CN1529521A - Multi-carrier auto-gain calibrating device and method - Google Patents

Abstract

Steps of the method are: (1) measuring power of baseband signal of each carrier input; (2) calibrating gain of baseband signal, data of baseband signal in I route and Q route are multiplied by gain calibration value Dk; (3) calibrated baseband signal is processed and converted to radio frequency signal, which is transmitted through antenna; (4) measuring output signal power of each carrier wave at transmitting end; (5) based on formula: Gk= G- (Poutk-Pink) and delta Dk= 10 (delta Gk/20), calculating calibration value Dk of linear gain in next cycle. Comparing with prior art, the invention overcomes disadvantages of low calibration accuracy caused by uneven gain of multicarrier transmitter in 3D mobile communication system. The invention realizes purpose of automatic calibrating carrier gain of 3D mobile communication system.

Description

Multicarrier automatic gain calibration apparatus and method

Technical field

The present invention relates to field of mobile communication, relate in particular to the transmitter automatic gain calibration system of third generation multicarrier mobile communcations system.

Background technology

(the 3G of third generation mobile system, Third Generation MobileCommunication System) downlink of base station partly comprises Base Band Unit and transmitter unit, and wherein transmitter unit is mainly finished functions such as modulation, Digital Up Convert, multi-transceiver combination, D/A conversion, simulation up-conversion, linear power amplification, filtering and power detection.In order to save cost, system closes the road in the emission medium-frequency part with a plurality of carrier signals, afterwards these a plurality of carrier signals is handled simultaneously, launches by antenna at last.According to of the requirement of third generation mobile system to the base station, transmitting power need rated power ± 2dB in, but because the working frequency range that emission covers compares broad, as the WCDMA system bandwidth is 60MHz, and comprise radio frequency units such as expelling plate, Linear Power Amplifier, duplexer filter in the emission path, can't guarantee to gain after circuits cascadings at different levels are integrated and in working frequency range, still be consistent, in addition, radio circuit is subjected to the influence of factors such as temperature, device aging, gain also has fluctuation, and final power output and flatness are difficult to reach requirement.

Transmitting gain calibration steps commonly used at present is: the total emission power of measuring system, and set up a control signal as reference point the gain of variable gain amplifier is controlled, thereby reach the purpose of controlling transmitting gain.The 99812978.X patent of U.S. Qualcomm Inc application has been announced, and a kind of " utilizing broadband power to measure the system and method that independent narrow band channel is carried out gain controlling " just adopted this processing means, Fig. 1 utilizes variable gain amplifier to carry out the systematic schematic diagram of gain controlling in the prior art, this gain control system is estimated by power estimator respectively the power of each carrier wave, and utilize to estimate that summer is sued for peace to each carrier power and obtain the estimating power value, total transmitting power is measured the measurement performance number by the broadband power meter, compare the estimating power value and measure performance number, produce error signal, as foundation the gain of variable gain amplifier is controlled with this error signal.But the gain of the physical channel of each carrier wave is difficult to be consistent in the broad band multicarrier signal of 3-G (Generation Three mobile communication system), correspondingly, require the controlled quentity controlled variable difference of each carrier gains, therefore, the device defect of in the prior art transmitting gain being controlled is, uses same control signal that a plurality of carrier gains are controlled, and can not adapt to the 3-G (Generation Three mobile communication system) multicarrier transmitter uneven characteristics that gain, cause calibration accuracy low, can't really reach the purpose of calibration.

Summary of the invention

The objective of the invention is to overcome multicarrier gain control system of the prior art uses same control signal that a plurality of carrier gains are controlled, can not adapt to the uneven characteristics of third generation mobile system multi-carrier transmitter gain, cause calibration accuracy low, can't really reach the purpose shortcoming of calibration, so that a kind of multicarrier automatic gain calibration method to be provided, realize the purpose of each carrier gains of real-time automatic calibrating system.

Core concept of the present invention is to detect every carrier wave power of baseband signal respectively, and and detected every carrier wave baseband signal power output ask difference to obtain the channel gain of every carrier wave, compare with nominal gain, every carrier wave that employing compensated respectively the gain deviation of each carrier wave before up-conversion detects calibration method respectively respectively, reaches the purpose of each carrier gains of real-time automatic calibrating.

