CN1627650A - Gain correction system for reception channel in radio frequency and method - Google Patents

Gain correction system for reception channel in radio frequency and method Download PDF

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Publication number
CN1627650A
CN1627650A CN 200310123619 CN200310123619A CN1627650A CN 1627650 A CN1627650 A CN 1627650A CN 200310123619 CN200310123619 CN 200310123619 CN 200310123619 A CN200310123619 A CN 200310123619A CN 1627650 A CN1627650 A CN 1627650A
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radio frequency
reception channel
frequency reception
gain
channel
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CN100373785C (en
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郦舟剑
蒲涛
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Huawei Technologies Co Ltd
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Huawei Technologies Co Ltd
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Abstract

The disclosed system and method includes following parts: radio frequency receiving channel in use for receiving radio frequency signal and outputting processed radio frequency signal; part of measuring power in use for testing output power of radio frequency receiving channel. Input end of radio frequency receiving channel is in open circuit or is matched to load. Output end of radio frequency receiving channel is connected to input end of power measurement part. Advantages of the system and method are: relative simple scheme for correcting radio frequency gain at up going channel, and raised maintainability.

Description

Radio frequency reception channel gain calibration system and method thereof
Technical field
The present invention relates to gain calibration system and method thereof in the wireless communication system, particularly the gain calibration system and the method thereof of the receive path of up parts in the radio communication.
Background technology
As shown in Figure 1, in the radio communication receiving system, the electromagnetic signal of radio frequency reception channel reception antenna induction is also handled, and the signal after the processing outputs to digital processing device and carries out digital processing.
Some cellular systems, as global system for mobile communications (Global System fbr MobileCommunication, abbreviation " GSM "), Wideband Code Division Multiple Access (WCDMA) (Wideband Code DivisionMultiple Access, abbreviation " WCDMA ") in the system, the signal magnitude that generally needs the calculating radio frequency to receive is received signal field intensity (Receive Signal Strength Indicator, be called for short " RSSI "), RSSI is sent into the logical circuit of receiving system, for network switches and power is controlled foundation is provided.The method of the general RSSI of calculating is as follows in these systems: partly calculate the received signal size that radio frequency reception channel is exported by Digital Signal Processing, extrapolate the signal magnitude RSSI that the radio-frequency channel receives then, as shown in the formula,
RSSI=Power (radio frequency reception channel output signal power)-Gain (radio frequency reception channel gain)
Gain wherein is the radio frequency reception channel gain, and General System just sets at initial operating stage, is a constant.Need to prove that RSSI and Power are power level, unit is generally dBm, the gain that Gain also represents for dB.
Radio frequency Return Reception Dept. branch adopts analogue device often, and there is batch conforming problem in the radio frequency analog device, so can there be bigger fluctuation in the radio frequency reception channel gain, generally can reach 6~8dB.This has brought bigger error for system-computed RSSI, so producing or the initial general radio-frequency channel gain (Gain) that needs to proofread and correct of beginning.By proofreading and correct, reduce the gain error of radio frequency reception channel, make error can satisfy the requirement of system.
The system of now more common radio-frequency channel gain calibration scheme forms as Fig. 2, illustrates below in conjunction with Fig. 2:
This system comprises following part: parts 10 are power meters, are used to measure the power of input power meter; Parts 20 are radio frequency reception channel, and this radio frequency reception channel is supported gain calibration, and design has the Gain Adjustable device, can be the voltage controlled gain amplifier, also can be the voltage controlled attenuator; Parts 30 are signal source, are used for exporting a certain size signal.
The input of power meter 10 is connected with the output of radio frequency reception channel 20, and the input of radio frequency reception channel 20 links to each other with the output of signal source 30.
It is Gain that supposing the system requires channel gain.
The step of this method is as follows:
Step 1, with the tone signal that signal source input radio frequency receive path can receive, input signal power is fixed as P1, unit is dBm;
The power P 2 of step 2, usefulness power instrumentation amount radio frequency reception channel output signal, unit is dBm;
Step 3, can calculate radio frequency reception channel and proofread and correct the gain of preceding physical channel and be Gain1=P2-P1;
Step 4, calculate gain after, according to system requirements, regulate the gain of radio frequency reception channel;
Execution in step 2, step 3, step 4 repeatedly are until Gain1=Gain.
In actual applications, there is following problem in such scheme: adopt signal source and power meter to carry out the gain calibration of radio frequency reception channel simultaneously, the cost height of system, bearing calibration more complicated.
No matter cause a main cause of this situation to be, be to produce to proofread and correct or straightened up in place, and all needs increase instrument and dispose: signal source and power meter or frequency spectrograph, and cost will increase; If radio frequency reception channel is to be formed by connecting on frame by a plurality of modules, so just be not suitable for when producing, proofreading and correct, need in the time of beginning, carry out straightened up in place, it is very inconvenient that instrument is carried at the scene, and the maintainability of system can reduce greatly.
Summary of the invention
The technical problem to be solved in the present invention provides a kind of radio frequency reception channel gain calibration system and method thereof, makes that radio frequency upstream channel gain correcting scheme is simple relatively, and cost reduces, and the maintainability of system improves greatly.
