CN101610230A - Signal imbalance compensation arrangement and method - Google Patents

Abstract

The invention provides signal imbalance compensation arrangement and method, this signal imbalance compensation arrangement comprises: signal imbalance detector (311,313) is used to detect the signal imbalance value of input signal; Signal imbalance compensator (312,314) is used for according to the detected signal imbalance value of described signal imbalance detector, and the described signal imbalance of described input signal is compensated; Judging unit (401), be used to judge described input signal or through described imbalance compensation device compensated through compensating signal whether in preset range; Signal imbalance detection signal generation unit (402), according to the judged result of described judging unit, output unbalance detection signal of enabling signal or the unbalance detection signal of stop signal; When the unbalance detection signal of described signal imbalance detection signal generation unit output stop signal, the signal imbalance value of detected input signal before described signal imbalance detector (311, the 313) output.

Description

Signal imbalance compensation arrangement and method

Technical field

The quadrature demodulator that the present invention relates to use in quadrature receiver relates to signal imbalance compensation arrangement and the method in the quadrature demodulator phase imbalance and the amplitude imbalance of IQ signal being estimated and compensated particularly.

Background technology

Quadrature receiver uses two independently branch road generation vector signals, in this case, the mismatch of the sum of errors amplitude of the I channel of simulation and the phase shift of Q interchannel (specified 90 degree), can cause the unbalance of phase place between I channel signal and the Q channel signal and amplitude, be called IQ unbalance (or claiming signal imbalance).When IQ is unbalance, between in-phase channel and orthogonal channel, just occurred crosstalking.

Unbalance for IQ, use special training sequence usually or utilize the statistical property of received signal to estimate also and then the method that compensates.Because the increase of using the method for training sequence can bring system complexity, the statistical property of utilizing received signal is more easy solution.The article of FredHarris " Digital Filter Equalization of Analog Gain and PhaseMismatch in I-Q receiver " Universal Personal communications, 1996.Record, 1996 5th IEEE International Conference on, page 793-796 Vol.2 has introduced a kind of method that is simple and easy to usefulness, and this method utilizes phase place and amplitude balance ring to come phase place and amplitude imbalance are estimated and compensated.According to this article, U.S. Pat 7,187,725 disclose a kind of like this method, and this method utilization comes compensation of phase and amplitude imbalance with the variable loop amplitude that the mean value of the error signal between I channel signal and the Q channel signal becomes.

Fig. 1 shows the schematic block diagram according to the quadrature demodulator of prior art.As shown in Figure 1, simulating partly (also claiming fore-end) 100, signal splitter 101 is divided into first signal section and secondary signal part with the RF/IF signal that receives.First signal section is sent to first multiplier 102, and secondary signal partly is sent to second multiplier 103.First multiplier 102 generates the I channel signal by first signal section is mixed mutually with the carrier signal of exporting from local carrier generator 104.Second multiplier 103 by with secondary signal part with mix mutually from 104 outputs of local carrier generator and by the carrier signal that 90 ° of phase shifters 105 have carried out 90 ° of phase shifts, generate the Q channel signal.First analog to digital converter 106 and second analog to digital converter 107 are converted to digital I channel signal with Simulation with I channel signal and simulation Q channel signal respectively

With digital Q channel signal

, wherein, k is the positive integer of expression signal sampling sequence number.Need to prove,, for the purpose of correctly receiving operation, may also need other assembly, as filter, amplifier etc. though do not illustrate among Fig. 1.Those skilled in the art can make suitable arrangement to this fully.

This simulation part branch causes phase imbalance and amplitude imbalance, input signal can not be divided into identical two parts as signal splitter 101, and 90 ° of phase shifters 105 can not just in time carry out 90 ° of phase shifts etc.