For achieving the above object, the present invention proposes a kind of multicarrier automatic gain calibration method, it is characterized in that, may further comprise the steps:

The first step is measured the power of baseband signal of each carrier wave input, and this step further may further comprise the steps:

Step 1 detects the voltage of the baseband signal of each carrier wave input at first respectively, according to formula $D_{\mathrm{rmsk}}=\sqrt{\frac{{\mathrm{\&Sigma;}}_{n=1}^N({\mathrm{<figure-callout\; id="2"\; label="I\; n"\; filenames="A0313598900191.png"\; state="\{\{state\}\}">I</figure-callout>}}_n^{}+Q_n^2)}{N}}$ Calculate the root mean square D of the magnitude of voltage of the baseband signal of k carrier wave in a period of time _Rmsk, wherein, I _nAnd Q _nExpression t _nMoment baseband signal I road and Q circuit-switched data, n=1,2,3......N, N are the number of participating in the data of calculating in this section period;

Step 2 is according to formula P _Ink=201gD _Rmsk-101g50 is with baseband signal rms voltage D _RmskBe converted into performance number P _Ink

Second step, baseband signal is carried out gain calibration, gain calibration value D is multiply by on I road and Q roadbed band signal data respectively _k

The 3rd step, the baseband signal after the calibration is handled, convert radiofrequency signal to and launch from antenna, this step further may further comprise the steps again:

Step 1 is modulated the baseband signal of each carrier wave;

Step 2 is carried out Digital Up Convert and multi-carrier signal is closed the road the baseband signal after each carrier modulation;

Step 3, the baseband signal behind the involutory road is carried out the D/A conversion, the output analog signal;

Step 4 is simulated up-conversion to the baseband signal of each carrier wave, makes signaling bearer on tranmitting frequency;

Step 5 is amplified the baseband signal of each carrier wave;

Step 6 is carried out filtering to the baseband signal of each carrier wave, to suppress spuious outside the operating frequency range;

Step 7 is launched radiofrequency signal by antenna;

The 4th step, the output signal power of each carrier wave of transmitting terminal is detected respectively, this step is further wrapped following steps:

Step 1 is carried out down-conversion to radiofrequency signal to be checked;

Step 2 is carried out analog-to-digital conversion and quantification to the intermediate-freuqncy signal after the frequency conversion;

Step 3 is according to formula $P_{\mathrm{oulk}}=\sqrt{\frac{{\mathrm{\&Sigma;}}_{m=1}^M{P_m}^2}{M}}$ Calculate the performance number of the data correspondence after quantizing, wherein P _OutkBe the power output of k carrier wave, M is the sampling number in certain period, P _mIt is the performance number of m sampled point;

The 5th step is according to formula G _k=G-(P _Outk-P _Ink) and formula ${\mathrm{\&Delta;}D}_k={10}^{({\mathrm{\&Delta;G}}_k/20)}$ Calculate the linear gain calibration value D in next circulation _k

The invention allows for a kind of multicarrier automatic gain calibration device, comprise passage processing module, power output detection module and CPU computing module, it is characterized in that, also comprise programmable logic array (FPGA, Field Programmable Gate Array) detect calibration module, described FPGA detects at first receiving baseband signal and with the baseband signal magnitude of voltage that measures and convert power P to of calibration module _Ink, the yield value D that baseband signal and every carrier wave need be compensated again _kMultiply each other, thereby adjust the emission path gain, make path gain maintain target gain G, the result exports described passage processing module to, baseband signal after described passage processing module will be calibrated converts radiofrequency signal to launches from antenna, and described power output detection module detects the performance number P of described passage processing module output _Outk, the result imports described CPU computing module, and described CPU computing module detects detected baseband signal power P in the calibration module according to described FPGA _Ink, the detected power output P of described power output detection module _Outk, and the target gain G that determines, calculate the yield value that needs compensation and be converted into corresponding linear numerical D _kImport described FPGA and detect calibration module, multicarrier is carried out automatic gain calibration.

