A simplified passive intermodulation detection, cancellation method and system

Abstract

The application discloses a simplified passive intermodulation detection and elimination method and system, and belongs to the field of mobile communication. The application detects passive intermodulation signals, calculates the power of a sending signal and a receiving signal when the passive intermodulation signals exist, and detects the carrier frequency band of the sending signal. Then, the application calculates the gain value between the sending signal and the receiving signal through component construction and component frequency shifting of the passive intermodulation signals, so as to complete the elimination of the passive intermodulation signals, and solves the technical problem of excessive system power consumption caused by the constant opening of the passive intermodulation signal elimination module in the prior art.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of mobile communication, and particularly relates to a simplified passive intermodulation detection and elimination method and system. BACKGROUND

[0002] The English abbreviation of passive intermodulation is PIM, which represents Passive intermodule. The distortion from passive devices, such as 3rd order intermodulation and 5th order intermodulation, often exists in passive devices such as antennas and couplers and related hardware. These distortions can greatly increase the noise floor of the receiver of RX in the FDD system, and greatly reduce the sensitivity of RX. Therefore, a method is needed to identify such passive intermodulation, and a suitable method is needed to eliminate such passive intermodulation and improve the sensitivity of RX. In addition, the commonly used elimination method often involves matrix inversion to calculate the distortion coefficient. However, this calculation often consumes a large amount of resources due to the matrix inversion operation. Therefore, a PIM elimination method with reduced calculation amount needs to be considered. PS represents Powersaving, and PIMC represents Passive InterModulation cancel.

[0003] The prior art does not contain any PIM detection scheme, and the PIMC module needs to be turned on all the time, thus consuming a large amount of power. The prior art needs a matrix inversion operation, which consumes a large amount of software and hardware resources. Therefore, a simplified low-power passive intermodulation detection and elimination method needs to be considered. SUMMARY

[0004] In view of the problem of excessive system consumption in the prior art, the application provides a simplified passive intermodulation detection and elimination method, which comprises the following steps:

[0005] S1: detecting whether there is a passive intermodulation signal;

[0006] S2: constructing components of the passive intermodulation signal;

[0007] S3: transmitting the passive intermodulation signal component of the sending signal to a frequency point corresponding to the receiving signal;

[0008] S4: calculating the delay value between the sending signal and the receiving signal;

[0009] S5: calculating the gain value between the sending signal and the receiving signal;

[0010] S6: calculating the value of the receiving signal after eliminating the passive intermodulation signal, and completing the elimination of the passive intermodulation signal.

[0011] Preferably, the S1 step further comprises the following process:

[0012] A1: first calculate the power of the transmitted signal;

[0013] A2: then calculate the power of the received signal;

[0014] A3: finally determine whether the carrier frequency band of the transmitted signal will cause the passive intermodulation signal component to fall in the received signal, and complete the detection of the passive intermodulation signal.

[0015] Preferably, in the process of A1, the power of the transmitted signal is calculated as follows: let the transmitted signal be TX(n), where n represents the nth moment of the transmitted data, RX(n) represents the received signal, and the power of the transmitted signal is:

[0016] where N represents the total sampling time, real represents the real part, and imag represents the imaginary part.

[0017] If

[0018]

[0019] where thr1 represents threshold 1, then

[0020]

[0021] Otherwise

[0022] .

[0023] Preferably, in the process of A2, the power of the received signal is calculated as follows: let the power of the received signal be RXP, then:

[0024] If

[0025]

[0026] where thr2 represents threshold 2, then

[0027]

[0028] Otherwise

[0029] .

[0030] Preferably, in the process of A3, the determination method is as follows: let the carrier frequency of the transmitted signal from low to high be , … , where T represents the number of transmitted carriers, and the bandwidth of the tth (0 < t < T+1) carrier is BW; the transmission frequency band of the transmitted signal is​​ to , the frequency band of the received signal is to ;

[0031] If

[0032]

[0033] or

[0034]

[0035] then

[0036]

[0037] otherwise

[0038]

[0039] If , , , and 1 at the same time, it means that the passive intermodulation signal is detected, and is counted into the passive intermodulation modulation module, otherwise it is considered that the passive intermodulation signal is not detected, and the passive intermodulation modulation module is closed; entp represents the decision result of the sending power, enrp represents the detection result of the receiving power, and enft represents the final decision result of the sending carrier.

[0040] Preferably, the S2 step constructs the passive intermodulation signal component as follows: let the component of the input signal be , then

[0041]

[0042] wherein represents the amplitude value of the signal.

[0043] Preferably, in the S3 step, the process corresponding to the passive intermodulation signal and the received signal is as follows:

[0044] wherein exp represents the exponential operation of the natural logarithm, represents the circular constant 3.1415926… infinite non-cyclic decimal.

