CN101136654B - A method and device for eliminating narrowband interference in a communication system - Google Patents

Abstract

The present invention provides a method and device for eliminating narrow-band interference in a communication system, wherein the method includes the following steps: Step A: After performing windowing transformation and fast Fourier transform (FFT) on the sampling signal of the first length including N points, respectively Calculate the signal energy of each point, and accumulate the signal energy of each point separately; Step B: When the accumulation reaches the predetermined time, compare each accumulated value with the preset target value, and record the accumulated value greater than the target value The signal position information corresponding to the numerical value; step C: adjust the signal amplitude of the position to be consistent with the target value, and then output it after inverse fast Fourier transform IFFT. The invention can process real-time interference, has small calculation amount, and reduces the occupation of hardware resources.

Description

A method and device for eliminating narrowband interference in a communication system

technical field

The invention relates to the technical field of communication, in particular to a method and device for eliminating narrowband interference in a communication system.

Background technique

In the communication system, the spread spectrum communication system is more and more popular in today's world, and the spread spectrum communication technology is becoming more and more mature. The inherent spread spectrum gain of spread spectrum technology makes the spread spectrum communication system have stronger anti-interference ability than other communication systems. When the bandwidth of the interference signal is smaller than the bandwidth of the spreading code itself, the interference signal will spread to the entire frequency band after despreading at the receiving site, thereby reducing the impact of interference. Therefore, the spread spectrum signal can weaken the narrowband interference to a certain extent, and the degree of weakening is related to the ratio of the bandwidth of the spread spectrum code to the bandwidth of the interference signal.

A spread-spectrum signal, such as a typical spectrum spread by a pseudorandom noise (Pseudo Noise, PN) sequence, is submerged in noise, as shown in Figure 1, which is a schematic diagram of the spectrum energy of a general spread-spectrum signal, where the "ideal signal" It refers to the signal energy actually sent by the mobile station, and "noise" refers to those additive interferences. After spreading, the ideal signal energy in the unit frequency domain is generally less than the same noise energy; "strong interference" generally refers to blocking signals or caused by wired Stations, wireless stations, or nearby communication equipment; "typical interference" refers to those signals emitted by low-power sources, such as amateur radios, walkie-talkies, etc.; "processing gain" indicates the level of interference signals that mobile station extension signals can tolerate. The spread spectrum signal can be recovered when it is affected by typical interference, but when strong interference occurs, the signal cannot be recovered at all, and even if it is typical interference, although the signal can be recovered, the system performance will also decline.

The International Frequency Committee has regulations on the frequency bands used by spread spectrum communication systems. At the same time, different countries and regions have also allocated dedicated frequency bands for spread spectrum communication systems, which prepares spectrum resources for the application of spread spectrum communication systems. Before the operator intends to adopt the spread spectrum communication system, it usually applies for the frequency band to be used to ensure the legal use of the frequency band used. Spread spectrum communication system.

However, due to the burst characteristics of some burst interference signals, it is not easy to be completely prohibited, and there are various reasons for the spectrum allocation in some countries and regions, so that the spread spectrum communication system will inevitably encounter narrowband interference in actual use. Narrowband interference will increase the congestion rate and call drop rate of the spread spectrum communication system, overload the RF power control system, increase the power consumption of the mobile station, and reduce the coverage of the base station. In extreme cases, high-power interference may even block the entire cell, making normal communication impossible. Therefore, a good solution must be found to eliminate or weaken the influence of narrowband interference signals on the spread spectrum communication system so that the communication quality can be guaranteed.

Existing methods for dealing with narrowband interference can generally be divided into two categories:

(1) For signals that are usually processed in analog, pass them through a narrow-band notch filter or notch filter group.

This method is generally realized by surface acoustic wave technology. Make some estimates of the frequency of the interference signal. According to the estimation results, place a narrow-band notch device where there is an interference signal. For example, a phase-locked loop can also be used to track the interference signal. However, due to the limitations of the simulation technology itself, most of them are not flexible enough.