In numerical portion 110 (comprising signal imbalance compensation arrangement and other Base-Band Processing part), phase imbalance detector 111 receives digital I channel signal and digital Q channel signal, detect the issuable phase error of defective because of 90 ° of phase shifters, 105 analogue devices such as grade, thus the output phase imbalance values.Phase imbalance compensator 112 is in response to revising digital Q channel signal by the phase imbalance value of phase imbalance detector 111 outputs

, compensate described phase error, thereby after the generation phase compensation

The Q channel signal that amplitude imbalance detector 113 receives after phase compensation With the I channel signal, detect amplitude imbalance values and output between them.Amplitude imbalance compensation device 114 compensates the Q channel signal in response to the amplitude imbalance values from 113 outputs of amplitude imbalance detector

Amplitude, generate signal through phase place and amplitude compensation Here be reference signal with the I channel signal.

Deliver to other Base-Band Processing parts 115 through the signal of phase place and amplitude compensation and carry out subsequent treatment.

A kind of typical case that Fig. 2 shows according to the signal imbalance compensation arrangement of prior art realizes, can be with reference to article " Digital Filter Equalization of Analog Gain andPhase Mismatch in I-Q receiver " the Universal Personal communications of Fred Harris, 1996.Record, 1996 5th IEEE International Conference on, page 793-796 Vol.2.Among Fig. 2, phase imbalance detector 200 is equivalent to the phase imbalance detector 111 among Fig. 1, phase imbalance compensator 210 is equivalent to the phase imbalance compensator 112 among Fig. 1, amplitude imbalance detector 220 is equivalent to the amplitude imbalance detector 113 among Fig. 1, and amplitude imbalance compensation device 230 is equivalent to the amplitude imbalance compensation device 114 among Fig. 1.Multiplier 201 output current phase error e (k), multiplier 202 is adjusted the size of error, and adder 203 and delay retainer 204 have constituted phase imbalance value output unit and have exported current phase imbalance value $\widehat{\mathrm{\α}}\left(k\right)=\widehat{\mathrm{\α}}(k-1)+{\mathrm{\μ}}_1\×\tilde{I}\left(k\right)\×\tilde{Q}\left(k\right)$ Phase imbalance compensator 210 is made of multiplier 211 and adder 212, according to the phase imbalance value of phase imbalance detector output, is the phase imbalance of benchmark compensation Q channel signal with the I channel signal.Absolute value maker 221, absolute value maker 222 and adder 223 output current range error d (k), multiplier 224 is adjusted error size, and adder 225 and delay retainer 226 constitute the amplitude imbalance values output units and export current amplitude imbalance values $\widehat{\mathrm{\γ}}\left(k\right)=\widehat{\mathrm{\γ}}(k-1)+{\mathrm{\μ}}_2\×\left(\right|\tilde{I}\left(k\right)|-|\tilde{Q}\left(k\right)\left|\right)$ Amplitude imbalance compensation device 230 is made of multiplier 231, according to the amplitude imbalance values of amplitude imbalance detector output, is the amplitude imbalance of benchmark compensation Q channel signal, μ here with the I channel signal ₁Be the loop gain in phase imbalance estimation loop, μ ₂Be the loop gain in amplitude imbalance estimation loop, for guaranteeing the stable of loop, their value is usually less than 1.

All there is a major defect in the method for utilizing the input signal statistical property to carry out unbalance estimation of IQ and compensation at present, its statistical property can be changed after input signal is through some non-linearization devices such as digital to analog converter, cause the unbalance estimation of IQ mistake to occur, thereby cause whole amplitude and phase compensation mechanism to lose efficacy.

Summary of the invention

The present invention has been proposed in view of the above problems.The invention provides the apparatus and method that IQ phase place and amplitude imbalance are compensated in a kind of quadrature receiver, one or more problem in order to limitation and the shortcoming that overcomes owing to prior art causes provides a kind of useful selection at least.

Particularly, the application provides following invention.