In order to solve the problems of the technologies described above, the invention provides a kind of radio frequency reception channel gain calibration system, comprise:
Radio frequency reception channel is used for received RF signal, and described radiofrequency signal is handled back output;
The power measurement parts are used to measure the power output of described radio frequency reception channel; Wherein,
The input open circuit or the matched load of described radio frequency reception channel, the output of described radio frequency reception channel links to each other with the input of described power measurement parts.
Wherein, described power measurement parts are power meter.
Described power measurement parts are digital signal processor.
The present invention also provides a kind of radio frequency reception channel gain calibration method, comprises following steps:
A measures the noise power output of radio frequency reception channel;
The gain that B calculates described radio frequency reception channel according to the described noise power output that records;
C judges whether the gain of described radio frequency reception channel meets the requirements, if undesirable, then regulates the gain of described radio frequency reception channel, enters steps A.
In a scheme, described radio frequency reception channel input open circuit.
Among the described step B, calculate the gain G of radio frequency reception channel according to following formula:
G=P/(K*T*Bd*(F-1))
Wherein, P is the noise power output of described radio frequency reception channel, and K is Boltzmann's parameter, and T is the system works temperature, and Bd is the bandwidth of described radio frequency reception channel, and F is the channel noise coefficient of described radio frequency reception channel.
In another scheme, described radio frequency reception channel input termination matched load.
Among the described step B, calculate the gain G of radio frequency reception channel according to following formula:
G=P/(K*T*Bd*F)
Wherein, P is the noise power output of described radio frequency reception channel, and K is Boltzmann's parameter, and T is the system works temperature, and Bd is the bandwidth of described radio frequency reception channel, and F is the channel noise coefficient of described radio frequency reception channel.
By relatively finding, technical scheme difference with the prior art of the present invention is, this programme has utilized the relatively stable principle of noise factor of radio-frequency channel, utilizes radio-frequency channel noise power output to calculate the gain of passage, and undesired signal source input signal can be tested.
Difference on this technical scheme has brought comparatively significantly beneficial effect, i.e. this scheme test is simple, only needs the output noise power of testing radio frequency receive path; Testing cost descends, and has saved the cost of testing source; When system's beginning is safeguarded, do not need to carry signal source and just can proofread and correct the radio-frequency channel gain, improved the maintainability of system greatly; In the actual measurement, under the open circuit mode, the fluctuation of system noise factor generally can be controlled in the 1dB, the error of gain calculating is generally about ± 1dB, under matching way, the fluctuation of system noise factor generally can be controlled in the 1dB, and the error of gain calculating is generally less than ± 0.5dB, and these proofread and correct the result can satisfy the common engineering application need.
Description of drawings
Fig. 1 is a wireless receiving channel system schematic diagram;
Fig. 2 is the structure chart of traditional radio frequency reception channel gain calibration system;
Fig. 3 is a radio frequency reception channel gain calibration system construction drawing according to an embodiment of the invention;
Fig. 4 is a radio frequency reception channel gain calibration method flow chart according to an embodiment of the invention.
Embodiment
For making the purpose, technical solutions and advantages of the present invention clearer, the present invention is described in further detail below in conjunction with accompanying drawing.
This programme utilizes the relatively stable fact of noise factor of radio frequency reception channel, utilizes radio frequency reception channel noise power output to calculate the gain of passage.
This scheme has two kinds of different corrective systems and method:
First kind is the open circuit mode:
Open circuit radio frequency receive path noise power output (Pnoise-out) can be drawn by following formula:
Pnoise-out=K*T0*B*(F-1)*Gain
Wherein, K is Boltzmann's parameter 1.38*10-23; T0 can get 300K (K is temperature unit Kelvin) for the system works temperature; B is the bandwidth of receive path, and unit is Hz (hertz), can directly draw according to design; F is the channel noise coefficient, can directly draw according to design, and F is more stable.
So Gain=Pnoise-out/ (K*T0*B* (F-1))
Can draw by analyzing: in changing among a small circle Δ G/G=(Δ F/F) * (F/ (F-1)) 2 wherein, Δ F is the variation of noise factor, Δ G is a change in gain, G is the abbreviation of gain G ain.
This mode is because open a way in the input port, radio-frequency channel, and the radio-frequency channel shielding is bad, when there is larger interference in the external world, can make that test is incorrect.So this mode is fit to the little occasion of external interference and uses.
Below in conjunction with a specific embodiment this scheme is described, this embodiment system forms as Fig. 3, radio frequency reception channel gain calibration system is made up of interconnective power measurement parts 40 and radio frequency reception channel 20, and radio frequency reception channel 20 also comprises the input 21 of radio frequency reception channel.
Power measurement parts 40 are used to measure the power output of radio frequency reception channel.Be power meter in the present embodiment.Those of ordinary skill in the art are appreciated that with digital signal processor and substitute the measurement that power meter can be realized power equally.
