WO2009024085A1 - Anti-interference mehod for receiver, anti-interference receiver and anti-interference device - Google Patents

Abstract

An anti-interference receiver, anti-interference device and method for the receiver are provided, and relate to the receiver technology. The anti-interference receiver comprises an interference cancellation module which adapts to cancel the interference signal, which is included in the signal to be processed, within the frequency band of the useful signal and adapts to output the signal which has cancelled the interference. The device comprises: a main channel, a feed-forward path and an analog cancellation module. The method comprises the step of canceling the interference signal, which is included in the signal to be processed, within the frequency band of the useful signal and the step of output the signal which has cancelled the interference.. It can suppress the in-band interference signal in the signal to be processed in the receiver, and improve the system performance.

Description

 Anti-interference method in receiver, anti-interference receiver and anti-interference device

 The present invention relates to receiver technology, and more particularly to an anti-interference method in a receiver, an anti-interference receiver, and an anti-jamming device.

 Say

Background technique

 In a mobile communication base station, it is necessary to receive a wireless signal through a receiver. In order to improve the communication capacity, a multi-carrier receiver is often used in a mobile communication base station, that is, a single radio frequency channel includes multiple radio carriers, and more specifically, in some parts of the radio frequency channel, such as a coaxial cable or a pair of differential lines. The signal book contains multiple carriers. Referring to FIG. 1, a schematic diagram of a carrier configuration of a multi-carrier receiver in the prior art, in which fc is centered, five carriers in a range of bandwidth B are useful signals.

 The multi-carrier configuration of a multi-carrier receiver varies depending on the specific circumstances of the mobile communication system. For example, for a multi-carrier receiver in a Wideband Code Division Multiple Access (WCDMA) system, four carriers with a bandwidth of 5 MHz may be configured in the range of fc=190 MHz and B=20 MHz, where B may be called For the useful signal bandwidth of the receiver; for example, for a multi-carrier receiver in the Global System of Mobil Communications (GSM) system, 4~8 may be sparsely configured in the range of fc=83MHz and B=10MHz. A carrier with a bandwidth of 200 kHz. The center frequency of these carriers may vary with the network configuration of the mobile communication system, and some carriers may not be configured. Interference signals may occur at the unconfigured carrier locations and at locations other than the carriers within the useful signal bandwidth. Of course, in addition to the useful signal bandwidth, interfering signals may also occur, and the interfering signals may The amplitude may be greater than the amplitude of the useful signal. Referring to Figure 2, there is shown a schematic diagram of interference in a multi-carrier receiver in the prior art. The interference shown in the figure may be interference from base station signals of neighboring cells, and may also be interference of other undesired wireless signals. How to effectively filter out these interferences is a key issue that multi-carrier receivers need to solve.

 In the prior art, a bandpass filter is typically employed to suppress interfering signals outside the useful signal bandwidth of the receiver. See picture

3 is a schematic structural diagram of a receiver in the prior art. The spatial radio wave carrying the information is received by the antenna 301, converted into an electrical signal in the coaxial cable, and sent to the analog receiving channel 302. The analog receive channel pass 302 can perform variable frequency filter amplification on the electrical signal, often including a low noise amplifier, a one or more stage mixer, a filter and a variable gain amplifier, and the like. The signal received through the antenna 301 is a radio frequency signal, and the signal after passing through the mixer in the analog receiving channel 302 is an intermediate frequency signal with a reduced frequency. The signal after the analog receiving channel 302 still has interference, as shown in Figure 2. The band pass filter 303 will be described below. Referring to FIG. 4, which is a schematic diagram of the characteristics of the bandpass filter in the prior art, the bandpass filter is represented by a filter having a center frequency of fc and a passband width of B. In this embodiment, a useful signal of the receiver is assumed. The bandwidth and the passband bandwidth of the bandpass filter 303 are the same, both being B. The attenuation in the bandpass filter is small, such as 0~2dB, and the attenuation outside the band is large relative to the in-band, for example 50~70dB. The relationship between the signal after the analog receiving channel 302 and the filtering characteristics of the band pass filter is as shown in FIG. The bandpass filter has an inhibitory effect on the interference signal outside the useful signal bandwidth. See Fig. 6, which is a schematic diagram of the signal after passing through the bandpass filter 303 of Fig. 3. It can be seen that the bandpass filter has interference outside the bandband bandwidth. The signal, that is, the interference signal whose frequency is less than fc-B/2, and the interference signal whose frequency is greater than fc+B/2 are greatly suppressed.

 An analog-to-digital converter (ADC) converts the signal input from the band pass filter 303 into a digital signal and outputs it.

 In the process of implementing the present invention, the inventors have found that the prior art has the following problems: In the prior art, a band pass filter is used to suppress a receiver interference signal, although interference outside the useful signal bandwidth is suppressed, but for a useful signal Interference within the bandwidth does not inhibit.

 Interference within the useful signal bandwidth introduces a number of problems, such as the analog-to-digital conversion of the above-described signal after the bandpass filter, which has the following problems:

 The signal in the useful signal bandwidth of the analog-to-digital converter for analog-to-digital conversion includes the interference signal and the carrier signal. If the interference signal and the carrier signal exceed the highest point of the dynamic range of the analog-to-digital converter, the analog-to-digital converter will be overloaded if the carrier The signal is less than the lowest point of the dynamic range of the analog-to-digital converter, and the analog-to-digital converter will have difficulty detecting the carrier signal. Therefore, in order to overload the analog-to-digital converter, the interference signal of the input analog-to-digital converter and the useful signal cannot be higher than the highest point of the dynamic range of the analog-to-digital converter. At the same time, the carrier signal of the input analog-to-digital converter must be passed. Small, it is necessary to amplify the carrier signal by increasing the gain of the analog receiving channel, so that the carrier signal of the input analog-to-digital converter is higher than the lowest point of the dynamic range of the analog-to-digital converter. However, the amplified carrier signal also amplifies the interference signal, and the amplified interference signal may be larger than the highest point of the analog-to-digital converter and exceed the dynamic range of the analog-to-digital converter, overloading the analog-to-digital converter, causing the receiver performance to be affected. Seriously, the receiver communication will be interrupted. Summary of the invention

 Embodiments of the present invention provide an anti-jamming receiver and apparatus and a method for resisting interference in a receiver, which can suppress interference signals in a useful signal bandwidth in a receiver.