(2) Frequency domain elimination methods are generally realized through digital processing. After the signal is digitized, it is transformed into the frequency domain by some kind of operation (for example: discrete Fourier transform FFT). There are two ways to deal with interference signals in the frequency domain: one method is to use a filter to filter out the influence of interference on the frequency domain data. This method is suitable for situations where the interference bandwidth and location are known. When the position of the interference in the frequency domain, the interference bandwidth and the number cannot be clearly determined, this method will have certain limitations; another method is to calculate the signal amplitude on each frequency, and then compare it with the threshold that will exceed the threshold The signal is set to 0 or dropped to the noise level. The method can adaptively process multiple interferences, different interference bandwidths and interference frequency changes.

However, this method has defects in spectrum elimination, because the use of rectangular window truncation introduces spectrum expansion, and the discrete Fourier transform of non-periodic signals makes the interference diffuse in the entire spectrum space; Normal signals are compressed at the front and back of the data segment, which also affects signal quality.

In addition, the above methods have certain difficulties in the real-time implementation of hardware, because each data sample point must be processed and operated during processing, and it is necessary to continuously perform spectrum estimation and limit the power spectrum within a certain range. For high-speed broadband system data, the demand for calculation is relatively large.

Contents of the invention

The purpose of the present invention is to provide a method for eliminating narrowband interference in a communication system, which can handle real-time interference on the premise of occupying less hardware resources.

Another object of the present invention is to provide a device for eliminating narrowband interference in a communication system, which can handle real-time interference while occupying less hardware resources.

The method for eliminating narrowband interference in a communication system of the present invention comprises the following steps:

Step A: after performing windowing transformation and fast Fourier transform (FFT) on the sampling signal including N points of the first length, calculating the signal energy of each point respectively, and accumulating the signal energy of each point respectively;

Step B: When the accumulated value reaches the predetermined time, compare each accumulated value with a preset target value, and record the signal position information corresponding to the accumulated value greater than the target value;

Step C: Adjust the signal amplitude of the position to be consistent with the target value, and then output it after inverse fast Fourier transform IFFT.

The method for eliminating narrow-band interference in a communication system of the present invention may also be to expand the sampling signal of the first length in the step A into a sampling signal of the second length containing M points, where M=2 ^k*N, 2^k is the number of sections including N-length data point segments in the M-length data point, k>0, then carry out FFT transformation after the M-point signal after the expansion is carried out windowing transformation, and in step C After the IFFT recovery, discard the data of M-N points other than N points and output it.

Wherein, in the step B, when no accumulated value greater than the target value is found, the data without interference cancellation will be output.

Wherein, the signal energy is the square of the modulus of the signal at each point, and the accumulation time can be set in advance, depending on the characteristics of different systems, for example, it can be set to 60-120 ms in a CDMA system.

In addition, the method for eliminating narrowband interference in the communication system of the present invention further includes the following steps: performing delay compensation on the data transformed by the IFFT.

The device for eliminating narrowband interference in a communication system of the present invention includes an FFT transformation unit, an interference elimination unit, an IFFT transformation unit, and an interference elimination control unit, wherein the FFT transformation unit is used to transform the first-length samples containing N points The signal is subjected to windowing transformation and FFT transformation, and the transformed data is output to the interference elimination unit and the interference elimination control unit; the interference elimination control unit is configured to transmit the N points according to the FFT transformation unit Data, calculate the signal energy of each point, and accumulate the signal energy of each point respectively, when the accumulation reaches the predetermined time, compare each accumulated value with the preset target value, and record the accumulated value greater than the target value The corresponding signal position information, and then send the target value and the position information of the signal to the interference elimination unit; the interference elimination unit is used to adjust the signal amplitude of the position to the target value After matching, the signals are sent to the IFFT transformation unit; the IFFT transformation unit is configured to perform IFFT transformation on the signal sent by the interference elimination unit.