Invention 1, a kind of signal imbalance compensation arrangement, this signal imbalance compensation arrangement comprises:

The signal imbalance detector is used to detect the signal imbalance value of input signal;

The signal imbalance compensator is used for according to the detected signal imbalance value of described signal imbalance detector, and the described signal imbalance of described input signal is compensated;

Judging unit, be used to judge described input signal or through described imbalance compensation device compensated through compensating signal whether in preset range;

Signal imbalance detection signal generation unit, according to the judged result of described judging unit, output unbalance detection signal of enabling signal or the unbalance detection signal of stop signal;

When the unbalance detection signal of described signal imbalance detection signal generation unit output stop signal, the signal imbalance value of detected input signal before the described signal imbalance detector output.

The invention 2, according to the invention 1 described signal imbalance compensation arrangement, it is characterized in that, described judging unit by judge described input signal or described judge through the position of compensating signal on the IQ plane described input signal or described through compensating signal whether in preset range.

Invention 3, according to invention 2 described signal imbalance compensation arrangements, it is characterized in that, described preset range be on described IQ plane the I coordinate greater than predetermined low threshold value less than the scope of predetermined high threshold.

Invention 4, according to invention 2 described signal imbalance compensation arrangements, it is characterized in that, described preset range be on described IQ plane the Q coordinate greater than predetermined low threshold value less than the scope of predetermined high threshold.

The invention 5, according to the invention 1 described signal imbalance compensation arrangement, it is characterized in that described signal imbalance compensation arrangement also comprises the signal update control unit, be used for the renewal of signal is controlled.

The invention 6, according to the invention 5 described signal imbalance compensation arrangements, it is characterized in that described signal update control unit comprises:

The signal update controller is used to determine to carry out the timing of signal update,

Trigger is used to make described signal imbalance compensator only to carry out the compensation of described input signal in the determined timing of described signal update controller.

The invention 7, according to the invention 1 described signal imbalance compensation arrangement, it is characterized in that described signal imbalance detector comprises:

The unbalance detector of current demand signal is used to detect the signal imbalance value of current demand signal;

Last signal imbalance follower is used to export the signal imbalance value of detected last signal before;

Selector, when the unbalance detection signal of described signal imbalance detection signal generation unit output enabling signal, described selector is selected the output of the unbalance detector of described current demand signal, and offers described signal imbalance compensator; When the unbalance detection signal of described signal imbalance detection signal generation unit output stop signal, described selector is selected the output of described last signal imbalance follower, and offers described signal imbalance compensator.

The invention 8, according to the invention 1 described signal imbalance compensation arrangement, it is characterized in that, described signal imbalance detector comprises phase imbalance detector and amplitude imbalance detector, described signal imbalance compensator comprises phase imbalance compensator and amplitude imbalance compensation device, and described signal imbalance detection signal generation unit generates identical unbalance detection signal of enabling signal or the identical unbalance detection signal of stop signal and controls described phase imbalance detector and described amplitude imbalance detector.

The invention 9, according to the invention 1 described signal imbalance compensation arrangement, it is characterized in that, described signal imbalance detector comprises phase imbalance detector and amplitude imbalance detector, described signal imbalance compensator comprises phase imbalance compensator and amplitude imbalance compensation device, and described signal imbalance detection signal generation unit generates different unbalance detection signal of enabling signal or the different unbalance detection signals of stop signal and controls described phase imbalance detector and described amplitude imbalance detector respectively.

Invention 10, according to invention 1 described signal imbalance compensation arrangement, it is characterized in that described signal imbalance compensation arrangement also comprises high pass filter, be used for carrying out filtering to being input to the signal that described signal imbalance detects controller and/or described unbalance detector.

The invention 11, according to the invention 1 described signal imbalance compensation arrangement, it is characterized in that, described input signal comprises the input signal that two-way is identical, wherein said signal imbalance detector, described judging unit and described signal imbalance detection signal generation unit carry out work at road input signal in the identical input signal of described two-way, and described signal imbalance compensator compensates another road input signal in the identical input signal of described two-way according to the detected signal imbalance of described signal imbalance detector.