[0045] Preferably, in the S4 step, the delay value calculation process between the sending signal and the received signal is as follows:

[0046] wherein conv represents the convolution calculation, and arg represents the independent variable;

[0047] and then aligning with the received signal, the delay result is obtained, the signal after the passive intermodulation signal is shifted,

[0048]

[0049] In the S5 step, the gain value between the sending signal and the receiving signal is calculated as follows:

[0050]

[0051] gain is the gain between the receiving signal and the sending signal.

[0052] Preferably, in the S6 step, the value after the receiving signal eliminates the passive intermodulation signal is calculated as follows: let RX eliminate PIM result be , the result after the passive intermodulation signal elimination is as follows:

[0053] .

[0054] A simplified passive intermodulation detection and elimination system, comprising the following modules: a passive intermodulation signal detection module, a signal component construction module, a signal component shifting module, a delay value calculation module, a gain value calculation module, and a passive intermodulation elimination module.

[0055] The passive intermodulation signal detection module: first, calculate the power of the sending signal, then calculate the power of the receiving signal,

[0056] Finally, detect whether the carrier frequency band of the sending signal will cause the passive intermodulation signal component to fall in the receiving signal, and complete the detection of the passive intermodulation signal.

[0057] The signal component construction module: constructs the components of the received passive intermodulation signal.

[0058] The signal component shifting module: shifts the passive intermodulation signal component of the sending signal to the frequency point corresponding to the receiving signal.

[0059] The delay value calculation module: calculates the delay value between the sending signal and the receiving signal.

[0060] The gain value calculation module: calculates the gain value between the sending signal and the receiving signal.

[0061] The passive intermodulation elimination module: calculates the value after the receiving signal eliminates the passive intermodulation signal, and completes the elimination of the passive intermodulation signal.

[0062] Compared with the prior art, the technical scheme of the present application has the following advantages / benefits:

[0063] ​1. The present application detects the passive intermodulation signal, judges whether to start the passive intermodulation signal elimination module according to the detection result, saves a large amount of system resources and reduces system power consumption compared with the prior art of always-on passive intermodulation signal elimination module.

[0064] 2. The present application obtains distortion coefficients by component construction of the passive intermodulation signal, without matrix inversion, reducing resource consumption of the passive intermodulation signal elimination step.

[0065] 3. The present application completes distortion coefficient calculation by calculating gain value, removes coefficient update process, reduces matrix inversion process, greatly reduces system resource consumption, and enhances system energy efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0066] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments, and it should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation to the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor.

[0067] Figure 1 is a flow chart of a simplified passive intermodulation detection and elimination method of the present application.

[0068] Figure 2 is a schematic diagram of a simplified passive intermodulation detection and elimination system of the present application. DETAILED DESCRIPTION

[0069] In order to make the purpose, technical solutions and advantages of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely below, and obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. Therefore, the detailed description of the embodiments of the present application provided below is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application.

[0070] It should be noted that: similar labels and letters represent similar items in the following drawings, and therefore, once an item is defined in one drawing, it can not be further defined and explained in subsequent drawings.

[0071] Embodiment 1: The English abbreviation for passive intermodulation is PIM, which is distortion from passive devices, such as 3rd order intermodulation, 5th order intermodulation, etc. PIM often exists in passive devices, such as antennas, couplers, and related hardware, and these distortions can greatly raise the noise floor of the receiver of the received signal in an FDD system, resulting in a significant reduction in the sensitivity of the received signal. Moreover, various distortions exist in various passive devices, and appropriate methods need to be used to eliminate such passive intermodulation and improve the sensitivity of the received signal. In addition, the commonly used elimination method in the prior art often involves matrix inversion to calculate distortion coefficients, but such calculation often consumes a large amount of resources due to the matrix inversion operation. Therefore, a passive intermodulation elimination method that can reduce the amount of calculation and identify passive intermodulation signals needs to be considered

[0072] The present application provides a simplified passive intermodulation detection and elimination method, comprising the following steps:

[0073] S1: detecting whether there is a passive intermodulation signal;

[0074] S2: when it is detected in step S1 that there is a passive intermodulation signal, constructing components of the passive intermodulation signal;

[0075] S3: transmitting the passive intermodulation signal component of the sending signal to a frequency point corresponding to the received signal;

[0076] S4: calculating the delay value between the sending signal and the received signal;

[0077] S5: calculating the gain value between the sending signal and the received signal;

[0078] S6: calculating the value of the received signal after eliminating the passive intermodulation signal, and completing the elimination of the passive intermodulation signal.