Wherein, the interference elimination control unit includes an energy calculation module, an accumulative control output module, a target value module, a comparison module and a position registration module, wherein the energy calculation module is used to respectively receive the information sent by the FFT transformation unit N points of data, and calculate the signal energy of each point, and then send it to each accumulation control output module; the accumulation control output module is used to receive the signal energy of each point sent by the corresponding energy calculation module, and send each point The signal energy is accumulated with its previous signal energy, and when the accumulation reaches a predetermined time, each accumulated value is output to the target value module and the comparison module; the target value module is used to receive the information sent by the accumulation control output module Accumulate data, and set a target value, and send the target value to the interference elimination unit; the comparison module is used to compare the N accumulated values sent by the accumulation control output module with the target value sent by the target value module performing a comparison, and sending the accumulated value greater than the target value to the position registration module; the position registration module is used to record the signal position corresponding to the accumulated value sent by the comparison module, and store the position information of the signal sent to the interference cancellation unit.

Wherein, the FFT transformation unit further includes an extension module, which is used to extend the sampling signal of the first length to a sampling signal containing M points of the second length, wherein M=2^k*N, 2^ k is the number of M-length data points including N-length data point segments, k>0; the IFFT transformation unit is further used to discard M-N point data other than N points after performing IFFT transformation on the M-point signal.

In addition, the device for eliminating narrowband interference in a communication system of the present invention may further include a parameter controller and a selection module, wherein the parameter controller is used to control the selection module to select an output without the Data operated by the interference cancellation unit and the IFFT transformation unit.

Wherein, the signal energy is the square of the modulus of the signal at each point, and the accumulation time can be set in advance, depending on the characteristics of different systems, for example, it can be set to 60-120 ms in a CDMA system.

In addition, the device for eliminating narrowband interference in a communication system of the present invention may further include a data delay compensation module for performing delay compensation on the data transformed by the IFFT.

The beneficial effects of the present invention are: according to the method and device for eliminating narrowband interference in a communication system of the present invention, the power spectrum is estimated by averaging multiple periodograms within a period of time, and then using the obtained power spectrum to obtain a certain target value The multiple is used as the judgment threshold of narrowband interference, which can adapt to various situations to prevent misjudgment; at the same time, the power spectrum estimated for a period of time is used to judge narrowband interference, and the location of narrowband interference is recorded. The processing of real-time data is only in the According to the data at the location of the narrowband interference obtained in the previous time period, the amount of calculation is significantly reduced; and the minimum value and comparison operations are only performed at intervals, and it is not necessary to operate on each piece of data, which greatly reduces the impact on the hardware. Requirements for real-time processing; the present invention is also designed with a selection control module, which can shield the execution of modules with a large amount of calculation when there is no narrowband interference, such as the IFFT transformation unit, thereby further reducing the occupation of hardware resources.

Description of drawings

Fig. 1 is a schematic diagram of the spectrum energy of a general spread spectrum signal;

Fig. 2 is a schematic diagram of the implementation of the narrowband interference elimination device of the present invention;

FIG. 3 is a schematic diagram of an FFT transformation unit in the narrowband interference elimination device of the present invention;

FIG. 4 is a schematic diagram of an IFFT transformation unit in a narrowband interference cancellation device of the present invention;

Fig. 5 is a schematic diagram of time-domain waveform without M expansion IFFT;

Fig. 6 is a schematic diagram of time-domain waveforms with M expansion before FFT and N extraction after IFFT output.

Detailed ways

Hereinafter, a method and device for eliminating narrowband interference in a communication system of the present invention will be described in detail with reference to FIGS. 1 to 6 .

