CN109995394B - Device and method for self-adaptively counteracting passive intermodulation signal - Google Patents

Device and method for self-adaptively counteracting passive intermodulation signal Download PDF

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CN109995394B
CN109995394B CN201811467208.9A CN201811467208A CN109995394B CN 109995394 B CN109995394 B CN 109995394B CN 201811467208 A CN201811467208 A CN 201811467208A CN 109995394 B CN109995394 B CN 109995394B
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signal
passive intermodulation
frequency
intermodulation
coupler
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CN109995394A (en
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孟庆南
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Hongkong Vanlin Technology Co ltd
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Hongkong Vanlin Technology Co ltd
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/40—Circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/40—Circuits
    • H04B1/50—Circuits using different frequencies for the two directions of communication
    • H04B1/52—Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa
    • H04B1/525—Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa with means for reducing leakage of transmitter signal into the receiver

Abstract

The invention discloses a device for self-adaptively counteracting a passive intermodulation signal, wherein one main access port of a coupler is connected with an antenna port of a duplexer, the other main access port of the coupler is connected with an antenna feeder component on an antenna link, and a coupling port of the coupler is electrically connected with a radio frequency port of a counteractor circuit; the input end of the passive intermodulation detection circuit is electrically connected with the receiving port of the duplexer, and the output end of the passive intermodulation detection circuit is electrically connected with the input end of the digital processing unit; the digital processing unit is electrically connected with the transmitting circuit unit through the transmitting signal frequency discrimination circuit, and the output end of the digital processing unit is respectively and electrically connected with the passive intermodulation detection circuit, the transmitting circuit unit and the input end of the canceller circuit; and the output end of the transmitting circuit unit is electrically connected with the input end of the duplexer. The invention can cancel the components of passive intermodulation signals generated by other devices or components on the wireless transceiver and the section from the antenna port of the device to the antenna, which fall into a receiving frequency band.

Description

Device and method for self-adaptively counteracting passive intermodulation signal
Technical Field
The present invention relates to the field of wireless communications. In particular, the present invention relates to an apparatus and method for adaptively canceling a passive intermodulation signal.
Background
In communication systems, there are a large number of applications for wireless transceiving equipment. The wireless transceiver itself includes devices for generating passive intermodulation signals, such as radio frequency duplexers, filters, combiners, etc.; the link from the antenna port of the transceiver to the antenna also contains many devices that generate passive intermodulation signals, such as couplers, rf cables, tower top amplifiers, etc. For a wireless transceiving system, how to suppress intermodulation interference generated to a receiver of a wireless transceiving device caused by a transmitting signal in the wireless transceiving system is a key problem of the system. Therefore, when the wireless transceiver device is in operation, the level of the passive intermodulation signal generated by the transmitting channel is required to be as low as possible so as to prevent the passive intermodulation signal from falling into the receiving channel and causing intermodulation interference to the receiving channel. The current passive intermodulation cancellation technology generally has two modes:
the reference CN100490307C discloses a name: the invention relates to a signal processing circuit, a base station and a method for eliminating intermodulation products, which divides an original carrier wave input into a nonlinear unit into two paths, respectively inputs the two paths of the original carrier waves into two branches, the first path of the original carrier wave generates a processing signal containing a first group of intermodulation products through the nonlinear unit, and the second path of the original carrier wave passes through a branching unit, a frequency multiplier, a mixer and a regulating circuit. And generating a control signal containing a second group of high-order intermodulation products, and finally superposing the two paths of signals. The second group of high-order intermodulation products have the same frequency, nearly the same amplitude and opposite phase with the first group of intermodulation products, and the intermodulation signals are counteracted.
The technical scheme has the following defects: 1. the technical scheme is not applicable to passive devices, the intermodulation value difference of different positions in the nonlinear unit is not considered, the difference is obvious for the passive devices, and the amplitude attenuation and the phase change degree of transmission signals are very large in the passive circuit. Under the condition of intermodulation generated at a plurality of positions, intermodulation signals generated at the front end of the circuit are greatly attenuated in the signal transmission process, and the intermodulation signals output by the circuit only contain intermodulation signals generated at the tail end of the circuit, so that the generated intermodulation cancellation signals cannot be cancelled with the intermodulation signals of the antenna port if the signals are taken from the front end of the nonlinear unit for the duplexer; 2. the intermodulation cancellation signals generated by the technical scheme, namely the second group of high-order intermodulation products, are limited to fixed-order intermodulation products, and only the intermodulation signals of the nonlinear units in the corresponding frequency band can be eliminated, so that the method has limitation.
Reference 201310048951.1 discloses a name: the invention relates to an intermodulation cancellation device for a passive device, which is characterized in that a transmitting signal containing a high-order intermodulation product is directly coupled from an output end of the passive device, is adjusted by a passive regulator and transmitted to the tail end of a radio frequency link with an intermodulation signal generator to be reflected, then a cancellation signal with the same frequency, level and opposite phase of the intermodulation signal of the transmitting signal of the passive device is obtained through adjustment of the passive regulator again, and the cancellation signal is superposed with a transmitting signal of an output end of a passive nonlinear unit through a coupler to realize intermodulation cancellation.
The technical scheme has the following defects: 1. according to the technical scheme, the passive regulator is adopted, amplitude regulation and phase regulation are passive devices, and if the passive regulator needs to be driven by means of external force, such as motor driving or direct manual driving, the modes can cause high practical application cost and are inconvenient to commercialize; 2. because there is no feedback detection circuit for the passive intermodulation cancellation result, the cancellation result cannot be monitored and adjusted in real time.
In addition, other methods for reducing the level of the passive intermodulation signal mainly focus on the structure and the process, which often require additional cost, and the electroplating process of thickening the metal coating often increases the pollution.
Disclosure of Invention
It is an object of the present invention to overcome the above-mentioned drawbacks of the prior art by providing a digital adaptive apparatus for canceling passive intermodulation signals in a wireless transceiver system, so as to cancel the passive intermodulation signals generated by other devices or components in a wireless transceiver and a link from an antenna port of the device to an antenna, which fall into a receiving band.
The invention provides a device for self-adaptively counteracting a passive intermodulation signal, which is characterized in that: the passive intermodulation detection circuit comprises a first coupler, a canceller circuit, a second coupler, a passive intermodulation detection circuit, a digital processing unit, a duplexer, a transmitting circuit unit, an antenna feed assembly and an antenna; one main access port of the first coupler is connected with an antenna port of the duplexer, the other main access port of the first coupler is connected with an antenna feeder component on an antenna link, and a coupling port of the first coupler is connected with a radio frequency port of the canceller circuit; one main access port of the second coupler is connected with the receiving port of the duplexer, the other main access port of the second coupler is connected with the passive intermodulation detection circuit, and the coupling port of the second coupler is connected with the other radio frequency port of the canceller circuit; the output end of the passive intermodulation detection circuit is electrically connected with the input end of the digital processing unit, the digital processing unit is electrically connected with the transmitting circuit unit through the transmitting signal frequency discrimination circuit, and the output end of the digital processing unit is electrically connected with the input ends of the passive intermodulation detection circuit, the transmitting circuit unit and the canceller circuit respectively; the output end of the transmitting circuit unit is electrically connected with the input end of the duplexer;
the signals of the transmitting circuit unit, which are larger than a certain radio frequency power value, enable the duplexer and the antenna link thereof to generate passive intermodulation signals, and the passive intermodulation signals contain components which fall into the receiving frequency band of the duplexer and have a certain frequency interval with the receiving signals;
the first coupler couples the radio frequency signal from the link of the antenna port of the duplexer and outputs the radio frequency signal to the canceller circuit; the radio frequency signals comprise transmitting signals, passive intermodulation signals and receiving signals; one main access port of the first coupler is connected with an antenna port of the duplexer, the other main access port of the first coupler is connected with an antenna feeder component on an antenna link, and a coupling port of the first coupler is connected with one radio frequency port of the canceller circuit; the second coupler superposes an intermodulation cancellation signal generated by the canceller circuit on a link behind a receiving port of a duplexer, one main access port of the second coupler is connected with the receiving port of the duplexer, the distance needs to be controlled within the range of 0-1 meter, the specific length is determined by the optimal effect of passive intermodulation cancellation, the main access port is a first main access port, the other main access port is connected with a passive intermodulation detection circuit to form a second main access port, and the coupling port of the second coupler is connected with the other radio frequency port of the canceller circuit;
the intermodulation signals generated on the canceller circuit by the power of the passive intermodulation signals and the received signals in the radio frequency signals coupled to the canceller circuit are coupled and output to the main channel of the second coupler through amplitude adjustment and phase adjustment to form intermodulation cancellation signals which have the same frequency, the same amplitude and opposite phase with the components of the passive intermodulation signals which fall into the receiving frequency band and have certain frequency intervals with the received signals,
a radio frequency port of the passive intermodulation detection circuit is connected with a second main access port of a second coupler behind a duplexer receiving port to acquire a component of a receiving signal and a passive intermodulation signal falling into a receiving frequency band, and the receiving dynamic range of the passive intermodulation detection circuit is larger than the difference value between the maximum power value of the receiving signal and the power value corresponding to the passive intermodulation preset value; the passive intermodulation detection circuit is connected with the digital processing unit through a high-speed analog-to-digital converter, and the sampling rate of the high-speed analog-to-digital converter is more than or equal to 2 times of the receiving frequency band bandwidth of the duplexer;
the digital processing unit calculates the detection amplitude of the passive intermodulation signal according to the frequency information of the transmitting signal and the sampling data of the passive intermodulation detection circuit and compares the detection amplitude with a passive intermodulation preset value; when the detected amplitude is larger than the preset value, controlling the canceller circuit to generate an intermodulation cancellation signal to cancel the component falling into the receiving frequency band in the passive intermodulation signal, and keeping the working state that the cancellation result of the component falling into the receiving frequency band in the passive intermodulation signal is smaller than or equal to the preset value according to the detected amplitude of the passive intermodulation signal; the digital processing unit is connected with the canceller circuit through a multi-channel digital-to-analog converter and transmits the control quantity of the amplitude and the phase to the canceller circuit, and the requirements of the amplitude adjustment precision and the phase adjustment precision of the canceller circuit mainly come from the requirements of the passive intermodulation signal cancellation capacity.
In the above technical solution, a duplexer in the apparatus represents a passive device in the wireless transceiver; the antenna feed assembly and the antenna represent passive devices in an antenna link of a wireless transceiver system, and the antenna feed assembly represents a combination of single or multiple passive devices in the antenna link, including but not limited to cables, connectors, couplers, and combiners.
In the above technical solution, the transmitting signal inputted to the radio frequency signal of the canceller circuit is processed by the radio frequency switch, the amplitude modulation circuit, the circulator and the intermodulation signal generator to generate an intermodulation signal with the same frequency, different amplitude and different phase as the passive intermodulation signal, and the intermodulation signal falls into a single 3-order component, a single 5-order component or a single higher-order component of the receiving frequency band, or 3-order components of a plurality of different frequency points, or 5-order components of a plurality of different frequency points, or higher-order components of a plurality of different frequency points, or simultaneously the amplitude relation and the phase relation between the 3-order component, the 5-order component and even higher-order components and the single 3-order component, or the single 5-order component, or the single higher-order component, or the plurality of different 3-order components, the single 3-order component, the single higher-order component, or the plurality of different 3-order components, Or 5-order components of a plurality of different frequency points, or higher-order components of a plurality of different frequency points, or simultaneously, the amplitude relation and the phase relation between 3-order components, 5-order components and even higher-order components are basically consistent;
the amplitude of the intermodulation signal generated on the intermodulation signal generator by the power of the receiving signal and the passive intermodulation signal in the radio frequency signal coupled to the canceller circuit is far smaller than that of the passive intermodulation signal, and the passive intermodulation cancellation result is not influenced;
after the intermodulation signal is reflected, the intermodulation signal passes through the circulator again, passes through the filter, is subjected to amplitude adjustment and phase adjustment of amplitude modulation and phase modulation 1, is coupled and output to a main channel of a second coupler, and forms an intermodulation cancellation signal which has the same frequency, the same amplitude and the opposite phase with a component which falls into a receiving frequency band in the passive intermodulation signal and has a certain frequency interval with the receiving signal, the intermodulation cancellation signal is cancelled with the component which falls into the receiving frequency band in the passive intermodulation signal, and the cancelled passive intermodulation signal is less than or equal to a passive intermodulation preset value; meanwhile, the transmitting signals and the receiving signals in the duplexer and the antenna link thereof normally operate in the duplexer and the antenna link thereof.
In the above technical solution, the digital processing unit calculates the method according to the frequency information of the transmission signal as follows:
the digital processing unit firstly calculates frequency information of passive intermodulation signals related to the frequency information of the transmitting signals according to the frequency information of the transmitting signals, converts the frequency information into filtering parameters of the passive intermodulation signals, then obtains frequency intervals among the frequency information and the bandwidth information of the receiving signals and the frequency and the bandwidth information of the passive intermodulation signals according to the frequency and the bandwidth information of the receiving signals, selects a corresponding digital filtering mode and an integrating mode, and finally realizes amplitude detection of the passive intermodulation signals; then comparing the detection amplitude of the passive intermodulation signal with a passive intermodulation preset value;
when the detection amplitude is smaller than or equal to the preset value, the canceller circuit does not generate intermodulation cancellation signals and does not affect passive intermodulation indexes of the duplexer and the antenna link thereof;
when the detected amplitude is larger than the preset value, the canceller circuit is controlled to adjust the amplitude and the phase to generate intermodulation cancellation signals with the same frequency, the same amplitude and the opposite phase with the passive intermodulation signals of the duplexer and the antenna link thereof, and the passive intermodulation signals in the radio frequency signals are cancelled, and the amplitude and the phase of the canceller circuit are regulated in real time according to the amplitude detection result of the passive intermodulation signals, so that the working state of the passive intermodulation signal cancellation result is smaller than or equal to the preset value is kept.
In the technical scheme, the digital processing unit acquires a transmitting signal from a transmitting circuit unit of the device through a transmitting signal frequency discrimination circuit, converts the transmitting signal into a digital signal, inputs the digital signal into the digital processing unit for frequency discrimination processing to acquire frequency information of a related transmitting signal, and calculates frequency information of a corresponding receiving signal according to a duplex frequency interval between the transmitting signal and the receiving signal; or directly obtaining the input information of the device through an information interaction interface in the digital processing unit; the digital processing unit generates a trigger signal and outputs the trigger signal to the transmitting circuit unit so as to trigger the transmitting circuit unit to generate a radio frequency signal.
In the above technical solution, the signal for exciting the duplexer and the antenna link thereof to generate the passive intermodulation signal and the signal for exciting the intermodulation signal generator to generate the intermodulation signal are homologous, and both of the signals are from the transmitting signal of the transmitting circuit unit, so that the passive intermodulation signal generated by the passive device and the intermodulation signal generated by the intermodulation signal generator have the same frequency and the same bandwidth; the antenna link is a link from the antenna port of the duplexer to the antenna, and the antenna feed component represents a combination of single or multiple passive devices in the antenna link, including but not limited to cables, connectors, couplers, and combiners; the transmission signal is formed by a multi-tone signal or a multi-carrier modulation signal.