Radio frequency reception channel 20 is used for received RF signal, signal is handled and is sent into the power measurement parts, these parts are the radio frequency reception channel that needs correcting gain, and gain can be regulated by voltage controlled gain amplifier or voltage controlled attenuator, and this depends on the manufacturer of these parts.Present embodiment adopts the voltage controlled gain amplifier to regulate.
The input 21 of radio frequency reception channel is used to connect the load of radio frequency reception channel, and receives the signal that load transmitted, and the input 21 of radio frequency reception channel is open circuit in the present embodiment.
The method step that uses the open circuit mode to proofread and correct is described below in conjunction with Fig. 4:
As shown in Figure 4, enter step 110 when proofreading and correct beginning, the user obtains the bandwidth B and the channel noise coefficient F of radio frequency reception channel according to the design objective of radio frequency reception channel.
Then enter step 120, the user uses the power measurement component to measure the power output of radio frequency reception channel, this power unit mW, and measurement component is a power meter in this embodiment.Those of ordinary skill in the art are appreciated that with digital signal processor and substitute the measurement that power meter can be realized power equally.
Then enter step 130, according to the gain that formula calculates radio frequency reception channel, formula is Gain=Pnoise-out/ (K*T0*B* (F-1)) in the present embodiment.
Then enter step 140, judge the whether compliance with system requirement that gains, if meet then correcting process finishes, if do not meet then enter step 150.
In step 150, judge that whether the ratio of gains of radio frequency reception channel requires bigger than normal, if enter step 170, do not enter step 160.For example the ratio of gains requires the step step 160 that just enters less than normal.
In step 160, regulate the gain controlling of radio frequency reception channel, the radio frequency reception channel gain is increased, then enter step 120.For example, the adjusting of gain is regulated by the voltage controlled gain amplifier in this embodiment.
In step 170, regulate the gain controlling of radio frequency reception channel, the radio frequency reception channel gain is reduced, then enter step 120.Operation in its method and the step 160 is opposite.
Test case according to real system sees that (the real system channel gain is about 60dB, pink noise coefficient 3dB), the fluctuation of system noise factor generally can be controlled in the 1dB, the error of gain calculating generally reaches ± 1dB, and this precision can reasonablely satisfy system requirements generally speaking.
Second kind is matching way:
Radio-frequency channel noise power output can be drawn by following formula:
Pnoise-out=K*T0*B*F*Gain,
Wherein K is Boltzmann's parameter 1.38*10-23; T0 can get 300K (K is temperature unit Kelvin) for the system works temperature; B is the bandwidth of receive path, and unit is Hz (hertz), can directly draw according to design; F is the channel noise coefficient, can directly draw according to design, and F is more stable.
So Gain=Pnoise-out/ (K*T0*B*F)
Can draw by analyzing: Δ G/G=Δ F/F in dynamic change among a small circle; Wherein, Δ F is the variation of noise factor, and Δ G is a change in gain, and G is the abbreviation of gain G ain.
Below in conjunction with a specific embodiment embodiment is described, system's composition of the system's composition of this embodiment and the embodiment of open circuit mode has only a unique difference: in Fig. 3, radio frequency reception channel input 21 connects a matched load in addition, for example uses a metal cap that has 50 Ohmic resistances.Therefore omit system's composition diagram of matching way at this.
Its bearing calibration can illustrate in conjunction with Fig. 4 equally:
As shown in Figure 4, enter step 110 when proofreading and correct beginning, the user obtains the bandwidth B and the channel noise coefficient F of receive path according to the design objective of radio frequency reception channel.
Then enter step 120, the user uses the power measurement component to measure the power output of radio frequency reception channel, this power unit mW, and measurement component is a power meter in this embodiment.Those of ordinary skill in the art are appreciated that with digital signal processor and substitute the measurement that power meter can be realized power equally.
Then enter step 130, according to the gain that formula calculates radio frequency reception channel, formula is Gain=Pnoise-out/ (K*T0*B*F) in the present embodiment.
Then enter step 140, judge the whether compliance with system requirement that gains, if meet then correcting process finishes, if do not meet then enter step 150.
In step 150, judge that whether the ratio of gains of radio frequency reception channel requires bigger than normal, if enter step 170, do not enter step 160.For example the ratio of gains requires the step step 160 that just enters less than normal.
In step 160, regulate the gain controlling of radio frequency reception channel, the radio frequency reception channel gain is increased, then enter step 120.For example, the adjusting of gain is regulated by the voltage controlled gain amplifier in this embodiment.
In step 170, regulate the gain controlling of radio frequency reception channel, be that the radio frequency reception channel gain reduces, then enter step 120.Operation in its method and the step 160 is opposite.
The source of error that matching way calculates the radio frequency reception channel gain mainly is the batch consistency of channel noise coefficient, test case according to real system sees that (the real system channel gain is about 60dB, pink noise coefficient 3dB), the fluctuation of system noise factor generally can be controlled in the 1dB, so the error of gain calculating is generally less than ± 0.5dB, this error system generally can bear.
Measurement result by theory analysis and practical embodiments can be reached a conclusion: the mode correction error of the radio-frequency channel gain calibration of use matching way can be littler than the mode of the radio-frequency channel gain calibration of using the open circuit mode.
Though by reference some preferred embodiment of the present invention, the present invention is illustrated and describes, but those of ordinary skill in the art should be understood that, can do various changes to it in the form and details, and the spirit and scope of the present invention that do not depart from appended claims and limited.