Describe in detail the method for eliminating narrowband interference in a communication system of the present invention, the method includes the following steps:

Step 100: After performing windowing transformation and fast Fourier transform (FFT) transformation on the sampling signal including predetermined point (for example N) length, calculate the signal energy of each point respectively, and respectively accumulate the signal energy of each point, when the accumulation reaches the predetermined When the time is reached, each accumulated value is output.

Wherein, in the embodiment of the present invention, the bandwidth of the spread spectrum signal in the embodiment is 1.2288MHz, and the data sampling rate is 2×1.2288MHz. 3) = 81.92 points, which is the FFT of 128 points. As we all know, the more FFT points, the stronger the ability to distinguish narrowband interference, and the greater the amount of calculation for hardware implementation, you can actually select the N value according to your own system and requirements for the identification accuracy of narrowband interference. In one of the above embodiments N=256 is used.

In addition, the above-mentioned signal energy is the square of the modulus of each point signal.

In addition, the preset accumulation time may be 60-120 ms, and this value will not greatly affect the system's ability to respond to narrowband interference. In the embodiment of the present invention, selecting approximately 106 ms as the accumulated time length does not affect the ability of the system to eliminate narrowband interference and can obtain a relatively stable power spectrum estimation result.

Step 200: Receive each accumulated value, and set a target value according to a predetermined rule.

Wherein, the target value may be, for example, the minimum value, average value or other certain value jointly determined by all or part of the energy statistics specified by the parameters among the N accumulated values. It can also be a certain multiple of the target value to eliminate interference beyond a certain range. After simulation, the multiple is generally 3.0.

Step 300: compare each accumulated value with the target value, and record the position information corresponding to the accumulated value greater than the target value, and then adjust the signal amplitude of the position to be consistent with the target value to eliminate interference, and then Output after fast Fourier transform IFFT.

In addition, in step 100, the following steps may be further included:

Step 11: expand the sampling signal comprising predetermined point (such as N) length, expand to M points, M=2^k*N, 2^k is the segment number including N length data point segment in the M length data point, k ≥0, then perform FFT transformation on the expanded M points after windowing transformation.

Due to the expansion of the data points, the amplitude attenuation on both sides of the data caused by the window function mainly acts on the M-N points other than the N points; after the subsequent IFFT restoration, the M-N points other than the N points are discarded, and after recombination, the data amplitude The degree of attenuation is greatly reduced. Repeat the above process to store and calculate the next set of M-length data to obtain a section of N-length signal data, and combine these sections to form the final output data.

In addition, it can also be controlled to select whether to perform interference elimination processing on the originally received sampling signal, and if not, directly output the originally received sampling signal.

Since the device for eliminating narrowband interference in the communication system of the present invention needs to perform FFT transformation calculation and IFFT transformation calculation on the signal, and the transformation calculation requires time delay, therefore, based on the above, the data after the IFFT transformation can be delayed compensate.

Hereinafter, the device for eliminating narrowband interference in a communication system of the present invention will be described in detail, including an FFT transformation unit, an interference elimination unit, an IFFT transformation unit, and an interference elimination control unit.

Wherein, the FFT transformation unit is used to perform windowing transformation on the N-point data sent by the data storage unit and then perform FFT transformation, and output the transformed data to the interference elimination unit and the interference elimination control unit;

The interference elimination control unit is used to calculate the signal energy of each point according to the N point data sent by the FFT transformation unit, and accumulate the signal energy of each point respectively, and when the accumulation reaches a predetermined time, compare each accumulated value with the preset The target value is compared, and the signal position information corresponding to the accumulated value greater than the target value is recorded, and then the target value and the signal position information are sent to the interference elimination unit.

The interference elimination unit is configured to adjust the signal amplitude at the position to be consistent with the target value, and then send it to the IFFT transformation unit.

The IFFT transformation unit is configured to perform IFFT transformation on the data after the interference cancellation sent by the interference elimination unit, and output the transformed data to a subsequent unit, such as a despreading unit, for subsequent processing.