An anti-interference receiver includes an interference cancellation module for performing cancellation processing on an interference signal in a useful signal bandwidth in a signal to be processed, and outputting a cancelled signal. An anti-jamming device, the device comprising a main channel, a feedforward branch and an analog cancellation module;

 The main channel is configured to receive a signal to be processed and output the signal to the analog cancellation module;

 The feedforward branch is configured to perform a notch processing on a carrier signal in a signal to be processed, and transmit the processed signal to the analog cancellation module;

 The analog cancellation module cancels the signal transmitted by the main channel and the signal transmitted by the feedforward branch, and outputs the cancelled signal.

 A method for resisting interference in a receiver, the method comprising:

 The interference signal in the useful signal bandwidth in the signal to be processed input to the receiver is subjected to cancellation processing to obtain a signal after cancellation.

 As can be seen from the above solution, the embodiment of the present invention obtains the cancelled signal by canceling the interference signal in the wanted signal bandwidth of the signal of the receiver, thus suppressing the bandwidth of the useful signal in the receiver. Interfering signals improve system performance. DRAWINGS

 1 is a schematic diagram of carrier configuration of a multi-carrier receiver in the prior art;

 2 is a schematic diagram of interference in a multi-carrier receiver in the prior art;

 3 is a schematic structural diagram of a receiver in the prior art;

 4 is a schematic diagram showing characteristics of a band pass filter in the prior art;

 5 is a schematic diagram showing the relationship between the signal after the analog receiving channel 302 and the filtering characteristics of the band pass filter in FIG. 3; FIG. 6 is a schematic diagram of the signal after passing through the band pass filter 303 in FIG.

 7a is a schematic structural diagram of a receiver for anti-interference according to an embodiment of the present invention;

 Figure 7b is a schematic structural view of the interference cancellation module of Figure 7a;

 8 is a schematic structural diagram of a first embodiment of the interference cancellation module 704 of FIG. 7;

 9 is a schematic structural diagram of the cascade implementation of the analog useful signal notch module 802 in FIG. 8;

 Figure 10-1 is a schematic diagram of the notch characteristics of the notch module 1 when the notch module of Figure 9 is five;

 Figure 10-2 is a schematic diagram of the notch characteristics of the notch module 2 when the notch module of Figure 9 is five;

 Figure 10-3 is a schematic diagram of the notch characteristics of the notch module 3 when the notch module of Figure 9 is five;

 Figure 10-4 is a schematic diagram of the notch characteristics of the notch module 4 when the notch module of Figure 9 is five;

 Figure 10-5 is a schematic diagram of the notch characteristics of the notch module 5 when the notch module of Figure 9 is five;

11 is a schematic diagram showing the configuration of a notch module of five frequency points in FIG. 10; 12 is a schematic diagram of the response of the 5-stage notch shown in FIG. 11;

 Figure 13 is a schematic diagram of the signal after the analog useful signal notch module shown in Figure 11;

 14 is a schematic diagram of signals after the analog cancellation module 73 in FIG. 7b;

 15 is a schematic structural diagram of a second embodiment of the interference cancellation module 704 of FIG. 7;

 16 is a schematic structural diagram of a third embodiment of the interference cancellation module 704 of FIG. 7;

 17 is an exemplary flowchart of a method for anti-interference in a receiver according to an embodiment of the present invention;

 18 is a flowchart of a first example of a method for resisting interference in a receiver according to an embodiment of the present invention;

 19 is a flowchart of a second example of a method for resisting interference in a receiver according to an embodiment of the present invention;

 FIG. 20 is a flowchart of a third example of a method for resisting interference in a receiver according to an embodiment of the present invention. detailed description

 In order to make the objects, the technical solutions and the advantages of the present invention more comprehensible, the present invention will be further described in detail below with reference to the embodiments and drawings.

 In the embodiment of the present invention, the interference signal in the useful signal bandwidth in the signal to be processed in the receiver is subjected to cancellation processing, and the signal after the cancellation processing is obtained. The signal to be processed may be a signal between an antenna and an analog to digital converter within the receiver. Here, the module for performing cancellation processing in the receiver is called an interference cancellation module, and the position of the interference cancellation module is flexible, and can be implemented on the radio frequency or on the intermediate frequency. The anti-interference scheme of the embodiment of the present invention will be specifically described below by taking the structure shown in FIG. 7 as an example. In Figure 7, the interference cancellation module is placed between the bandpass filter 703 and the ADC 705, and the signal to be processed is the signal input by the bandpass filter 703 into the interference cancellation module 704. Of course, other devices such as a mixer, a low noise amplifier, a variable gain amplifier, etc. may be included between the band pass filter 703 and the ADC 705.

 Referring to FIG. 7a, a schematic structural diagram of an anti-interference receiver according to an embodiment of the present invention includes an antenna 701, an analog receiving channel 702, a bandpass filter 703, an interference cancellation module 704, and an ADC 705. In the receiver of the embodiment of the present invention, the band pass filter 703 can also be placed between the interference cancellation module 704 and the ADC 705. In this case, the signal output by the analog receiving channel 702 is first used by the interference cancellation module 704. The interference signal in the signal bandwidth is suppressed, and the band-pass filter is used to suppress the interference signal outside the bandwidth of the useful signal. If the receiver uses analog IQ demodulation for baseband sampling, the ADC 705 is a dual ADC. If the receiver uses IF sampling, the ADC 705 is a single ADC.

Here, the receiver of the embodiment of the present invention will be described with the band pass filter 703 placed before the analog receiving channel 702 and the receiver using the intermediate frequency sampling, that is, the ADC 705 is a single channel ADC. Different from the receivers in the prior art, the interference cancellation module 704 is added to the embodiment of the present invention. Referring to FIG. 7b, which is a schematic structural diagram of the interference cancellation module 704 in FIG. 7a, the interference cancellation module 704 is configured to perform interference signals in a useful signal bandwidth in the received signal. Disposal processing. The interference cancellation module 704 includes a main channel 71, a feedforward branch 72, and an analog cancellation module 73.

 The main channel 71 is connected to the analog cancellation module 73.

 The main channel 71 can be realized by an analog delay compensation module, and the analog delay compensation module is used for performing analog delay compensation processing on the signal input to the main channel. The analog delay compensation module may be composed of an ultrasonic delay line or an LC delay line, which functions to compensate for the difference in delay between the main channel 71 and the feedforward branch 72. If the signal input to the main channel 71 is a narrowband signal, the delay between the main channel 71 and the feedforward branch 72 has little effect on the cancellation performance of the analog cancellation module 73, and no delay compensation can be performed. Does not include analog delay compensation module.

 The feedforward branch 72 is configured to notch the useful signal in the input signal transmitted by the band pass filter 703, and transmit the processed signal to the analog cancellation module 73. The useful signal may be a carrier signal, and an embodiment of the present invention will be described below with the useful signal as a carrier signal.