Invention 12, a kind of signal imbalance compensation method is characterized in that described signal imbalance compensation method comprises:

Determining step, be used to judge input signal or through the signal of imbalance compensation whether in preset range;

The signal imbalance detection signal generates step, according to the judged result of described determining step, and output unbalance detection signal of enabling signal or the unbalance detection signal of stop signal;

Imbalance values detects step, detects the signal imbalance value of described input signal;

The imbalance compensation step, when described signal imbalance detection signal generates the unbalance detection signal of step output stop signal, compensate according to the signal imbalance of detected signal imbalance value before input signal, when described signal imbalance detection signal generated the unbalance detection signal of step output enabling signal, the signal imbalance value that goes out according to current detection compensated the signal imbalance of input signal.

The invention 13, according to the invention 12 described signal imbalance compensation methodes, it is characterized in that, described method also comprises step along separate routes, described input signal is divided into two paths of signals, wherein said determining step and described imbalance values detect step carries out at road signal in the described two paths of signals, and described imbalance compensation step is carried out at another road signal in the described two paths of signals.

The invention 14, according to the invention 13 described signal imbalance compensation methodes, it is characterized in that described method also comprises the high-pass filtering step, be used for described one road signal is carried out high-pass filtering.

Invention 15, a kind of signal imbalance compensation arrangement, this signal imbalance compensation arrangement is transfused to the identical input signal of two-way, and this signal imbalance compensation arrangement comprises:

Signal imbalance detector (620,640) is used for detecting the signal imbalance value of the identical input signal of described two-way one road input signal;

Signal imbalance compensator (630,650) is used for according to the detected signal imbalance value of described signal imbalance detector another road input signal in the identical input signal of described two-way being compensated.

Invention 16, a kind of signal imbalance compensation method, this signal imbalance compensation method is handled the identical input signal of two-way of input, and wherein, this signal imbalance compensation method comprises:

Signal imbalance detects step, is used for detecting the signal imbalance value of the identical input signal of described two-way one road input signal;

The signal imbalance compensation process is used for according to the detected signal imbalance value of described signal imbalance detector another road input signal in the identical input signal of described two-way being compensated.

Compared with prior art, the advantage that phase place of the present invention and amplitude imbalance compensation apparatus and method have is to fully take into account the change of nonlinear devices such as the imperfect in short-term statistical property of signal, dynamic range of signals, digital to analog converter to characteristics of signals, by the estimation of phase place and amplitude imbalance, compensation are controlled, solve the estimation and the compensation problem of phase place and amplitude imbalance under the situation that has DC component.

Description of drawings

Accompanying drawing shows the preferred embodiments of the present invention, has constituted the part of specification, is used for explaining principle of the present invention in further detail with explanatory note.Wherein:

Fig. 1 shows the block diagram according to the signal imbalance compensation arrangement of prior art;

A kind of typical case that Fig. 2 shows according to the signal imbalance compensation arrangement of prior art realizes;

Fig. 3 shows the schematic block diagram according to signal imbalance compensation arrangement of the present invention;

How signal imbalance detected controller according to the I channel letter of input and the example of the unbalance detection signal of Q channel letter output starting/stop during Fig. 4 showed according to the present invention;

A kind of typical case that Fig. 5 shows according to signal imbalance compensation arrangement of the present invention realizes;

Another typical case that Fig. 6 shows according to signal imbalance compensation arrangement of the present invention realizes;

Fig. 7 shows to adopt phase place and the amplitude imbalance values under the situation of the present invention and do not adopt typical curve under the situation of the present invention with contrasting;

Fig. 8 is another kind of schematic block diagram according to signal imbalance compensation arrangement of the present invention; And

Fig. 9 shows the flow chart according to the signal imbalance compensation method of one embodiment of the present invention.