In the above technical solution, when only a single 3-order, or a single 5-order, or a single higher-order component in a passive intermodulation signal, which is generated by a single duplexer or an antenna feed component or an antenna or is formed by simultaneously generating and superimposing multiple passive devices and has a certain frequency interval with a received signal, falls into a receiving band of the duplexer and causes a passive intermodulation index tested from a duplexer receiving port to fail to meet a preset value requirement, in order to make a passive intermodulation value behind a second main path port of a second coupler behind the duplexer receiving port meet the preset value requirement: the maximum amplitude of the intermodulation cancellation signal which can be generated by the intermodulation signal generator is larger than the amplitude of a single component falling into the corresponding frequency of a receiving frequency band in the passive intermodulation signal of the duplexer and the antenna link thereof;
when only 3-order of a plurality of different frequencies, or 5-order of a plurality of different frequencies, or higher-order components of a plurality of different frequencies in a passive intermodulation signal which is generated by a duplexer or an antenna feed component or an antenna or is formed by simultaneously generating and superposing a plurality of passive devices and has a certain frequency interval with a receiving signal fall into a receiving frequency band of the duplexer and cause a passive intermodulation index tested from a duplexer receiving port to not meet a preset value requirement, in order to enable a passive intermodulation value behind a second main channel port of a second coupler behind the duplexer receiving port to meet the preset value requirement: the maximum amplitude of the intermodulation cancellation signal corresponding to the passive intermodulation product frequency, which can be generated by the intermodulation signal generator, is greater than the amplitudes of a plurality of corresponding frequency components falling into a receiving frequency band in the passive intermodulation signals of the duplexer and the antenna link thereof; the phase relationship between a plurality of specific order components in the intermodulation signal generated by the intermodulation signal generator is substantially identical to the phase relationship between a plurality of specific order components in the passive intermodulation signal generated by the duplexer and the antenna link thereof;
when 3-order, 5-order or higher-order components simultaneously exist in passive intermodulation signals which are generated by the duplexer or the antenna feed component or the antenna or are formed by simultaneously generating and superposing a plurality of passive devices and have certain frequency intervals with the receiving signals, and the passive intermodulation indexes tested from the duplexer receiving port do not meet the preset value requirement, the passive intermodulation value behind the second main channel port of the second coupler behind the duplexer receiving port meets the preset value requirement; the maximum amplitude of the intermodulation cancellation signal corresponding to the passive intermodulation product frequency, which can be generated by the intermodulation signal generator, is greater than the amplitudes of a plurality of corresponding frequency components falling into a receiving frequency band in the passive intermodulation signals of the duplexer and the antenna link thereof; the amplitude relationship and phase relationship between the specific order components in the intermodulation signals generated by the intermodulation signal generator 2 are substantially identical to the amplitude relationship and phase relationship between the specific order components in the passive intermodulation signals generated by the duplexer and its antenna link.
In the above technical solution, when the radio frequency signal in the passive intermodulation detection circuit is too large to cause a link blockage, the digital processing unit will reduce the link gain of the passive intermodulation detection circuit so as to normally process the received signal and stop detecting the amplitude of the passive intermodulation signal; when the passive intermodulation detection circuit is not blocked, the digital processing unit includes a passive intermodulation signal and a receiving signal in the passive intermodulation amplitude calculation process, and a certain frequency interval exists between the passive intermodulation signal and the receiving signal.
In the above technical solution, the method for calculating the passive intermodulation signal amplitude by the digital processing unit includes:
the digital processing unit firstly calculates the frequency information of the passive intermodulation signal related to the frequency information of the transmitting signal according to the frequency information of the transmitting signal, then obtains the frequency interval between the frequency information and the bandwidth information of the receiving signal and the frequency information and the bandwidth information of the passive intermodulation signal according to the frequency interval, and selects a proper algorithm to calculate the amplitude of the passive intermodulation signal according to the frequency interval;
the algorithm for calculating the amplitude of the passive intermodulation signal includes, but is not limited to, a direct filter integration method and a segmented filter integration method:
the direct filtering integration method is to perform direct digital filtering and integrate to obtain amplitude according to the bandwidth of the passive intermodulation signal, at the moment, the frequency interval between each order component of the passive intermodulation signal falling into a receiving frequency band and the receiving signal is more than or equal to the bandwidth of a transition band from a passband to a stopband of a digital filter in a digital filtering algorithm of the passive intermodulation signal, and the frequency interval is the basis of adopting the direct filtering integration method;
the segmented filtering integration method is to divide the bandwidth of the passive intermodulation signal into a plurality of sub-bandwidths, perform digital filtering and integral calculation on the amplitude according to each sub-bandwidth, and then accumulate the amplitudes corresponding to all the sub-bandwidths to obtain the amplitude of the whole signal, wherein the frequency interval between each order component and the received signal is greater than or equal to the transition bandwidth from the digital filter passband of each order component side sub-band signal to the stopband, and the frequency interval is the basis of the segmented filtering integration method.
In the above technical solution, one port of the canceller circuit is connected to an antenna link behind an antenna port of a duplexer through a first coupler, or connected to a transmit link in front of a transmit port of the duplexer through the first coupler; the other port of the canceller circuit is connected with a link behind the receiving port of the duplexer through a second coupler; a first main access port of the second coupler is connected with a receiving port of the duplexer, the connection distance needs to be controlled within the range of 0-1 m, the specific length is determined by the optimal effect of passive intermodulation cancellation, a second main access port of the second coupler is connected with a radio frequency input end of the passive intermodulation detection circuit, and a coupling port of the second coupler is connected with a canceller circuit; the coupling port of the first coupler is a forward coupling port relative to the transmitting signal; the bearing power of the first coupler needs to be larger than the maximum transmission power peak value of the device, the bandwidth of the first coupler needs to contain a transmission frequency band, and the gain fluctuation in the frequency band of the first coupler is related to the transmission frequency band and needs to be within a certain threshold value range; the passive intermodulation index of the first coupler meets the requirement of the passive intermodulation index of the antenna feeder component; the coupling port of the second coupler is a reverse coupling port relative to the receiving signal; the bandwidth of the second coupler needs to include a receiving frequency band, and the gain fluctuation in the frequency band of the second coupler is related to the receiving frequency band and needs to be within a certain threshold value range; the load power threshold value of the canceller circuit is larger than or equal to the difference value between the power threshold value of the first coupler and the coupling degree of the first coupler; in order to enable an intermodulation signal generator in a canceller circuit to generate a passive intermodulation cancellation signal, the minimum value of the transmitting signal power loaded on the canceller circuit needs to be larger than a certain power threshold value.
In the above technical solution, the passive intermodulation detection circuit includes a low-noise amplifier, a down-conversion module, and a high-speed analog-to-digital converter, wherein an input end of the noise amplifier is electrically connected to a receiving port of the duplexer, an output end of the noise amplifier is electrically connected to an input end of the high-speed analog-to-digital converter through the down-conversion module, and an output end of the high-speed analog-to-digital converter is electrically connected to an input end of the digital processing unit;
the gain of the passive intermodulation detection circuit is determined by a required passive intermodulation preset value, the minimum sampling power of a high-speed analog-to-digital converter in the passive intermodulation detection circuit, a link noise coefficient and the like; the maximum value of the received signal power of the passive intermodulation detection circuit is greater than or equal to the maximum received signal power specified by the communication standard actually corresponding to the device.
In the above technical solution, the digital processing unit has at least one information interaction interface, and its functions include but are not limited to program downloading, configuration information input, remote alarm and maintenance; the configuration information to be input comprises the signal transmitting bandwidth and frequency band, the signal receiving bandwidth and frequency band, the order and frequency band information of main interference components in the passive intermodulation signals, the preset value of the passive intermodulation signals, a curve changing along with time and the maximum offset times of the passive intermodulation signals; the digital processing unit can acquire the frequency information of the transmitted signal and the frequency information of the received signal through the information interaction interface; the information interaction interface can also perform data interaction with internet background resources: uploading a passive intermodulation value in the operation process of the equipment, an experience curve of the passive intermodulation value changing along with time, and state information of each module circuit in the passive intermodulation signal self-adaptive offset device; or downloading the passive intermodulation signal preset value after comprehensive optimization and a curve changing along with time;
at least two interfaces exist between the digital processing unit and the passive intermodulation detection circuit: one interface is used for acquiring a sampling signal of a high-speed analog-to-digital converter in the passive intermodulation detection circuit so as to perform digital filtering and amplitude calculation on the passive intermodulation signal; the other interface is used for configuring parameters of the passive intermodulation detection circuit through the bus;
when the method for acquiring the frequency information of the transmitted signal and the frequency information of the received signal by the digital processing unit is to use a transmitted signal frequency discrimination circuit, a radio frequency port of the transmitted signal frequency discrimination circuit is connected with a certain position on a transmission link in the transmitting circuit unit, and the transmitted signal frequency discrimination circuit is connected with the digital processing unit through a high-speed analog-to-digital converter; meanwhile, an interface is arranged between the digital processing unit and the transmission signal frequency discrimination circuit, and is used for configuring parameters of the transmission signal frequency discrimination circuit, such as local oscillator frequency, link gain and the like through a bus, wherein the bus comprises but is not limited to an I2C bus and an SPI bus;
the digital processing unit is provided with at least one information interaction interface which has the functions of but not limited to program downloading, configuration information input, remote alarm and maintenance; the configuration information to be input comprises the signal transmitting bandwidth and frequency band, the signal receiving bandwidth and frequency band, the order and frequency band information of main interference components in the passive intermodulation signals, the preset value of the passive intermodulation signals, a curve changing along with time and the maximum offset times of the passive intermodulation signals; the digital processing unit can acquire the frequency information of the transmitted signal and the frequency information of the received signal through the information interaction interface; the information interaction interface can also perform data interaction with internet background resources: uploading a passive intermodulation value in the operation process of the equipment, an experience curve of the passive intermodulation value changing along with time, and state information of each module circuit in the passive intermodulation signal self-adaptive offset device; or downloading the passive intermodulation signal preset value after comprehensive optimization and the value which changes along with time;
the digital processing unit at least comprises a logic processing and operation processing device with a digital signal processing function, and is used for receiving digital signals, performing algorithm processing, outputting digital signals, controlling, outputting configuration signals and the like, wherein the logic processing and operation processing device comprises but is not limited to a field programmable gate array device, a central processing unit and a digital signal processor; the hardware of the information interaction interface of the digital processing unit comprises but is not limited to an Ethernet interface, an optical fiber interface and an RS-485 bus interface; the digital-to-analog converter in the digital processing unit has a bit range of 10-18 bits and at least 3 digital-to-analog converters.
In the above technical solution, one end of an amplitude modulation circuit in the canceller circuit is directly connected to the coupling port of the first coupler, or is connected to the coupling port of the first coupler through a radio frequency switch; the other end is connected with an intermodulation signal generator through a circulator; the intermodulation signal generator is connected with the filter through the circulator, one end of the amplitude modulation phase modulator is connected with the filter 5, and the other end of the amplitude modulation phase modulator is connected with the coupling port of the second coupler.
In the above technical solution, one end of an amplitude modulation circuit in the canceller circuit is directly connected to the coupling port of the first coupler, or is connected to the coupling port of the first coupler through a radio frequency switch; the other end is connected with an intermodulation signal generator through a circulator; the intermodulation signal generator is connected with the amplitude modulation phase modulator through the circulator, one end of the filter is connected with the amplitude modulation phase modulator, and the other end of the filter is connected with the coupling port of the second coupler.
In the technical scheme, the amplitude modulation phase modulator consists of an amplitude modulation circuit and a phase modulation circuit; the amplitude modulation circuit at least comprises 1 adjustable attenuator; the phase modulation circuit at least comprises 2 adjustable phase shifters; the amplitude modulation circuit consists of a fixed attenuator or an adjustable attenuator; the frequency bandwidth of the circulator comprises a transmitting frequency band and a receiving frequency band of the duplexer; the working frequency band of the amplitude modulation phase modulator comprises the receiving frequency band of the duplexer, and the gain fluctuation in the frequency band of the amplitude modulation phase modulator is related to the receiving frequency band and needs to be within a certain threshold value range; the passband frequency band of the filter is the receiving frequency band of the duplexer, and the out-of-band rejection index requirement of the filter is determined by the out-of-band rejection index of the receiving frequency band of the duplexer, the coupling degree of the first coupler, the coupling degree of the second coupler, the link loss between the coupling end of the first coupler and the coupling end of the second coupler in the canceller circuit and the like; the bearing power of an amplitude modulation circuit in the canceller circuit is larger than or equal to a bearing power threshold value of the canceller circuit;
the intermodulation signal generator comprises but is not limited to a single diode, a single triode or a parallel connection of a plurality of diodes; the specific type of the diode or the specific type of the triode is related to the amplitude characteristic and the phase characteristic of the intermodulation signal of 3 th order, 5 th order or higher order, which are generated by the intermodulation signal, and the requirements of the amplitude characteristic and the phase characteristic are the requirements of the intermodulation signal generator; when a plurality of diodes with the same type are connected in parallel, the intensity of intermodulation signals is enhanced; the carrier power of the intermodulation signal generator is greater than or equal to the difference between the canceller circuit carrier power threshold and the link loss from the canceller circuit radio frequency input port to the intermodulation signal generator.
In the above technical solution, the passive intermodulation detection circuit at least includes a low noise amplifier, a down-conversion module, and a high-speed analog-to-digital converter; the passive intermodulation detection circuit is connected with the digital processing unit through a high-speed analog-to-digital converter;
the down-conversion module can convert the received radio frequency signal into an intermediate frequency signal, or convert the received radio frequency signal into a zero intermediate frequency signal; the sampling dynamic range of the high-speed analog-to-digital converter is required to be larger than the difference value between the maximum power value of the received signal and the power value corresponding to the passive intermodulation preset value;
the minimum power which can be sampled by the passive intermodulation detection circuit is less than or equal to the passive intermodulation power value corresponding to the preset value, and meanwhile, the circuit can adjust the link gain according to the amplitude of the total power of the received radio-frequency signals so as to avoid link blockage caused by received signals or other signals; the gain of the passive intermodulation detection circuit is determined by a required passive intermodulation preset value, the minimum sampling power of a high-speed analog-to-digital converter in the passive intermodulation detection circuit and a link noise coefficient; the maximum value of the received signal power of the passive intermodulation detection circuit is greater than or equal to the maximum received signal power specified by the communication standard actually corresponding to the device.
In the technical scheme, the passive intermodulation detection circuit comprises a low-noise amplifier, a radio frequency filtering and small signal amplifying unit, a mixer, an intermediate frequency filter, an intermediate frequency amplifier and an analog-to-digital converter which are electrically connected in sequence, wherein a local oscillator is electrically connected with the mixer; the input end of the low-noise amplifier is electrically connected with the output end of the duplexer; the output end of the analog-to-digital converter is electrically connected with the input end of the digital processing unit.
In the above technical solution, the passive intermodulation detection circuit includes a low noise amplifier, a radio frequency filtering and small signal amplifying unit and a down-conversion and analog-to-digital conversion unit which are electrically connected in sequence; the input end of the low-noise amplifier is electrically connected with the output end of the duplexer; the output end of the down-conversion and analog-to-digital conversion unit is electrically connected with the input end of the digital processing unit.
The invention provides a wireless transceiver, which comprises a device for adaptively counteracting a passive intermodulation signal, wherein a duplexer of the device for adaptively counteracting the passive intermodulation signal is a duplexer of the wireless transceiver; the passive intermodulation detection circuit of the device for adaptively counteracting the passive intermodulation signal reuses components or units of a receiving link of wireless transceiver equipment, or a passive intermodulation detection circuit is newly added in the wireless transceiver equipment; the transmitting circuit unit of the device for adaptively counteracting the passive intermodulation signal multiplexes components or units of a transmitting link of the wireless transceiving equipment; the digital processing unit of the device for adaptively counteracting the passive intermodulation signal multiplexes components or units of a digital processing unit of wireless transceiving equipment, or a digital processing unit is newly added in the wireless transceiving equipment and is integrated in the whole program of the wireless transceiving equipment; a first coupler of the device for adaptively counteracting the passive intermodulation signal needs to be newly added in the wireless transceiver, and one main access port of the first coupler is connected with a duplexer antenna port of the wireless transceiver, or one main access port of the first coupler is connected with a duplexer transmitting port of the wireless transceiver, and the coupling port of the first coupler is a forward coupling port relative to a transmitting signal of the wireless transceiver; a second coupler of the device for adaptively canceling the passive intermodulation signals needs to be newly added in the wireless transceiver, one main access port of the second coupler is connected with a duplexer receiving port of the wireless transceiver, the distance needs to be controlled within the range of 0-1 meter, the specific length is determined by the optimal effect of the passive intermodulation cancellation, and the coupling port of the second coupler is a reverse coupling port relative to the signals received by the wireless transceiver; the canceller circuit of the device for adaptively cancelling the passive intermodulation signal needs to be newly added in the wireless transceiver, one radio frequency input port of the canceller circuit is directly connected with the coupling port of the first coupler, the other radio frequency output port of the canceller circuit is directly connected with the coupling port of the second coupler, and the amplitude adjustment and the phase adjustment of the canceller circuit are realized by the amplitude and phase control parameters output by the operation of the digital processing unit; the antenna feeder component and the antenna of the device for adaptively counteracting the passive intermodulation signal are the corresponding component and the antenna on the antenna link of the wireless transceiver;
when the wireless transceiver has a plurality of transceiving links, the duplexer in each transceiving link needs to be provided with a set of first coupler, second coupler and canceller circuit.
