CN107547145B - Method and device for detecting local oscillator leakage signal - Google Patents
Method and device for detecting local oscillator leakage signal Download PDFInfo
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- CN107547145B CN107547145B CN201610485577.5A CN201610485577A CN107547145B CN 107547145 B CN107547145 B CN 107547145B CN 201610485577 A CN201610485577 A CN 201610485577A CN 107547145 B CN107547145 B CN 107547145B
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Abstract
The embodiment of the invention discloses a device for detecting local oscillator leakage signals, which comprises: the transmission link is used for acquiring a first signal, performing up-conversion on the first signal according to a local oscillator signal generated by a local oscillator to obtain a second signal, and sending the second signal to the radio frequency power amplifier, wherein the second signal comprises the up-converted first signal and the local oscillator leakage signal; the radio frequency power amplifier is configured to amplify the second signal, acquire an intermodulation signal generated when the second signal is amplified, select a third signal from the intermodulation signal, and send the third signal to a feedback link; the feedback link is used for processing the third signal and sending the processed third signal to the processor; the processor is configured to detect a power of the processed third signal. The embodiment of the invention also discloses a method for detecting the local oscillator leakage signal.
Description
Technical Field
The present invention relates to the field of wireless communications, and in particular, to a method and an apparatus for detecting a local oscillator leakage signal.
Background
In a wireless communication system, a transmitted signal is generally required to have characteristics of large bandwidth and high linearity, which puts high demands on spurious indicators and linearity indicators of the wireless communication system. In a Radio Remote Unit (RRU), a transmission signal is transmitted through a transmission link, an up-conversion module in the transmission link generally uses quadrature modulation to implement up-conversion, and devices in the up-conversion module, such as a modulator, have inherent dc offset, so that in the up-conversion process, unwanted signals such as local oscillator leakage signals may be generated, and the local oscillator leakage signals may cause stray indexes not meeting related standards and directly affect the linearity of the system, so reducing the local oscillator leakage is very necessary.
At present, local oscillator leakage is generally reduced by detecting and calibrating local oscillator leakage power, and the local oscillator leakage power can generate parameter drift along with frequency, temperature and time, so if the local oscillator leakage power is to be eliminated, the local oscillator leakage power generally needs to be detected and calibrated at a specific temperature and time.
However, in the radio frequency transceiver shown in fig. 1, the transmission link 2 and the feedback link 4 are connected to the same local oscillator (or local oscillator) 1, and the feedback link 4 adopts an ac coupling design, so that the local oscillator leakage signal generated by the transmission link 2 passes through the feedback link 4 and becomes a zero frequency signal, and the processor 5, such as a Field Programmable Gate Array (FPGA), cannot detect the local oscillator leakage power in the feedback link 4. If the local oscillator leakage power is to be detected, an independent local oscillator needs to be added to the feedback link 4, or as shown in fig. 2, an auxiliary local oscillator 7 and a radio frequency switch 8 are added, where the radio frequency switch 8 is used to select to switch the connection between the feedback link 4 and the local oscillator 1 or the auxiliary local oscillator 7, and when the local oscillator leakage power needs to be detected, the radio frequency switch 8 is switched to the auxiliary local oscillator 7, and the local oscillator leakage frequency can be shifted to the intermediate frequency by changing the frequency of the auxiliary local oscillator 7, so that the processor 5 can detect the local oscillator leakage power in the feedback link 4.
However, adding an independent local oscillator or an auxiliary local oscillator and a radio frequency switch to the feedback link increases the cost and does not meet the requirement of miniaturization of the device design; however, if these modules are not added, the local oscillator leakage power cannot be detected, and even the local oscillator leakage power cannot be calibrated on line, so that the linear index of the system is affected, and the fault related to the local oscillator leakage is difficult to be located in an external field, thereby increasing the later repair and maintenance cost of the equipment in the system.
Disclosure of Invention
In order to solve the existing technical problem, embodiments of the present invention provide a method and an apparatus for detecting a local oscillator leakage signal, which can reduce cost and simplify a feedback link design.