Embodiment

Below, with reference to accompanying drawing, be elaborated to of the present invention.

Fig. 3 shows the schematic block diagram of the quadrature demodulator that uses according to the present invention in quadrature receiver.

As shown in Figure 3, quadrature demodulator 30 comprises simulation part 300 and numerical portion 310.

Simulation part 300 comprises signal splitter 301, first multiplier 302, second multiplier 303,304,90 ° of phase shifters 305 of local carrier generator, first analog to digital converter (ADC) 306 and second analog to digital converter 307.

Signal splitter 301 receives the RF/IF signal, and the signal that receives is divided into first signal section and secondary signal part.First signal section is sent to first multiplier 302, and secondary signal partly is sent to second multiplier 303.First multiplier 302 generates the I channel signal by first signal section is mixed mutually with the carrier signal of exporting from local carrier generator 304.Second multiplier 303 by with secondary signal part with mix mutually from 304 outputs of local carrier generator and by the carrier signal that 90 ° of phase shifters 305 have carried out 90 ° of phase shifts, generate the Q channel signal.First analog to digital converter 306 and second analog to digital converter 307 are converted to digital I channel signal and digital Q channel signal with Simulation with I channel signal and simulation Q channel signal respectively, and wherein, k is the positive integer of expression signal sampling sequence number.

Should be noted that above-mentioned explanation to simulation part is schematically, is not limitation of the present invention, and those of ordinary skill in the art can adopt any other mode known in the art to realize this simulation part.

As shown in Figure 3, numerical portion 310 comprises signal imbalance compensation arrangement and other base band signal process part 315, and the signal imbalance compensation arrangement comprises phase imbalance detector 311, amplitude imbalance detector 313, phase imbalance compensator 312 and amplitude imbalance compensation device 314.In addition, signal imbalance compensation arrangement of the present invention comprises that also signal imbalance detects controller 321.

Signal imbalance detects controller 321 according to the I channel signal that receives and the characteristic of Q channel signal, and output starts unbalance detection signal or stops unbalance detection signal.

The operating state of phase imbalance detector 311 detects controller 321 by signal imbalance and controls.When signal imbalance detects controller 321 output startup phase imbalance detection signals, phase imbalance detector 311 receives digital I channel signal and digital Q channel signals, and detects because of the phase imbalance of the undesirable I that brings of characteristic of simulation part and Q channel signal and export current phase imbalance value and give phase imbalance compensator 312.Phase imbalance compensator 312 is according to the phase imbalance that compensates I and Q channel signal from the current phase imbalance value of phase imbalance detector 311.When 321 outputs of signal imbalance detection controller stopped unbalance detection signal, the phase imbalance value of the previous sampling instant of phase imbalance detector 311 outputs was used to compensate the phase imbalance of I and Q channel signal for phase imbalance compensator 312.

Phase imbalance compensator 312 carries out the unbalance compensation of respective phase according to the output of phase imbalance detector 311.Its compensation way can pursue the compensation of sampling point according to the output of phase imbalance detector 311, also can adopt according to the output of phase imbalance detector 311 periodically or aperiodicity compensate.

Similarly, the operating state of amplitude imbalance detector 313 is controlled by signal imbalance detection controller 321.When signal imbalance detects controller 321 output startup amplitude imbalance detection signals, amplitude imbalance detector 311 receives digital I channel signal and digital Q channel signals, and detects because of the amplitude imbalance of the undesirable I that brings of characteristic of simulation part and Q channel signal and export current amplitude imbalance values and give amplitude compensator 314.Amplitude compensator 314 is according to the phase imbalance that compensates I and Q channel signal from the current phase imbalance value of phase imbalance detector.When 321 outputs of signal imbalance detection controller stopped unbalance detection signal, the phase imbalance value of the previous sampling instant of amplitude imbalance detector 313 outputs was used to compensate the amplitude imbalance of I and Q channel signal for amplitude imbalance compensation device 314.