Multicarrier automatic gain calibration device and method of the present invention has overcome the multicarrier gain control system that exists in the prior art and has used same control signal that a plurality of carrier gains are controlled, can not adapt to the uneven characteristics of third generation mobile system multi-carrier transmitter gain, and cause calibration accuracy low, can't really reach defectives such as alignment purpose, every carrier wave that employing compensates respectively the gain deviation of each carrier wave detects calibration method respectively respectively, has realized the purpose of each carrier gains of real-time automatic calibrating third generation mobile system.

Description of drawings

Fig. 1 utilizes variable gain amplifier to carry out the systematic schematic diagram of gain controlling in the prior art.

Fig. 2 is a multicarrier automatic gain calibration method flow diagram of the present invention.

Fig. 3 is a multicarrier automatic gain calibration structure drawing of device of the present invention.

Fig. 4 is the FPGA fundamental diagram.

Fig. 5 is the workflow diagram of CPU computing module.

Embodiment

Fig. 1 utilizes variable gain amplifier to carry out the systematic schematic diagram of gain controlling in the prior art.The transmitting power control loop is controlled the power that transmits by the gain that control is applied on the signal, the transmitting power track loop is used for measuring power, received power modulation orders and adjusts power, the estimating power by each narrow band signal relatively and and the power of detected modulation broadband signal between error realize gain controlling.Carry out open loop control by receiving the open loop order.

Fig. 2 is a multicarrier automatic gain calibration method schematic diagram of the present invention.Multicarrier automatic gain calibration method of the present invention may further comprise the steps:

The first step is measured the power of baseband signal of each carrier wave input, and this step further may further comprise the steps:

Step 1 detects the voltage of the baseband signal of each carrier wave input at first respectively, according to formula $D_{\mathrm{rmsk}}=\sqrt{\frac{{\mathrm{\&Sigma;}}_{n=1}^N({\mathrm{<figure-callout\; id="2"\; label="I\; n"\; filenames="A0313598900191.png"\; state="\{\{state\}\}">I</figure-callout>}}_n^{}+Q_n^2)}{N}}$ Calculate the root mean square D of the magnitude of voltage of the baseband signal of k carrier wave in a period of time _Rmsk, wherein, I _nAnd Q _nExpression t _nMoment baseband signal I road and Q circuit-switched data, n=1,2,3......N, N are the number of participating in the data of calculating in this section period, what this step adopted is root mean square (RMS, Root Mean Square) detection mode;

Step 2 is according to formula P _Ink=201gD _Rmsk-101g50 is with baseband signal rms voltage D _RmskBe converted into performance number P _Ink

Second step, baseband signal is carried out gain calibration, gain calibration value D is multiply by on I road and Q roadbed band signal respectively _k, in first circulation of gain calibration, D _k=1, D in the later circulation _kValue the 5th the step in according to formula G _k=G-(P _Outk-P _Ink) determine;

The 3rd step, the baseband signal after the calibration is handled, convert radiofrequency signal to and launch through antenna, this step further may further comprise the steps again:

Step 1 is modulated the baseband signal of each carrier wave;

Step 2 is carried out Digital Up Convert and multi-carrier signal is closed the road the baseband signal after each carrier modulation;

Step 3, the baseband signal behind the involutory road is carried out the D/A conversion, the output analog signal;

Step 4 is simulated up-conversion to the baseband signal of each carrier wave, makes signaling bearer on tranmitting frequency;

Step 5 is amplified the baseband signal of each carrier wave;

Step 6 is carried out filtering to the baseband signal of each carrier wave, to suppress spuious outside the operating frequency range;

Step 7 is launched radiofrequency signal by antenna;

The 4th step, the output signal power of each carrier wave of transmitting terminal is detected respectively, this step is further wrapped following steps:

Step 1 is carried out down-frequency conversion to radiofrequency signal to be checked;

Step 2 is carried out analog-to-digital conversion and quantification to the intermediate-freuqncy signal after the frequency conversion;

Step 3 is according to formula $P_{\mathrm{outk}}=\sqrt{\frac{{\mathrm{\&Sigma;}}_{m=1}^M{P_m}^2}{M}}$ Calculate quantification back power of baseband signal value,

P wherein _OutkBe the power output of carrier wave k, M is the sampling number in certain period, P _mIt is the performance number of m sampled point;