 The analog cancellation module 73 is configured to cancel the signal input from the main channel 71 and the signal input from the feedforward branch 72 to obtain a cancellation signal after cancellation. The cancellation may be: subtracting the signal input from the main channel 71 with the signal input from the feedforward branch 72.

 In a specific implementation, the interference cancellation module 704 has two implementations of an analog feedforward method and a digital feedforward method, which are respectively described below with reference to FIG. 8, FIG. 19 and FIG.

 Referring to FIG. 8, FIG. 8 is a schematic structural diagram of a first embodiment of the interference cancellation module 704 of FIG. At this time, the interference cancellation module 704 is implemented by an analog feedforward method, the main channel 71 ώ analog delay compensation module 801, and the feedforward branch 72 is composed of an analog useful signal notch module 802 and an analog amplitude compensation module 803.

 The analog delay compensation module 801 is configured to perform delay compensation processing on the signal input to the main channel.

 Since the feedforward branch has a delay in the process of signal processing, the signal is subjected to delay compensation processing on the main channel, so that the main channel signal and the feedforward branch signal arriving at the analog cancellation module 705 are the same.

 The analog useful signal notch module 802 is configured to notch the carrier signal in the input signal to extract the interference signal. The analog useful signal notch module 802 can be implemented with one or more notch modules, and the notch frequency of the notch module is the signal frequency of the carrier in the feedforward tributary signal. When the analog useful signal notch module 802 needs to notch the carrier signals of multiple frequency points, the analog useful signal notch module 802 is implemented by cascadeing a plurality of notch modules, each of which traps a carrier. Referring to FIG. 9, FIG. 8 is a schematic structural diagram of the cascading implementation of the analog signal trapping module 802 in FIG. Each of the notch modules in Figure 9 is controlled by a corresponding switch.

If the operating frequency of the carrier in the feedforward tributary signal is completely fixed, or substantially fixed, each notch module may be a fixed frequency notch module; if the operating frequency of each carrier in the feedforward tributary signal is not fixed However, instead of being variable over a range of frequencies, each notch module can be a variable frequency notch module. If the frequency band of each notch module The width is basically constant, and the center frequency of the notch modules of each level can be varied within a certain range, as is the case for multi-carrier receivers in the GSM system. At this time, the control of the useful signal notch module is controlled. In addition to the control of the switches at all levels, the center frequency of the trap modules at each level can be adjusted.

 The following description of the analog useful signal notch module 802 is exemplified: In the receiver of the WCDMA system, the control of the analog useful signal notch module 802 is the control of the switches of each notch module; in the GSM system receiver, each notch Whether the module works depends on the configuration of the operating frequency of each carrier, and since the operating frequency of each carrier changes greatly, not only the switching of each notch module but also the trapping module is also required. The working frequency is controlled; when the WCDMA and GSM carriers are mixed, that is, the WCDMA carrier and the GSM carrier need to be processed simultaneously in the receiver. At this time, the notch module in FIG. 9 includes the notch module of the WCDMA bandwidth and the notch of the GSM bandwidth. Module, which requires corresponding control of each notch module according to the configuration of the network frequency. The working principle of the analog useful signal trap module 802 is illustrated by taking five working carriers as an example. At this time, there are five notch modules in FIG. 9, including the notch modules 1, 2, 3, 4, and 5. It is assumed that the five working carriers are carriers 1, 2, 3, 4 and 5, respectively, and the operating frequency is increased from carrier 1 to carrier 5 in order. The notch module 1 notches the carrier 1, FIG. 10-1 is a notch characteristic of the notch module 1; the notch module 2 notches the carrier 2, and FIG. 10-2 is the notch of the notch module 2 Schematic diagram of the feature; the notch module 3 notches the carrier 3, Figure 10-3 is the notch characteristic of the notch module 3; the notch module 4 notches the carrier 4, Figure 10-4 is the notch module Schematic diagram of the notch characteristic of 4; The notch module 5 notches the carrier 5, and FIG. 10-5 is a schematic diagram of the notch characteristic of the notch module 5. In Figure 10-1 to Figure 10-5, B is the useful signal bandwidth of the receiver, and fc is the center frequency of the useful signal bandwidth range. Of course, in actual use, how the frequency of each notch module of the analog useful signal notch module 802 is distributed depends on the specific design, and does not necessarily increase in the order in which the notch modules are placed.

 Assuming that carrier 2 and carrier 4 are not working, the switches of notch module 2 and notch module 4 should be closed, that is, the two stages of notches are bypassed, see Fig. 11, which is the five frequency points in Fig. 10. Schematic diagram of the configuration of the notch module. Accordingly, the response of the level 5 notch of Fig. 11 is as shown in Fig. 12.

 Referring to Figure 13, is a schematic diagram of the signal after the analog useful signal notch module shown in Figure 11. It can be seen from Fig. 13 that the useful signal bandwidth after simulating the useful signal notch module is mainly the interference signal in the useful signal bandwidth. The individual carrier signals in Figure 13 also have some residuals due to the non-ideality of the actual analog useful signal notch block.

 As shown in FIG. 8, the analog useful signal notch module 802 can include an analog useful signal notch sub-module 81 and an analog notch characteristic control sub-module 82.

 The analog useful signal notch sub-module 81 is configured to notch the carrier signal in the input signal under the control of the analog notch characteristic control sub-module 82.

The analog notch characteristic control sub-module 82 is configured to control the analog useful signal notch sub-module 81 to perform notch processing. Mode The control of the analog useful signal notch sub-module 81 by the notch characteristic control sub-module 82 includes: under the operating parameter configuration, the control analog useful signal notch sub-module 81 performs notch processing, the working parameters including the operating frequency of each carrier Point, and the bandwidth of the working signal at each working frequency, and so on.

 The analog amplitude and phase compensation module 803 is configured to perform amplitude and phase compensation on the signal input by the analog useful signal notch module 802. The module is optional, and when selected, the analog cancellation module 73 can better perform interference signal cancellation processing. The analog amplitude and phase compensation module 803 includes an analog amplitude and phase compensation sub-module 83 and an optimal analog amplitude and phase compensation coefficient calculation sub-module 84.

 The analog amplitude and phase compensation sub-module 83 is configured to perform amplitude and phase compensation on the signal input by the analog useful signal notch sub-module 81 according to the optimal amplitude and phase compensation coefficient input by the sub-module 84 of the optimal analog amplitude and phase compensation coefficient. The amplitude and phase compensation is performed to maximize the carrier-to-interference ratio of the signal after the cancellation of the analog useful signal notch module 802. The carrier-to-interference ratio refers to the ratio of the sum of the powers of the individual carrier signals to the total interference signal power.

