CN101436876B - Method and system for cancellation of test signal - Google Patents

Abstract

The invention discloses a method and system for canceling a test signal. The system includes a test signal cancellation module for receiving a digital test signal sent by a test signal generator and canceling the test signal included in the digital signal output by the receiver. components, avoiding the influence of test signal components on subsequent service signals.

Description

A method and system for canceling a test signal

technical field

The invention relates to the technical field of communication, in particular to a method and system for canceling test signals. the

Background technique

The block diagram of the receiver in the wireless communication system is shown in Figure 1. The radio frequency signal received by the antenna is sent to the analog receiver through the duplexer, and after being amplified and frequency-converted to a low-frequency analog signal, it is sent to the ADC (Analog to Digital Converter , analog-to-digital converter), converted into a digital signal, and then the digital receiver performs digital filtering and extraction processing on the digital signal, and then converts the digital signal into a digital baseband signal. the

Due to the non-ideality of the wireless communication receiver, the prior art usually injects an analog test signal into the input terminal of the receiver, and inputs the digital form corresponding to the analog test signal into the channel correction module to calculate the non-ideal characteristics of the channel, and the receiver’s The output signal is corrected. Specifically, a receiver calibration block diagram is shown in Figure 2, which includes a test signal generating device, which generates a certain form of test signal, and at the input end of the receiver, it is mixed with the input signal in the form of a coupler or a resistor network , and then sent to the input of the receiver to complete the test signal injection process. The test signal generating device also sends the digital test signal corresponding to the analog test signal to the channel correction module, which is used for the channel correction module to calculate the non-ideal characteristics of the channel and perform corresponding correction. The function of the digital test signal sent to the channel calibration module is only to compare with the test signal passed through the receiver, so as to obtain the channel characteristic of the receiver, and then use the inverse of the characteristic of the receiver to calibrate the receiver. However, the digital signal output by the receiver still contains a test signal component after correction, and the test signal component brings interference to subsequent service signals. the

Contents of the invention

Embodiments of the present invention provide a method and system for canceling a test signal, which eliminates the test signal component contained in the digital signal output by the receiver, and avoids the impact of the test signal component on subsequent service signals. the

An embodiment of the present invention provides a system for canceling test signals, including a coupler, an analog receiver, an analog-to-digital converter, a digital receiver, a test signal generator, a channel corrector, and a test signal canceling device, wherein ,

The test signal generator is used to generate an analog test signal and a digital test signal corresponding to the analog test signal, send the analog test signal to the coupler, and send the digital test signal to the test Signal cancellation device;

The coupler is configured to inject the received analog test signal into an analog input signal;

the analog receiver for sending the analog input signal mixed with the analog test signal to the analog-to-digital converter;

The analog-to-digital converter is used to convert the analog input signal mixed with the analog test signal into a digital signal, and the digital signal includes a test signal component;

The digital receiver is used to receive the digital signal and send the digital signal to the channel corrector;

The channel corrector is used to receive the digital signal sent by the digital receiver and correct the digital signal;

The test signal cancellation device is used to receive the digital signal output by the channel corrector and the digital test signal sent by the test signal generator, and eliminate the test signal component contained in the digital signal output by the channel corrector, The test signal cancellation device includes:

an equalizer for receiving the digital signal output by the channel corrector, the digital test signal sent by the test signal generator and the digital signal fed back from the output end of the test signal canceling device, and equalizing the digital test signal and output;

The subtractor is used to receive the digital signal output by the channel corrector and the equalized digital test signal output by the equalizer, and eliminate the test signal component contained in the digital signal output by the channel corrector. the

The embodiment of the present invention also provides a system for canceling test signals, including a coupler, an analog receiver, an analog-to-digital converter, a digital receiver, a test signal generator, a channel corrector, and a test signal canceling device, in,

The test signal generator is used to generate an analog test signal and a digital test signal corresponding to the analog test signal, send the analog test signal to the coupler, and send the digital signal to the test signal Cancellation device;

The coupler is configured to inject the received analog test signal into an analog input signal;

the analog receiver for sending the analog input signal mixed with the analog test signal to the analog-to-digital converter;