[0079] Because the passive intermodulation signal eliminated in the present application is the PIM component leaked from the TX antenna coupler into the RX received signal, the power of the TX needs to be detected.

[0080] In step S1, the following process is also included:

[0081] A1: first, calculate the power of the sending signal;

[0082] A2: then, calculate the power of the received signal;

[0083] A3: finally, determine whether the carrier frequency band of the sending signal will cause the passive intermodulation signal component to fall in the received signal, and complete the detection of the passive intermodulation signal.

[0084] In A1 process, the power calculation method of the sending signal is as follows: let the sending signal be TX(n), wherein n represents the sending data of the nth moment, RX(n) represents the receiving signal, and the power of the sending signal is:

[0085] wherein N represents the total sampling time, real represents the real part, and imag represents the imaginary part;

[0086]

[0087]

[0088] wherein thr1 represents threshold 1, and then

[0089]

[0090] otherwise

[0091] .

[0092] In A2 process, the power calculation method of the receiving signal is as follows: let the power of the receiving signal be RXP, and then

[0093] if

[0094]

[0095] wherein thr2 represents threshold 2, and then

[0096]

[0097] otherwise

[0098] .

[0099] In A3 process, the judgment method is as follows: let the carrier frequency of the sending signal sending carrier from low to high be , … wherein T represents the number of the sending carrier, wherein the bandwidth of the tth (0 to , and the frequency band received by the receiving signal is to ;

[0100] if

[0101]

[0102] or

[0103] ​​​

[0104] Then

[0105]

[0106] Else

[0107]

[0108] If , , If the value is 1, it means that the passive intermodulation signal is detected, and the passive intermodulation modulation module is turned on, otherwise it is considered that the passive intermodulation signal is not detected, and the passive intermodulation modulation module is turned off; entp represents the decision result of the sending power, enrp represents the detection result of the receiving power, and enft represents the final decision result of the sending carrier.

[0109] The S2 step is the component construction process of the passive intermodulation signal, which is as follows: let the component of the input signal be Then there is:

[0110]

[0111] Wherein represents the amplitude value of the signal.

[0112] In the S3 step, the process corresponding to the passive intermodulation signal and the received signal is as follows:

[0113] Wherein exp represents the exponential operation of the natural logarithm, represents the circular constant 3.1415926… infinite non-cyclic decimal.

[0114] In the S4 step, the delay value calculation process between the sending signal and the received signal is as follows:

[0115] Wherein conv represents convolution calculation, and arg represents the independent variable;

[0116] Then align and the received signal to obtain the delay result, that is, the signal after frequency shifting of the passive intermodulation signal,

[0117] ;

[0118] In the S5 step, the gain value calculation process between the sending signal and the received signal is as follows:

[0119]

[0120] gain, i.e. the gain between the received signal and the transmitted signal.

[0121] Preferably, in the step S6, the numerical calculation process after the received signal eliminates the passive intermodulation signal is as follows: let RX eliminate PIM result be i.e. the result after the passive intermodulation signal elimination is as follows:

[0122] .

[0123] Embodiment 2:

[0124] As shown in Figure 2 , the application also provides a simplified passive intermodulation detection and elimination system, comprising the following modules: a passive intermodulation signal detection module, a signal component construction module, a signal component frequency transfer module, a delay numerical calculation module, a gain numerical calculation module, and a passive intermodulation elimination module.

[0125] The passive intermodulation signal detection module: first, calculate the power of the transmitted signal, then calculate the power of the received signal,

[0126] and finally detect whether the carrier frequency band of the transmitted signal will cause the passive intermodulation signal component to fall in the received signal, thereby completing the detection of the passive intermodulation signal.

[0127] The signal component construction module: constructs the components of the received passive intermodulation signal.

[0128] The signal component frequency transfer module: transfers the passive intermodulation signal component of the transmitted signal to the frequency point corresponding to the received signal.

[0129] The delay numerical calculation module: calculates the delay numerical value between the transmitted signal and the received signal.

[0130] The gain numerical calculation module: calculates the gain numerical value between the transmitted signal and the received signal.

[0131] The passive intermodulation elimination module: calculates the numerical value after the received signal eliminates the passive intermodulation signal, thereby completing the elimination of the passive intermodulation signal.

[0132] The above is only the preferred embodiment of the application, and it should be noted that the above preferred embodiment should not be regarded as a limitation of the application, and the protection scope of the application should be limited by the scope defined by the claims. For ordinary skilled persons in the art, without departing from the spirit and scope of the application, a number of improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the application.