Claims (8)

1. a radio frequency reception channel gain calibration system is characterized in that, comprises:
Radio frequency reception channel is used for received RF signal, and described radiofrequency signal is handled back output;
The power measurement parts are used to measure the power output of described radio frequency reception channel; Wherein,
The input open circuit or the matched load of described radio frequency reception channel, the output of described radio frequency reception channel links to each other with the input of described power measurement parts.
2. radio frequency reception channel gain calibration according to claim 1 system is characterized in that described power measurement parts are power meter.
3. radio frequency reception channel gain calibration according to claim 1 system is characterized in that described power measurement parts are digital signal processor.
4. a radio frequency reception channel gain calibration method is characterized in that, comprises following steps:
A measures the noise power output of radio frequency reception channel;
The gain that B calculates described radio frequency reception channel according to the described noise power output that records;
C judges whether the gain of described radio frequency reception channel meets the requirements, if undesirable, then regulates the gain of described radio frequency reception channel, enters steps A.
5. radio frequency reception channel gain calibration method according to claim 4 is characterized in that, described radio frequency reception channel input open circuit.
6. radio frequency reception channel gain calibration method according to claim 5 is characterized in that, among the described step B, calculates the gain G of radio frequency reception channel according to following formula:
G=P/(K*T*Bd*(F-1))
Wherein, P is the noise power output of described radio frequency reception channel, and K is Boltzmann's parameter, and T is the system works temperature, and Bd is the bandwidth of described radio frequency reception channel, and F is the channel noise coefficient of described radio frequency reception channel.
7. radio frequency reception channel gain calibration method according to claim 4 is characterized in that, described radio frequency reception channel input termination matched load.
8. radio frequency reception channel gain calibration method according to claim 7 is characterized in that, among the described step B, calculates the gain G of radio frequency reception channel according to following formula:
G=P/(K*T*Bd*F)
Wherein, P is the noise power output of described radio frequency reception channel, and K is Boltzmann's parameter, and T is the system works temperature, and Bd is the bandwidth of described radio frequency reception channel, and F is the channel noise coefficient of described radio frequency reception channel.
CNB2003101236193A 2003-12-12 2003-12-12 Gain correction system for reception channel in radio frequency and method Expired - Lifetime CN100373785C (en)

