unit, unit unit, and also can be variously adjusted according to the mounting position of the present invention.

As an example, the output signal level based on the connection point of the LNA module of the CDMA receiving system can be modeled as follows. That is, the value of +/- 40dBm is set as the upper limit maximum value and the lower limit minimum value based on the reference level 0dBm, and the value exceeding this range is processed by the overflow (Overflow) to perform the gain control.

In addition, the output threshold level of the system is set to +/- 20dBm based on the reference level (0dBm) so that each value has a dynamic output range of 40dBm using the upper and lower thresholds. Therefore, when the signal output level exists between the maximum value and the upper limit threshold and between the minimum value and the lower limit threshold, gain control is performed so that the level of the output signal is within the dynamic output range.

9 is a diagram illustrating an embodiment of the adaptive interference cancellation filter of FIG. 6 according to the present invention.

As a detailed design of the adaptive noise canceling filter (ANF) 602 of the interference noise controller 402, a description thereof has already been made with reference to FIG. 6.

Adaptive Noise Filter (ANF) 602 is comprised of combiners 900, 902, time delay 904, and multiple multipliers 906.

The third combiner 900 is a combiner that performs the same function as the second combiner 608 of FIG. 6, and estimates the output error value ε _k ( ) And Output Estimation of Adaptive Interference Cancellation Filter The feedback feedback of the ).

Input signal of adaptive interference cancellation filter ) Is a finite impulse response (FIR filter) produced by multiplying the time-delayed signal by the T _c sized time delay with the adaptive weighting factor (a _{i, k} ) produced by the adaptive transfer function of the LMS algorithm. Alternatively, the digital adaptive filter may be configured as an infinite impulse response filter (IIR), and the fourth combiner 902 may add the entirety of the output modeled by the digital adaptive filter to the third combiner 900. Backward feedback output, and the adaptive weighting coefficient algorithm is shown in Equation (2).

10 is a flowchart illustrating a narrowband interference noise control method in a code division multiple access system according to the present invention.

Since the detailed description has already been made in the relevant part, the overall method will be described here (see FIGS. 3 to 9).

Receives an RF / IF analog signal containing CDMA information and converts it into a digital signal (1000), selects a desired FA from an A / D converted signal converted to an appropriate sampling rate in the IF band and quantized. In operation 1002, the digital signal of the selected IF band is converted into a baseband and decimated from 1/4 to 1/8 in order to facilitate digital processing of the oversampled signal.

Subsequently, autoregressive and adaptive algorithms (LMS algorithms) are applied to remove and suppress narrowband interference noise, and control the final output within a predetermined reference range (1004).

Then, the baseband is converted to decimation from 1/4 to 1/8, and the narrowband interference noise is removed or suppressed to the original RF / IF signal and interpolated. Later 1006 converts the upconverted digital signal to an initially received analog RF / IF signal.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by.

The present invention as described above has the following excellent effects.

First, in a system using a CDMA technology, a narrowband interference noise signal introduced from the outside can be removed and suppressed using an adaptive algorithm to smoothly transmit a CDMA information signal.

Secondly, it maintains a constant level of output signal by eliminating and suppressing a narrow level of narrowband interference noise, thereby improving the stability and efficiency of the system.

Third, the interference signal is removed before despreading, which increases efficiency and enables the centralization of various scattered interference noise canceling functions.

Fourth, it is possible to prevent an error due to the rapid change of the power level due to the input of a large level of sudden interference noise signal and to prevent the failure of the system by the input of a large power signal.

Fifth, it is possible to prevent the call disconnection of the subscriber caused by the narrowband interference noise signal.

Sixth, proper gain control for stabilization of the output level is possible for irregularly changing received signals.

Seventh, the steady state convergence time can be shortened by adjusting the values of the adaptive coefficients by the adaptive algorithm and autoregression.

Eighth, after reaching a steady state, the signal can be traced in detail and quickly responded to sudden power changes in the received signal.

Ninth, the interference caused by the narrowband noise can be prevented by removing the narrowband interference noise mixed in the original transmission signal in the frequency band for transmitting a specific information signal.

The tenth step is the development of the first stage of SDR (Software Defined Radio) technology, which can be applied as a basic technology of the future wireless communication system.

Eleventh, it is possible to apply to a system and a repeater system by developing a module for removing a narrowband interference noise signal component by one core module.

Twelfth, it can be applied to a terminal by light and short reduction of the module.

Thirteenth, due to the CDMA technical characteristics, it is possible to use a CDMA frequency by overlapping with a narrowband frequency that is being used, and to improve frequency utilization efficiency.

Fourteenth, it is possible to apply to cellular and PCS system, IMT-2000 system and CDMA technology that are currently commercially available.