The invention provides a method for self-adaptively counteracting a passive intermodulation signal in a wireless transceiving system, which is characterized by comprising the following steps: the method comprises the following steps of,
s1: acquiring information such as transmission signal bandwidth and frequency band, receiving signal bandwidth and frequency band, order and frequency band information of main interference components in the passive intermodulation signals, an expected passive intermodulation preset value, initial empirical data of curves, amplitudes and phases changing along with time, maximum cancellation times and the like through a digital processing unit, and converting the information into corresponding configuration parameters;
s2: according to the configuration parameters of the relevant transmitting signals in the step S1, the digital processing unit obtains the frequency points of the passive intermodulation signals, converts the frequency points into corresponding digital filtering parameters and stores the parameters into a parameter configuration table;
s3: according to the configuration parameters related to the received signal, the configuration parameters of the passive intermodulation signal and the digital filtering parameters of the passive intermodulation signal obtained in the step S2 in the step S1, the digital processing unit performs digital filtering on the sampling signal of the passive intermodulation detection circuit, filters out other signal components except the passive intermodulation signal, and obtains the amplitude value of the passive intermodulation signal falling into the receiving frequency band; the algorithm for obtaining the amplitude value includes, but is not limited to, a piecewise integration method, a direct integration method according to the signal bandwidth;
s4: judging the current working state; the state identification default values of the working states are: "initial operating mode"; if the state identification value of the operation state is the "initial operation mode", continuing to the step S5-1, otherwise continuing to the step S5-2;
s5-1: comparing the passive intermodulation signal amplitude value obtained in the step S3 with the passive intermodulation preset value in the step S1 to determine whether the passive intermodulation signal amplitude is less than or equal to the passive intermodulation preset value;
s6: if the judgment result of the step S5-1 is 'yes', the canceller circuit continues to keep the high-isolation state of the link between the intermodulation signal generator and the first coupler; and returns to step S2;
s7: if the judgment result of the step S5-1 is 'NO', the canceller circuit is switched to a low-isolation state of a link between the intermodulation signal generator and the first coupler; and the state identification value of the working state is set as the 'counteracting working state'; continuing to execute step S8;
s5-2: comparing the passive intermodulation signal amplitude value obtained in the step S3 with the passive intermodulation preset value in the step S1 to determine whether the passive intermodulation signal amplitude is less than or equal to the passive intermodulation preset value; if the judgment result of the step S5-2 is YES, the state is maintained, and the process returns to the step S2; if the judgment result of the step S5-2 is NO, executing a step S8;
s8: calculating the amplitude and phase adjustment values of the canceller circuit according to the amplitude value of the passive intermodulation signal in the step S3; and the signals are distributed to an amplitude modulator and a phase modulator in a canceller circuit to implement cancellation; after the current round of cancellation processing is completed, the process will continue to return to step S2 to continue the next round of cancellation processing; the algorithm for obtaining the amplitude and phase adjustment value includes, but is not limited to, a two-dimensional minimum variance algorithm.
The invention can cancel the passive intermodulation signal generated by the wireless transceiver and the component of the passive intermodulation signal generated by any device or component in the link behind the antenna port of the wireless transceiver, which falls into the receiving frequency band, on the radio frequency link in the wireless transceiver, and obtain a result which is better than the preset passive intermodulation requirement index at the receiving port of the passive device. The invention can reduce the requirement on the passive intermodulation index of each device in the wireless transceiving system under the condition of keeping the passive intermodulation index of the system unchanged, thereby reducing the manufacturing cost of each passive device. The invention can also be used to eliminate the effect of passive intermodulation index degradation due to the increase of the operating time of the components or antennas on the duplexer or its antenna link, thereby prolonging the life cycle of the wireless transceiving system. The invention can also promote the index to be above the preset value when the system needs a better passive intermodulation index. When the passive intermodulation cancellation of the duplexer of the wireless transceiver and the antenna link thereof is carried out and a result which is better than a preset passive intermodulation requirement index is obtained at the receiving port of the duplexer, the invention does not generate adverse effect on the linear performance of the transmitting signal and the linear performance of the receiving signal. The invention adopts the active intermodulation offset circuit, so that the adjustment of the phase and the amplitude of the signal can be quantized, and the adjustment precision and the accuracy are improved. The passive intermodulation signal cancellation effect can be monitored in real time and dynamically adjusted in a self-adaptive manner due to the adoption of the feedback link of the passive intermodulation signal cancellation effect, so that when the power level and the working frequency of a signal passing through the passive device or a subsequent link are changed and the environmental temperature and the like are changed, the passive intermodulation signal cancellation effect can be dynamically responded in real time, and the passive intermodulation signal cancellation result meets an expected target value.
Drawings
Fig. 1 is a schematic structural diagram of a first apparatus for adaptively canceling a passive intermodulation signal according to an embodiment of the present invention.
Fig. 2 is a schematic structural diagram of a second position of the first coupler a in the apparatus according to the embodiment of the present invention.
Fig. 3 is a schematic diagram of a superheterodyne structure of the passive intermodulation detection circuit D in the embodiment of the present invention.
Fig. 4 is a schematic diagram of a receiving zero intermediate frequency structure of the passive intermodulation detection circuit D in the embodiment of the present invention.
Fig. 5 is a flowchart illustrating a method for adaptively canceling a passive intermodulation signal in a wireless transceiving system according to an embodiment of the present invention.
Table 1 shows a passive intermodulation cancellation test record for an apparatus according to an embodiment of the present invention.
FIG. 6 is a diagram of the cancellation effect of the 3 rd order component of the apparatus according to the embodiment of the present invention.
Fig. 7 is a diagram illustrating the cancellation effect of the 5 th order component after the 3 rd order component is cancelled by the apparatus according to the embodiment of the present invention.
Fig. 8 is a schematic structural diagram of a wireless transceiver device with a function of adaptively canceling a passive intermodulation signal according to an embodiment of the present invention.
Fig. 9 is a diagram illustrating the cancellation effect of the 3 rd order component after the embodiment of the present invention is applied to the wireless transceiver device.
Fig. 10 is a diagram illustrating a result of ACPR testing of low frequency point signals in dual carrier transmit signals when the passive intermodulation cancellation function is not turned on after the wireless transceiver device is used in accordance with an embodiment of the present invention.
Fig. 11 is a diagram illustrating a result of ACPR testing of a high frequency signal in a dual carrier transmission signal when the passive intermodulation cancellation function is not turned on after the wireless transceiver device is used in an embodiment of the present invention.
Fig. 12 is a diagram illustrating a result of ACPR testing of low frequency point signals in dual carrier transmit signals when the passive intermodulation cancellation function is turned on after the wireless transceiver device according to the embodiment of the present invention.
Fig. 13 is a diagram illustrating a result of ACPR testing of a high frequency signal in a dual carrier transmission signal when the passive intermodulation cancellation function is turned on after the wireless transceiver device according to the embodiment of the present invention.
Fig. 14 is a diagram illustrating a low frequency point signal EVM test result when the passive intermodulation cancellation function is not turned on and the received signal is looped back to the transmission link after the wireless transceiver device according to the embodiment of the present invention is used.
Fig. 15 is a diagram illustrating a result of an EVM test of a high-frequency point signal when a passive intermodulation cancellation function is not turned on and a received signal is looped back to a transmission link after the wireless transceiver device according to the embodiment of the present invention is used.
Fig. 16 is a diagram illustrating a low frequency point signal EVM test result when the passive intermodulation cancellation function is turned on and then the received signal is looped back to the transmission link after the wireless transceiver device according to the embodiment of the present invention is used.
Fig. 17 is a diagram illustrating a result of an EVM test of a high-frequency point signal when the passive intermodulation cancellation function is turned on and a received signal is looped back to a transmission link after the wireless transceiver device according to the embodiment of the present invention is used.
FIG. 18 is a schematic structural diagram of a wireless repeater according to an embodiment of the present invention, capable of adaptively canceling a passive intermodulation signal.
Fig. 19 is a schematic structural diagram of a microwave transceiver capable of adaptively canceling a passive intermodulation signal according to an embodiment of the present invention.
Fig. 20 is a diagram illustrating an example of a wireless transceiver device and one of a plurality of transceiver links in accordance with an embodiment of the present invention.
Fig. 21 is a diagram illustrating an example of a wireless transceiver device having multiple transceiving links in accordance with an embodiment of the present invention.
Detailed Description
The invention will be further described in detail with reference to the following drawings and specific examples, which are not intended to limit the invention, but are for clear understanding.
As shown in fig. 1, the present invention relates to an apparatus for adaptively canceling a passive intermodulation signal, which comprises a first coupler a, a canceller circuit B, a second coupler B5, a passive intermodulation detection circuit D, a digital processing unit E, a duplexer a0, a transmitting circuit unit F, an antenna feed assembly a2, and an antenna a 1; the duplexer a0 in the apparatus represents a passive device in the radio; the antenna feed assembly a2 and antenna a1 represent passive devices in an antenna link of a wireless transceiver system, and the antenna feed assembly a2 represents a combination of single or multiple passive devices in the antenna link, including but not limited to cables, connectors, couplers, and combiners.
The transmitting circuit unit F receives the control signal from the digital processing unit E and sends a transmitting signal, and the transmitting signal of the transmitting circuit unit F which is larger than a certain radio frequency power value enables the duplexer A0 and the antenna link thereof to generate a passive intermodulation signal; the transmission signal is formed by a multi-tone signal or a multi-carrier modulation signal. In this embodiment, the signal of the transmitting circuit unit F greater than 40dBm causes the duplexer a0 and the antenna feed module a2 and the antenna a1 on the antenna link thereof to generate a passive intermodulation signal, and the passive intermodulation signal has a component which falls into the receiving band of the duplexer a0 and has a certain frequency interval with the receiving signal, and the component which falls into the receiving band of the duplexer a0 may include a single 3-order component, or a single 5-order component, even a single higher-order component, or a plurality of different frequency 3-order components, or a plurality of different frequency 5-order components, even a plurality of different frequency higher-order components, or both A3-order component and a 5-order component, or even a higher-order component depending on the different configuration of the transmitting signal; in the embodiment, the transmitting frequency range is 925MHz to 960MHz, and the receiving frequency range is 880MHz to 915 MHz;
the first coupler A couples a radio frequency signal from a link of an antenna port of the duplexer A0 and outputs the radio frequency signal to a canceller circuit B; the radio frequency signals comprise transmitting signals, passive intermodulation signals and receiving signals; one main path port of the first coupler A is directly connected with an antenna port of the duplexer A0, the other main path port of the first coupler A is connected with an antenna feeder component A2 on an antenna link, and a coupling port of the first coupler A is connected with one radio frequency port of a canceller circuit B; the second coupler B5 superimposes the intermodulation cancellation signal generated by the canceller circuit B on the link behind the duplexer a0 receiving port, one main path port of the second coupler B5 is directly connected with the duplexer a0 receiving port, and the distance needs to be controlled within a range of 0 to 1 meter, in this embodiment, the distance is 0 meter, and the specific length is determined by the optimal effect of passive intermodulation cancellation. The main path port is a first main path port, the other main path port is connected with the passive intermodulation detection circuit D to form a second main path port, and the coupling port of the second coupler B5 is connected with the other radio frequency port of the canceller circuit B.
When only a single 3-order, or a single 5-order or a single higher-order component in a passive intermodulation signal which is generated by the duplexer a0 or the antenna feed component a2 or the antenna a1 at the same time or is generated by a plurality of passive devices and superimposed at a certain frequency interval with a receiving signal falls into a receiving frequency band of the duplexer a0 and causes a passive intermodulation index tested from a receiving port of the duplexer a0 to not meet a preset value requirement, in order to enable a passive intermodulation value behind a second main channel port of a second coupler B5 behind the receiving port of the duplexer a0 to meet the preset value requirement and enable the cancellation capacity of the device to be greater than 20 dB:
the canceller circuit B using the transmit signal in the obtained radio frequency signal to generate an intermodulation signal at an intermodulation signal generator B2 in canceller circuit B having the same frequency, different amplitude and different phase as the passive intermodulation signal; the amplitude of the intermodulation signal generated by the power of the receiving signal and the passive intermodulation signal in the radio frequency signal on the intermodulation signal generator B2 is much smaller than that of the passive intermodulation signal, and does not affect the passive intermodulation cancellation result; after the intermodulation signals are reflected, the intermodulation signals are subjected to amplitude adjustment and phase adjustment through an amplitude modulation phase modulator B1 in a canceller circuit B, and are coupled and output to a main channel of a second coupler B5, intermodulation cancellation signals which are the same in frequency, the same in amplitude and opposite in phase with components falling into a receiving frequency band and having a certain frequency interval with the receiving signals in the passive intermodulation signals are formed, the intermodulation cancellation signals are cancelled with the components falling into the receiving frequency band in the passive intermodulation signals, and the cancelled passive intermodulation signals are smaller than or equal to a passive intermodulation preset value; meanwhile, the transmitting signal and the receiving signal in the duplexer A0 and the antenna link thereof normally operate in the duplexer A0 and the antenna link thereof; in addition, the maximum amplitude of the intermodulation cancellation signal that can be generated by the intermodulation signal generator B2 is greater than the amplitude of a single component of the passive intermodulation signal of the duplexer a0 and its antenna link that falls within the frequency corresponding to the receiving band;
when only 3-order of a plurality of different frequencies, or 5-order of a plurality of different frequencies, or higher-order components of a plurality of different frequencies, in a passive intermodulation signal which is generated by a single duplexer A0 or an antenna feed component A2 or an antenna A1 or is formed by simultaneously generating and superposing a plurality of passive devices and has a certain frequency interval with a receiving signal fall into a receiving frequency band of the duplexer A0 and causes a passive intermodulation index tested from a receiving port of the duplexer A0 to be not up to a preset value requirement, the passive intermodulation value behind a second main channel port of a second coupler B5 behind the receiving port of the duplexer A0 meets the preset value requirement and the cancellation capability of the device is larger than 20 dB.
The transmitting signal input into the radio frequency signal of the canceller circuit B is processed by a radio frequency switch B3, an amplitude modulation circuit 3, a circulator 4 and an intermodulation signal generator B2 to generate an intermodulation signal with the same frequency, different amplitude and different phase as the passive intermodulation signal, and the intermodulation signal falls into a single 3-order component, a single 5-order component or a single higher-order component of a receiving frequency band, or 3-order components of a plurality of different frequency points, or 5-order components of a plurality of different frequency points, or higher-order components of a plurality of different frequency points, or simultaneously the amplitude relation and the phase relation between the 3-order component, the 5-order component and even higher-order components and the single 3-order component, or the single 5-order component, or the single higher-order component, or the 3-order components of a plurality of different receiving frequency points in the passive intermodulation signal generated by the duplexer A0 and an antenna link thereof, Or 5-order components of a plurality of different frequency points, or higher-order components of a plurality of different frequency points, or simultaneously, the amplitude relation and the phase relation between 3-order components, 5-order components and even higher-order components are basically consistent; the amplitude of the intermodulation signal generated by the power of the receiving signal and the passive intermodulation signal in the radio frequency signal on the intermodulation signal generator B2 is much smaller than that of the passive intermodulation signal, and does not affect the passive intermodulation cancellation result; after the intermodulation signals are reflected, the intermodulation signals are subjected to amplitude adjustment and phase adjustment through an amplitude modulation phase modulator B1 in a canceller circuit B, and are coupled and output to a main channel of a second coupler B5, intermodulation cancellation signals which are the same in frequency, the same in amplitude and opposite in phase with components falling into a receiving frequency band and having a certain frequency interval with the receiving signals in the passive intermodulation signals are formed, the intermodulation cancellation signals are cancelled with the components falling into the receiving frequency band in the passive intermodulation signals, and the cancelled passive intermodulation signals are smaller than or equal to a passive intermodulation preset value; meanwhile, the transmitting signal and the receiving signal in the duplexer A0 and the antenna link thereof normally operate in the duplexer A0 and the antenna link thereof; furthermore, the maximum amplitude of the intermodulation cancellation signal of the corresponding passive intermodulation product frequency which can be generated by the intermodulation signal generator B2 is greater than the amplitude of the corresponding frequency components falling into the reception band in the passive intermodulation signal of the duplexer a0 and its antenna link.