 The optimal analog amplitude and phase compensation coefficient calculation sub-module 84 calculates the optimal analog amplitude and phase compensation coefficient and transmits it to the analog amplitude and phase compensation sub-module 83. The calculating the optimal analog amplitude and phase compensation coefficient is: adaptively according to the change between the useful signal and the interference signal in the signal output by the ADC 705, the current operating parameter, and the amplitude and phase compensation mode in the analog amplitude and phase compensation module, etc. Calculate the best analog amplitude and phase compensation coefficient.

 The analog amplitude and phase compensation module 803 can also be placed on the main channel, for example, between the analog delay compensation module 801 and the analog cancellation module 73, or placed before the analog delay compensation module 801 for the main channel 71. The upper signal is amplitude-phase compensated. At this time, the feedforward branch 72 may include an analog useful signal notch module 802 for notching the useful signal in the signal to be processed, and transmitting the processed signal to the analog cancellation module 73.

 The analog cancellation module 73 is configured to cancel the signal input from the main channel 71 and the signal input from the feedforward branch 72 to obtain a canceled cancellation signal.

 Referring to Fig. 14, is a schematic diagram of the signal after the analog cancellation module 73 in Fig. 7b. As can be seen from Fig. 14, the interference signal in the signal passing through the analog cancellation module 73 is greatly reduced. Figure 14 shows the signal after the bandpass filter and the interference cancellation. Compared with the signal of the prior art only through the bandpass filter, it can be seen that the interference signal in the useful signal bandwidth in Figure 14 is greatly reduced. . In this way, when it is necessary to amplify the useful signal by increasing the gain of the analog receiving channel, since the interference signal is greatly reduced, even if the amplification is useful and the interference signal is amplified, there is no problem that the amplified interference signal overloads the ADC 705, thereby , so that receiver performance is not affected.

The interference cancellation module 704 is implemented by the analog feedforward method, and the analog useful signal notch module 802 is inflexible for adjusting the operating frequency and bandwidth of each carrier. The number of notch modules constituting the analog useful signal notch module 802, the center frequency and bandwidth of each notch module are generally determined, it is difficult to add a new notch module, and it is difficult to change the center frequency of each notch module. And bandwidth. Although theoretically composing the center frequency and bandwidth of each notch module of the analog signal trap module 802 can be In a certain way, such as voltage-controlled capacitors, fine-tuning within a certain range, but the range is limited, the precision is not high, and the use of very complicated circuits is required to realize the change of the center frequency band and the bandwidth, which makes it difficult to simulate the composition in practical use. The notch module of the useful signal notch module 802 is adjusted.

 In order to solve the problem that the analog feedforward method brings to the receiver, the embodiment of the present invention proposes a scheme for implementing the interference cancellation module 704 by the digital feedforward method. The digital feedforward method can be implemented on the digital intermediate frequency or on the digital baseband, which will be described below in conjunction with Figs. 15 and 16.

 Referring to FIG. 15, which is a schematic structural diagram of a second embodiment of the interference cancellation module 704 of FIG. 7, the analog delay compensation module 1501 and the analog cancellation module 73 are similar to the corresponding modules in FIG. 8, and are not described herein again.

 The attenuation module 1504 is configured to attenuate the signal of the input interference cancellation module 704, and input the processed signal to the feedforward ADC 1505. Attenuation module 1504 is optional.

 If the saturation points of the feedforward ADC 1505 and ADC 705 are the same, the attenuation module 1504 is selected to extend the saturation point of the feedforward branch, which is the input signal level that saturates the ADC. The attenuation module 1504 can be configured as a fixed attenuation mode or an automatic attenuation mode to further improve the performance. The automatic attenuation mode is an automatic gain control (AGC) mode, and the AGC mode can use a feedforward control mode. Feedback control can also be used. In the case of the feedback control mode, the output of the feedforward ADC 1505 is fed back to the attenuation module 1504, as indicated by the dashed line in the figure.

 The feedforward ADC 1505 is configured to convert the signal input by the attenuation module 1504 into a digital signal, and the converted digital signal is transmitted to the digital intermediate frequency useful signal notch module 1502.

 The digital intermediate frequency useful signal notch module 1502 includes a digital intermediate frequency useful signal notch sub-module 151 and a digital intermediate frequency notch characteristic control sub-module 152 for notching the carrier signal in the input signal to extract the interference signal. The digital IF useful signal notch module 1502 is similar to the analog useful signal notch module 802 except that the notch processing is implemented on the digital intermediate frequency, and will not be described here.

 The digital intermediate frequency and phase compensation module 1503 includes a digital intermediate frequency and phase compensation submodule 153 and an optimal digital intermediate frequency and phase compensation coefficient calculation submodule 154 for performing a feedforward tributary signal input by the digital intermediate frequency useful signal notch module 1502. Amplitude and phase compensation. The digital IF amplitude and phase compensation module 1503 is similar to the analog amplitude and phase compensation module 803 except that the amplitude and phase compensation is implemented on the digital intermediate frequency. For example, the digital intermediate frequency amplitude and phase compensation module sub-module 153 can be implemented by an FIR or IIR digital filter. Accordingly, the optimal digital amplitude and phase compensation coefficient calculation sub-module 154 calculates the optimal digital amplitude and phase compensation coefficient as the filter coefficient. . The analog amplitude and phase compensation sub-module 83 can be implemented by an attenuator and a phase shifter. Accordingly, the optimal analog amplitude and phase coefficient calculated by the optimal analog amplitude and phase compensation coefficient calculation sub-module 84 is configured according to the attenuation amount and the phase shift amount. The amount of analog or digital control.

Digital to Analogue Converter (DAC) 1506, used to digital phase amps The signal input by the module 153 is converted into an analog signal, which is transmitted to the intermediate frequency filtering module 1507.

 The intermediate frequency filtering module 1507 is configured to filter the signal input by the DAC 1506. After the intermediate frequency filtering module 1507, an analog intermediate frequency signal that filters out digital image interference is obtained. The IF filter module 1507 can be implemented with an LC filter.

 The up-conversion module 1508 is configured to perform up-conversion processing on the signal input by the intermediate frequency filtering module 1507, and transmit the upconverted signal to the analog cancellation module 73. The frequency of the signal output by the DAC 1506 and the frequency of the main channel signal may be the same or different. If different, the upconversion module 1508 is required to convert the intermediate frequency signal output by the DAC 1506 to the same intermediate frequency signal as in the main channel; if the same, the upconversion module 1508 is not required.