In order to achieve the above purpose, the technical solution of the embodiment of the present invention is realized as follows:
in a first aspect, an embodiment of the present invention provides a device for detecting a local oscillator leakage signal, where the device includes: a local oscillator, a transmit chain, a radio frequency power amplifier, a feedback chain, and a processor, wherein,
the local oscillator is used for generating a local oscillation signal and sending the local oscillation signal to the transmitting link;
the transmitting link is used for acquiring a first signal, performing up-conversion on the first signal according to a received local oscillator signal to obtain a second signal, and sending the second signal to the radio frequency power amplifier, wherein the second signal comprises the up-converted first signal and a local oscillator leakage signal;
the radio frequency power amplifier is configured to receive and amplify the second signal, acquire an intermodulation signal generated when the second signal is amplified, select a third signal from the intermodulation signal, and send the third signal to the feedback link;
the feedback link is configured to receive the third signal, process the third signal, and send the processed third signal to the processor;
the processor is configured to receive the processed third signal and detect a power of the processed third signal.
In the above scheme, the transmission link includes: a digital-to-analog conversion module, a first intermediate frequency filtering module and a modulation module, wherein,
the digital-to-analog conversion module is used for acquiring an analog signal and sending the analog signal to the first intermediate frequency filtering module;
the first intermediate frequency filtering module is configured to receive the analog signal, filter the analog signal to obtain a first signal, and send the first signal to the modulating module;
the modulation module is configured to receive the first signal and a local oscillator signal sent by the local oscillator, perform up-conversion on the first signal according to the local oscillator signal to obtain a second signal, and send the second signal to the radio frequency power amplifier.
In the above scheme, the feedback link includes: a small signal amplifying module, a demodulating module, a second intermediate frequency filtering module and an analog-to-digital converting module, wherein,
the small signal amplification module is configured to receive a third signal sent by the radio frequency power amplifier, amplify the third signal, and send the amplified third signal to the demodulation module;
the demodulation module is configured to receive the amplified third signal, down-convert the frequency of the amplified third signal to a preset frequency, and send the down-converted third signal to the second intermediate frequency filtering module;
the second intermediate frequency filtering module is configured to receive the third signal after the down-conversion, filter the third signal after the down-conversion, and send the filtered third signal to the analog-to-digital conversion module;
the analog-to-digital conversion module is configured to receive the filtered third signal, perform analog-to-digital conversion on the filtered third signal, and send the analog-to-digital converted third signal to the processor.
In the above scheme, the third signal is a third-order intermodulation signal.
In the foregoing scheme, the processor is further configured to adjust the offset compensation voltage of the digital-to-analog conversion module when it is detected that the power of the third signal is greater than a preset threshold value, until the power of the third signal is less than or equal to the preset threshold value.
In a second aspect, an embodiment of the present invention provides a method for detecting a local oscillator leakage signal, where the method includes:
acquiring a first signal, and performing up-conversion on the first signal according to a generated local oscillator signal to obtain a second signal, wherein the second signal comprises the up-converted first signal and a local oscillator leakage signal;
amplifying the second signal to obtain an intermodulation signal generated when the second signal is amplified, and selecting a third signal from the intermodulation signal; and processing the third signal, and detecting the power of the processed third signal.
In the foregoing scheme, the obtaining a first signal and performing up-conversion on the first signal according to a generated local oscillator signal to obtain a second signal includes:
acquiring an analog signal;
filtering the analog signal to obtain a first signal;
and carrying out up-conversion on the first signal according to the generated local oscillation signal to obtain a second signal.
In the foregoing scheme, the processing the third signal includes:
amplifying the third signal;
down-converting the frequency of the amplified third signal to a preset frequency;
filtering the down-converted third signal;
and performing analog-to-digital conversion on the filtered third signal.
In the above scheme, the third signal is a third-order intermodulation signal.
In the above aspect, the method further includes:
and when the power of the third signal is detected to be larger than a preset threshold value, adjusting the bias compensation voltage when the analog signal is acquired until the power of the third signal is smaller than or equal to the preset threshold value.