The 5th step is according to formula G _k=G-(P _Outk-P _Ink) and formula $\mathrm{\&Delta;}{D}_k={10}^{(\mathrm{\&Delta;}{G}_k/20)}$ Calculate the linear gain calibration value D in next circulation _k

Fig. 3 is a multicarrier automatic gain calibration structure drawing of device of the present invention.Multicarrier automatic gain calibration device of the present invention comprises passage processing module 2, power output detection module 3, it is characterized in that, comprise that also FPGA detects calibration module 1, CPU computing module 4, described FPGA detects at first receiving baseband signal and with the baseband signal magnitude of voltage that measures and convert power P to of calibration module 1 _Ink, the yield value D that baseband signal and every carrier wave need be compensated again _kMultiply each other, thereby adjust the emission path gain, make path gain maintain target gain G, the result exports described passage processing module 2 to, baseband signal after described passage processing module 2 will be calibrated converts radiofrequency signal to launches from antenna, and described power output detection module 3 detects the performance number P of described passage processing module 2 outputs _Outk, import described CPU computing module 4, described CPU computing module 4 detects detected baseband signal power P in the calibration module 1 according to described FPGA _Ink, described power output detection module 3 detected power output P _OutkAnd the target gain G that determines, calculate the yield value that needs compensation and be converted into corresponding linear numerical D _kImport described FPGA and detect calibration module 1, multicarrier is carried out automatic gain calibration.Wherein, described passage processing module 2 comprises modulator 5, digital up converter 6, mixer 7, D/A converter 8, simulation upconverter 9, amplifier 10, filter 11 and antenna 12, described modulator 5 carries out quaternary phase shift keying (QPSK to the baseband signal of each carrier wave, QuadriPhase Shift Keying) the described digital up converter 6 of modulation input, the baseband signal of described digital up converter 6 after to each carrier modulation carried out the described mixer 7 of output after the Digital Up Convert, the multicarrier baseband signal that described mixer 7 will close behind the road is imported described D/A converter 8,8 pairs of signals of described D/A converter carry out digital to analog conversion, the output analog signal is to described simulation upconverter 9, simulate up-conversion by 9 pairs of signals of described simulation upconverter, make signaling bearer on tranmitting frequency, afterwards, carry out linear amplification by 10 pairs of signals of described amplifier, carry out filtering by 11 pairs of signals of described filter, to suppress spuious outside the operating frequency range, at last, described antenna 12 is launched signal.Described power output detection module adopts RMS detection mode, detects frequency and is generally every 100ms detection once.In the WCDMA system, according to the requirement of WCDMA relevant criterion, need 100ms to detect once, in other system, then need 1s to detect once.

Fig. 4 is the FPGA fundamental diagram.The workflow that FPGA detects calibration module is: FPGA detects the baseband signal that calibration module reads each carrier wave, detects the voltage of each carrier wave baseband signal and according to formula $D_{\mathrm{rmsk}}=\sqrt{\frac{{\mathrm{\&Sigma;}}_{n=1}^N({\mathrm{<figure-callout\; id="2"\; label="I\; n"\; filenames="A0313598900191.png"\; state="\{\{state\}\}">I</figure-callout>}}_n^{}+Q_n^2)}{N}}$ Calculate the root mean square D of the magnitude of voltage of the baseband signal of k carrier wave in a period of time _Rmsk, wherein, I _nAnd Q _nRepresent t respectively _nMoment baseband signal I road and Q circuit-switched data, n=1,2,3......N, N is the number of participating in the data of calculating in this section period, get 2048 at this N (this numerical value be make computing time as far as possible less and the compromise of computational accuracy between big as far as possible consider, can carry out value according to real needs under the different situations), promptly calculate the root-mean-square value of baseband I, Q two paths of signals in 2048 chip times, baseband signal represents that with 16 figure places the signal spreading rate is (for the baseband signal of WCDMA, with the chip is unit, and have 3.84M chip each second one) be 3.84MHz; Again according to formula P _Ink=201gD _Rmsk-101g50 is with baseband signal rms voltage D _RmskBe converted into performance number P _Ink, and the performance number P that detection is obtained _InkStandby by read-write logic input CPU computing module, from CPU computing module register, read gain calibration value D simultaneously _k, with the I road of baseband signal and Q circuit-switched data respectively with gain calibration value D _kMultiply each other, the result exports passage processing module 2 to, and CPU does not also provide D in first circulation of calibration _kValue makes D ₁=1, the D in the later circulation _kValue calculates according to the input and output power detection value of previous circulation, and the frequency of gain calibration is difficult for too high to avoid power oscillation, can select every 1s to carry out once.