For the above three cases, when actually selecting the specific device constituting the intermodulation signal generator B2, the intermodulation signal generator B2 should generate the intermodulation signal with the same frequency, different amplitude and different phase as the passive intermodulation signal in the radio frequency signal, and the intermodulation signal falls into the single 3 rd order component, or the single 5 th order component, or the single higher order component of the receiving band, or the 3 rd order components of a plurality of different frequency points, or the 5 th order components of a plurality of different frequency points, or the higher order components of a plurality of different frequency points, or the amplitude relationship and the phase relationship between the 3 rd order component, the 5 th order component and even the higher order component, and the single 3 rd order component, or the single 5 th order component, or the single higher order component, or the 3 rd order components of a plurality of different frequency points in the intermodulation signal generated by the duplexer a0 and the antenna link thereof, Or 5-order components of a plurality of different frequency points, or higher-order components of a plurality of different frequency points, or simultaneously, the amplitude relation and the phase relation between 3-order components, 5-order components and even higher-order components are basically consistent; and the maximum amplitude of the intermodulation cancellation signal of the corresponding passive intermodulation product frequency which can be generated by the intermodulation signal generator B2 is greater than the amplitude of the corresponding frequency components falling into the receiving band in the passive intermodulation signal of the duplexer a0 and its antenna link;
for the three cases above, the first coupler a has a second position: the first coupler A is connected in series in a transmitting circuit unit F of the device, and one main path port is connected with a transmitting port of a duplexer A0; at the moment, the first coupler A directly couples the transmitting signal and outputs the transmitting signal to the canceller circuit B;
in the three cases, the amplitude adjustment and the phase adjustment of the amplitude modulation phase modulator B1 are realized by calculating the output amplitude and phase control parameters of the digital processing unit E; the calculation of the amplitude and phase control parameters of the digital processing unit E also requires a sampling signal of the passive intermodulation detection circuit D;
the radio frequency switch B3 in the canceller circuit B may be disabled when the amount of attenuation of the amplitude modulation circuit 3 may be such that the intermodulation signal generator B2 does not generate the intermodulation signals capable of affecting the passive intermodulation performance of the duplexer a 0; the filter 5 in the canceller circuit B may be located between the circulator 4 and the amplitude modulation phase modulator B1, or between the amplitude modulation phase modulator B1 and the second coupler B5;
the passive intermodulation detection circuit D is used for amplifying a radio frequency signal after the receiving port of the duplexer a0 with adjustable gain, performing down-conversion, finally converting the radio frequency signal into a digital signal and inputting the digital signal to the digital processing unit E, wherein the radio frequency port of the passive intermodulation detection circuit D is directly connected with the second main access port of the second coupler B5 after the receiving port of the duplexer a0, the radio frequency signal obtained by the circuit contains a component which falls into a receiving frequency band in the received signal and the passive intermodulation signal, and the receiving dynamic range of the circuit is greater than the difference between the maximum power value of the received signal and the power value corresponding to the passive intermodulation preset value; the passive intermodulation detection circuit D is connected with the digital processing unit E through a high-speed analog-to-digital converter, and the sampling rate of the high-speed analog-to-digital converter is more than or equal to 2 times of the receiving frequency band bandwidth of the duplexer A0.
When the radio frequency signal in the passive intermodulation detection circuit D is too large to cause the link blockage, the digital processing unit E reduces the link gain of the passive intermodulation detection circuit D so as to normally process the received signal and stop detecting the amplitude of the passive intermodulation signal; when the passive intermodulation detection circuit D is not blocked, the digital processing unit E includes a passive intermodulation signal and a reception signal in the passive intermodulation amplitude calculation process, and the signal from the passive intermodulation detection circuit D to be processed includes the passive intermodulation signal and the reception signal with a certain frequency interval therebetween; the method for calculating the amplitude of the passive intermodulation signal comprises the following steps: the digital processing unit E firstly calculates the frequency information of the passive intermodulation signal related to the frequency information of the transmitting signal according to the frequency information of the transmitting signal, then obtains the frequency interval between the frequency information and the bandwidth information of the receiving signal and the frequency and the bandwidth information of the passive intermodulation signal according to the frequency interval, and selects a proper algorithm to calculate the amplitude of the passive intermodulation signal according to the frequency interval; the algorithm for calculating the amplitude of the passive intermodulation signal includes, but is not limited to, a direct filter integration method and a segmented filter integration method: the direct filtering integration method is to perform direct digital filtering and integrate to obtain amplitude according to the bandwidth of the passive intermodulation signal, at the moment, the frequency interval between each order component of the passive intermodulation signal falling into a receiving frequency band and the receiving signal is more than or equal to the bandwidth of a transition band from a passband to a stopband of a digital filter in a digital filtering algorithm of the passive intermodulation signal, and the frequency interval is the basis of adopting the direct filtering integration method; the segmented filtering integration method is to divide the bandwidth of the passive intermodulation signal into a plurality of sub-bandwidths, perform digital filtering and integral calculation on the amplitude according to each sub-bandwidth, and then accumulate the amplitudes corresponding to all the sub-bandwidths to obtain the amplitude of the whole signal, wherein the frequency interval between each order component and the received signal is greater than or equal to the transition bandwidth from the digital filter passband of each order component side sub-band signal to the stopband, and the frequency interval is the basis of the segmented filtering integration method.
The digital processing unit E firstly calculates frequency information of the passive intermodulation signal related to the frequency information of the transmitting signal according to the frequency information of the transmitting signal, converts the frequency information into a filtering parameter of the passive intermodulation signal, then obtains a frequency interval between the frequency information and the bandwidth information of the receiving signal and the frequency and the bandwidth information of the passive intermodulation signal according to the frequency and the bandwidth information of the receiving signal, and selects a corresponding digital filtering mode and an integral mode to finally realize amplitude detection of the passive intermodulation signal; then comparing the detection amplitude of the passive intermodulation signal with a passive intermodulation preset value: when the detected amplitude is smaller than or equal to the preset value, the canceller circuit B does not generate intermodulation cancellation signals and does not affect the passive intermodulation indexes of the duplexer a0 and the antenna link thereof; when the detected amplitude is larger than the preset value, the canceller circuit B is controlled to adjust the amplitude and the phase thereof to generate an intermodulation cancellation signal with the same frequency, the same amplitude and the opposite phase as the passive intermodulation signal of the duplexer a0 and the antenna link thereof, and the passive intermodulation signal in the radio frequency signal is cancelled, and the amplitude and the phase of the canceller circuit B are regulated and controlled in real time according to the amplitude detection result of the passive intermodulation signal, so that the passive intermodulation signal cancellation result is smaller than or equal to the preset value.
One method for acquiring the frequency information of the transmitting signal and the frequency information of the receiving signal by the digital processing unit E is to acquire the transmitting signal from the transmitting circuit unit F of the device by using a transmitting signal frequency discrimination circuit E1, convert the transmitting signal into a digital signal, input the digital signal to the digital processing unit E for frequency discrimination processing, acquire the frequency information of the relevant transmitting signal, and calculate the frequency information of the corresponding receiving signal according to the duplex frequency interval between the transmitting signal and the receiving signal; another method for obtaining the frequency information of the transmitted signal and the frequency information of the received signal is to obtain the frequency information of the transmitted signal and the frequency information of the received signal directly from the input information of the device through an information interaction interface in the digital processing unit E.
In this embodiment, the first coupler a has a second position, as shown in fig. 2: the first coupler A is connected in series in a transmitting circuit unit F of the device, one main access port is connected with a transmitting port of a duplexer A0, and the other main access port is connected with a radio frequency output port of a power amplifier in the transmitting circuit unit F; at the moment, the first coupler A directly couples the transmitting signal and outputs the transmitting signal to the canceller circuit B;
the device can be applied to digital wireless transceiving equipment and an antenna link thereof so as to offset unqualified passive intermodulation generated by a passive device, so that passive intermodulation indexes of the wireless transceiving equipment and the antenna link thereof meet a passive intermodulation preset value; when a plurality of wireless transceiving equipment are used simultaneously and the antenna links of each equipment are combined by the combiner and then connected with the antenna, the device corresponding to each antenna link can also counteract unqualified passive intermodulation generated by the passive devices on the antenna link, so that passive intermodulation indexes of the wireless transceiving equipment and the antenna links thereof meet a passive intermodulation preset value; the digital wireless transceiver includes, but is not limited to, a radio remote unit, a repeater, a radio station, a microwave transceiver, and the like, and the antenna link includes, but is not limited to, a cable, a connector, a coupler, a combiner, and an antenna.
The signals of the duplexer a0 and the antenna link thereof for generating the passive intermodulation signals and the signals for exciting the intermodulation signal generator B2 for generating the intermodulation signals are homologous and both originate from the transmitting signal of the transmitting circuit unit F, so that the passive intermodulation signals generated by the passive device and the intermodulation signals generated by the intermodulation signal generator B2 have the same frequency and the same bandwidth; the antenna link is a link from a duplexer a0 antenna port to an antenna a1, and the antenna feed assembly a2 represents a combination of single or multiple passive devices in the antenna link, including but not limited to cables, connectors, couplers, and combiners; the transmitting signal is composed of a multi-tone signal or a multi-carrier modulation signal;
when only a single 3-order, or a single 5-order or a single higher-order component in a passive intermodulation signal which is generated by the duplexer a0 or the antenna feed component a2 or the antenna a1 at the same time or is generated by a plurality of passive devices and superimposed at a certain frequency interval with a receiving signal falls into a receiving frequency band of the duplexer a0 and causes a passive intermodulation index tested from a receiving port of the duplexer a0 to not meet a preset value requirement, in order to enable a passive intermodulation value behind a second main channel port of a second coupler B5 behind the receiving port of the duplexer a0 to meet the preset value requirement and enable the cancellation capacity of the device to be greater than 20 dB: the maximum amplitude of the intermodulation cancellation signal generated by the intermodulation signal generator B2 is greater than the amplitude of a single component of the passive intermodulation signal of the duplexer a0 and its antenna link that falls into the corresponding frequency of the receiving band;
when only 3-order of a plurality of different frequencies, or 5-order of a plurality of different frequencies, or higher-order components of a plurality of different frequencies, in a passive intermodulation signal which is generated by a single duplexer A0 or an antenna feed component A2 or an antenna A1 or is formed by simultaneously generating and superposing a plurality of passive devices and has a certain frequency interval with a receiving signal, fall into a receiving frequency band of the duplexer A0 and cause a passive intermodulation index tested from a receiving port of the duplexer A0 to be not meet a preset value requirement, in order to enable a passive intermodulation value behind a second main channel port of a second coupler B5 behind the receiving port of the duplexer A0 to meet the preset value requirement and enable the cancellation capacity of the device to be greater than 20 dB: the maximum amplitude of the intermodulation cancellation signal corresponding to the passive intermodulation product frequency, which can be generated by the intermodulation signal generator B2, is greater than the amplitudes of the corresponding frequency components falling into the receiving band in the passive intermodulation signals of the duplexer a0 and its antenna link; the phase relationship between the plurality of specific order components in the intermodulation signal generated at the intermodulation signal generator B2 is substantially identical to the phase relationship between the plurality of specific order components in the passive intermodulation signal generated by the duplexer a0 and its antenna link;
when 3-, 5-or higher-order components simultaneously fall into a receiving band of the duplexer a0 and passive intermodulation indexes tested from a receiving port of the duplexer a0 do not meet a preset value requirement in a passive intermodulation signal which is generated by the duplexer a0 or an antenna feed component a2 or an antenna a1 singly or is formed by simultaneously generating and superposing a plurality of passive devices and has a certain frequency interval with the receiving signal, in order to enable the passive intermodulation value after a second main path port of a second coupler B5 behind the receiving port of the duplexer a0 to meet the preset value requirement and enable the cancellation capability of the device to be greater than 20 dB: the maximum amplitude of the intermodulation cancellation signal of the corresponding passive intermodulation product frequency which can be generated by the intermodulation signal generator B2 is greater than the amplitude of the corresponding frequency components falling into the receiving band in the passive intermodulation signal of the duplexer a0 and its antenna link; the magnitude and phase relationships between the particular order components in the intermodulation signals generated at the intermodulation signal generator B2 are substantially identical to the magnitude and phase relationships between the particular order components in the passive intermodulation signals generated by the duplexer a0 and its antenna link.
In the above technical solution, the requirement for the passive intermodulation index of the duplexer a0 or the antenna feeder module a2 and the antenna a1 on the antenna link of the apparatus can be reduced, so that the passive intermodulation index of the apparatus can be maintained to meet a preset value by the passive intermodulation cancellation function of the apparatus, and even when the apparatus has surplus cancellation capability, the passive intermodulation index of the apparatus is better, so as to improve or promote the sensitivity of the receiver caused by the deterioration of the passive intermodulation. Meanwhile, the influence of the deterioration of the passive intermodulation index caused by the increase of the antenna feed component A2 or the antenna A1 along with the working time on the duplexer A0 or the antenna link thereof in the device can be eliminated, and the passive intermodulation index of the device is better even when the device has surplus cancellation capability so as to improve or promote the sensitivity of a receiver caused by the deterioration of the passive intermodulation; furthermore, when the passive intermodulation index of the duplexer a0 or the antenna feed module a2 and the antenna a1 on the antenna link of the device needs to be better, the passive intermodulation index value of the device can be improved, so as to further improve the sensitivity of the receiver caused by insufficient passive intermodulation.
One port of the canceller circuit B is directly connected with the antenna port of the duplexer A0 through the first coupler A, or is directly connected with the transmitting port of the duplexer A0 through the first coupler A; the other port of the canceller circuit B is connected with a link behind a receiving port of the duplexer A0 through a second coupler B5; the first main path port of the second coupler B5 is connected to the receiving port of the duplexer a0, and the connection distance needs to be controlled within a range of 0 to 1 meter, in this embodiment, the distance is 0 meter when the coupler is directly connected. A second main channel port of the second coupler B5 is connected with a radio frequency input end of the passive intermodulation detection circuit D, and a coupling port of the second coupler B5 is connected with the canceller circuit B; the insertion loss of the first coupler A is less than 0.2 dB; the coupling degree of the first coupler a ranges from 25dB to 45dB, and about 30dB is selected in the present embodiment. The coupling port of the first coupler A is a forward coupling port relative to the transmitting signal; the carrying power of the first coupler a needs to be larger than the maximum transmission power peak value of the device, in this embodiment, the average power carried by the first coupler a is larger than 100 watts and the carried peak power is larger than 1000 watts. The bandwidth of the first coupler A needs to include a transmitting frequency band, and the gain fluctuation in the frequency band of the first coupler A is related to the transmitting frequency band and needs to be within a certain threshold value range; the passive intermodulation index of the first coupler A is-117 dBm/Hz; the insertion loss of the second coupler B5 is less than 0.2 dB; the coupling degree of the second coupler B5 ranges from 20dB to 40dB, and the coupling degree of the second coupler B5 in the embodiment is about 25 dB. The coupling port of the second coupler B5 is a reverse coupling port with respect to the received signal; the bandwidth of the second coupler B5 needs to include the receiving frequency band, and the gain fluctuation in the frequency band of the second coupler B5 is related to the receiving frequency band and needs to be within a certain threshold range; the threshold value of the load power of the canceller circuit B needs to be greater than or equal to the difference between the threshold value of the power of the first coupler a and the coupling degree of the first coupler a, that is, the threshold value of the average power loaded by the canceller circuit B is greater than or equal to 20dBm and the threshold value of the peak power loaded by the canceller circuit B is greater than or equal to 30 dBm. In order for the intermodulation signal generator B2 in the canceller circuit B to generate a passive intermodulation cancellation signal, the minimum value of the transmit signal power applied to the canceller circuit B needs to be greater than 10 watts;
the radio frequency port of the passive intermodulation detection circuit D is connected to the second main path port of the second coupler B5 behind the receiving port of the duplexer a0, so as to obtain a component that the received signal and the passive intermodulation signal fall into the receiving frequency band, and the receiving dynamic range of the passive intermodulation detection circuit D is greater than the difference between the maximum power value of the received signal and the power value corresponding to the passive intermodulation preset value. The receiving dynamic range of the passive intermodulation detection circuit D is larger than 70 dB; the passive intermodulation detection circuit D is connected with the digital processing unit E through a high-speed analog-to-digital converter, and the sampling rate of the high-speed analog-to-digital converter is more than or equal to 2 times of the receiving frequency band bandwidth of the duplexer A0;
the digital processing unit E is connected with the canceller circuit B through a multi-channel digital-to-analog converter, the control quantity of the amplitude and the phase is transmitted to the canceller circuit B, and the requirements of the amplitude adjustment precision and the phase adjustment precision of the canceller circuit B mainly come from the requirements of the passive intermodulation signal cancellation capacity. The digital-to-analog converter in the digital processing unit E has a bit range of 10-18 bits, and at least 3 digital-to-analog converters. In this embodiment, the amplitude adjustment precision of the canceller circuit B is less than 0.1dB and the phase adjustment precision is less than 1 degree.