The embodiment of the invention provides a method and a device for detecting local oscillator leakage signals, wherein the detection device comprises the following steps: the method comprises the following steps that firstly, the local oscillator generates a local oscillation signal and sends the local oscillation signal to a transmitting link; then, the transmitting link acquires a first signal, performs up-conversion on the first signal according to a received local oscillation signal to obtain a second signal, and sends the second signal to the radio frequency power amplifier; the radio frequency power amplifier acquires intermodulation signals generated when the second signals are amplified, selects a third signal from the intermodulation signals and sends the third signal to the feedback link; next, the feedback link processes the third signal and sends the processed third signal to the processor; finally, the processor detects the power of the processed third signal. Because the frequency of the local oscillator leakage signal becomes zero through the processing of the feedback link, the processor cannot detect the local oscillator leakage power, but the frequency of the intermodulation signal is not zero, and the power of the intermodulation signal and the local oscillator leakage power have the characteristic of positive linear correlation, therefore, the detection device can represent the power of the local oscillator leakage signal by detecting the power of the intermodulation signal without changing the existing link design, and compared with the prior art that an independent local oscillator is added on the feedback link or an auxiliary local oscillator and a radio frequency switch are added, the cost is reduced, and the feedback link design is simplified.
Drawings
Fig. 1 is a block diagram of a prior art rf transceiver;
fig. 2 is a block diagram of a local oscillator leakage signal detection apparatus in the prior art;
fig. 3 is a block diagram of a local oscillator leakage signal detection apparatus according to embodiment 1 of the present invention;
fig. 4 is a schematic flowchart of a method for detecting a local oscillator leakage signal according to embodiment 2 of the present invention;
FIG. 5 is a graph of a spectrum of a signal in a low local oscillator scheme;
fig. 6 is a graph of the spectrum of a signal in a high local oscillator scheme.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.
Example 1
The present embodiment provides a local oscillator leakage signal detection apparatus, as shown in fig. 3, the apparatus includes: local oscillator 1, transmission link 2, radio frequency power amplifier 3, feedback link 4 and processor 5. The local oscillator 1 is respectively connected with a transmitting link 2 and a feedback link 4, and the feedback link 4 adopts an alternating current coupling design; the input end of the transmitting link 2 is connected with the processor 5, and the output end of the transmitting link 2 is connected with the radio frequency power amplifier 3; the output end of the radio frequency power amplifier 3 is connected with the input end of the feedback link 4, and the output end of the feedback link 4 is connected with the processor 5; the output end of the radio frequency power amplifier 3 is also connected with a transmitting antenna 6.
With reference to the embodiment of the present invention, in the above detection apparatus, the local oscillator 1 is configured to generate a local oscillator signal, and send the local oscillator signal to the transmission link 2.
And the transmitting link 2 is configured to acquire a first signal, perform up-conversion on the first signal according to the received local oscillation signal to obtain a second signal, and send the second signal to the radio frequency power amplifier 3, where the second signal includes the up-converted first signal and the local oscillation leakage signal.
Here, the first signal may be generated by the transmission link 2, or may be generated by the processor 5, and in the process of performing up-conversion on the first signal according to the local oscillator signal, the transmission link 2 may generate a local oscillator leakage signal, where the local oscillator leakage signal and the up-converted first signal form a second signal; the frequency of the first signal after the up-conversion is the sum of the frequency of the first signal and the frequency of the local oscillator signal, and the frequency of the local oscillator leakage signal is the same as the frequency of the local oscillator signal.
Optionally, when both the first signal and the local oscillator leakage signal are single tone signals, the second signal is a double tone signal. Of course, the first signal may also be other signals, such as a modulation signal, and is not particularly limited in the present invention.
And the radio frequency power amplifier 3 is configured to receive and amplify the second signal, acquire intermodulation signals generated when the second signal is amplified, select a third signal from the intermodulation signals, and send the third signal to the feedback link 4.
It should be noted that, due to the nonlinear distortion characteristic of the rf power amplifier 3, the signal output by the rf power amplifier 3 includes, in addition to the amplified second signal, a plurality of intermodulation signals related to local oscillator leakage signals, where the intermodulation signals include a third-order intermodulation signal, a fifth-order intermodulation signal, and the like, and the rf power amplifier 3 selects a third signal from the intermodulation signals and sends the third signal to the feedback link 4.