 Referring to FIG. 16, which is a schematic structural diagram of a third embodiment of the interference cancellation module 704 of FIG. 7, wherein the analog delay compensation module 1601 and the analog cancellation module 73 are similar to the corresponding modules in FIG. 8, and the attenuation module 1604, front The feed ADC1605, the digital baseband signal notch submodule 161 and the digital baseband notch characteristic control submodule 162 comprise a digital baseband signal notch module 1602, a digital baseband amplitude and phase compensation submodule 163 and an optimal digital baseband amplitude phase The digital baseband amplitude and phase compensation module 1603, the DAC 1606, the intermediate frequency filtering module 1607, and the up-conversion module 1608 composed of the compensation coefficient calculation sub-module 164 are similar to the corresponding modules in FIG. 15, and are not described herein again.

 The digital down conversion module 1609 is configured to down-convert the signal input by the feedforward ADC 1605 into a baseband signal, and transmit the down-converted baseband signal to the digital decimation filter module 1610.

 The digital decimation filter module 1610 is configured to perform decimation filtering processing on the signal input by the digital down conversion module 1609, and transmit the processed signal to the digital baseband signal notch module 1602.

 The digital interpolation filtering module 1611 is configured to perform interpolation filtering on the signal input by the digital baseband amplitude and phase compensation sub-module 163, and transmit the processed signal to the digital up-conversion module 1612.

 The digital up-conversion module 1612 is configured to perform up-conversion processing on the signal input by the digital interpolation filtering module 1611, and transmit the up-converted signal to the DAC 1606. The signal transmitted between the digital down conversion module 1609 and the digital up conversion module 1612 is a digital complex signal, that is, an IQ signal.

 Optionally, the ADC 705 is previously preceded by an AGC module. Thus, when the cancellation of the analog cancellation module 73 is incomplete, the ADC is not overloaded and does not generate large nonlinear distortion. This is the best digital intermediate frequency amplitude compensation coefficient calculation sub-module 154 or the best digital baseband amplitude compensation. The coefficient calculation sub-module 164 is advantageous in calculating the optimal amplitude and phase compensation coefficients. The AGC can be a feedforward AGC for analog detection, a feedback AGC for analog detection, a feedback AGC for digital detection, or real-time switching of a step gain branch.

The digital feedforward method implemented on the digital intermediate frequency is compared with the digital feedforward method implemented on the digital baseband. The digital feedforward method uses the signal notch module 1602 and the digital baseband amplitude. Phase compensation module 1603, or digital intermediate frequency useful signal notch module 1502 and digital intermediate frequency amplitude compensation module 1503. The advantage of the digital feedforward method implemented on the digital baseband is that the digital decimation filtering module 1610 transmits the signal after the decimation filtering process to the digital base with the signal notch module 1602 for notch processing, and then to the digital baseband amplitude and phase compensation module 1603. The amplitude and phase compensation process can greatly reduce the digital resources according to the low frequency of the baseband signal.

 However, since the digital feedforward method implemented on the digital baseband increases the processing link on the feedforward branch, the processing delay on the feedforward branch is increased correspondingly, which increases the difficulty of the implementation of the analog delay compensation module 1601. .

 Therefore, in the case of limited resources, the digital feedforward method implemented on the digital baseband can be considered. In the case where the delay of the feedforward branch is limited, the digital feedforward method implemented on the digital intermediate frequency can be prioritized.

 The interference cancellation module 704 is implemented by the digital feedforward method. Since the feedforward branch is implemented through the digital domain, the digital intermediate frequency useful signal notch module 1502 or the digital baseband signal notch module 1602 is flexible in adjusting the frequency and bandwidth. The filter coefficients of the digital notch module constituting the digital intermediate frequency useful signal notch module 1502 or the digital base with the signal notch module 1602 may be changed. Moreover, the number of digital notch modules, the center frequency and bandwidth of each digital notch module are variable, and new notch points can be added, that is, new digital notch modules are added. The scheme of the interference cancellation module 704 is implemented by the digital feedforward method, and has the following advantages -

(1) The service configuration can be changed on the original receiver. For example, the digital intermediate frequency useful signal notch module 1502 of the original receiver or the digital baseband signal notch module 1602 is composed of four digital notches, that is, can accommodate up to four carriers. Due to the expanded system capacity, it is convenient to upgrade 4 carriers to 5, 6 or more carriers.

 (2) It is possible to switch between various formats. For example, it is necessary to switch the receiver from the receiving GSM mode to the receiving WCDMA mode, since the center frequency and bandwidth of the digital notch module constituting the digital intermediate frequency useful signal notch module 1502 or the digital baseband signal notch module 1602 can be easily changed. Switching is very convenient.

 (3) It can support frequency hopping work. Since the digital can easily change the digital intermediate frequency useful signal notch module

The 1502 or digital base has a parameter configuration of the digital notch module of the signal notch module 1602, and can be guaranteed to change in synchronization with the signal, so that frequency hopping can be supported.

 (4) Digital IF phase compensation module 1503 or digital baseband amplitude and phase compensation module 1603 digital amplitude and phase compensation can be realized in different ways. For example, in-band equalization filtering, that is, different amplitude and phase compensation for each carrier frequency, and for the analog feedforward method, the adjustment of the amplitude and phase characteristics within the useful signal bandwidth is the same. Moreover, the digital amplitude and phase compensation can perform accurate amplitude and phase compensation, which improves the cancellation performance of the analog cancellation module 73.

 (5) The digital notch module that constitutes the digital intermediate frequency useful signal notch module 1502 or the digital base with the signal notch module 1602 has no device aging problem, and the notch performance is ensured.

The above embodiment is based on the assumption that cancellation is performed on the intermediate frequency before the ADC 705, that is, there is one or more stages of mixing in the analog receiving channel 703, and there is no mixing after the interference cancellation module 704. Anti-receptor in the receiver of the embodiment of the invention The interference scheme can also use the following situations: cancellation on the RF before the ADC 705; multi-level intermediate frequency in the analog receive channel 703, at this time, the cancellation is not implemented on the intermediate frequency of the ADC 705, but closer to the antenna The 701 is implemented on a certain intermediate frequency.

 The anti-interference receiver provided by the embodiment of the invention cancels the cancellation signal after canceling the interference signal in the signal bandwidth of the receiver, thereby suppressing the useful signal in the receiver. Interference signals within the bandwidth, thereby improving system performance.

 The embodiment of the invention further provides an anti-interference device in a receiver, the device comprising a main channel, a feedforward branch and an analog cancellation module;

 The main channel is configured to receive a signal to be processed and output the signal to the analog cancellation module;

 The feedforward branch is configured to perform notch processing on the useful signal in the signal to be processed, and transmit the processed signal to the analog cancellation module;

 The analog cancellation module cancels the signal transmitted by the main channel and the signal transmitted by the feedforward branch, and outputs the cancelled signal.