The analog-to-digital converter is used to convert the analog input signal mixed with the analog test signal into a digital signal, and the digital signal includes a test signal component;

The digital receiver is used to receive the digital signal and send the digital signal to the test signal cancellation device;

The test signal canceling device is used to receive the digital signal sent by the digital receiver and the digital test signal sent by the test signal generator, and eliminate the test signal contained in the digital signal output by the digital receiver Component, the test signal cancellation device includes:

The equalizer is used to receive the digital signal sent by the digital receiver, the digital test signal sent by the test signal generator and the digital output signal fed back from the output terminal of the test signal cancellation device, and equalize the test signal The digital test signal produced by the generator is output;

A subtractor, configured to receive the digital signal output by the digital receiver and the equalized digital test signal output by the equalizer, and eliminate the test signal component contained in the digital signal output by the digital receiver;

The channel corrector is used to receive the digital signal output by the test signal cancellation device, and correct the digital signal. the

The embodiment of the present invention eliminates the test signal component included in the digital signal output by the receiver by adding a test signal cancellation device, thereby avoiding the impact of the test signal component on subsequent service signals. the

Description of drawings

Figure 1 is a block diagram of a receiver in a wireless communication system;

Fig. 2 is a kind of receiver correction block diagram;

Fig. 3 is a system block diagram of a kind of cancellation test signal that the embodiment of the present invention provides;

Fig. 4 is the block diagram of a kind of test signal cancellation device provided by the embodiment of the present invention;

Fig. 5 is a system block diagram of another kind of cancellation test signal that the embodiment of the present invention provides;

Fig. 6 is a block diagram of a test signal cancellation device under the multi-carrier state provided by the embodiment of the present invention;

Fig. 7 is a system block diagram of another kind of cancellation test signal that the embodiment of the present invention provides;

Fig. 8 is a system block diagram of another kind of cancellation test signal that the embodiment of the present invention provides;

Fig. 9 is a method for canceling a test signal provided by an embodiment of the present invention;

Fig. 10 is another method for canceling a test signal provided by an embodiment of the present invention. the

Detailed ways

The embodiment of the present invention provides a method and system for canceling a test signal. The system eliminates the test signal component contained in the digital signal output by the receiver by adding a test signal canceling device, thereby avoiding the impact of the test signal component on subsequent services. The impact of the signal. In terms of specific implementation, the position of the test signal canceling device in the system can be adjusted. According to the different positions of the test signal canceling device, the specific implementation of the receiver is also very different, and the detailed implementation will be implemented later. Example will be described. the

As shown in FIG. 3 , a system block diagram of a cancellation test signal provided by an embodiment of the present invention includes a coupler 301, an analog receiver 302, an analog-to-digital converter 303, a digital receiver 304, and a test signal generator 307. The channel corrector 305 also includes a test signal cancellation device 306, wherein,

The coupler 301 receives the analog test signal sent by the test signal generator 307, and injects the analog test signal into the analog input signal, and the analog input signal passes through the analog receiver 302, the analog-to-digital converter 303, and the digital receiver 304 after mixing the analog test signal , and then obtain the corresponding digital signal, which carries the digital test signal generated by the analog test signal through the above-mentioned channel;

The channel corrector 305 receives the digital signal, corrects the digital signal according to an existing channel correction algorithm, and obtains a corrected digital signal. At this time, the digital signal still has a digital test signal component. the

The test signal cancellation device 306 receives the digital test signal sent by the test signal generator 307, and eliminates the digital test signal component contained in the digital signal output by the channel corrector 305. the

Specifically, as shown in FIG. 4 , it is a block diagram of the test signal cancellation device 306 , and the test signal cancellation device 306 includes an equalizer 401 , a subtractor 402 and a feedback branch 403 . A is the first input terminal of the test signal cancellation device 306, the input signal is the digital signal containing the test signal component output by the channel corrector 305, and the first input port is sent to the equalizer 401 and the subtractor 402 in the test signal cancellation device 306 Provide input signal; C is the second input end of test signal cancellation device 306, and input signal is the digital test signal that test signal generator 307 produces, and this digital test signal is the digital form corresponding to the analog test signal of input coupler 301; B is the output terminal of the test signal cancellation device 306, and the digital signal output by the output terminal is a digital output signal after canceling the test signal component. the