Optionally, because the frequency of the third-order intermodulation signals in the intermodulation signals is closer to the frequency of the second signal input by the input end of the radio-frequency power amplifier 3, the frequency of the third-order intermodulation signals usually falls within the effective frequency bandwidth of the radio-frequency power amplifier 3, and cannot be filtered out during filtering, while other intermodulation signals are easily filtered out, so that the selected third signal may be the third-order intermodulation signals.
Here, the radio frequency power amplifier 3 may be a non-linear radio frequency power amplifier, and of course, the radio frequency power amplifier 3 may also be a linear radio frequency power amplifier, which is not limited in the present invention.
And the feedback link 4 is configured to receive the third signal, process the third signal, and send the processed third signal to the processor 5.
It should be noted that, the feedback link 4 may receive, through a coupling module (not shown in the figure), a mixed signal sent by the rf power amplifier 3, where the mixed signal includes the second signal and the third signal, however, after the second signal and the third signal are processed by the feedback link 4, a frequency of the processed first signal becomes a difference between a frequency of the up-converted first signal and a frequency of the local oscillator signal, the processed local oscillator leakage signal becomes a zero frequency signal, that is, a frequency of the processed local oscillator leakage signal becomes zero, and a frequency of the processed third signal becomes a preset frequency.
And a processor 5, configured to receive the processed third signal and detect a power of the processed third signal.
Since the local oscillator leakage signal processed by the feedback link 4 becomes a zero frequency signal, the processor 5 cannot detect the power of the processed local oscillator leakage signal. While the third signal processed by the feedback link 4 is not a zero-frequency signal, the processor 5 may receive and detect the power of the processed third signal.
Since the power of the processed third signal is directly and linearly related to the power of the local oscillator leakage signal, the detection apparatus may characterize the power of the local oscillator leakage signal, that is, the local oscillator leakage power, by the detected power of the third signal. Therefore, the detection device can realize indirect detection of the local oscillator leakage power on the basis of not increasing the existing link design, and compared with the existing detection device, the detection device has the advantages of reducing the cost, simplifying the feedback link design and meeting the requirement of equipment miniaturization design.
Here, the processor 5 may be a Field Programmable Gate Array (FPGA), a Digital Signal Processor (DSP), or the like, and the processor 5 may also be another processor, which is not limited in the present invention.
Optionally, the processor 5 is further configured to adjust the offset compensation voltage of the digital-to-analog conversion module 21 in the feedback link 4 when it is detected that the power of the third signal is greater than a preset threshold value, until the power of the third signal is less than or equal to the preset threshold value. Accordingly, the detection device can adjust the power of the third signal by adjusting the offset compensation voltage of the digital-to-analog conversion module 21 in the feedback link 4, and accordingly, when the power of the third signal is adjusted to be less than or equal to the preset threshold value, the local oscillator leakage power is also calibrated, so that the linear index of the wireless communication system cannot be influenced by local oscillator leakage, and in addition, the fault related to the local oscillator is easily positioned outside the field, and the later repair and maintenance cost of equipment in the system is reduced.
Further, in connection with practical applications, as shown in fig. 3, the transmission chain 2 in the embodiment of the present invention includes, from the processor 5 to the transmission antenna 6: the digital-to-analog conversion module 21, the first intermediate frequency filtering module 22 and the modulation module 23 are connected in sequence; wherein:
the digital-to-analog conversion module 21 is configured to obtain an analog signal and send the analog signal to the first intermediate frequency filtering module 22.
Here, the analog signal may be generated by the digital-to-analog conversion module 21, or may be generated by the processor 5 as a digital signal and then converted into an analog signal by the digital-to-analog conversion module 21.
Optionally, the analog signal may be a single-tone signal, and of course, the analog signal may also be other signals, such as a modulation signal, which is not specifically limited in the present invention.
The first intermediate frequency filtering module 22 is configured to receive the analog signal, filter the analog signal to obtain a first signal, and send the first signal to the modulating module 23.
Here, the first intermediate frequency filtering module 22 may be a low pass filter.
Optionally, when the analog signal may be a monophonic signal, the first signal is also a monophonic signal.