Specifically, the interference elimination control unit includes an energy calculation module, an accumulation control output module, a target value module, a normalization module, a comparison module and a position registration module.

Among them, the energy calculation module is used to receive the N-point data sent by the FFT transformation unit, each energy calculation module receives its corresponding 1-point data, and calculates the signal energy corresponding to the point data, and sends the signal energy of each point to Cumulative counting control module.

Wherein, the signal energy calculated in the energy calculation module is the square of the modulus of the signal at each point. Obviously, the above calculation result is the periodogram of the data segment.

The accumulation control output module is used to receive the signal energy of each point sent by the corresponding energy calculation module, and accumulate the signal energy of each point with the previous signal energy. When the accumulation reaches the predetermined time, output each accumulated value to the target value module and compare modules.

Wherein, the accumulation time in the accumulation control output module may be 60-120ms, and this value will not have a great impact on the system's ability to respond to narrowband interference. In the embodiment of the present invention, about 106 ms is selected as the accumulation time length, and the simulation results show that choosing this length will not affect the ability of the system to eliminate narrowband interference and can obtain relatively stable power spectrum estimation results.

The target value module is used to receive the accumulation data sent by the accumulation control output module, set the target value according to predetermined rules, and send the target value to the normalization module. Wherein, the target value may be, for example, the minimum value, average value or other certain value jointly determined by all or part of the energy statistics specified by the parameters among the N accumulated values.

In the embodiment of the present invention, the target value takes the minimum value, because the power spectrum is relatively stable at this time, and there will be no too low value, but the average value will be greatly affected by the amount and intensity of narrowband interference. Influence. In addition, finding the minimum value only requires some comparison operations, and the amount of calculation is relatively small.

The comparison module is used to compare the N accumulated values sent by the accumulation control output module with the target value sent by the target value module, and send the accumulated values greater than the target value to the position register module.

Since the position registration module and the target value module can be updated at regular intervals, they can be adaptively changed with changes in the surrounding conditions to achieve better results.

The position registration module is used to record the signal position corresponding to the accumulated value sent by the comparison module, and send the position information of the signal to the interference elimination unit.

In addition, the target value module can be further used to send the data sent by the accumulation control output module to the comparison module after being multiplied by a multiplier;

The comparison module multiplies the received target value by a predetermined multiple as a decision threshold, compares it with the data sent by the accumulation control output module, and sends the value greater than the decision threshold to the position register module. In addition, in order not to affect the useful signal being judged as interference, the selection of the multiplier will affect the performance of the final system. After simulation, the multiplier is generally taken as 3.0.

In addition, as shown in Figure 3, the FFT transformation unit in the device for eliminating narrowband interference in the communication system of the present invention can further include an M-point extension module, which is used to extend the data length of the data segment formed by the original N data points , including other M-N data points before and after the current data segment together to form a longer M-length data segment, and then the expanded M points are windowed and transformed by FFT, and the transformed data is output To the interference elimination unit and the interference elimination control unit; correspondingly, the interference elimination control unit includes M energy calculation modules and M accumulation modules, wherein the functions of the energy calculation module and the accumulation module have not changed as described above, only Quantity transformation.

Based on the above, the windowing operation is to perform the multiplication operation of the sum of the window function in the time domain on the M-length data segment. In order to better suppress the spectrum expansion introduced by narrowband interference when truncation, it is necessary to suppress the side lobe by the window function. In the embodiment of the present invention, the Hanning window of M points is selected; The M-point data of the window is subjected to FFT operation. It can be seen from Figure 5 that due to the introduction of the window function, there will be amplitude attenuation on both sides of the useful signal, which will have a nonlinear impact on the useful signal, and then affect the signal-to-noise ratio (SNR) of the signal. In order to reduce the impact of the window function on the useful data, and at the same time not weaken the suppression of the sidelobe of the interference signal by the window function, the role of the M-point expansion module can be reflected. The data is expanded from N points to M points, the number of FFT points in the subsequent stage increases, and the calculation amount increases by M/N times, so the selection of M affects the complexity of the hardware. Due to the expansion of the data points, the amplitude attenuation on both sides of the data caused by the window function mainly acts on the M-N points other than the N points; after the subsequent IFFT restoration, the M-N points other than the N points are discarded, and after recombination, the data amplitude The degree of attenuation is greatly reduced.