Fig. 5 is the workflow diagram of CPU computing module, may further comprise the steps:

The first step is opened the gain controlling switch;

In second step, from FPGA detection calibration module 1, read in each carrier wave power of baseband signal value P _Ink

In the 3rd step, from power output detection module 3, read in output power value P _Outk

In the 4th step, utilize input power value P _InkWith output power value P _OutkAnd nominal gain value G is according to formula G _k=G-(P _Outk-P _Ink) calculated gains calibration value G _k, produce vibration for fear of control system, adopt big stepping to approach mode during calibration earlier, after reaching certain thresholding, gain difference adopts small stepping, thresholding (gain difference G-(P _Outk-P _Ink)=G-G _0k) definite method be: establishing current gain value is G _0k=P _Outk-P _Ink, work as G-G _0kDuring＜-0.79dB, adopt big stepping to approach mode, wherein, G _k=-0.79; Work as G-G _0kDuring＞0.79dB, adopt big stepping (to work as G-G _0kDuring＞0.79dB, G _k=0.79, big stepping is represented if the absolute value of gain difference surpasses 0.79dB, with regard to direct compensation 0.79dB or-0.79dB) approach mode, wherein G _k=0.79; As-0.79＜G-G _0kDuring＜0.79dB, can once finish calibration, then adopt small stepping (as-0.79＜G-G _0kDuring＜0.79dB, G _k=G-G _0kIf the meaning of small stepping is exactly that the absolute value of gain difference is no more than 0.79dB, just compensation by formula, difference what just compensation what), directly according to formula G _k=G-G _0kCalculate G _kAbove-mentioned 0.79 determine according to repetition test, but not calculate, and system must be stable at G-0.79 to this scope of G+0.79 in generally speaking, if above this scope, then may overflow or computational accuracy can't guarantee., the gain or the decay that bring comprising amplifiers at different levels, filter, frequency mixer etc.Detect calibration module 1 for the ease of FPGA and calculate, according to formula $\mathrm{\&Delta;}{D}_k={10}^{(\mathrm{\&Delta;}{G}_k/20)}$ G with logarithmic form _kBe converted to corresponding linear yield value D _k, then with the gain calibration value D that calculates _kInput FPGA detects the register of calibration module 1, detects calibration module 1 for FPGA and calibrates.

Claims (8)

1. a multicarrier automatic gain calibration method is characterized in that, may further comprise the steps:

The first step is measured the power of baseband signal of each carrier wave input;

Second step, baseband signal is carried out gain calibration, gain calibration value D is multiply by on I road and Q roadbed band signal data respectively _k

The 3rd step, the baseband signal after the calibration is handled, convert radiofrequency signal to and launch from antenna;

In the 4th step, the output signal power of each carrier wave of transmitting terminal is detected respectively; The 5th step is according to formula G _k=G-(P _Outk-P _Ink) and formula ${\mathrm{\&Delta;D}}_k=10^{({\mathrm{\&Delta;G}}_k/20)}$ Calculate the linear gain calibration value D in next circulation _k

2. multicarrier automatic gain calibration method according to claim 1 is characterized in that the described first step further may further comprise the steps:

Step 1 detects the voltage of the baseband signal of each carrier wave input respectively, according to formula $D_{\mathrm{rmsk}}=\sqrt{\frac{{\mathrm{\&Sigma;}}_{n=1}^N(I_n^2+Q_n^2)}{N}}$ Calculate the root mean square D of the magnitude of voltage of the baseband signal of k carrier wave in a period of time _Rmsk, wherein, I _nAnd Q _nExpression t _nMoment baseband signal I road and Q circuit-switched data, n=1,2,3......N, N are the number of participating in the data of calculating in this section period;

Step 2 is according to formula P _Ink=201gD _Rmsk-101g50 is with baseband signal rms voltage D _RmskBe converted into performance number P _Ink

3. multicarrier automatic gain calibration method according to claim 2 is characterized in that, the data number N that participates in calculating in the described step 1 gets 2048 baseband signals and represents that with 16 figure places spreading rate is 3.84MHz.