The modulation module 23 is configured to receive the first signal and the local oscillation signal sent by the local oscillation, perform up-conversion on the first signal according to the local oscillation signal to obtain a second signal, and send the second signal to the radio frequency power amplifier 3.
Further, in connection with practical applications, as shown in fig. 3, the feedback link 4 in the embodiment of the present invention includes, from the transmitting antenna 6 to the processor 5: a small signal amplifying module 41, a demodulating module 42, a second intermediate frequency filtering module 43 and an analog-to-digital conversion module 44 which are connected in sequence; local oscillator 1 is connected with modulation module 23 and demodulation module 42 respectively, wherein:
the small signal amplifying module 41 is configured to receive a third signal sent by the radio frequency power amplifier 3, amplify the third signal, and send the amplified third signal to the demodulating module 42.
A demodulation module 42, configured to receive the amplified third signal, down-convert the frequency of the amplified third signal to a preset frequency, and send the down-converted third signal to a second intermediate frequency filtering module 43.
The second intermediate frequency filtering module 43 is configured to receive the down-converted third signal, filter the down-converted third signal, and send the filtered third signal to the analog-to-digital converting module 44.
An analog-to-digital conversion module 44, configured to receive the filtered third signal, perform analog-to-digital conversion on the filtered third signal, and send the analog-to-digital converted third signal to the processor 5.
Example 2
The present embodiment provides a method for detecting a local oscillator leakage signal, as shown in fig. 4, a processing flow of the method of the present embodiment includes the following steps:
step 401, acquiring a first signal, and performing up-conversion on the first signal according to a generated local oscillation signal to obtain a second signal, wherein the second signal includes the up-converted first signal and a local oscillation leakage signal;
Optionally, the obtaining a first signal, and performing up-conversion on the first signal according to the generated local oscillator signal to obtain a second signal includes: acquiring an analog signal; filtering the analog signal to obtain a first signal; and carrying out up-conversion on the first signal according to the generated local oscillation signal to obtain a second signal.
Optionally, the processing the third signal includes: amplifying the third signal; down-converting the frequency of the amplified third signal to a preset frequency; filtering the down-converted third signal; and performing analog-to-digital conversion on the filtered third signal.
Optionally, the third signal is a third-order intermodulation signal.
Optionally, the method further includes: when the power of the third signal is detected to be larger than a preset threshold value, adjusting the bias compensation voltage when the analog signal is acquired until the power of the third signal is smaller than or equal to the preset threshold value
For example, based on the local oscillator leakage signal detection apparatus shown in fig. 3, it is assumed that the operating frequency band of the wireless system is 3400MHz-3600MHz, and the frequency of the signal that can be received by the second intermediate frequency filter module is 245MHz +/-200 MHz; when the low local oscillation frequency matching scheme is adopted, the frequency of the local oscillation signal is lower than the frequency of the radio frequency signal subjected to the preset up-conversion and the frequency f of the preset local oscillation signalLOThe method for detecting the local oscillator leakage signal is 3315MHz, and comprises the following steps:
step 501, the digital-to-analog conversion module 21 outputs a single tone signal and sends the single tone signal to the first intermediate frequency filtering module 22;
here, the single tone signal has a frequency fDAC_IF168MHz, the tone amplitude of the tone signal is-17 dBFs when the rated power of the device antenna port is 43 dBm. The frequency setting of the mono signal is sized in consideration of the frequency bandwidth of the signal that can be received by the second intermediate frequency filtering module 43, and the frequency of the received signal should be lower than the frequency bandwidth of the second intermediate frequency filtering module 43.
Step 502, the first intermediate frequency filtering module 22 receives the single tone signal, filters the single tone signal to obtain a filtered single tone signal, and sends the filtered single tone signal to the modulating module 23.
Step 503, the local oscillator 1 generates a local oscillator signal, and sends the local oscillator signal to the modulation module 23.
Here, the local frequency f of the local oscillator signalLO＝3315MHz。
Step 504, the modulation module 23 receives the filtered single tone signal and the local oscillator signal, performs up-conversion on the filtered single tone signal according to the local oscillator signal to obtain an up-converted single tone signal and a local oscillator leakage signal, and sends the up-converted single tone signal and the local oscillator leakage signal to the radio frequency power amplifier 3.