As shown in FIG. 4 , it is a schematic diagram of an IFFT transformation unit, and the IFFT transformation unit includes an IFFT operation module and an N-point extraction unit. The IFFT operation module is to perform IFFT operation on the M-point data after interference elimination. As can be seen from Figure 5, due to the introduction of the window function, there will be amplitude attenuation on both sides of the useful signal, which will have a nonlinear impact on the useful signal, and then affect the signal-to-noise ratio (SNR) of the signal. It can be seen that the IFFT is restored to the time domain, which has a great impact on the demodulation of the subsequent stage; the N-point extraction unit is to extract the N-point data of the corresponding position from the M-point data output by the IFFT, and after recombining, the degree of data amplitude attenuation It is greatly reduced, and then the demodulation capability can be improved; FIG. 6 shows the processing process inside the intermediate FFT transformation unit and the IFFT transformation unit of the embodiment of the present invention.

In addition, since the device for eliminating narrowband interference in the communication system of the present invention needs to perform FFT transformation calculation and IFFT transformation calculation on the signal, and the transformation calculation requires time delay, for this reason, the embodiment of the present invention can further include a data delay compensation unit , used to compensate for the time delay to prevent data distortion.

In addition, it may further include a parameter controller and a selection module, wherein the parameter controller is used to manually or automatically control whether the interference elimination device is in the through mode. When there is no narrowband interference, for example, if the location registration module shows that no location information is recorded, then The parameter controller controls the direct mode, and the selection module selects and outputs the data that has not been operated by the interference elimination unit and the IFFT transformation unit. By shielding the execution of the module with a large amount of calculation, the operation of the hardware is reduced and the hardware overhead is saved.

In summary, according to the method and device for eliminating narrowband interference in a communication system of the present invention, the signal is transformed into the frequency domain, and the power spectrum is estimated by averaging multiple periodograms within a period of time, and then the obtained power spectrum is used to The multiple of a certain target value is used as the judgment threshold of narrowband interference, which can adapt to various situations to prevent misjudgment; at the same time, the power spectrum estimated for a period of time is used to judge narrowband interference, record the location of narrowband interference, and analyze the real-time data The processing is only based on the data at the location of the narrow-band interference obtained in the previous time period, and the amount of calculation is significantly reduced; and the minimum value and comparison operations are only performed at intervals, and there is no need to operate on each piece of data. The requirement of hardware for real-time processing is greatly reduced; the present invention is also designed with a selection control module, which can shield the execution of a module with a large amount of calculation when it is found that there is no narrowband interference, such as the IFFT transformation unit, thereby further reducing the occupation of hardware resources .

The above is a detailed description of the present invention for those skilled in the art to understand the present invention, but it is conceivable that other changes and modifications can be made without departing from the scope covered by the claims of the present invention. Variations and modifications are within the scope of the present invention.

Claims (11)

1. the method for narrow band interference in the cancellation in communication systems is characterized in that, comprises the following steps:

Steps A: the sampled signal that N orders that comprises to first length is expanded, expand to the sampled signal that M is ordered that comprises of second length, wherein, M=2^k*N, 2^k is the hop count that comprises N length number strong point section in the M length number strong point, and k＞0 is after the M point signal after will expanding then carries out windowing conversion and fast fourier transform FFT, calculate the signal energy of each point respectively, and respectively the signal energy of each point is added up;

Step B: when being added to the scheduled time, each accumulating values and preset target value are compared, and record is greater than the pairing signal location information of the accumulating values of described desired value;

Step C: the signal amplitude of described position is adjusted to consistent, after abandoning the M-N point data outside the N point after the anti-fast fourier transform IFFT conversion, exported then with described desired value.