Claims

1. A simplified method of passive intermodulation detection and cancellation, characterized in that, The method comprises the following steps: S1: detecting whether there is a passive intermodulation signal, and entering step S2 when the passive intermodulation signal is detected, or directly ending the process; S2: constructing components of the passive intermodulation signal; S3: moving the passive intermodulation signal component in the sending signal to a frequency point corresponding to the receiving signal; S4: calculating a delay value between the sending signal and the receiving signal, and time-domain aligning the signal after the passive intermodulation signal component is moved in frequency and the receiving signal; S5: calculating a gain value between the sending signal and the receiving signal; S6: calculating a value after the receiving signal eliminates the passive intermodulation signal, and completing elimination of the passive intermodulation signal. The S2 step for constructing the passive intermodulation signal component is as follows: let the component of the input signal be So, there is: wherein represents taking the amplitude value of the signal.

2. The method of claim 1, wherein, In the S1 step, the following process is further included: A1: first calculating the power of the sending signal; A2: then calculating the power of the receiving signal; A3: finally judging whether the carrier frequency band of the sending signal will cause the passive intermodulation signal component to fall in the receiving signal, and completing detection of the passive intermodulation signal.

3. The method of claim 2, wherein the method is a simplified passive intermodulation detection and cancellation method, characterized in that, In the A1 process, the power of the transmitted signal is calculated as follows: let TX(n) be the transmitted signal, where n represents the nth moment of the transmitted data, and RX(n) represent the received signal, then the power of the transmitted signal is: where N represents the total sampling time, real represents the real part of the sought, and imag represents the imaginary part of the sought. If where thr1 represents threshold 1, then Otherwise 。 4. The method of claim 3, wherein the method is a simplified passive intermodulation detection and cancellation method, characterized in that, In the A2 process, the power calculation method of the received signal is as follows: let the power of the received signal be RXP, then If where thr2 represents threshold 2, then Otherwise 。 5. The method of claim 4, wherein the method is a simplified passive intermodulation detection and cancellation method, characterized in that, The judgment method in the A3 process is as follows: the carrier frequencies of the sending signals are arranged from low to high as , … , wherein T represents the number of the sending carriers, wherein the bandwidth of the tth (0 to , and the frequency band for receiving the receiving signals is to ; If or then Otherwise If , , If both are 1, it means that the passive intermodulation signal is detected, and the process goes to step S2, otherwise, it ends directly. entp represents a decision result of the sending power, enrp represents a detection result of the receiving power, and enft represents a final decision result of the sending carrier.

6. The method of claim 1, wherein the method is a simplified passive intermodulation detection and cancellation method. In the S3 step, the process corresponding to the passive intermodulation signal and the received signal is as follows: where exp represents the exponential operation on the natural logarithm, represents the circumference ratio 3.1415926… infinite non-cyclic decimal.

7. The method of claim 6, wherein the method is a simplified passive intermodulation detection and cancellation method. In the S4 step, the delay value between the sending signal and the receiving signal is calculated as follows: Where conv represents convolution calculation, and arg represents argument; Then the and the received signal, to obtain the delay result, that is, the signal after the frequency transfer of the passive intermodulation signal, 。 8. The method of claim 7, wherein the method is a simplified passive intermodulation detection and cancellation method. The numerical calculation process after receiving signal elimination of passive intermodulation signal in the S6 step is as follows: let RX eliminate PIM result be That is, the result after passive intermodulation signal elimination is as follows: ； The The calculation process is as follows: where gain represents the gain ratio between the transmitted signal and the received signal, and TXgain represents the transmitted signal component used to cancel the passive intermodulation signal.

9. A simplified passive crosstalk detection cancellation system, characterized by The method comprises the following modules: a passive intermodulation signal detection module, a signal component construction module, a signal component moving module, a delay value calculation module, a gain value calculation module, and a passive intermodulation elimination module. The passive intermodulation signal detection module: first calculating the power of the sending signal, then calculating the power of the receiving signal, finally detecting whether the carrier frequency band of the sending signal will cause the passive intermodulation signal component to fall in the receiving signal, entering the signal component construction module when the passive intermodulation signal is detected, or directly ending the process, and completing detection of the passive intermodulation signal; The signal component constructing module constructs the components of the received passive intermodulation signal, and the construction process is as follows: let the components of the input signal be Then, there is: wherein represents taking the amplitude value of the signal; The signal component moving module: moving the passive intermodulation signal component in the sending signal to a frequency point corresponding to the receiving signal; The delay value calculation module: calculating a delay value between the sending signal and the receiving signal, and time-domain aligning the signal after the passive intermodulation signal component is moved in frequency and the receiving signal; The gain value calculation module: calculating a gain value between the sending signal and the receiving signal; The passive intermodulation elimination module: calculating a value after the receiving signal eliminates the passive intermodulation signal, and completing elimination of the passive intermodulation signal.

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