Here, the frequency f of the up-converted single tone signalRF＝fDAC_IF+fLO3483MHz, the frequency of the local oscillator leakage signal is 3315MHz, which is lower than the frequency of the single tone signal after up-conversion.
Step 505, the radio frequency power amplifier 3 receives and amplifies the single-tone signal and the local-oscillator leakage signal after the up-conversion, obtains an intermodulation signal generated when the single-tone signal and the local-oscillator leakage signal after the up-conversion are amplified, selects a third-order intermodulation signal from the intermodulation signal, and sends the third-order intermodulation signal to the small-signal amplification module 41.
Here, as shown in fig. 5, the frequency difference Δ f between the single-tone signal and the local oscillator leakage signal is 168 MHz; frequency f of the third order intermodulation signalIM3＝2fRF-fLOOr fIM3＝2fLO-fRFAnd a frequency of 2fRF-fLOThe power of the third-order intermodulation signal is larger than the frequency of 2fLO-fRFOf the third order intermodulation signal, therefore, the frequency 2f is selectedRF-fLOIs sent to the small-signal amplification module 41 as a detection signal with a frequency fIM3＝3651MHz。
Step 506, the small-signal amplification module 41 receives the third-order intermodulation signal sent by the radio-frequency power amplifier 3, amplifies the third-order intermodulation signal, and sends the amplified third-order intermodulation signal to the demodulation module 42.
In step 507, the demodulation module 42 receives the amplified third-order intermodulation signal, down-converts the frequency of the amplified third-order intermodulation signal to a preset frequency, and sends the down-converted third-order intermodulation signal to the second intermediate frequency filtering module 43.
Here, the frequency of the single-tone signal after up-conversion is changed into 168MHz after down-conversion; the frequency of the local oscillator leakage signal becomes zero after down-conversion, the zero-frequency signal cannot be directly detected, and the frequency of the third-order intermodulation signal becomes f after down-conversionIM3_IF＝fIM3-fLO＝336MHz。
Step 508, the second intermediate frequency filtering module 43 receives the third-order intermodulation signal after the down-conversion, filters the third-order intermodulation signal after the down-conversion, and sends the filtered third-order intermodulation signal to the analog-to-digital conversion module 44.
Step 509, the analog-to-digital conversion module 44 receives the filtered third-order intermodulation signals, performs analog-to-digital conversion on the filtered third-order intermodulation signals, and sends the third-order intermodulation signals after the analog-to-digital conversion to the processor 5.
Step 510, the processor 5 receives the third-order intermodulation signal after the analog-to-digital conversion, and detects the power of the third-order intermodulation signal after the analog-to-digital conversion.
The working frequency range of the wireless system is assumed to be 3400MHz-3600MHz, and the frequency of the signal which can be received by the second intermediate frequency filter module is-245 MHz +/-200 MHz; by using high-cost vibrationIn the frequency allocation scheme, the frequency of the local oscillator signal is higher than the frequency of the radio frequency signal subjected to the preset up-conversion, and the frequency f of the preset local oscillator signalLOThe method for detecting the local oscillator leakage signal is 3775MHz, and comprises the following steps:
step 601, the digital-to-analog conversion module 21 outputs a single tone signal, and sends the single tone signal to the modulation module 23 after being filtered by the first intermediate frequency filtering module 22.
Here, the single tone signal has a frequency fDAC_IFWhen the rated power of the device antenna port is 43dBm, -168MHz, the tone amplitude of the tone signal is-17 dBFs.
Step 602, the local oscillator 1 generates a local oscillator signal, and sends the local oscillator signal to the modulation module 23.
Here, the local frequency f of the local oscillator signalLO＝3775。
Step 603, the modulation module 23 performs up-conversion on the filtered single tone signal according to the local oscillator signal to obtain an up-converted single tone signal and a local oscillator leakage signal, and sends the up-converted single tone signal and the local oscillator leakage signal to the radio frequency power amplifier 3.
Here, the frequency f of the up-converted single tone signalRF＝fDAC_IF+fLO3607MHz, the frequency of the local oscillator leakage signal is 3775MHz, which is higher than the frequency of the single tone signal after the up-conversion.