 Further, the main channel includes an analog delay compensation module, configured to perform delay compensation processing on the signal input to the main channel, and transmit the processed signal to the analog cancellation module.

 The foregoing apparatus provided by the embodiment of the present invention may be implemented by using an analog feedforward method and a digital feedforward method. The specific process is the same as that in the anti-interference receiver provided by the embodiment of the present invention, and details are not described herein again.

 The anti-interference device in the receiver provided by the embodiment of the invention cancels the cancellation signal after canceling the interference signal in the signal bandwidth of the receiver, thereby suppressing the cancellation signal in the receiver. Interfering signals within the useful signal bandwidth, thereby improving system performance.

 Referring to FIG. 17, an exemplary flowchart of a method for anti-interference in a receiver according to an embodiment of the present invention includes the following steps: Step 11: Perform interference signals in a wanted signal bandwidth of a signal to be processed input to a receiver After the cancellation process, the signal after the cancellation process is obtained.

 Step 12: Convert the cancelled signal into a digital signal. This step is optional.

 The step 11 may specifically include: dividing the to-be-processed signal of the input receiver into a main channel signal and a feedforward branch signal; performing notch processing on the useful signal in the feedforward branch signal to obtain a notch processed a signal; the main channel signal and the notch processed signal are cancelled, and the degraded signal is the cancelled signal.

 The signal to be processed input to the receiver in step 11 may be a signal subjected to band pass filtering on the electrical signal in the receiver.

The signal to be processed of the input receiver in step 11 may be an electrical signal. At this point, before step 12, the method package And performing band-pass filtering processing on the signal after the cancellation processing to obtain a band-pass filtered signal; and correspondingly, step 12 is: converting the band-pass filtered signal into a digital signal.

 18 is a flowchart of a method for anti-interference in a receiver according to an embodiment of the present invention. The method includes the following steps: Step 21: The signal to be processed of the input receiver is divided into a main channel signal and a feedforward tributary signal. .

 Step 22: Perform delay compensation processing on the main channel signal to obtain a signal after delay compensation processing.

 Step 23: Notch the carrier signal in the feedforward branch signal to obtain a notch processed signal. Step 24: Perform amplitude-phase compensation on the notch-processed signal to obtain a phase-phase compensated signal.

 Steps 23 to 24 can be performed simultaneously with step 22, that is, steps 23 to 24 are executed first, and then step 22 is performed.

 Step 25, the signal after the delay compensation processing obtained in step 22 and the signal after the amplitude phase compensation are cancelled to obtain a canceled signal.

 For a detailed description of the steps shown in Fig. 18, refer to the related description of Fig. 8.

 19 is a flowchart of a second method for anti-interference in a receiver according to an embodiment of the present invention. The method includes the following steps: Step 31: The signal to be processed of the input receiver is divided into a main channel signal and a feedforward branch. signal.

 Step 32: Perform delay compensation processing on the main channel signal to obtain a signal after delay compensation processing.

 Step 33: Perform attenuation processing on the feedforward branch signal to obtain a signal after the attenuation processing. This step is optional. Step 34: Convert the attenuation processed signal into a digital signal.

 Step 35: Notch processing the carrier signal in the converted digital signal to obtain a notch-processed signal. Step 36: Perform amplitude and phase compensation on the notch processed signal to obtain a phase phase compensated signal.

 Step 37: Convert the amplitude-phase compensated signal into an analog signal.

 Step 38: Perform filtering processing on the analog signal to obtain a filtered signal.

 Step 39: Perform up-conversion processing on the filtered signal to obtain an up-converted signal. This step is optional.

 Steps 33 to 39 can be performed simultaneously with step 32, and then steps 33 to 39 are executed first, and then step 32 is executed.

 Step 40: Decipher the up-converted signal and the delay-compensated signal obtained in step 32 to obtain an cancelled signal.

 For a detailed description of the steps shown in Fig. 19, refer to the related description of Fig. 15.

 20 is a flowchart of a third method for anti-interference in a receiver according to an embodiment of the present invention. The method includes the following steps: Step 41: The signal to be processed of the input receiver is divided into a main channel signal and a feedforward branch. signal.

 Step 42: Perform delay compensation processing on the main channel signal to obtain a signal after delay compensation processing.

Step 43: Perform attenuation processing on the feedforward branch signal to obtain an attenuation processed signal. This step is optional. Step 44: Convert the feedforward branch signal into a digital signal.

 Step 45: Downconvert the converted digital signal to a baseband signal.

 Step 46: Perform decimation filtering processing on the baseband signal to obtain a signal after decimation filtering processing.

 Step 47: Perform notch processing on the carrier signal in the demodulated and filtered signal to obtain a notch-processed signal.

 Step 48: Perform amplitude and phase compensation on the signal after the notch processing to obtain a signal after amplitude and phase compensation.

 Step 49: Perform interpolation filtering processing on the amplitude-compensated signal to obtain an interpolation filtered signal. Step 410: Perform up-conversion processing on the interpolation-filtered signal to obtain an up-converted signal.

 Step 411: Convert the upconverted signal into an analog signal.

 Step 412: Perform filtering processing on the analog signal to obtain a filtered signal.

 Step 413: Perform up-conversion processing on the filtered signal to obtain an up-converted signal. This step is optional.

 Steps 43 to 413 can be performed simultaneously with step 42, and steps 43 to 413 are executed first, and then step 42 is performed. Step 414, canceling the filtered signal and the delay compensated signal obtained in step 42 to obtain a demodulated signal.

 For a detailed description of the steps shown in Fig. 20, refer to the related description of Fig. 16.

 The anti-interference scheme in the receiver of the embodiment of the present invention can be applied not only to a multi-carrier receiver but also to a single-carrier receiver.

 The anti-interference method in the receiver of the embodiment of the invention cancels the cancellation signal after canceling the interference signal in the wanted signal bandwidth of the receiver signal, thereby suppressing the useful signal in the receiver. Interference signals within the bandwidth, thereby improving system performance.

 All or part of the technical solutions provided by the above embodiments may be implemented by software programming, and the software programs thereof are stored in a readable storage medium such as a hard disk, an optical disk or a floppy disk in a computer.

 The above described specific embodiments of the present invention are further described in detail, and it is to be understood that the foregoing description is only The scope of the protection, any modifications, equivalents, improvements, etc., made within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

Claim

An anti-interference receiver, characterized in that the receiver comprises an interference cancellation module for performing cancellation processing on an interference signal in a useful signal bandwidth in a signal to be processed, and outputting a signal after cancellation processing.