Amplitude imbalance compensation device 314 carries out the compensation of corresponding amplitude imbalance according to the output of amplitude imbalance detector 313.Its compensation way can pursue the compensation of sampling point according to the output of amplitude imbalance detector 313, also can adopt according to the output of amplitude imbalance detector 313 periodically or aperiodicity compensate.

The known technology content that other Base-Band Processing parts 315 are this areas, and not critical to the present invention, therefore no longer they are described in detail at this.Need to prove,, for the purpose of correctly receiving operation, may also need other assembly, as amplifier, filter etc. though do not illustrate among Fig. 3.Those skilled in the art can make suitable arrangement fully to this, therefore, repeat no more their concrete layout, so that main points of the present invention are more outstanding.

In addition, as can be seen, the difference of the maximum of the present invention and prior art is to have increased signal imbalance and detects controller 321 from top explanation.Below signal imbalance being detected controller 321 is described in detail.

In the present invention, the input signal that signal imbalance detects controller 321 can be phase compensation and the preceding signal of amplitude compensation, also can be the signal after phase compensation, the amplitude compensation.

The input signal that at first signal imbalance is detected controller 321 is that the situation of the signal before phase compensation and the amplitude compensation describes below.This situation i.e. as shown in Figure 3 situation.

Fig. 4 A shows the schematic block diagram that detects controller according to the signal imbalance of one embodiment of the present invention.

Shown in Fig. 4 A, detect controller according to the signal imbalance of one embodiment of the present invention and comprise judging unit 401 and signal generation unit 402.

Under the situation of Fig. 3, at first judging unit 401 judges whether the signal that has phase place and amplitude imbalance (hereinafter claiming input signal) of analog to digital converter 306 and 307 outputs falls in the predetermined scope.If judging unit 401 is judged this input signal and fallen in the predetermined scope (estimation error is put the letter district), then described signal generation unit 402 generates the unbalance detection signal of enabling signal, comprises starting the amplitude imbalance detection signal and starting the phase imbalance detection signal.If judging unit 401 is judged this input signal and do not fallen in the predetermined scope, then described signal generation unit 402 generates the unbalance detection signal of stop signal, comprises stopping the amplitude imbalance detection signal and stopping the phase imbalance detection signal.Here at phase place and amplitude imbalance can adopt identical, also can adopt different preset ranges to control.

Fig. 4 B, Fig. 4 C, Fig. 4 D, Fig. 4 E show several exemplary limiting pattern to described preset range.As shown in the figure, output starts unbalance detection signal when shadow region (being that estimation error is put the letter district) that the I channel signal and the Q channel signal of the unbalance detection controller 321 of input signal is positioned at the IQ plane, and output stops unbalance detection signal when the I channel signal of the unbalance detection controller 321 of input signal and Q channel signal are positioned at other zones.

The following describes at these preset ranges the judgment processing of judging unit 401.

The shadow region of Fig. 4 B can be expressed as:

$\left(\right|\tilde{I}|<(\&le;){\mathrm{Th}}_{\mathrm{high}}\mathrm{and}|\tilde{Q}|<(\&le;){\mathrm{Th}}_{\mathrm{high}})\mathrm{and}\left(\right|\tilde{I}|<(\&le;){\mathrm{Th}}_{\mathrm{high}}\mathrm{or}|\tilde{Q}|>(\&GreaterEqual;){\mathrm{Th}}_{\mathrm{low}})$

The shadow region of Fig. 4 C is expressed as:

${\tilde{I}}^2+{\tilde{Q}}^2<(\&le;){\mathrm{Th}}_{\mathrm{high}})\mathrm{and}({\tilde{I}}^2+{\tilde{Q}}^2>(\&GreaterEqual;){\mathrm{Th}}_{\mathrm{low}})$

The shadow region of Fig. 4 D is expressed as:

$\left(\right|\tilde{I}|<(\&le;){\mathrm{Th}}_{\mathrm{high}}\mathrm{and}|\tilde{Q}|<(\&le;){\mathrm{Th}}_{\mathrm{high}})\mathrm{and}\left(\right|\tilde{I}|>(\&GreaterEqual;){\mathrm{Th}}_{\mathrm{low}}\mathrm{and}|\tilde{Q}|>(\&GreaterEqual;){\mathrm{Th}}_{\mathrm{low}})$

The shadow region of Fig. 4 E is expressed as:

$\left(\right|\tilde{I}|<(\&le;){\mathrm{Th}}_{\mathrm{high}}\mathrm{or}|\tilde{Q}|<(\&le;){\mathrm{Th}}_{\mathrm{high}})\mathrm{and}\left(\right|\tilde{I}|>(\&GreaterEqual;){\mathrm{Th}}_{\mathrm{low}}\mathrm{or}|\tilde{Q}|>(\&GreaterEqual;){\mathrm{Th}}_{\mathrm{low}})$

In above-mentioned Fig. 4 B, Fig. 4 C, Fig. 4 D, Fig. 4 E shadow region expression,

With

I channel signal and the Q channel signal of representing the unbalance detection controller 321 of input signal respectively, Th _HighThe predetermined big threshold value of expression, Th _LowThe predetermined little threshold value of expression, and: 0≤Th _Low＜Th _High≤ ADCOUT _Max, ADCOUT wherein _MaxRepresent the maximum output valve of digital to analog converter.

Thereby according to the I channel signal and the Q channel signal of input, whether the signal that the judging unit 401 of signal imbalance detection controller 321 can be judged input is positioned at predetermined scope.

Should be noted that, though preset range has been carried out example in the above, but those skilled in the art obviously can visualize different scopes according to the present invention, for example the scope among Fig. 4 B-Fig. 4 E is cut apart combination etc., for example Fig. 4 F is by Fig. 4 B and Fig. 4 C combination, the shape that Fig. 4 G is come by Fig. 4 D and Fig. 4 E combination etc., but these are all within the scope of the invention.

Alternatively, described preset range can be to have got rid of I road or Q road on the IQ plane less than the signaling point of predetermined little threshold value and greater than the scope of the point of predetermined big threshold value.Big threshold value here and little threshold value can be by emulation or are rule of thumb obtained.

Fig. 5 shows a kind of specific implementation of the signal imbalance compensation arrangement that the Q channel signal is compensated as reference signal with the I channel signal.

As shown in Figure 5, the signal imbalance compensation arrangement 50 according to one embodiment of the present invention comprises: signal imbalance detects controller 500, phase imbalance detector 510, phase imbalance compensator 520, amplitude imbalance detector 530, amplitude imbalance compensation device 540.

Wherein, signal imbalance detects controller 500 and detects controller 321 corresponding to signal imbalance shown in Figure 3, phase imbalance detector 510 is corresponding to the phase imbalance detector 311 of Fig. 3, phase imbalance compensator 520 is corresponding to phase imbalance compensator 312 shown in Figure 3, amplitude imbalance detector 530 is corresponding to the amplitude imbalance detector 313 of Fig. 3, and amplitude imbalance compensation device 540 is corresponding to the amplitude imbalance compensation device 314 of Fig. 3.

In this specific implementation, signal imbalance detects the control mode that controller 500 adopts shown in Fig. 4 D, works as input signal

With

Drop on the unbalance detection signal of output startup in the shadow region shown in Fig. 4 D.Need to prove, detect at phase place and amplitude imbalance and can adopt identical control signal also can adopt different control signals, if adopt identical control signal, be divided into and start unbalance detection signal and stop unbalance detection signal, if adopt different control signals, be divided into startup phase imbalance detection signal, stop the phase imbalance detection signal, start the amplitude imbalance detection signal and stop the amplitude imbalance detection signal.