Step 604, selecting a third-order intermodulation signal from the intermodulation signals generated by the single-tone signal and the local oscillator leakage signal after the up-conversion through the radio frequency power amplifier 3, and sending the third-order intermodulation signal to the demodulation module 42 through the small signal amplification module 41.
Here, as shown in fig. 6, the frequency difference Δ f between the single-tone signal and the local oscillator leakage signal is-168 MHz; frequency f of the third order intermodulation signalIM3＝2fRF-fLOOr fIM3＝2fLO-fRFAnd a frequency of 2fRF-fLOThe power of the third-order intermodulation signal is larger than the frequency of 2fLO-fRFOf the third order intermodulation signal, thereby selecting the frequencyRate of 2fRF-fLOThe third-order intermodulation signal, i.e. the third-order intermodulation signal of the low side, is used as the detection signal and sent to the demodulation module 42 through the small-signal amplification module 41, and the frequency of the detection signal is fIM3＝3439MHz。
Step 605, the demodulation module 42 down-converts the frequency of the amplified third-order intermodulation signal to a preset frequency, and sends the down-converted third-order intermodulation signal to the processor 5 after digital-to-analog conversion by the second intermediate frequency filtering module 43 and the analog-to-digital conversion module 44.
Here, the local oscillator leakage signal is down-converted to zero in frequency, the zero frequency signal cannot be directly detected, and the third order intermodulation signal is down-converted to f in frequencyIM3_IF＝fIM3-fLO＝-336MHz。
Step 605, the processor receives the third-order intermodulation signal after the analog-to-digital conversion, and detects the power of the third-order intermodulation signal after the analog-to-digital conversion.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.
Claims (8)
1. A device for detecting a local oscillator leakage signal, the device comprising: a local oscillator, a transmit chain, a radio frequency power amplifier, a feedback chain, and a processor, wherein,
the local oscillator is used for generating a local oscillation signal and sending the local oscillation signal to the transmitting link;
the transmitting link is used for acquiring a first signal, performing up-conversion on the first signal according to a received local oscillator signal to obtain a second signal, and sending the second signal to the radio frequency power amplifier, wherein the second signal comprises the up-converted first signal and a local oscillator leakage signal;
the radio frequency power amplifier is configured to receive and amplify the second signal, acquire an intermodulation signal generated when the second signal is amplified, select a third signal from the intermodulation signal, and send the third signal to the feedback link;
the feedback link, comprising: a small signal amplifying module, a demodulating module, a second intermediate frequency filtering module and an analog-to-digital converting module, wherein,
the small signal amplification module is configured to receive a third signal sent by the radio frequency power amplifier, amplify the third signal, and send the amplified third signal to the demodulation module;
the demodulation module is configured to receive the amplified third signal, down-convert the frequency of the amplified third signal to a preset frequency, and send the down-converted third signal to the second intermediate frequency filtering module;
the second intermediate frequency filtering module is configured to receive the third signal after the down-conversion, filter the third signal after the down-conversion, and send the filtered third signal to the analog-to-digital conversion module;
the analog-to-digital conversion module is configured to receive the filtered third signal, perform analog-to-digital conversion on the filtered third signal, and send the analog-to-digital converted third signal to the processor;
the processor is configured to receive the processed third signal and detect a power of the processed third signal.
2. The apparatus of claim 1, wherein the transmit chain comprises: a digital-to-analog conversion module, a first intermediate frequency filtering module and a modulation module, wherein,
the digital-to-analog conversion module is used for acquiring an analog signal and sending the analog signal to the first intermediate frequency filtering module;
the first intermediate frequency filtering module is configured to receive the analog signal, filter the analog signal to obtain a first signal, and send the first signal to the modulating module;
the modulation module is configured to receive the first signal and a local oscillator signal sent by the local oscillator, perform up-conversion on the first signal according to the local oscillator signal to obtain a second signal, and send the second signal to the radio frequency power amplifier.
3. The apparatus of claim 1, wherein the third signal is a third order intermodulation signal.
4. The apparatus of claim 2,
the processor is further configured to adjust the offset compensation voltage of the digital-to-analog conversion module when it is detected that the power of the third signal is greater than a preset threshold value, until the power of the third signal is less than or equal to the preset threshold value.