Claims (10)

An interference noise control apparatus applied to a code division multiple access system, Analog-to-digital (A / D) conversion means for converting the received analog signal into a digital signal; Digital downconversion means (DDC) for converting the converted digital signal into a baseband signal; Adaptive interference noise control means for removing narrowband interference noise signal components from the converted baseband signal using an autoregressive and least squares average (LMS) algorithm and controlling a final output within a predetermined reference range; Digital upconverting means (DUC) for converting the digital signal from which the narrowband interference noise is removed into a digital upconverting frequency band signal; And Digital-to-analog (D / A) converting means for converting the converted digital upconverted frequency band signal into an analog signal Narrowband interference noise control device comprising a. The method of claim 1, The adaptive interference noise control means, First average analyzing means for generating a control signal by obtaining an average value of the digital output signal of the digital down-converting means and comparing the predetermined reference values with respect to the output of the digital-to-analog (D / A) converting means; Interference noise control means for controlling narrowband interference noise signal components from the transformed baseband signal using an autoregressive and least squares average (LMS) algorithm; And Second comparative analysis means for adjusting the output of the interference noise removing means according to the control signal of the first comparative analysis means Narrowband interference noise control device comprising a. The method of claim 2, The first comparative analysis means, An absolute value and an average value calculating means for obtaining an absolute value of the digital output signal of the digital downconverting means, setting a predetermined window to obtain a peak value among sampling values, and calculating an average of the peak values obtained in each window; And After sensing the output of the absolute value and the average value calculation unit and comparing it with predetermined reference values for the output of the digital-to-analog (D / A) converting means, the output of the detected absolute value and average value calculation unit is the interference Signal detection and control signal generation means for transmitting to the noise control means, and generating and transmitting the control signal to the second comparison analysis means according to the comparison result. Narrowband interference noise control device comprising a. The method according to any one of claims 1 to 3, The interference noise control means, First combining means for obtaining an error signal between an output signal of the first comparison analysis means and an estimated output value of the adaptive interference cancellation filtering means; Second combining means for combining the estimated value of the error signal of the first combining means with the estimated output value of the adaptive interference cancellation filtering means to generate an input value of the adaptive interference cancellation filtering means; Adaptive weighting coefficient generating means for generating an adaptive weighting coefficient function by square-averaging the estimated value of the error signal of the first combining means; And The adaptive interference elimination filtering means for eliminating interference noise by combining the generated adaptive weighting factor after delaying the output of the second combining means Narrowband interference noise control device comprising a. The method of claim 4, wherein The adaptive weighting coefficient function generating means, An apparatus for controlling narrowband interference noise, which generates an adaptive weighting coefficient function using a least mean square (LMS) algorithm. An interference noise control method applied to a narrowband interference noise control apparatus in a code division multiple access system, A first step of converting the received analog signal into a digital signal; Converting the converted digital signal into a baseband signal; A third step of controlling narrowband interference noise signal components from the transformed baseband signal using an autoregressive and least squares average (LMS) algorithm and controlling a final output within a predetermined reference range; Converting the digital signal from which the narrowband interference noise has been removed into a digital upconversion frequency band signal; And A fifth step of converting the converted digital up-converted frequency band signal into an analog signal Narrowband interference noise control method comprising a. The method of claim 6, The third step, A sixth step of obtaining an average value for the baseband digital signal of the second step and then generating a control signal by comparing the predetermined values with respect to a final output; A seventh step of controlling narrowband interference noise signal components from the converted baseband digital signal using an autoregressive and least squares average (LMS) algorithm; An eighth step of adjusting the output of the seventh step according to the control signal of the sixth step Narrowband interference noise control method comprising a. The method of claim 7, wherein The sixth step, A ninth step of obtaining an absolute value of the baseband digital signal, setting a predetermined window to obtain a peak value among sampling values, and obtaining an average of peak values obtained from each window; And A tenth step of sensing the output of the ninth step and generating the control signal according to a comparison result with predetermined reference values for the final output stored therein; Narrowband interference noise control method comprising a. The method according to any one of claims 6 to 8, The seventh step, The adaptive weighting coefficient function is generated by square-averaging the error signal between the output signal of the sixth step and the estimated value of the final output. The adaptive weighting coefficient function is delayed by combining the time-delayed error signal with the estimated value of the final output. Narrow band interference noise control method characterized in that by repeatedly performing the process of multiplying to remove / suppress the narrow band interference noise. In a narrowband interference noise control device having a processor for controlling narrowband interference noise in a code division multiple access system, A first function of converting the received analog signal into a digital signal; A second function of converting the converted digital signal into a baseband signal; A third function for controlling narrowband interference noise signal components from the converted baseband signal using an autoregressive and least squares average (LMS) algorithm and controlling a final output within a predetermined reference range; A fourth function of converting the digital signal from which the narrowband interference noise is removed into a digital upconversion frequency band signal; And A fifth function of converting the converted digital upconversion frequency band signal into an analog signal A computer-readable recording medium having recorded thereon a program for realizing this.