The equalizer 401 in the test signal cancellation device 306 receives the digital signal sent by the first input terminal, the digital test signal sent by the second input terminal and the digital output signal output by the output terminal of the test signal cancel device 306, the digital output signal Feedback to the equalizer 401 via the feedback branch 403 . The equalizer 401 is an adaptive equalizer, which can be implemented in the time domain or the frequency domain, and can realize complex amplitude and phase adjustments, thereby canceling the digital test signal component in the digital signal. When the adaptive equalization is time-domain equalization, the digital test signal is equalized by using FIR (Finite Impulse Response, finite impulse response) or IIR (Infinite Impulse Response, infinite impulse response) filtering; when the adaptive When the equalization is frequency domain equalization, the digital test signal is equalized by using FFT (Fast Fourier Transform, Fast Fourier Transform), frequency domain amplitude-phase weighting, and IFFT (Inverse Fast Fourier Transform, Inverse Fast Fourier Transform). Regardless of whether it is in the time domain or the frequency domain, the equalizer can use the LMS algorithm (Least Mean Square, least mean square), LS algorithm (least squares, least squares), RLS algorithm (Recursive least squares, recursive least squares) or Other standard adaptive algorithms. the

The digital test signal input at the C terminal is equalized by the equalizer 401, and the equalized digital test signal is sent to the subtractor 402 to eliminate the digital test signal component in the digital signal. Ideally, the test signal component will be completely canceled. The digital output signal output from the output terminal of the subtractor 402 does not contain any test signal component, which avoids the impact of the test signal component on subsequent services. the

When the receiver is a multi-carrier receiver, here, the multi-carrier receiver means that multiple radio frequency carriers are accommodated on the receiving channel, rather than multi-carrier modulation, that is, OFDM modulation. For example, in a 4-carrier receiver that accommodates four WCDMA carriers with a 5MHz bandwidth within a 20MHz bandwidth, the test signal cancellation can be implemented on each carrier. As shown in FIG. 5 , it is a system block diagram of another cancellation test signal provided by the embodiment of the present invention. The digital signal output by the digital receiver 504 includes n channels of carriers, and the digital signal passes through the channel corrector 505 to generate n channels of corrected digital signals, and the n channels of corrected digital signals are input into the test signal cancellation device 506 . As shown in FIG. 6 , it is a block diagram of a test signal cancellation device 506 in a multi-carrier state. At this time, the test signal cancellation device 506 includes an n-channel cancellation sub-module 601 and a multi-carrier branching module 602, and the n-channel cancellation sub-module 601 performs a test signal cancellation operation on each digital signal. The digital test signal input by the C terminal is passed through the multi-carrier splitting module 602 to obtain n-channel digital test signals, and the n-channel digital test signals are respectively injected into n-channel cancellation sub-modules, and each channel contains the corrected digital signal of the test signal component Cancellation is performed, and the specific cancellation principle of each carrier is the same as that described in FIG. 4 . the

In the embodiment of the present invention, by adding a test signal cancellation device 506 after the channel corrector 505, the digital test signal generated by the test signal generator 507 is used to cancel the digital signal including the test signal component output by the channel corrector 505. Whether it is single carrier or multi-carrier, it can effectively eliminate the impact of test signal components on subsequent services. the

As shown in Figure 7, the system block diagram of another kind of cancellation test signal that the embodiment of the present invention provides, described system comprises coupler 701, analog receiver 702, analog-to-digital converter 703, digital receiver 704, test signal generation device 707, a test signal cancellation device 705, a coefficient converter 708, and a channel corrector 707. Different from the above-mentioned embodiments, after the digital receiver 704 outputs the digital signal, the test signal component is canceled by the test signal cancellation device 705 first, and then the digital signal output by the test signal cancellation device 705 is processed by the channel corrector 706 For correction, the coefficient converter 708 calculates the equalizer coefficients in the channel corrector 706 according to the coefficients of the equalizer 401 in the test signal canceling device 705, specifically, the equalizer in the channel corrector 706 is the equalizer in the test signal canceling device The inverse filter of the device 401, that is, the time-domain impulse response after the two equalizers are connected in series is a Dirac impulse function. In this way, the channel correction device can be constructed according to the structure of the equalizer in the test signal cancellation device. Equalizer. the