At least two interfaces exist between the digital processing unit E and the passive intermodulation detection circuit D: one interface is used for acquiring a sampling signal of a high-speed analog-to-digital converter in the passive intermodulation detection circuit D so as to perform digital filtering and amplitude calculation on the passive intermodulation signal; the other interface is used for configuring parameters of the passive intermodulation detection circuit D, such as local oscillation frequency, amplifier gain and the like, through a bus, including but not limited to an I2C bus, an SPI bus;
when the method for acquiring the frequency information of the transmitting signal and the frequency information of the receiving signal by the digital processing unit E is to use the transmitting signal frequency discrimination circuit E1, the rf port of the transmitting signal frequency discrimination circuit E1 is connected to a certain position on the transmitting link in the transmitting circuit unit F, and the transmitting signal frequency discrimination circuit E1 is connected to the digital processing unit E through a high-speed analog-to-digital converter; meanwhile, an interface is arranged between the digital processing unit E and the transmission signal frequency discrimination circuit E1, and the function of the interface is to configure parameters of the transmission signal frequency discrimination circuit E1, such as local oscillator frequency, link gain and the like, through a bus, wherein the bus comprises but is not limited to an I2C bus and an SPI bus.
In order to meet the configuration requirement and monitoring requirement for the canceller circuit B, the passive intermodulation detection circuit D, or the transmission signal discriminator circuit E1, even the transmission circuit unit F, etc., the digital processing unit E at least comprises a logic processing and operation processing device with digital signal processing function for receiving digital signals, processing algorithms, outputting digital signals, controlling and configuring signals, etc., and the logic processing and operation processing device comprises but is not limited to a field programmable gate array device, a central processing unit, a digital signal processor.
The digital processing unit E is provided with at least one information interaction interface which has the functions of program downloading, configuration information input, remote alarm and maintenance; the configuration information to be input comprises the signal transmitting bandwidth and frequency band, the signal receiving bandwidth and frequency band, the order and frequency band information of main interference components in the passive intermodulation signals, the preset value of the passive intermodulation signals, a curve changing along with time and the maximum offset times of the passive intermodulation signals; the digital processing unit E can acquire the frequency information of the transmitted signal and the frequency information of the received signal through an information interaction interface; the information interaction interface can also perform data interaction with internet background resources: uploading a passive intermodulation value in the operation process of the equipment, an experience curve of the passive intermodulation value changing along with time, and state information of each module circuit in the passive intermodulation signal self-adaptive offset device; or downloading the passive intermodulation signal preset value after comprehensive optimization and the curve changing along with time.
One end of an amplitude modulation circuit 3 in the canceller circuit B is directly connected with a coupling port of the first coupler A, or is connected with the coupling port of the first coupler A through a radio frequency switch B3; the other end is connected with an intermodulation signal generator B2 through a circulator 4; from the intermodulation signal generator B2 to the second coupler B5 in the canceller circuit B. There are two configurations of links coupling ports: the first one is that an intermodulation signal generator B2 is connected with a filter 5 through a circulator 4, then one end of an amplitude modulation phase modulator B1 is connected with the filter 5, and the other end is connected with a coupling port of a second coupler B5; the second one is that an intermodulation signal generator B2 is connected with an amplitude modulation and phase modulation device B1 through a circulator 4, then one end of a filter 5 is connected with an amplitude modulation and phase modulation device B1, and the other end is connected with a coupling port of a second coupler B5; the amplitude modulation and phase modulation device B1 is composed of an amplitude modulation circuit 1 and a phase modulation circuit 2; the amplitude modulation circuit 1 at least comprises 1 adjustable attenuator; the phase modulation circuit 2 at least comprises 2 adjustable phase shifters; the amplitude modulation circuit 3 is composed of a fixed attenuator or an adjustable attenuator; the frequency bandwidth of the circulator 4 comprises the transmitting frequency band and the receiving frequency band of the duplexer a 0; the amplitude adjustment range of the amplitude modulation phase modulator B1 is larger than 30dB, and the phase adjustment range is larger than 180 degrees; the working frequency band of the amplitude modulation phase modulator B1 comprises the receiving frequency band of the duplexer A0, and the gain fluctuation in the frequency band of the amplitude modulation phase modulator B1 is related to the receiving frequency band and needs to be in a certain threshold value range; the passband frequency band of the filter 5 is the receiving frequency band of the duplexer a0, and the out-of-band rejection index requirement of the filter 5 is determined by the out-of-band rejection index of the receiving frequency band of the duplexer a0, the coupling degree of the first coupler a, the coupling degree of the second coupler B5, the link loss between the coupling end of the first coupler a and the coupling end of the second coupler B5 in the canceller circuit B, and the like; the carrying power of the amplitude modulation circuit 3 in the canceller circuit B is greater than or equal to the carrying power threshold of the canceller circuit B in claim 5. In this embodiment, the average power threshold value carried by the amplitude modulation circuit 3 in the canceller circuit B is greater than or equal to 20dBm, and the peak power threshold value carried by the amplitude modulation circuit is greater than or equal to 30 dBm;
further, the transmitting signal input to the canceller circuit B is input to the am circuit 3 through the rf switch B3 or directly input to the am circuit 3, and then is input to the intermodulation signal generator B2 through the circulator 4 after being adjusted by the power of the am circuit 3, so that the intermodulation signal generator B2 generates an intermodulation signal having the same frequency, different amplitude and different phase from the passive intermodulation signal, and the intermodulation signal falls into a single 3-order component, or a single 5-order component, or a single higher-order component of the receiving band, or 3-order components of a plurality of different frequency points, or 5-order components of a plurality of different frequency points, or higher-order components of a plurality of different frequency points, or the amplitude relationship and phase relationship between the 3-order components, 5-order components and even higher-order components of the passive intermodulation signal generated by the duplexer a0 and the antenna link thereof fall into the single 3-order component of the receiving band, Or a single 5-order component, or a single higher-order component, or 3-order components of a plurality of different frequency points, or 5-order components of a plurality of different frequency points, or higher-order components of a plurality of different frequency points, or simultaneously, the amplitude relation and the phase relation between the 3-order components, the 5-order components and even the higher-order components are basically consistent; after the intermodulation signals are reflected, the intermodulation signals pass through the circulator 4 again, pass through the filter 5, pass through amplitude adjustment and phase adjustment of the amplitude modulation phase modulator B1, and are coupled and output to a main channel of a second coupler B5, so that intermodulation cancellation signals which are the same as the frequency of components falling into a receiving frequency band in the passive intermodulation signals and have certain frequency interval with the receiving signals, have the same amplitude and are opposite in phase are formed, the intermodulation cancellation signals are cancelled with the components falling into the receiving frequency band in the passive intermodulation signals, and the cancelled passive intermodulation signals are smaller than or equal to a passive intermodulation preset value; meanwhile, the transmitting signal and the receiving signal in the duplexer A0 and the antenna link thereof normally operate in the duplexer A0 and the antenna link thereof; the radio frequency switch B3 in the canceller circuit B may be disabled when the amount of attenuation of the amplitude modulation circuit 3 may be such that the intermodulation signal generator B2 does not generate the intermodulation signals capable of affecting the passive intermodulation performance of the duplexer a 0; the filter 5 in the canceller circuit B may be located between the circulator 4 and the amplitude modulation phase modulator B1 or between the amplitude modulation phase modulator B1 and the second coupler B5.
The intermodulation signal generator B2 in the canceller circuit B includes, but is not limited to, a single diode, a single triode, or a parallel configuration of multiple diodes; the specific type of the diode or the specific type of the triode is related to the amplitude characteristic and the phase characteristic of the intermodulation signal of 3 rd order, 5 th order or higher order, which are required by the intermodulation signal generator B2; when a plurality of diodes with the same type are connected in parallel, the intensity of intermodulation signals is enhanced; the intermodulation signal generator B2 has a carrying power greater than or equal to the difference between the canceller circuit B carrying power threshold and the link loss from the canceller circuit B radio frequency input port to the intermodulation signal generator B2. The carrying power of the intermodulation signal generator B2 in this embodiment is greater than or equal to 20 dBm.
The passive intermodulation detection circuit D at least comprises a low-noise amplifier, a down-conversion module and a high-speed analog-to-digital converter; the noise coefficient of the low noise amplifier is less than 1 dB; the down-conversion module can convert the received radio frequency signal into an intermediate frequency signal; the sampling dynamic range of the high-speed analog-to-digital converter needs to be larger than the difference value between the maximum power value of the received signal and the power value corresponding to the passive intermodulation preset value. In this embodiment, the sampling dynamic range of the high-speed analog-to-digital converter needs to be greater than 70dB, the number of bits of the analog-to-digital converter is 14 bits, and the sampling rate is greater than or equal to 2 times of the receiving frequency band bandwidth of the duplexer a 0. The minimum power that the passive intermodulation detection circuit D can sample is less than or equal to a passive intermodulation power value corresponding to a preset value, and in this embodiment, the minimum power that the passive intermodulation detection circuit D can sample is less than or equal to-115 dBm. Meanwhile, the circuit can adjust the gain of the link according to the amplitude of the total power of the received radio-frequency signals so as to avoid link blockage caused by received signals or other signals; the gain of the passive intermodulation detection circuit D is determined by a required passive intermodulation preset value, the minimum sampling power of a high-speed analog-to-digital converter in the passive intermodulation detection circuit D, a link noise coefficient and the like; the maximum value of the received signal power of the passive intermodulation detection circuit D is equal to or greater than the maximum received signal power specified by the communication standard to which the device actually corresponds. In this embodiment, the maximum value of the received signal power of the passive intermodulation detection circuit D is equal to or greater than-50 dBm.
The passive intermodulation detection circuit D may adopt a superheterodyne receiving structure as shown in fig. 3 to convert a radio frequency signal into an intermediate frequency signal and then perform analog-to-digital conversion, and at this time, the passive intermodulation detection circuit D is composed of a low noise amplifier D1, a radio frequency filtering and small signal amplifying unit D2, a mixer D3, a local oscillator D4, an intermediate frequency filter D5, an intermediate frequency amplifier D6, and an analog-to-digital converter D7, wherein a passband frequency band of a filter component in the radio frequency filtering and small signal amplifying unit D2 is a receiving frequency band of the duplexer a 0; the passive intermodulation detection circuit D may alternatively adopt a zero-if-frequency receiving structure as shown in fig. 4 to convert the radio frequency signal into a zero-if-frequency signal and then perform analog-to-digital conversion, and at this time, the passive intermodulation detection circuit D is composed of a low noise amplifier D1, a radio frequency filtering and small signal amplifying unit D2, and a down-conversion and analog-to-digital conversion unit D8, wherein a passband frequency band of a filtering component in the radio frequency filtering and small signal amplifying unit D2 is a receiving frequency band of the duplexer a0, and the down-conversion and analog-to-digital conversion unit D8 functions to directly convert the radio frequency signal into the zero-if-frequency signal and perform analog-to-digital conversion.
In this embodiment, the digital processing unit E at least includes a logic processing and operation processing device with a digital signal processing function, which is used for receiving digital signals, performing algorithm processing, outputting digital signals, controlling and configuring signals, and the like, and the logic processing and operation processing device includes but is not limited to a field programmable gate array device, a central processing unit, and a digital signal processor; the hardware of the information interaction interface of the digital processing unit E comprises but is not limited to an Ethernet interface and an RS-485 bus interface; the number of bits of the digital-to-analog converter in the digital processing unit E is within a range of 10 to 18 bits, in this embodiment, 12 bits, and at least 3 digital-to-analog converters are provided; the digital processing unit E runs a program corresponding to "a method for adaptively canceling a passive intermodulation signal in a wireless transceiving system", and a flowchart of the method is shown in fig. 5.
A method for self-adaptively canceling a passive intermodulation signal in a wireless transceiving system is characterized in that: the method comprises the following steps of,
s1: acquiring information such as the transmission signal bandwidth and frequency band, the receiving signal bandwidth and frequency band, the order and frequency band information of main interference components in the passive intermodulation signals, an expected passive intermodulation preset value, initial empirical data of curves, amplitudes and phases changing along with time, the maximum cancellation times and the like through a digital processing unit E, and converting the information into corresponding configuration parameters;
s2: according to the configuration parameters related to the transmitting signals in the step S1, the digital processing unit E obtains the frequency points of the passive intermodulation signals, converts the frequency points into corresponding digital filtering parameters, and stores the parameters into a parameter configuration table;
s3: according to the configuration parameters related to the received signal, the configuration parameters of the passive intermodulation signal and the digital filtering parameters of the passive intermodulation signal obtained in the step S2 in the step S1, the digital processing unit E performs digital filtering on the sampling signal of the passive intermodulation detection circuit D, filters out other signal components except the passive intermodulation signal, and obtains an amplitude value of the passive intermodulation signal falling into the receiving frequency band; the algorithm for obtaining the amplitude value includes, but is not limited to, a piecewise integration method, a direct integration method according to the signal bandwidth;
s4: judging the current working state; the state identification default values of the working states are: "initial operating mode"; if the state identification value of the operation state is the "initial operation mode", continuing to the step S5-1, otherwise continuing to the step S5-2;
s5-1: comparing the passive intermodulation signal amplitude value obtained in the step S3 with the passive intermodulation preset value in the step S1 to determine whether the passive intermodulation signal amplitude is less than or equal to the passive intermodulation preset value;
s6: if the judgment result of the step S5-1 is yes, the canceller circuit B continues to maintain the high isolation state of the link between the intermodulation signal generator and the first coupler a; and returns to step S2;
s7: if the judgment result of the step S5-1 is 'NO', the canceller circuit B switches to a low-isolation state of a link between the intermodulation signal generator and the first coupler A; and the state identification value of the working state is set as the 'counteracting working state'; continuing to execute step S8;
s5-2: comparing the passive intermodulation signal amplitude value obtained in the step S3 with the passive intermodulation preset value in the step S1 to determine whether the passive intermodulation signal amplitude is less than or equal to the passive intermodulation preset value; if the judgment result of the step S5-2 is YES, the state is maintained, and the process returns to the step S2; if the judgment result of the step S5-2 is NO, executing a step S8;
s8: calculating the amplitude and phase adjustment values of the canceller circuit according to the amplitude value of the passive intermodulation signal in the step S3; and the signals are distributed to an amplitude modulator and a phase modulator in a canceller circuit to implement cancellation; after the current round of cancellation processing is completed, the process will continue to return to step S2 to continue the next round of cancellation processing; the algorithm for obtaining the amplitude and phase adjustment value includes, but is not limited to, a two-dimensional minimum variance algorithm.