 2. The receiver according to claim 1, wherein the interference cancellation module comprises a main channel, a feedforward branch, and an analog cancellation module;

 The main channel is configured to receive a signal to be processed and output the signal to the analog cancellation module;

 The feedforward branch is configured to perform notch processing on the useful signal in the signal to be processed, and transmit the processed signal to the analog cancellation module;

 The analog cancellation module is configured to cancel the signal transmitted by the main channel and the signal transmitted by the feedforward branch, and output the cancelled signal.

 The receiver according to claim 2, wherein the main channel includes an analog delay compensation module, configured to perform delay compensation processing on a signal input to the main channel, and transmit the processed signal to the Analog cancellation module.

 4. The receiver according to claim 2, wherein the main channel comprises an analog amplitude and phase compensation module for performing amplitude and phase compensation on a signal on the main channel;

 The feedforward branch includes an analog useful signal notch module for notching the useful signal in the signal to be processed, and transmitting the processed signal to the analog cancellation module.

 The receiver according to claim 2, wherein the feedforward branch comprises an analog useful signal notch module and an analog amplitude and phase compensation module;

 The analog useful signal notch module is configured to perform notch processing on the useful signal in the signal to be processed, and transmit the processed signal to the analog amplitude and phase compensation module;

 The analog amplitude and phase compensation module is configured to perform amplitude and phase compensation on a signal input by the analog useful signal notch module, and transmit the amplitude and phase compensated signal to the analog cancellation module.

 6. The receiver of claim 5, wherein the analog useful signal notch module comprises an analog useful signal notch sub-module and an analog notch characteristic control sub-module; the analog amplitude-phase compensation module includes an analog Amplitude and phase compensation sub-module and optimal analog amplitude and phase compensation coefficient calculation sub-module;

 The analog useful signal notch sub-module is configured to perform notch processing on the useful signal in the to-be-processed signal under the control of the analog notch characteristic control sub-module;

The analog notch characteristic control sub-module is configured to control the analog useful signal notch sub-module to perform notch processing; the analog amplitude and phase compensation sub-module is configured to calculate a sub-phase compensation coefficient according to the optimal simulation The optimal amplitude and phase compensation coefficient of the module input, amplitude and phase compensation of the signal input by the analog useful signal notch sub-module, after amplitude and phase compensation Signal is transmitted to the analog cancellation module;

 The optimal analog amplitude and phase compensation coefficient calculation sub-module is used to calculate an optimal analog amplitude and phase compensation coefficient.

 7. The receiver of claim 2, wherein the feedforward branch comprises a feedforward ADC, a digital intermediate frequency useful signal notch module, a digital intermediate frequency amplitude phase compensation module, a digital to analog converter DAC, and an intermediate frequency filter. Module

 The feedforward ADC is configured to convert the to-be-processed signal into a digital signal and transmit the signal to the digital intermediate frequency useful signal notch module;

 The digital intermediate frequency useful signal notch module is configured to notch the useful signal in the signal input by the feedforward ADC, and transmit the processed signal to the digital intermediate frequency amplitude compensation module;

 The digital intermediate frequency amplitude and phase compensation module is configured to perform amplitude and phase compensation on a signal input by the digital intermediate frequency useful signal notch module, and transmit the amplitude phase compensated signal to the DAC;

 The DAC is configured to convert a signal input by the digital intermediate frequency and phase compensation module into an analog signal, and transmit the analog signal to the intermediate frequency filtering module;

 The intermediate frequency filtering module is configured to filter a signal input by the DAC, and transmit the processed signal to the analog cancellation module.

 The receiver according to claim 7, wherein the digital intermediate frequency useful signal notch module comprises a digital intermediate frequency useful signal notch submodule and a digital intermediate frequency notch characteristic control submodule; The compensation module comprises a digital intermediate frequency amplitude and phase compensation sub-module and an optimal digital intermediate frequency amplitude compensation coefficient calculation sub-module;

 The digital intermediate frequency useful signal notch submodule is configured to perform notch processing on the useful signal in the signal input by the feedforward ADC under the control of the digital intermediate frequency notch characteristic control submodule, and after processing The signal is transmitted to the digital intermediate frequency amplitude compensation submodule;

 The digital intermediate frequency notch characteristic control sub-module is configured to control the digital intermediate frequency useful signal notch sub-module to perform notch processing;

 The digital intermediate frequency amplitude and phase compensation submodule is configured to calculate an optimal amplitude and phase compensation coefficient input by the submodule according to the optimal digital intermediate frequency and amplitude phase compensation coefficient, and perform a signal input by the digital intermediate frequency useful signal notch submodule Amplitude and phase compensation, transmitting the amplitude phase compensated signal to the DAC;

 The optimal digital intermediate frequency amplitude compensation coefficient calculation sub-module is used to calculate an optimal digital intermediate frequency amplitude compensation coefficient.

The receiver according to claim 7 or S, wherein the receiver further comprises an attenuation module connected to the feedforward ADC, wherein the intermediate frequency filtering module and the analog cancellation module are included Frequency conversion module;

The attenuation module is configured to perform attenuation processing on the signal to be processed, and input the processed signal to the feedforward ADC; and the up-conversion module is configured to perform up-conversion processing on the signal input by the intermediate frequency filtering module, Will be upconverted The processed signal is transmitted to the analog cancellation module.

 10. The receiver of claim 2, wherein the feedforward branch comprises a feedforward ADC, a digital down conversion module, a digital decimation filter module, a digital baseband signal notch module, and a digital baseband amplitude phase compensation Module, digital interpolation filter module, digital up-conversion module, DAC and IF filter module;

 The feedforward ADC is configured to convert the to-be-processed signal into a digital signal and transmit the signal to the digital down-conversion module; the digital down-conversion module is configured to down-convert the signal input by the feedforward ADC to a baseband a signal, the downconverted signal is transmitted to the digital decimation filter module;

 The digital decimation filtering module is configured to perform decimation filtering processing on a signal input by the digital down conversion module, and transmit the processed signal to the digital baseband signal notch module;

 The digital base is provided with a signal notch module for notching the useful signal in the signal input by the digital decimation filter module, and transmitting the processed signal to the digital baseband amplitude and phase compensation module;

 The digital baseband amplitude and phase compensation module is configured to perform amplitude and phase compensation on a signal input by the digital baseband signal trapping module, and transmit the amplitude phase compensated signal to the digital interpolation filtering module;

 The digital interpolation filtering module is configured to perform interpolation filtering processing on a signal input by the digital baseband amplitude and phase compensation module, and transmit the processed signal to the digital up-conversion module;

 The digital up-conversion module is configured to perform up-conversion processing on the signal input by the digital interpolation filtering module, and transmit the up-converted signal to the DAC;

 The DAC is configured to convert a signal input by the digital up-conversion module into an analog signal, and transmit the converted signal to the intermediate frequency filtering module;

 The intermediate frequency filtering module is configured to filter a signal input by the DAC, and transmit the processed signal to the analog cancellation module.