5. A method for detecting a local oscillator leakage signal, the method comprising:
acquiring a first signal, and performing up-conversion on the first signal according to a generated local oscillator signal to obtain a second signal, wherein the second signal comprises the up-converted first signal and a local oscillator leakage signal;
amplifying the second signal to obtain an intermodulation signal generated when the second signal is amplified, and selecting a third signal from the intermodulation signal; amplifying the third signal;
down-converting the frequency of the amplified third signal to a preset frequency;
filtering the down-converted third signal;
and performing analog-to-digital conversion on the filtered third signal, and detecting the power of the processed third signal.
6. The method of claim 5, wherein obtaining the first signal and performing the up-conversion on the first signal according to the generated local oscillator signal to obtain the second signal comprises:
acquiring an analog signal;
filtering the analog signal to obtain a first signal;
and carrying out up-conversion on the first signal according to the generated local oscillation signal to obtain a second signal.
7. The method of claim 5, wherein the third signal is a third order intermodulation signal.
8. The method of claim 6, further comprising:
and when the power of the third signal is detected to be larger than a preset threshold value, adjusting the bias compensation voltage when the analog signal is acquired until the power of the third signal is smaller than or equal to the preset threshold value.
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| CN201610485577.5A CN107547145B (en) | 2016-06-27 | 2016-06-27 | Method and device for detecting local oscillator leakage signal |
| PCT/CN2016/103494 WO2018000670A1 (en) | 2016-06-27 | 2016-10-27 | Method and device for detecting local oscillation signal |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101159458A (en) * | 2007-11-15 | 2008-04-09 | 中兴通讯股份有限公司 | Digital predistortion system and method |
| CN201717850U (en) * | 2009-04-28 | 2011-01-19 | 北京朗波芯微技术有限公司 | Carrier leakage correction circuit |
| CN204721354U (en) * | 2015-06-09 | 2015-10-21 | 珠海市杰理科技有限公司 | Radio frequency transceiver and radio-frequency (RF) local oscillator thereof leak restraining device |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1564897A1 (en) * | 2004-02-13 | 2005-08-17 | Thomson Licensing S.A. | Control of a power amplifier for reducing power consumption in a transceiver |
| CN102065041B (en) * | 2010-11-18 | 2014-11-05 | 中兴通讯股份有限公司 | Method, device and system for inhibiting local oscillator leakage |
| CN102223330A (en) * | 2011-06-24 | 2011-10-19 | 中兴通讯股份有限公司 | Method and device for IQ (intelligence quotient) signal real-time calibration |
| KR20150129087A (en) * | 2012-07-02 | 2015-11-19 | 한국전자통신연구원 | Frequency mixer |
| US9154080B2 (en) * | 2012-09-25 | 2015-10-06 | Airoha Technology Corp. | Mixer with calibration circuit and calibration method thereof |
| CN105471468B (en) * | 2015-11-11 | 2018-06-05 | 上海华为技术有限公司 | A kind of device, method and the microprocessor controller of local oscillator leakage signals correction |
-
2016
- 2016-06-27 CN CN201610485577.5A patent/CN107547145B/en active Active
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101159458A (en) * | 2007-11-15 | 2008-04-09 | 中兴通讯股份有限公司 | Digital predistortion system and method |
| CN201717850U (en) * | 2009-04-28 | 2011-01-19 | 北京朗波芯微技术有限公司 | Carrier leakage correction circuit |
| CN204721354U (en) * | 2015-06-09 | 2015-10-21 | 珠海市杰理科技有限公司 | Radio frequency transceiver and radio-frequency (RF) local oscillator thereof leak restraining device |
Non-Patent Citations (2)
| Title |
|---|
| A baseband technique for automated LO leakage suppression achieving < −80dBm in wideband passive mixer-first receivers;Suren Jayasuriya 等;《Proceedings of the IEEE 2014 Custom Integrated Circuits Conference》;20140917;全文 * |
| 单片零中频无线发射器载波泄漏消除技术研究;张长弓;《中国优秀硕士学位论文全文数据库》;20130815;全文 * |
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