In this embodiment, the receiver may also be a multi-carrier receiver, as shown in FIG. 8 , which is a system block diagram of another cancellation test signal provided by an embodiment of the present invention. The digital signal output by the digital receiver 804 includes n carriers, and the n carriers are input into the test signal cancellation device 805 . The n-channel digital signals after the test signal cancellation are input to the channel corrector 806 . At this time, the test signal cancellation device 805 includes a multi-carrier branching module 602 and an n-way cancellation sub-module 601, and the digital test signal input by the C terminal is passed through the multi-carrier branching module 602 to obtain n-way digital test signals, and the n-way The digital test signals are respectively injected into the n channels of cancellation sub-module 601 to cancel the corrected digital signals containing test signal components in each channel. The specific principle of canceling each channel carrier is the same as that described in FIG. 4 . The test signal canceling device 805 outputs n channels of digital signals after cancellation to the channel corrector 806 for correction, and the equalizer corresponding to each signal in the channel corrector 806 can be used by the coefficient converter 808 according to the corresponding signal in the test signal canceling device. The equalizer 401 calculates that the specific calculation method of each equalizer of the channel corrector is the same as that of the single carrier, and will not be repeated here. the

As shown in Figure 9, a method for canceling a test signal provided by an embodiment of the present invention includes:

Step 901: The test signal cancellation device receives the digital test signal sent by the test signal generator and the digital signal output by the channel corrector, and equalizes the digital test signal, and the digital signal output by the channel corrector includes the test signal component;

It should be further explained that the equalization may be adaptive equalization, wherein the adaptive equalization may be frequency domain or time domain equalization, and when the adaptive equalization is time domain equalization, FIR or IIR filtering is used to The digital test signal is equalized; when the adaptive equalization is frequency domain equalization, the digital test signal is equalized by using FFT, frequency domain amplitude-phase weighting, and IFFT. The adaptive algorithms adopted by the adaptive equalization include LMS, LS, RLS and so on. the

Step 902: The test signal canceling device cancels the digital signal output by the channel corrector and the equalized digital test signal to eliminate the test signal component included in the digital signal. the

As shown in Figure 10, another method for canceling the test signal provided by the embodiment of the present invention includes:

Step 1001: The test signal cancellation device receives the digital test signal sent by the test signal generator and the digital signal output by the digital receiver, and equalizes the digital test signal, and the digital signal output by the digital receiver includes a test signal component;

The equalization can be adaptive equalization, wherein the adaptive equalization can be frequency domain or time domain equalization, and when the adaptive equalization is time domain equalization, the digital test signal is filtered by FIR or IIR Equalization: when the adaptive equalization is frequency domain equalization, the digital test signal is equalized by using FFT, frequency domain amplitude-phase weighting, and IFFT. The adaptive algorithms adopted by the adaptive equalization include LMS, LS, RLS and so on. the

Step 1002: the test signal cancellation device cancels the digital signal output by the digital receiver and the equalized digital test signal, and eliminates the test signal component contained in the digital signal;

After the test signal cancellation device eliminates the test signal contained in the digital signal output by the digital receiver, it also includes:

Step 1003: The test signal cancellation device sends the output digital signal after cancellation to the channel corrector for correction. the

Embodiments of the present invention provide a method and system for canceling a test signal. The test signal cancellation module cancels the test signal included in the output digital signal, thereby avoiding the impact of the test signal component on subsequent services. the

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention. the

Claims (7)