In this example, as shown in table 1: two single-tone signals of 43dBm in the transmitting circuit unit F form a double-tone signal of 46dBm, the double-tone signal causes the duplexer A0 and an antenna link thereof to generate a passive intermodulation signal, and the amplitude of A3-order component in the passive intermodulation actually tested at a receiving port of the duplexer A0 is-95.5 dBm, a 5-order component is-125.4 dBm, and a 7-order component is under thermal noise of a spectrometer; the components falling into the receiving frequency band in the passive intermodulation signals of the duplexer A0 and the antenna link thereof are less than or equal to a preset value of-112 dBm, so that the 3-order passive intermodulation is mainly optimized, and the amplitude difference between the 3-order signal and the 5-order signal is 29.9 dB; the test value of the intermodulation signal generated by the selected specific diode at the receiving port of the duplexer a0 is: the amplitude of the 3-order component is-75.1 dBm, the amplitude of the 5-order component is-105.6 dBm, and the amplitude of the 7-order component is under the thermal noise of a frequency spectrograph, so that the difference between the amplitudes of the 3-order signal and the 5-order signal is 30.5 dB; when the passive intermodulation cancellation function is turned on, the amplitude of the 3 rd order component in the passive intermodulation tested at the receiving port of the duplexer a0 is-117.4 dBm as shown in fig. 6, and the amplitude of the 5 th order component is-131.4 dBm as shown in fig. 7, and the 7 th order component is under the thermal noise of the spectrometer; it can be seen that the 3 rd order component, which causes the device passive intermodulation to be poor, is optimized 21.9dB and the 5 th order component is also optimized simultaneously. At the moment, the frequency interval between each order component of the passive intermodulation signal falling into the receiving frequency band and the receiving signal is more than or equal to 200 KHz;
an example of the practical application of the apparatus of the present embodiment to the wireless transceiver is shown in fig. 8: at this time, the duplexer a0 of the present apparatus is the duplexer a0 of the wireless transmitting and receiving device; the passive intermodulation detection circuit D of the device multiplexes components or units of a receiving link of wireless transceiving equipment, or a passive intermodulation detection circuit D is newly added in the wireless transceiving equipment, and corresponding adjustment is carried out according to a receiving frequency band of the wireless transceiving equipment. The transmitting circuit unit F of the device multiplexes components or units of a transmitting link of the wireless transmitting and receiving equipment and carries out corresponding adjustment according to the transmitting frequency band of the wireless transmitting and receiving equipment; the digital processing unit E of the device multiplexes the components or units of the digital processing unit of the wireless transceiving equipment; or adding a digital processing unit E in the wireless transceiver, wherein a program corresponding to the 'method for adaptively counteracting the passive intermodulation signal in the wireless transceiver system' in the digital processing unit E is integrated in the whole program of the wireless transceiver. The first coupler A of the device has one main path port connected to the antenna port of the duplexer A0 of the radio transceiver or has one main path port connected to the transmitting port of the duplexer A0 of the radio transceiver. The coupling port of the first coupler a is a forward coupling port with respect to the wireless transceiving device transmit signal. The second coupler B5 of the apparatus needs to be added to the radio. One main path port of a second coupler B5 of the device is directly connected with a duplexer A0 receiving port of a wireless transceiver, and a coupling port of a second coupler B5 is a reverse coupling port relative to a receiving signal of the wireless transceiver; one radio frequency input port of a canceller circuit B of the device is directly connected with a coupling port of a first coupler A, the other radio frequency output port of the canceller circuit B is directly connected with a coupling port of a second coupler B5, and amplitude adjustment and phase adjustment of the canceller circuit B are realized by amplitude and phase control parameters output by the operation of a digital processing unit E.
The wireless transceiver is a radio frequency remote device with a transmitting frequency band of 1805MHz to 1880MHz, a receiving frequency band of 1710MHz to 1785MHz, and FDDLTE system, and sets a transmitting signal 1 to 1820MHz/43dBm and a transmitting signal 2 to 1860MHz/43dBm, where the dual-tone signal causes a duplexer a0 and an antenna link thereof to generate a passive intermodulation signal, as shown in fig. 9: the amplitude of the 3 rd order component in the passive intermodulation tested at the receiving port of the duplexer A0 is-107.6 dBm/1780MHz, and the 5 th order component and the 7 th order component are under the thermal noise of the spectrometer; the components falling into the receiving frequency band in the passive intermodulation signals of the duplexer A0 and the antenna link thereof are less than or equal to a preset value of-110 dBm, so that 3-order passive intermodulation components are mainly optimized; when the passive intermodulation cancellation function is turned on, the 3 rd order component in the passive intermodulation tested at the receiving port of the duplexer a0 is shown in fig. 9, and the amplitude is-128.1 dBm; the 3-order component of the passive intermodulation failure of the equipment is optimized by 20.5 dB; then, the radio frequency remote equipment and the device work under an FDD LTE dual carrier, at this time, a transmission signal 1 is 1820MHz/44 dBmPeak/signal peak-to-average ratio is 7 dB/IBW-20 MHz, a transmission signal 2 is 1860MHz/44 dBmPeak/signal peak-to-average ratio is 7 dB/IBW-20 MHz, after the equipment loads the dual carrier signal, when a passive intermodulation cancellation function of the device is not started, the power of an adjacent ACPR channel corresponding to the transmission signal 1 is 49.7dBc/60.4dBc as shown in fig. 10, the power of the adjacent ACPR channel corresponding to the transmission signal 2 is 47.9dBc/60.4dBc as shown in fig. 11, and at this time, the strength indication of an RSSI reported value receiving signal of a detection receiving link is-60.59 dBfs; after the passive intermodulation cancellation function of the device is started, the power ratio of the adjacent channel of the ACPR corresponding to the transmitting signal 1 is 50.2dBc/60.5dBc as shown in figure 12, the power ratio of the adjacent channel of the ACPR corresponding to the transmitting signal 2 is 48.5dBc/60.3dBc as shown in figure 13, and the strength indication of the received signal of the RSSI reported value of the detection receiving link is-60.69 dBfs at the moment; in addition, the frequency points of the received signal 1 corresponding to the transmitted signal 1 are 1725Mhz, IBW is 20Mhz, the frequency points of the received signal 2 corresponding to the transmitted signal 2 are 1765Mhz, IBW is 20Mhz, the received signal is looped back to the transmission link and the EVM is tested, when the passive intermodulation cancellation function of the device is not turned on, the EVM of the received signal 1 is about 3.1% as shown in fig. 14, and the EVM of the received signal 2 is about 3.06% as shown in fig. 15; after the passive intermodulation cancellation function of the device is started, the EVM of the received signal 1 is about 3.1% as shown in fig. 16, and the EVM of the received signal 2 is about 3.06% as shown in fig. 17; before and after the passive intermodulation cancellation function of the device is started, the comparison of the ACPR values of the signals with the same frequency point and the comparison of the relevant indexes of the receiving link show that the passive intermodulation cancellation function of the device basically does not have adverse effects on the linear performance and the receiving performance of the transmitting signals.
In addition, an example of the apparatus of the present embodiment applied to a wireless repeater is shown in fig. 18: the wireless repeater comprises a first coupler A-1, a first coupler A-2, a second coupler B5-1, a second coupler B5-2, a canceller circuit B-1, a canceller circuit B-2, a receiving circuit unit D-1, a receiving circuit unit D-2, a digital processing unit E, a duplexer A0-1, a duplexer A0-2, a transmitting circuit unit F-1 and a transmitting circuit unit F-2; the duplexer A0-1 and the duplexer A0-2 are used as passive intermodulation index optimization objects and form two sets of devices with passive intermodulation cancellation functions around the duplexer, and the devices with the passive intermodulation cancellation functions can cancel out components falling into a receiving frequency band in passive intermodulation signals generated in the corresponding duplexer and an antenna link of the duplexer; the device with the passive intermodulation cancellation function, which is formed by taking the duplexer A0-1 as the passive intermodulation index optimization object, is called as a first device for short, and the device with the passive intermodulation cancellation function, which is formed by taking the duplexer A0-2 as the passive intermodulation index optimization object, is called as a second device for short; the description for the first device is: the duplexer A0 of the device is a duplexer A0-1 of a wireless repeater; a passive intermodulation detection circuit D of the device multiplexes components or units of a receiving link of the wireless repeater to form a passive intermodulation detection circuit D-1; the transmitting circuit unit F of the device multiplexes the transmitting circuit unit F-1 of the wireless repeater; a digital processing unit E of the device multiplexes a digital processing unit E of the wireless repeater, and a program corresponding to a method for self-adaptively counteracting a passive intermodulation signal in a wireless transceiving system in the digital processing unit E is integrated in a whole program of the wireless repeater; a first coupler A of the device needs to be newly added in the wireless repeater and is called as a first coupler A-1 in the first device, one main access port of the first coupler A-1 is directly connected with an antenna port of a duplexer A0-1 of the wireless repeater, a coupling port of the first coupler A-1 is connected with a radio frequency input port of a canceller circuit B-1, and a coupling port of the first coupler A-1 is a forward coupling port relative to a transmitting signal of the duplexer A0-1; the second coupler B5 of the device needs to be added in the wireless repeater and is called as a second coupler B5-1 in the first device, one main access port of the second coupler B3578-1 is directly connected with a receiving port of a duplexer A0-1, the other main access port of the second coupler B5-1 is connected with a radio frequency input port of a passive intermodulation detection circuit D-1, a coupling port of the second coupler B5-1 is connected with the other radio frequency output port of a canceller circuit B-1, and a coupling port of the second coupler B5-1 is a reverse coupling port relative to a receiving signal of the duplexer A0-1; the canceller circuit B of the device needs to be newly added in the wireless repeater to form a canceller circuit B-1, and the amplitude adjustment and the phase adjustment of the canceller circuit B-1 are realized by the amplitude and phase control parameters output by the operation of the digital processing unit E; an antenna feed component A2 and an antenna A1 of the device are corresponding components A2-1 and an antenna A1-1 on an antenna link of the wireless repeater; the description for the second device is: the duplexer A0 of the device is a duplexer A0-2 of a wireless repeater; a passive intermodulation detection circuit D of the device multiplexes components or units of a receiving link of the wireless repeater to form a passive intermodulation detection circuit D-2; the transmitting circuit unit F of the device multiplexes the transmitting circuit unit F-2 of the wireless repeater; a digital processing unit E of the device multiplexes a digital processing unit E of the wireless repeater, and a program corresponding to a method for self-adaptively counteracting a passive intermodulation signal in a wireless transceiving system in the digital processing unit E is integrated in a whole program of the wireless repeater; the first coupler A of the device needs to be newly added in the wireless repeater and is called as a first coupler A-2 in a second device, one main access port of the first coupler A-2 is directly connected with a duplexer A0-2 antenna port of the wireless repeater, a coupling port of the first coupler A-2 is connected with a radio frequency input port of a canceller circuit B-2, and a coupling port of the first coupler A-2 is a forward coupling port relative to a transmitting signal of the duplexer A0-2; the second coupler B5 of the device needs to be added in the wireless repeater and is called as a second coupler B5-2 in the second device, one main access port of the second coupler B3578-2 is directly connected with a receiving port of a duplexer A0-2, the other main access port of the second coupler B5-2 is connected with a radio frequency input port of a passive intermodulation detection circuit D-2, a coupling port of the second coupler B5-2 is connected with the other radio frequency output port of a canceller circuit B-2, and the coupling port of the second coupler B5-2 is a reverse coupling port relative to a receiving signal of the duplexer A0-2; the canceller circuit B of the device needs to be additionally arranged in the wireless repeater to form a canceller circuit B-2, and the amplitude adjustment and the phase adjustment of the canceller circuit B-2 are realized by the amplitude and phase control parameters output by the operation of the digital processing unit E; an antenna feed component A2 and an antenna A1 of the device are corresponding components A2-2 and an antenna A1-2 on an antenna link of the wireless repeater; at this time, the connection mode of the first device and the second device in the wireless repeater is the same as that of the device described in the invention, and the first device and the second device are combined into a whole through the digital processing unit E.
In addition, an example of the apparatus of the present embodiment is applied to a microwave transceiver device, as shown in fig. 19: the microwave transceiver comprises a first coupler A, a second coupler B5, a canceller circuit B, a receiving circuit unit D, a digital processing unit E, a duplexer A0 and a transmitting circuit unit F; a duplexer A0 is used as a passive intermodulation index optimization object and surrounds the duplexer to form a device with a passive intermodulation cancellation function, and the device with the passive intermodulation cancellation function can cancel components falling into a receiving frequency band in passive intermodulation signals generated in a duplexer A0 and an antenna link of the duplexer A0; the duplexer A0 of the device is a duplexer A0 of microwave transceiving equipment; a passive intermodulation detection circuit D of the device multiplexes components or units of a receiving link of microwave transceiving equipment to form the passive intermodulation detection circuit D; the transmitting circuit unit F of the device multiplexes the transmitting circuit unit F of the microwave transceiving equipment; a digital processing unit E of the device multiplexes a digital processing unit E of microwave transceiving equipment, a program corresponding to a method for adaptively counteracting a passive intermodulation signal in a wireless transceiving system in the digital processing unit E is integrated in a whole program of the microwave transceiving equipment, and transmitted signal frequency information is obtained by analyzing information from an information interaction interface by the digital processing unit E; the first coupler A of the device is required to be additionally arranged in the microwave transceiver and is called as the first coupler A in the device, one main access port of the first coupler A is directly connected with a duplexer A0 antenna port of the microwave transceiver, a coupling port of the first coupler A is connected with a radio frequency input port of a canceller circuit B, and the coupling port of the first coupler A is a forward coupling port relative to a transmitting signal of a duplexer A0; a second coupler B5 of the device needs to be added in the microwave transceiver and is called as a second coupler B5 in the device, one main path port of the second coupler B3578 is directly connected with a receiving port of a duplexer a0, the other main path port of the second coupler B3578 is connected with a radio frequency input port of a passive intermodulation detection circuit D, a coupling port of the second coupler B5 is connected with the other radio frequency output port of a canceller circuit B, and a coupling port of the second coupler B5 is a reverse coupling port relative to a receiving signal of the duplexer a 0; the canceller circuit B of the device needs to be newly added in the microwave transceiver to form the canceller circuit B, and the amplitude adjustment and the phase adjustment of the canceller circuit B are realized by the amplitude and phase control parameters output by the operation of the digital processing unit E; an antenna feed component A2 and an antenna A1 of the device are corresponding components A2 and an antenna A1 on an antenna link of the microwave transceiving equipment;
in addition, the apparatus of this embodiment is applied to a wireless transceiver device and the wireless transceiver device has a plurality of transceiving links: a set of a first coupler A, a second coupler B5 and a canceller circuit B are required to be arranged behind each antenna port of the duplexer in each transceiving link;
in addition, the apparatus described in this embodiment is applied to a wireless transceiver device, and a schematic diagram of one of the multiple rf links in the usage example is shown in fig. 20 in the description: the whole link comprises a plurality of wireless transceiving devices, a multi-radio-frequency system combiner H, an antenna A1, an antenna feeder assembly A2 and the like; each branch is connected with a single transceiving link of the wireless transceiving equipment by a passive intermodulation cancellation device, and passive intermodulation generated by a duplexer A0, an antenna A1, an antenna feeder component A2 and the like on each branch link and a component of passive intermodulation generated by a combiner H of the multi-radio-frequency system falling into a receiving frequency band can be cancelled in a certain range;
in addition, when the apparatus of this embodiment is applied to a wireless transceiver device, and the wireless transceiver device has a plurality of transceiving links, a schematic diagram of one of the use examples is shown in fig. 21 of the specification: the whole link comprises a wireless transceiving device, a plurality of antennas A1-1, A1-2, … … and a plurality of antenna feeder assemblies A2-1, A2-2, … …; each receiving and transmitting link of the wireless receiving and transmitting equipment is connected with a passive intermodulation cancellation device, and the components of passive intermodulation generated by a duplexer, an antenna feeder component, an antenna and the like on each branch link and falling into a receiving frequency band can be cancelled in a certain range;
after the device designed by the invention is arranged in a wireless transceiving system, when the component of the link passive intermodulation signal falling into the receiving frequency band is-90 dBm/Hz to-95 dBm/Hz, the device can enable the cancellation result of the passive intermodulation signal to be more than 20dB, and when the component of the link passive intermodulation signal falling into the receiving frequency band is better than-95 dBm/Hz, the device can enable the cancellation result of the passive intermodulation signal to be at least better than-115 dBm/Hz.