 The receiver according to claim 10, wherein the digital baseband signal notch module comprises a digital baseband signal notch submodule and a digital baseband notch characteristic control submodule; The compensation module comprises a digital baseband amplitude and phase compensation sub-module and an optimal digital baseband amplitude and phase compensation coefficient calculation sub-module;

 The digital base is provided with a signal notch sub-module for notching the useful signal in the signal input by the digital decimation filtering module under the control of the digital baseband notch characteristic control sub-module, and processing The subsequent signal is transmitted to the digital baseband amplitude and phase compensation sub-module;

 The digital baseband notch characteristic control sub-module is configured to control the digital base with a signal trapping sub-module for notch processing;

The digital baseband amplitude and phase compensation submodule is configured to calculate a submodule input according to the optimal digital baseband amplitude and phase compensation coefficient Entering the optimal amplitude and phase compensation coefficient, performing amplitude and phase compensation on the signal input by the digital base with the signal notch submodule, and transmitting the amplitude and phase compensated signal to the digital interpolation filtering module;

 The optimal digital baseband amplitude and phase compensation coefficient calculation sub-module is used to calculate an optimal digital baseband amplitude and phase compensation coefficient.

The receiver according to claim 10 or 11, wherein the receiver further comprises an attenuation module connected to the feedforward ADC, wherein the intermediate frequency filtering module and the analog cancellation module are included Frequency conversion module;

 The attenuation module is configured to perform attenuation processing on the to-be-processed signal, and input the processed signal to the feedforward

ADC;

 The up-conversion module is configured to perform up-conversion processing on the signal input by the intermediate frequency filtering module, and transmit the processed signal to the analog cancellation module.

 13. The receiver of claim 1 wherein the signal to be processed is a signal between an antenna and an analog to digital converter within the receiver.

 14. A device for resisting interference in a receiver, the device comprising a main channel, a feedforward branch and an analog cancellation module;

 The main channel is configured to receive a signal to be processed and output the signal to the analog cancellation module;

 The feedforward branch is configured to perform notch processing on the useful signal in the signal to be processed, and transmit the processed signal to the analog cancellation module;

 The analog cancellation module cancels the signal transmitted by the main channel and the signal transmitted by the feedforward branch, and outputs the cancelled signal.

 The device according to claim 14, wherein the main channel comprises an analog delay compensation module, configured to perform delay compensation processing on the signal input to the main channel, and transmit the processed signal to the simulation. Cancellation module.

 16. A method of resisting interference in a receiver, the method comprising:

 The interference signal in the useful signal bandwidth in the signal to be processed input to the receiver is subjected to cancellation processing to obtain a signal after cancellation.

 17. The method of claim 16, wherein the cancellation processing comprises:

 The signal to be processed is divided into a main channel signal and a feedforward branch signal;

 Notching the useful signal in the feedforward branch signal;

 The main channel signal and the notch processed signal are cancelled, and the degraded signal is the cancelled signal.

The method according to claim 17, wherein after the signal input to the receiver is divided into a main channel signal and a feedforward branch signal, the method comprises: Performing delay compensation processing on the main channel signal to obtain a signal after delay compensation processing;

 Destructing the main channel signal and the notch processed signal into: canceling the delay compensation processed signal and the notch processed signal.

 The method of claim 18, wherein the notching the useful signal in the feedforward branch signal comprises:

 Amplitude and phase compensation is performed on the signal after the notch processing, and the amplitude phase compensated signal is obtained;

 Destructing the delay-compensated signal and the notch-processed signal to: canceling the delay-compensated signal and the amplitude-phase-compensated signal.

 The method according to claim 18, wherein the step of notching the useful signal in the feedforward branch signal comprises: converting the feedforward branch signal into a digital signal;

 Performing notch processing on the useful signal in the feedforward branch signal to: perform notch processing on the useful signal in the converted digital signal;

 After performing the notch processing on the useful signal in the converted digital signal, the method includes: performing amplitude and phase compensation on the notch processed signal to obtain a phase-phase compensated signal;

 Converting the amplitude compensated signal into an analog signal;

 Filtering the analog signal to obtain a filtered signal;

 Destructing the delayed compensation processed signal and the notch processed signal into: canceling the delayed compensation processed signal and the filtered processed signal.

 The method according to claim 20, wherein before the converting the feedforward branch signal into a digital signal, the method comprises:

 Attenuating the feedforward branch signal to obtain a signal after the attenuation processing;

 Converting the feedforward branch signal into a digital signal is: converting the attenuation processed signal into a digital signal; after the filtering processing the analog signal, the method includes: performing the filtering processing The latter signal is subjected to up-conversion processing to obtain a signal after up-conversion;

 Destructing the delayed compensation processed signal and the filtered processed signal to: canceling the delayed compensation processed signal and the upconverted signal.

 The method according to claim 18, wherein the step of notching the useful signal in the feedforward branch signal comprises: converting the feedforward branch signal into a digital signal;

 Downconverting the converted digital signal to a baseband signal;

Performing decimation filtering processing on the baseband signal to obtain a signal after decimation filtering processing; Performing notch processing on the useful signal in the feedforward branch signal to: performing notch processing on the useful signal in the signal after the decimation filtering process;

 After performing the notch processing on the useful signal in the demodulated filtered signal, the method includes: performing amplitude-phase compensation on the notch-processed signal to obtain a phase-phase compensated signal;

 Performing interpolation filtering processing on the amplitude-compensated signal to obtain a signal after interpolation filtering processing;

 Performing up-conversion processing on the interpolation-filtered signal to obtain an up-converted signal;

 Converting the upconverted signal into an analog signal;

 Filtering the analog signal to obtain a filtered signal;

 Destructing the delay-compensated signal and the notch-processed signal to: canceling the delay-compensated signal and the filtered-processed signal.

 23. The method of claim 22, wherein the method comprises: before converting the feedforward branch signal to a digital signal, the method comprising:

 Attenuating the feedforward branch signal to obtain a signal after the attenuation processing;

 Converting the feedforward branch signal into a digital signal is: converting the attenuation processed signal into a digital signal; after the filtering processing the analog signal, the method includes: performing the filtering processing The latter signal is subjected to up-conversion processing to obtain a signal after up-conversion;

 Destructing the delayed compensation processed signal and the filtered processed signal to: canceling the delayed compensation processed signal and the upconverted signal.