2. the method for narrow band interference is characterized in that in the cancellation in communication systems as claimed in claim 1, in described step B, when the accumulating values do not found greater than described desired value, with the data of output without interference eliminated.

3. the method for narrow band interference is characterized in that in the cancellation in communication systems as claimed in claim 1, signal energy be the each point signal mould square.

4. the method for narrow band interference is characterized in that in the cancellation in communication systems as claimed in claim 1, and the described scheduled time of adding up is 60～120ms.

5. the method for narrow band interference is characterized in that in the cancellation in communication systems as claimed in claim 1, comprises the following steps: the data after described IFFT conversion are carried out compensation of delay.

6. the device of narrow band interference in the cancellation in communication systems is characterized in that, comprises FFT converter unit, interference cancellation unit, IFFT converter unit and interference eliminated control unit, wherein,

Described FFT converter unit, be used for the sampled signal that N orders that comprises of first length is expanded, expand to the sampled signal that M is ordered that comprises of second length, wherein, M=2^k*N, 2^k are the hop counts that comprises N length number strong point section in the M length number strong point, k＞0, M point signal after the expansion is carried out windowing conversion and FFT conversion, and export the data after the conversion to described interference cancellation unit and described interference eliminated control unit;

Described interference eliminated control unit, be used for the data of sending according to described FFT converter unit, calculate the signal energy of each point, and respectively the signal energy of each point is added up, when being added to the scheduled time, each accumulating values and preset target value are compared, and write down greater than the pairing signal location information of the accumulating values of described desired value, the positional information with described desired value and described signal is sent to described interference cancellation unit then;

Described interference cancellation unit is used for the signal amplitude of described position is adjusted to after described desired value is consistent, is sent to the IFFT converter unit;

Described IFFT converter unit, the signal that is used for that described interference cancellation unit is sent carry out abandoning after the IFFT conversion M-N point data outside the N point.

7. the device of narrow band interference is characterized in that in the cancellation in communication systems as claimed in claim 6, and described interference eliminated control unit comprises the energy computing module, adds up and control output module, desired value module, comparison module and location register module, wherein,

Described energy computing module is used for receiving respectively the N point data that described FFT converter unit sends, and calculates the signal energy of each point, sends it to each control output module that adds up then;

The described control output module that adds up, be used to receive the each point signal energy that corresponding energy computing module sends, and each point signal energy signal energy last with it added up, when being added to the scheduled time, export each accumulating values to described desired value module and described comparison module;

Described desired value module is used to receive add up and controls the cumulative data that output module sends, and desired value is set, and this desired value is sent to described interference cancellation unit;

Described comparison module is used for the desired value that N accumulating values that the described control output module that adds up is sent and desired value module send and compares, and will be sent to the location register module greater than the accumulating values of described desired value;

Described location register module is used to write down the corresponding signal location of accumulating values that described comparison module sends, and the positional information of described signal is sent to described interference cancellation unit.

8. as the device of narrow band interference in claim 6 or the 7 described cancellation in communication systems, it is characterized in that, further comprise parameter controller and select module, wherein,

Described parameter controller is used for when not having narrow band interference to exist, and control selects module to select the data of output without described interference cancellation unit and the operation of IFFT converter unit.

9. as the device of narrow band interference in claim 6 or the 7 described cancellation in communication systems, it is characterized in that, described signal energy be the each point signal mould square.

10. as the device of narrow band interference in claim 6 or the 7 described cancellation in communication systems, it is characterized in that the described scheduled time of adding up is 60～120ms.

11. the device as narrow band interference in claim 6 or the 7 described cancellation in communication systems is characterized in that, further comprises the data delay compensating module, is used for the data after described IFFT conversion are carried out compensation of delay.

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