It should be understood that the above are only specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily made by those skilled in the art within the technical scope of the present invention disclosed herein should be covered within the scope of the present invention.

Claims (19)

1. An apparatus for adaptively canceling a passive intermodulation signal, comprising: the antenna comprises a first coupler (A), a canceller circuit (B), a second coupler (B5), a passive intermodulation detection circuit (D), a digital processing unit (E), a duplexer (A0), a transmitting circuit unit (F), an antenna feeder component (A2) and an antenna (A1); the signals of the transmitting circuit unit (F) which are larger than a certain radio frequency power value enable the duplexer (A0) and the antenna link thereof to generate passive intermodulation signals, and the passive intermodulation signals comprise components which fall into the receiving frequency band of the duplexer (A0) and have certain frequency intervals with the received signals; the first coupler (A) couples a radio frequency signal from a link of an antenna port of the duplexer (A0) and outputs the radio frequency signal to the canceller circuit (B); the radio frequency signal comprises a transmitting signal, a passive intermodulation signal and a receiving signal; one main path port of the first coupler (A) is connected with an antenna port of the duplexer (A0), the other main path port is connected with an antenna feeder component (A2) on an antenna link, and a coupling port of the first coupler (A) is connected with one radio frequency port of a canceller circuit (B); the second coupler (B5) superposes the intermodulation cancellation signal generated by the canceller circuit (B) on the link behind the receiving port of the duplexer (A0), one main path port of the second coupler (B5) is connected with the receiving port of the duplexer (A0), the main path port is a first main path port, the other main path port is connected with the passive intermodulation detection circuit (D) to be a second main path port, and the coupling port of the second coupler (B5) is connected with the other radio frequency port of the canceller circuit (B); an intermodulation signal generated by a transmitting signal in the radio frequency signal coupled to the canceller circuit (B) on the canceller circuit (B) is coupled and output to a main channel of a second coupler (B5) through amplitude adjustment and phase adjustment to form an intermodulation cancellation signal which has the same frequency, the same amplitude and the opposite phase with a component which falls into a receiving frequency band and has a certain frequency interval with the receiving signal in the passive intermodulation signal, a radio frequency port of the passive intermodulation detection circuit (D) is connected with a second main channel port of the second coupler (B5) behind a receiving port of a duplexer (a0) to obtain a component of the receiving signal and the passive intermodulation signal which fall into the receiving frequency band, and a receiving dynamic range of the passive intermodulation detection circuit (D) is larger than a difference value between a maximum power value of the receiving signal and a power value corresponding to a passive intermodulation preset value; the passive intermodulation detection circuit (D) is connected with the digital processing unit (E) through a high-speed analog-to-digital converter; the digital processing unit (E) calculates the detection amplitude of the passive intermodulation signal according to the frequency information of the transmitted signal and the sampling data of the passive intermodulation detection circuit (D) and compares the detection amplitude with a passive intermodulation preset value; when the detection amplitude is larger than the preset value, controlling the canceller circuit (B) to generate an intermodulation cancellation signal to cancel the component falling into the receiving frequency band in the passive intermodulation signal, and keeping the working state that the cancellation result of the component falling into the receiving frequency band in the passive intermodulation signal is smaller than or equal to the preset value according to the detection amplitude of the passive intermodulation signal; the digital processing unit (E) is connected with the canceller circuit (B) through a multi-channel digital-to-analog converter, and transmits the control quantity of the amplitude and the phase to the canceller circuit (B), and the requirements of the amplitude adjustment precision and the phase adjustment precision of the canceller circuit (B) mainly come from the requirement of the passive intermodulation signal cancellation capacity;
the digital processing unit (E) acquires a transmitting signal from a transmitting circuit unit (F) of the device through a transmitting signal frequency discrimination circuit (E1), converts the transmitting signal into a digital signal, inputs the digital signal into the digital processing unit (E) for frequency discrimination processing to acquire frequency information of the related transmitting signal, and calculates frequency information of the corresponding receiving signal according to a duplex frequency interval between the transmitting signal and the receiving signal; or directly obtaining the input information of the device through an information interaction interface in the digital processing unit (E); the digital processing unit (E) generates a trigger signal and outputs the trigger signal to the transmitting circuit unit (F) so as to trigger the transmitting circuit unit (F) to generate a radio frequency signal.
2. The apparatus of claim 1, wherein the apparatus is configured to adaptively cancel a passive intermodulation signal, and wherein: the duplexer (a0) in the apparatus represents a passive component in the radio; the antenna feed assembly (A2) and the antenna (A1) represent passive devices in an antenna link of a wireless transceiving system, and the antenna feed assembly (A2) represents a combination of single or multiple passive devices in the antenna link, wherein the passive devices comprise cables, connectors, couplers and combiners.
3. The apparatus of claim 1, wherein the apparatus is configured to adaptively cancel a passive intermodulation signal, and wherein: the transmitting signal input into the radio frequency signal of the canceller circuit (B) is processed by a radio frequency switch (B3), an amplitude modulation circuit (3), a circulator (4) and an intermodulation signal generator (B2) to generate an intermodulation signal which has the same frequency as the passive intermodulation signal, different amplitude and different phase, and a single 3-order component, a single 5-order component or a single higher-order component of the intermodulation signal, or 3-order components of a plurality of different frequency points, or 5-order components of a plurality of different frequency points, or higher-order components of a plurality of different frequency points, or simultaneously the amplitude relation and the phase relation between the 3-order components, the 5-order components and even higher-order components, and a single 3-order component, or a single 5-order component or a single higher-order component of the passive intermodulation signal generated by the duplexer (A0) and an antenna link thereof, which falls into the receiving frequency band, or 3-order components of a plurality of different frequency points, or 5-order components of a plurality of different frequency points, or higher-order components of a plurality of different frequency points, or simultaneously, the amplitude relation and the phase relation between the 3-order components, the 5-order components and even the higher-order components are consistent;
while the power of the passive intermodulation signal and the received signal in the radio frequency signal coupled to the canceller circuit (B) generates an intermodulation signal at the intermodulation signal generator (B2) having a magnitude much smaller than the magnitude of the passive intermodulation signal without affecting the passive intermodulation cancellation result;
after the intermodulation signals are reflected, the intermodulation signals pass through the circulator (4) again, pass through the filter (5), pass through amplitude adjustment and phase adjustment of the amplitude modulation phase modulator (B1), are coupled and output to a main channel of a second coupler (B5), intermodulation cancellation signals which have the same frequency, the same amplitude and the opposite phase with components falling into a receiving frequency band and having a certain frequency interval with the receiving signals in the passive intermodulation signals are formed, the intermodulation cancellation signals are cancelled with the components falling into the receiving frequency band in the passive intermodulation signals, and the cancelled passive intermodulation signals are smaller than or equal to a passive intermodulation preset value; meanwhile, the transmitting signals and the receiving signals in the duplexer (A0) and the antenna chain thereof normally operate in the duplexer (A0) and the antenna chain thereof.
4. The apparatus of claim 1, wherein the apparatus is configured to adaptively cancel a passive intermodulation signal, and wherein: the digital processing unit (E) calculates the method according to the frequency information of the transmitted signal as follows:
the digital processing unit (E) firstly calculates frequency information of the passive intermodulation signal related to the frequency information of the transmitting signal according to the frequency information of the transmitting signal, converts the frequency information into a filtering parameter of the passive intermodulation signal, then obtains a frequency interval between the frequency information and the bandwidth information of the receiving signal and the frequency and the bandwidth information of the passive intermodulation signal according to the frequency and the bandwidth information of the receiving signal, and finally selects a corresponding digital filtering mode and an integral mode to realize amplitude detection of the passive intermodulation signal; then comparing the detection amplitude of the passive intermodulation signal with a passive intermodulation preset value;
when the detected amplitude is smaller than or equal to the preset value, the canceller circuit (B) does not generate an intermodulation cancellation signal and does not affect the passive intermodulation index of the duplexer (A0) and the antenna link thereof;
when the detected amplitude is larger than the preset value, the canceller circuit (B) is controlled to adjust the amplitude and the phase to generate an intermodulation cancellation signal with the same frequency, the same amplitude and the opposite phase with the passive intermodulation signal of the duplexer (A0) and the antenna link thereof, and the passive intermodulation signal in the radio frequency signal is cancelled, and the working state that the amplitude and the phase of the canceller circuit (B) are regulated and controlled in real time according to the amplitude detection result of the passive intermodulation signal to enable the cancellation result of the passive intermodulation signal to be smaller than or equal to the preset value is kept.
5. The apparatus of claim 3, wherein the means for adaptively canceling a passive intermodulation signal is further configured to: the signals for exciting the duplexer (A0) and the antenna link thereof to generate passive intermodulation signals and the signals for exciting the intermodulation signal generator (B2) to generate intermodulation signals are of the same source and are both derived from the transmitting signal of the transmitting circuit unit (F), so that the passive intermodulation signals generated by the passive device and the intermodulation signals generated by the intermodulation signal generator (B2) have the same frequency and the same bandwidth; the antenna link is a link from an antenna port of a duplexer (A0) to an antenna (A1), and the antenna feed assembly (A2) represents a combination of single or multiple passive devices in the antenna link, wherein the passive devices comprise cables, connectors, couplers and combiners; the transmission signal is formed by a multi-tone signal or a multi-carrier modulation signal.
6. The apparatus of claim 1, wherein the apparatus is configured to adaptively cancel a passive intermodulation signal, and wherein: when only a single 3-order, or a single 5-order or a single higher-order component of a passive intermodulation signal which is generated by a single duplexer (A0), an antenna feed assembly (A2) or an antenna (A1) or is generated and superposed by a plurality of passive devices at the same time and has a certain frequency interval with a receiving signal falls into a receiving frequency band of the duplexer (A0) and causes a passive intermodulation index tested from a receiving port of the duplexer (A0) to not meet a preset value requirement, in order to enable a passive intermodulation value behind a second main access port of a second coupler (B5) behind the receiving port of the duplexer (A0) to meet the preset value requirement: the maximum amplitude of the intermodulation cancellation signal that the intermodulation signal generator (B2) can generate is larger than the amplitude of a single component of the passive intermodulation signal of the duplexer (a0) and its antenna link that falls into the corresponding frequency of the receiving band;
when only 3-order of a plurality of different frequencies, or 5-order of a plurality of different frequencies, or higher-order components of a plurality of different frequencies in a passive intermodulation signal which is generated by a single duplexer (A0) or an antenna feed assembly (A2) or an antenna (A1) or is simultaneously generated and superposed by a plurality of passive devices and has a certain frequency interval with a receiving signal fall into a receiving frequency band of the duplexer (A0) and a passive intermodulation index tested from a receiving port of the duplexer (A0) does not meet a preset value requirement, in order to enable a passive intermodulation value behind a second main channel port of a second coupler (B5) behind the receiving port of the duplexer (A0) to meet the preset value requirement: the maximum amplitude of the intermodulation cancellation signal corresponding to the passive intermodulation product frequency, which can be generated by the intermodulation signal generator (B2), is greater than the amplitude of the corresponding frequency components falling into the receiving band in the passive intermodulation signal of the duplexer (a0) and its antenna link; the phase relationship between the plurality of specific order components in the intermodulation signals generated at the intermodulation signal generator (B2) is identical to the phase relationship between the plurality of specific order components in the passive intermodulation signals generated by the duplexer (a0) and its antenna link;
when 3-, 5-or higher-order components simultaneously exist in a passive intermodulation signal which is generated by a single duplexer (A0), an antenna feed component (A2) or an antenna (A1) or is formed by simultaneously generating and superposing a plurality of passive devices and has a certain frequency interval with a receiving signal, the passive intermodulation signal falls into a receiving frequency band of the duplexer (A0), and the passive intermodulation index tested from a receiving port of the duplexer (A0) cannot meet the preset value requirement, in order to ensure that the passive intermodulation value behind a second main access port of a second coupler (B5) behind the receiving port of the duplexer (A0) meets the preset value requirement: the maximum amplitude of the intermodulation cancellation signal of the corresponding passive intermodulation product frequencies producible by the intermodulation signal generator (B2) is larger than the amplitude of the corresponding frequency components falling into the reception band in the passive intermodulation signals of the duplexer (a0) and its antenna link; the amplitude and phase relationships between the specific order components in the intermodulation signals generated at the intermodulation signal generator (B2) are consistent with the amplitude and phase relationships between the specific order components in the passive intermodulation signals generated by the duplexer (a0) and its antenna link.
7. The apparatus of claim 1, wherein the apparatus is configured to adaptively cancel a passive intermodulation signal, and wherein: when the radio frequency signal in the passive intermodulation detection circuit (D) is too large to cause link blockage, the digital processing unit (E) will reduce the link gain of the passive intermodulation detection circuit (D) to process the received signal normally and stop detecting the passive intermodulation signal amplitude; when the passive intermodulation detection circuit (D) is not blocked, the digital processing unit (E) includes a passive intermodulation signal and a received signal in the passive intermodulation amplitude calculation process, and a certain frequency interval exists between the passive intermodulation signal and the received signal.
8. The apparatus of claim 4, wherein the means for adaptively canceling a passive intermodulation signal is configured to: the method for calculating the amplitude of the passive intermodulation signal by the digital processing unit (E) comprises the following steps:
the digital processing unit (E) firstly calculates the frequency information of the passive intermodulation signal related to the frequency information of the transmitting signal according to the frequency information of the transmitting signal, then calculates the frequency interval between the frequency information and the bandwidth information of the receiving signal and the frequency and the bandwidth information of the passive intermodulation signal according to the frequency interval, and selects a proper algorithm to calculate the amplitude of the passive intermodulation signal according to the frequency interval;
the algorithm for calculating the amplitude of the passive intermodulation signal comprises a direct filtering integration method and a segmented filtering integration method:
the direct filtering integration method is to perform direct digital filtering and integrate to obtain amplitude according to the bandwidth of the passive intermodulation signal, at the moment, the frequency interval between each order component of the passive intermodulation signal falling into a receiving frequency band and the receiving signal is more than or equal to the bandwidth of a transition band from a passband to a stopband of a digital filter in a digital filtering algorithm of the passive intermodulation signal, and the frequency interval is the basis of adopting the direct filtering integration method;
the segmented filtering integration method is to divide the bandwidth of the passive intermodulation signal into a plurality of sub-bandwidths, perform digital filtering and integral calculation on the amplitude according to each sub-bandwidth, and then accumulate the amplitudes corresponding to all the sub-bandwidths to obtain the amplitude of the whole signal, wherein the frequency interval between each order component and the received signal is greater than or equal to the transition bandwidth from the digital filter passband of each order component side sub-band signal to the stopband, and the frequency interval is the basis of the segmented filtering integration method.
9. The apparatus of claim 1, wherein the apparatus is configured to adaptively cancel a passive intermodulation signal, and wherein:
one port of the canceller circuit (B) is connected with an antenna link behind an antenna port of the duplexer (A0) through a first coupler (A), or is connected with a transmitting link in front of a transmitting port of the duplexer (A0) through the first coupler (A); the other port of the canceller circuit (B) is connected with a link behind a receiving port of the duplexer (A0) through a second coupler (B5); the first main channel port of the second coupler (B5) is connected with the receiving port of the duplexer (A0), the connection distance needs to be controlled within the range of 0-1 m, the specific length is determined by the best passive intermodulation cancellation effect, the second main channel port of the second coupler (B5) is connected with the radio frequency input end of the passive intermodulation detection circuit (D), and the coupling port of the second coupler (B5) is connected with the canceller circuit (B); the coupling port of the first coupler (A) is a forward coupling port relative to the transmitting signal; the bearing power of the first coupler (A) needs to be larger than the maximum transmission power peak value of the device, the bandwidth of the first coupler (A) needs to comprise a transmission frequency band, and the gain fluctuation in the frequency band of the first coupler (A) is related to the transmission frequency band and needs to be within a certain threshold value range; the passive intermodulation index of the first coupler (A) meets the passive intermodulation index requirement of the antenna feeder component (A2); the coupling port of the second coupler (B5) is a reverse coupling port with respect to the received signal; the bandwidth of the second coupler (B5) needs to include a receiving frequency band, and the gain fluctuation in the frequency band of the second coupler (B5) is related to the receiving frequency band and needs to be within a certain threshold value range; the load power threshold value of the canceller circuit (B) is larger than or equal to the difference value between the power threshold value of the first coupler (A) and the coupling degree of the first coupler (A); in order for the intermodulation signal generator (B2) in the canceller circuit (B) to generate a passive intermodulation cancellation signal, the minimum value of the transmitted signal power applied to the canceller circuit (B) needs to be greater than a certain power threshold.