1. A system for canceling a test signal, comprising a coupler, an analog receiver, an analog-to-digital converter, a digital receiver, a test signal generator, and a channel corrector, characterized in that it also includes a test signal cancellation device, wherein , The test signal generator is used to generate an analog test signal and a digital test signal corresponding to the analog test signal, send the analog test signal to the coupler, and send the digital test signal to the test Signal cancellation device; The coupler is configured to inject the received analog test signal into an analog input signal; the analog receiver for sending the analog input signal mixed with the analog test signal to the analog-to-digital converter; The analog-to-digital converter is used to convert the analog input signal mixed with the analog test signal into a digital signal, and the digital signal includes a test signal component; The digital receiver is configured to receive the digital signal and send the digital signal to a channel corrector; The channel corrector is used to receive the digital signal sent by the digital receiver and correct the digital signal; The test signal canceling device is used to receive the digital signal output by the channel corrector and the digital test signal sent by the test signal generator, and eliminate the test signal component contained in the digital signal output by the channel corrector, The test signal cancellation device includes: The equalizer is used to receive the digital signal output by the channel corrector, the digital test signal sent by the test signal generator and the digital signal fed back from the output end of the test signal canceling device, and equalize the digital test signal and output; The subtractor is used to receive the digital signal output by the channel corrector and the equalized digital test signal output by the equalizer, and eliminate the test signal component contained in the digital signal output by the channel corrector. 2. The system of claim 1, wherein the equalizer is an adaptive equalizer. 3. The system according to claim 1, when the analog receiver and the digital receiver were multi-carrier receivers, the channel corrector output n roads contained digital signals of test signal components, characterized in that, The test signal cancellation device also includes: A multi-carrier splitting module, configured to divide the digital test signal into n paths and the digital test signal corresponding to the digital signal containing the test signal component of the n paths output by the channel corrector and output to the equalizer; The n is an integer greater than or equal to 2. 4. A system for canceling a test signal, comprising a coupler, an analog receiver, an analog-to-digital converter, a digital receiver, a test signal generator, and a channel corrector, characterized in that it also includes a test signal cancellation device, wherein , The test signal generator is used to generate an analog test signal and a digital test signal corresponding to the analog test signal, send the analog test signal to the coupler, and send the digital signal to the test signal Cancellation device; The coupler is configured to inject the received analog test signal into an analog input signal; the analog receiver for sending the analog input signal mixed with the analog test signal to the analog-to-digital converter; The analog-to-digital converter is used to convert the analog input signal mixed with the analog test signal into a digital signal, and the digital signal includes a test signal component; The digital receiver is used to receive the digital signal and send the digital signal to the test signal cancellation device; The test signal canceling device is used to receive the digital signal sent by the digital receiver and the digital test signal sent by the test signal generator, and eliminate the test signal contained in the digital signal output by the digital receiver component, the test signal cancellation device includes: The equalizer is used to receive the digital signal sent by the digital receiver, the digital test signal sent by the test signal generator and the digital output signal fed back from the output terminal of the test signal cancellation device, and equalize the test signal The digital test signal produced by the generator is output; A subtractor, configured to receive the digital signal output by the digital receiver and the equalized digital test signal output by the equalizer, and eliminate the test signal component contained in the digital signal output by the digital receiver; The channel corrector is used to receive the digital signal output by the test signal cancellation device, and correct the digital signal. 5. The system of claim 4, wherein the equalizer is an adaptive equalizer. 6. The system of claim 4, further comprising a coefficient converter, wherein, A coefficient converter, used to calculate the parameters of the equalizer in the channel corrector according to the equalizer parameters in the test signal canceling device; Correspondingly, the channel corrector is configured to construct the equalizer in the channel corrector according to the parameters of the equalizer in the channel corrector sent by the coefficient converter, and the digital output of the test signal cancellation device The signal is corrected. 7. The system according to claim 4, when the analog receiver and the digital receiver were multi-carrier receivers, the digital receiver output n paths contained digital signals of test signal components, characterized in that, The test signal cancellation device also includes: A multi-carrier splitting module, configured to divide the digital test signal into n paths and the digital test signals corresponding to the digital signals containing the test signal components of the n paths output by the digital receiver and output them to the equalizer; The n is an integer greater than or equal to 2.

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