4. multicarrier automatic gain calibration method according to claim 1 is characterized in that, described the 3rd step further may further comprise the steps:

Step 1 is modulated the baseband signal of each carrier wave;

Step 2 is carried out Digital Up Convert and multi-carrier signal is closed the road the baseband signal after each carrier modulation;

Step 3, the baseband signal behind the involutory road is carried out the D/A conversion, the output analog signal;

Step 4 is simulated up-conversion to the baseband signal of each carrier wave, makes signaling bearer on tranmitting frequency;

Step 5 is amplified the baseband signal of each carrier wave;

Step 6 is carried out filtering to the baseband signal of each carrier wave, to suppress spuious outside the operating frequency range;

Step 7 is launched radiofrequency signal by antenna.

5. multicarrier automatic gain calibration method according to claim 1 is characterized in that, described the 4th step further may further comprise the steps:

Step 1 is carried out down-conversion to radiofrequency signal to be checked;

Step 2 is carried out modulus to the intermediate-freuqncy signal after the frequency conversion and is quantized;

Step 3 is according to formula $P_{\mathrm{outk}}=\sqrt{\frac{{\mathrm{\&Sigma;}}_{m=1}^M{P_m}^2}{M}}$ Calculate the performance number of the data correspondence after quantizing, wherein P _OutkBe the power output of k carrier wave, M is the sampling number in certain period, P _mIt is the performance number of m sampled point.

6. multicarrier automatic gain calibration method according to claim 1 is characterized in that, the gain calibration value D in described second step _kValue is D in first calibration loop _k=1, D in the later circulation _kValue is according to formula G _k=G-(P _Outk-P _Ink) and formula ${\mathrm{\&Delta;D}}_k={10}^{({\mathrm{\&Delta;G}}_k/20)}$ Determine.

7. a multicarrier automatic gain calibration device comprises passage processing module (2), power output detection module (3), CPU computing module (4), it is characterized in that, comprises that also FPGA detects calibration module (1);

Described FPGA detects at first receiving baseband signal and with the baseband signal magnitude of voltage that measures and convert power P to of calibration module (1) _Ink, again with baseband signal and the yield value D that needs compensation _kMultiply each other, thereby adjust the emission path gain, make path gain maintain target gain G, the result exports described passage processing module (2) to, baseband signal after described passage processing module (2) will be calibrated converts radiofrequency signal to launches from antenna, and described power output detection module (3) detects the performance number P of described passage processing module (2) output _Outk, the result imports described CPU computing module (4), and described CPU computing module (4) detects detected baseband signal power P in the calibration module (1) according to described FPGA _Ink, the detected power output P of described power output detection module (3) _Outk, and the target gain G that determines, calculate the yield value that needs compensation and be converted into corresponding linear numerical D _kImport described FPGA and detect calibration module (1), multicarrier is carried out automatic gain calibration.

8. multicarrier automatic gain calibration device according to claim 7, it is characterized in that, described passage processing module (2) comprises modulator (5), digital up converter (6), mixer (7), D/A converter (8), simulation upconverter (9), amplifier (10), filter (11) and antenna (12), described modulator (5) carries out quaternary phase shift keying modulation input described digital up converter (6) to the baseband signal of each carrier wave, described digital up converter (6) carries out exporting described mixer (7) after the Digital Up Convert to the every carrier wave baseband signal after modulating, the multicarrier baseband signal that described mixer (7) will close behind the road is imported described D/A converter (8), described D/A converter (8) carries out digital to analog conversion to signal, the output analog signal is to described simulation upconverter (9), by described simulation upconverter (9) signal is simulated up-conversion, make signaling bearer on tranmitting frequency, carry out linear amplification by 10 pairs of signals of described amplifier again, by described filter (11) signal is carried out filtering, to suppress spuious outside the operating frequency range, described antenna (12) is launched signal.

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