10. The apparatus of claim 1, wherein the apparatus is configured to adaptively cancel a passive intermodulation signal, and wherein:
the passive intermodulation detection circuit (D) comprises a low-noise amplifier, a down-conversion module and a high-speed analog-to-digital converter, wherein the input end of the noise amplifier is electrically connected with the receiving port of the duplexer (A0), the output end of the noise amplifier is electrically connected with the input end of the high-speed analog-to-digital converter through the down-conversion module, and the output end of the high-speed analog-to-digital converter is electrically connected with the input end of the digital processing unit (E);
the gain of the passive intermodulation detection circuit (D) is determined by a required passive intermodulation preset value, the minimum sampling power of a high-speed analog-to-digital converter in the passive intermodulation detection circuit (D) and a link noise coefficient; the maximum value of the received signal power of the passive intermodulation detection circuit (D) is larger than or equal to the maximum received signal power specified by the communication standard actually corresponding to the device.
11. The apparatus of claim 5, wherein the means for adaptively canceling a passive intermodulation signal is configured to: the digital processing unit (E) is provided with at least one information interaction interface, and the functions of the digital processing unit (E) comprise program downloading, configuration information input, remote alarm and maintenance; the configuration information to be input comprises the signal transmitting bandwidth and frequency band, the signal receiving bandwidth and frequency band, the order and frequency band information of main interference components in the passive intermodulation signals, the preset value of the passive intermodulation signals, a curve changing along with time and the maximum offset times of the passive intermodulation signals; the digital processing unit (E) acquires the frequency information of the transmitted signal and the frequency information of the received signal through an information interaction interface; the information interaction interface performs data interaction with internet background resources: uploading a passive intermodulation value in the operation process of the equipment, an experience curve of the passive intermodulation value changing along with time, and state information of each module circuit in the passive intermodulation signal self-adaptive offset device; or downloading the passive intermodulation signal preset value after comprehensive optimization and a curve changing along with time;
at least two interfaces exist between the digital processing unit (E) and the passive intermodulation detection circuit (D): one interface is used for acquiring a sampling signal of a high-speed analog-to-digital converter in the passive intermodulation detection circuit (D) so as to carry out digital filtering and amplitude calculation on the passive intermodulation signal; the other interface is used for configuring parameters of the passive intermodulation detection circuit (D) through the bus;
when the digital processing unit (E) acquires the transmitting signal frequency information and the receiving signal frequency information by using a transmitting signal frequency discrimination circuit (E1), a radio frequency port of the transmitting signal frequency discrimination circuit (E1) is connected with a position on a transmitting link in the transmitting circuit unit (F), and a transmitting signal frequency discrimination circuit (E1) is connected with the digital processing unit (E) through a high-speed analog-to-digital converter; meanwhile, an interface is arranged between the digital processing unit (E) and the transmitting signal frequency discrimination circuit (E1) and is used for configuring parameters of the transmitting signal frequency discrimination circuit (E1) through a bus, and the bus comprises an I2C bus and an SPI bus;
the digital processing unit (E) is provided with at least one information interaction interface, and the functions of the digital processing unit (E) comprise program downloading, configuration information input, remote alarm and maintenance; the configuration information to be input comprises the signal transmitting bandwidth and frequency band, the signal receiving bandwidth and frequency band, the order and frequency band information of main interference components in the passive intermodulation signals, the preset value of the passive intermodulation signals, a curve changing along with time and the maximum offset times of the passive intermodulation signals; the digital processing unit (E) acquires the frequency information of the transmitted signal and the frequency information of the received signal through an information interaction interface; the information interaction interface performs data interaction with internet background resources: uploading a passive intermodulation value in the operation process of the equipment, an experience curve of the passive intermodulation value changing along with time, and state information of each module circuit in the passive intermodulation signal self-adaptive offset device; or downloading the passive intermodulation signal preset value after comprehensive optimization and the value which changes along with time;
the digital processing unit (E) at least comprises a logic processing and operation processing device with a digital signal processing function, and is used for receiving digital signals, processing algorithms, outputting digital signals, controlling and outputting configuration signals, wherein the logic processing and operation processing device comprises a field programmable gate array device, a central processing unit and a digital signal processor; the hardware of the information interaction interface of the digital processing unit (E) comprises an Ethernet interface, an optical fiber interface and an RS-485 bus interface; the digital-to-analog converter in the digital processing unit (E) has a bit range of 10-18 bits and at least 3 digital-to-analog converters.
12. The apparatus of claim 1, wherein the apparatus is configured to adaptively cancel a passive intermodulation signal, and wherein: one end of an amplitude modulation circuit (3) in the canceller circuit (B) is directly connected with the coupling port of the first coupler (A) or is connected with the coupling port of the first coupler (A) through a radio frequency switch (B3); the other end is connected with an intermodulation signal generator (B2) through a circulator (4); the intermodulation signal generator (B2) is connected with the filter (5) through the circulator (4), one end of the amplitude modulation phase modulator (B1) is connected with the filter (5), and the other end is connected with the coupling port of the second coupler (B5).
13. The apparatus of claim 1, wherein the apparatus is configured to adaptively cancel a passive intermodulation signal, and wherein: one end of an amplitude modulation circuit (3) in the canceller circuit (B) is directly connected with the coupling port of the first coupler (A) or is connected with the coupling port of the first coupler (A) through a radio frequency switch (B3); the other end is connected with an intermodulation signal generator (B2) through a circulator (4); the intermodulation signal generator (B2) is connected with an amplitude modulation and phase modulation device (B1) through a circulator (4), one end of a filter (5) is connected with the amplitude modulation and phase modulation device (B1), and the other end of the filter is connected with a coupling port of a second coupler (B5).
14. The apparatus of claim 13, wherein the means for adaptively canceling a passive intermodulation signal is configured to:
the amplitude modulation and phase modulation device (B1) is composed of an amplitude modulation circuit (1) and a phase modulation circuit (2); the amplitude modulation circuit (1) at least comprises 1 adjustable attenuator; the phase modulation circuit (2) at least comprises 2 adjustable phase shifters; the amplitude modulation circuit (3) is composed of a fixed attenuator or an adjustable attenuator; the frequency bandwidth of the circulator (4) comprises the transmitting frequency band and the receiving frequency band of the duplexer (A0); the working frequency band of the amplitude modulation phase modulator (B1) comprises the receiving frequency band of the duplexer (A0), and the gain fluctuation in the frequency band of the amplitude modulation phase modulator (B1) is related to the receiving frequency band and needs to be within a certain threshold value range; the passband frequency band of the filter (5) is the receiving frequency band of the duplexer (A0), and the out-of-band rejection index requirement of the filter (5) is determined by the out-of-band rejection index of the receiving frequency band of the duplexer (A0), the coupling degree of the first coupler (A), the coupling degree of the second coupler (B5) and the link loss between the coupling end of the first coupler (A) and the coupling end of the second coupler (B5) in the canceller circuit (B); the bearing power of an amplitude modulation circuit (3) in the canceller circuit (B) is larger than or equal to the bearing power threshold value of the canceller circuit (B);
the intermodulation signal generator (B2) is composed of a single diode, a single triode or a parallel connection of a plurality of diodes; the diode specific type or the transistor specific type is associated with a magnitude characteristic and a phase characteristic of an intermodulation signal of order 3, 5 or higher of the intermodulation signal, which are required by the intermodulation signal generator (B2) of claim 2; when a plurality of diodes with the same type are connected in parallel, the intensity of intermodulation signals is enhanced; the intermodulation signal generator (B2) has a carrying power equal to or greater than the difference between the canceller circuit (B) carrying power threshold and the link loss from the canceller circuit (B) radio frequency input to the intermodulation signal generator (B2).
15. The apparatus of claim 1, wherein the apparatus is configured to adaptively cancel a passive intermodulation signal, and wherein: the passive intermodulation detection circuit (D) comprises at least a low noise amplifier, a down conversion module, a high speed analog to digital converter; the passive intermodulation detection circuit (D) is connected with the digital processing unit (E) through a high-speed analog-to-digital converter;
the down-conversion module converts the received radio frequency signal into an intermediate frequency signal, or converts the received radio frequency signal into a zero intermediate frequency signal; the sampling dynamic range of the high-speed analog-to-digital converter is required to be larger than the difference value between the maximum power value of the received signal and the power value corresponding to the passive intermodulation preset value;
the minimum power which can be sampled by the passive intermodulation detection circuit (D) is less than or equal to a passive intermodulation power value corresponding to a preset value, and meanwhile, the circuit adjusts the gain of a link according to the amplitude of the total power of the received radio-frequency signals so as to avoid the link blockage caused by the received signals or other signals; the gain of the passive intermodulation detection circuit (D) is determined by a required passive intermodulation preset value, the minimum sampling power of a high-speed analog-to-digital converter in the passive intermodulation detection circuit (D) and a link noise coefficient; the maximum value of the received signal power of the passive intermodulation detection circuit (D) is larger than or equal to the maximum received signal power specified by the communication standard actually corresponding to the device.
16. An arrangement for adaptively cancelling passive intermodulation signals as claimed in claim 1, characterized in that the passive intermodulation detection circuit (D) comprises a low noise amplifier (D1), a radio frequency filter and small signal amplification unit (D2), a mixer (D3), an intermediate frequency filter (D5), an intermediate frequency amplifier (D6), an analog-to-digital converter (D7) electrically connected in sequence, the local oscillator (D4) being electrically connected to the mixer (D3); the input end of the low-noise amplifier (D1) is electrically connected with the output end of the duplexer (A0); the output end of the analog-to-digital converter (D7) is electrically connected with the input end of the digital processing unit (E).
17. Arrangement for adaptively cancelling passive intermodulation signals according to claim 1, characterized in that the passive intermodulation detection circuit (D) comprises a low noise amplifier (D1), a radio frequency filtering and small signal amplifying unit (D2) and a down-converting and analog-to-digital converting unit (D8) electrically connected in sequence; the input end of the low-noise amplifier (D1) is electrically connected with the output end of the duplexer (A0); the output end of the down-conversion and analog-to-digital conversion unit (D8) is electrically connected with the input end of the digital processing unit (E).
18. The apparatus for adaptively canceling a passive intermodulation signal as recited in claim 1 wherein the method of using the apparatus comprises the steps of,
s1: acquiring the bandwidth and frequency band of a transmitting signal, the bandwidth and frequency band of a receiving signal, the order and frequency band information of a main interference component in a passive intermodulation signal, an expected passive intermodulation preset value, initial empirical data of a curve, an amplitude and a phase which change along with time and maximum offset frequency information through a digital processing unit (E), and converting the initial empirical data and the maximum offset frequency information into corresponding configuration parameters;
s2: according to the configuration parameters related to the transmitting signals in the step S1, the digital processing unit (E) obtains the frequency points of the passive intermodulation signals, converts the frequency points into corresponding digital filtering parameters and stores the parameters into a parameter configuration table;
s3: according to the configuration parameters related to the received signal, the configuration parameters of the passive intermodulation signal and the digital filtering parameters of the passive intermodulation signal obtained in the step S2 in the step S1, the digital processing unit (E) performs digital filtering on the sampling signal of the passive intermodulation detection circuit (D), filters out other signal components except the passive intermodulation signal, and obtains an amplitude value of the passive intermodulation signal falling into the receiving frequency band; the algorithm for solving the amplitude value comprises a segmented integration method and a direct integration method according to the signal bandwidth;
s4: judging the current working state; the state identification default values of the working states are: "initial operating mode"; if the state identification value of the operation state is the "initial operation mode", continuing to the step S5-1, otherwise continuing to the step S5-2;
s5-1: comparing the passive intermodulation signal amplitude value obtained in the step S3 with the passive intermodulation preset value in the step S1 to determine whether the passive intermodulation signal amplitude is less than or equal to the passive intermodulation preset value;
s6: if the judgment result of the step S5-1 is yes, the canceller circuit (B) continues to maintain the high isolation state of the link between the intermodulation signal generator and the first coupler (a); and returns to step S2;
s7: if the judgment result of the step S5-1 is 'NO', the canceller circuit (B) switches to a low-isolation state of a link between the intermodulation signal generator and the first coupler (A); and the state identification value of the working state is set as the 'counteracting working state'; continuing to execute step S8;
s5-2: comparing the passive intermodulation signal amplitude value obtained in the step S3 with the passive intermodulation preset value in the step S1 to determine whether the passive intermodulation signal amplitude is less than or equal to the passive intermodulation preset value; if the judgment result of the step S5-2 is YES, the state is maintained, and the process returns to the step S2; if the judgment result of the step S5-2 is NO, executing a step S8;
s8: calculating the amplitude and phase adjustment values of the canceller circuit according to the amplitude value of the passive intermodulation signal in the step S3; and the signals are distributed to an amplitude modulator and a phase modulator in a canceller circuit to implement cancellation; after the current round of cancellation processing is completed, the process will continue to return to step S2 to continue the next round of cancellation processing; the algorithm for calculating the amplitude and phase adjustment values comprises a two-dimensional minimum variance algorithm.
19. A radio transceiver comprising the apparatus for adaptively canceling a passive intermodulation signal according to any one of claims 1 to 18, wherein the duplexer (a0) of the apparatus for adaptively canceling a passive intermodulation signal is a duplexer (a0) of the radio transceiver; the passive intermodulation detection circuit (D) of the device for adaptively counteracting the passive intermodulation signal multiplexes components or units of a receiving link of wireless transceiving equipment, or a passive intermodulation detection circuit (D) is additionally arranged in the wireless transceiving equipment; the transmitting circuit unit (F) of the device for adaptively counteracting the passive intermodulation signals multiplexes components or units of a transmitting link of the wireless transceiving equipment; the digital processing unit (E) of the device for adaptively counteracting the passive intermodulation signal multiplexes components or units of the digital processing unit of the wireless transceiver, or a digital processing unit (E) is additionally arranged in the wireless transceiver, and the digital processing unit (E) is integrated in the whole program of the wireless transceiver; the first coupler (A) of the device for adaptively counteracting the passive intermodulation signal needs to be additionally arranged in the wireless transceiver, one main access port of the first coupler (A) is connected with an antenna port of a duplexer (A0) of the wireless transceiver, or one main access port of the first coupler (A) is connected with a transmitting port of a duplexer (A0) of the wireless transceiver, and the coupling port of the first coupler (A) is a forward coupling port relative to the transmitting signal of the wireless transceiver; the second coupler (B5) of the device for adaptively canceling the passive intermodulation signals needs to be newly added in the wireless transceiver, one main access port of the second coupler (B8926) is connected with the receiving port of the duplexer (A0) of the wireless transceiver, the distance needs to be controlled within the range of 0-1 meter, the specific length is determined by the optimal effect of the passive intermodulation cancellation, and the coupling port of the second coupler (B5) is a reverse coupling port relative to the receiving signal of the wireless transceiver; a canceller circuit (B) of the device for adaptively cancelling the passive intermodulation signal needs to be newly added in the wireless transceiver, one radio frequency input port of the canceller circuit is directly connected with the coupling port of the first coupler (A), the other radio frequency output port of the canceller circuit is directly connected with the coupling port of the second coupler (B5), and the amplitude adjustment and the phase adjustment of the canceller circuit (B) are realized by amplitude and phase control parameters output by the operation of a digital processing unit (E); the antenna feed component (A2) and the antenna (A1) of the device for adaptively counteracting the passive intermodulation signals are corresponding components and antennas on an antenna link of the wireless transceiver equipment;
when the wireless transceiver has a plurality of transceiver chains, each duplexer in the transceiver chains needs to be provided with a set of a first coupler (a), a second coupler (B5) and a canceller circuit (B).
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