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102090004A (en) * 2008-07-10 2011-06-08 莱特普茵特公司 Method for testing radio frequency (RF) receiver to provide power correction data
CN105137375A (en) * 2014-05-28 2015-12-09 上海联影医疗科技有限公司 RF channel calibration method and device, SAR measurement method, and magnetic resonance system
CN101087162B (en) * 2006-06-09 2016-07-06 希捷科技有限公司 Method and apparatus for the automatic growth control of channel status auxiliary
WO2017041241A1 (en) * 2015-09-09 2017-03-16 Telefonaktiebolaget Lm Ericsson (Publ) Centralized power meter and centralized power calculation method
CN106712870A (en) * 2017-01-23 2017-05-24 上海联影医疗科技有限公司 Magnetic resonance receiving channel calibration method, calibration device and magnetic resonance equipment
CN110806558A (en) * 2020-01-07 2020-02-18 成都华日通讯技术有限公司 Direction finding method of three-channel direction finding system based on time slice rotation

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US5754533A (en) * 1995-08-23 1998-05-19 Qualcomm Incorporated Method and system for non-orthogonal noise energy based gain control
US5749051A (en) * 1996-07-18 1998-05-05 Ericsson Inc. Compensation for second order intermodulation in a homodyne receiver
US6286994B1 (en) * 1998-04-29 2001-09-11 Qualcomm Incorporated System, method and computer program product for controlling a transmit signal using an expected power level
KR100595839B1 (en) * 1999-10-04 2006-07-05 에스케이 텔레콤주식회사 Apparatus and method for compensating rf module gain using measured rf module noise
CN1177419C (en) * 2001-11-19 2004-11-24 华为技术有限公司 Method for measuring channel gain and gain error, delay and phase error

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101087162B (en) * 2006-06-09 2016-07-06 希捷科技有限公司 Method and apparatus for the automatic growth control of channel status auxiliary
CN102090004A (en) * 2008-07-10 2011-06-08 莱特普茵特公司 Method for testing radio frequency (RF) receiver to provide power correction data
CN105137375A (en) * 2014-05-28 2015-12-09 上海联影医疗科技有限公司 RF channel calibration method and device, SAR measurement method, and magnetic resonance system
CN105137375B (en) * 2014-05-28 2019-04-23 上海联影医疗科技有限公司 Radio-frequency channel calibration method and device, SAR measurement method, magnetic resonance system
WO2017041241A1 (en) * 2015-09-09 2017-03-16 Telefonaktiebolaget Lm Ericsson (Publ) Centralized power meter and centralized power calculation method
US10890958B2 (en) 2015-09-09 2021-01-12 Telefonaktiebolaget Lm Ericsson (Publ) Centralized power meter and centralized power calculation method
CN106712870A (en) * 2017-01-23 2017-05-24 上海联影医疗科技有限公司 Magnetic resonance receiving channel calibration method, calibration device and magnetic resonance equipment
CN110806558A (en) * 2020-01-07 2020-02-18 成都华日通讯技术有限公司 Direction finding method of three-channel direction finding system based on time slice rotation
CN110806558B (en) * 2020-01-07 2020-04-21 成都华日通讯技术有限公司 Direction finding method of three-channel direction finding system based on time slice rotation

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