When signal imbalance detects controller 500 output startup phase imbalance detection signals, the phase error e (k) of selector 514 output multipliers 512 outputs, the phase imbalance detector 510 of this moment is equivalent to the phase imbalance detector of prior art.When 500 outputs of signal imbalance detection controller stop the phase imbalance detection signal, the constant 0 of selector 514 output constants 0 follower 513 outputs.Constant 0 follower 513, selector 514, adder 515 and delay retainer 516 have constituted last phase imbalance value output unit at this moment, and output is without the phase imbalance value (effective phase imbalance value promptly) of change.

Phase imbalance compensator 520 is made of multiplier 521 and adder 522, according to the phase imbalance value of phase imbalance detector output, is the phase imbalance of benchmark compensation Q channel signal with the I channel signal.

When signal imbalance detects controller 500 output startup amplitude imbalance detection signals, the output amplitude error d (k) of selector 536 output multipliers 534, amplitude imbalance detector 530 is equivalent to detect controller with the signal imbalance of prior art at this moment.When 500 outputs of signal imbalance detection controller stop the amplitude imbalance detection signal, the constant 0 of selector 536 output constants 0 maker 535 outputs.This moment is by constant 0 maker 535, adder 537 and postpone the last amplitude imbalance values output unit that retainer 538 can think to be used to export amplitude imbalance values before.

Last phase imbalance value output unit and last amplitude imbalance values output unit or one of them have constituted last signal imbalance value output unit of the present invention.

Amplitude imbalance compensation device 540 is made of multiplier 541, according to the amplitude imbalance values of amplitude imbalance detector output, is the amplitude imbalance of benchmark compensation Q channel signal with the I channel signal.

μ among Fig. 5 ₁(k) and μ ₂(k) can also can be variable for constant.

In addition, though be as reference signal the Q channel signal to be compensated shown in Fig. 3 and Fig. 5, it will be appreciated by those skilled in the art that and to compensate the I channel signal as reference signal with the Q channel signal with the I channel signal.

In addition, should be noted that in Fig. 5 that when selector 514 had been selected the output of multiplier 512 according to signal imbalance detection controller 500 outputs startup amplitude imbalance detection signals, phase imbalance detector 510 was the same with the working method of prior art.In fact the present invention can use other phase imbalance detector 510 to the realization of phase imbalance detector 510 without limits.

Another typical case that Fig. 6 shows according to signal imbalance compensation arrangement of the present invention realizes.Fig. 6 shows the scheme that as reference signal the I channel signal is compensated with the Q channel signal.As shown in Figure 6, signal imbalance compensation arrangement 60 is made of 5 parts: signal imbalance detects controller 610, phase imbalance detector 620, phase imbalance compensator 630, amplitude imbalance detector 640, amplitude imbalance compensation device 650 and update controller 660, also has high pass filter 601,602, trigger 603,604 in addition.

Input signal

With

By output respectively behind the high pass filter 601,602

With

This tributary signal is used to carry out phase place and amplitude imbalance estimation, and high pass filter 601,602 is used to eliminate the influence that DC component is brought phase place and amplitude imbalance estimation, at the DC component by under the removed situation of other schemes, can not use high pass filter 601,602, at this moment ${\tilde{I}}^{\&prime;}=\tilde{I},$ ${\tilde{Q}}^{\&prime;}=\tilde{Q}.$

In Fig. 6, signal imbalance detects controller 610 and adopts control mode shown in Fig. 4 E, works as input signal With When not dropping in the shadow region shown in Fig. 4 E, output stops unbalance detection signal.

When signal imbalance detects controller 610 output startup phase imbalance detection signals, the phase error e (k) of selector 624 output multipliers 622 outputs, when 610 outputs of signal imbalance detection controller stop the phase imbalance detection signal, the constant 0 that selector 624 output constants 0 maker 623 generates; Multiplier 621, multiplier 622, selector 624, adder 625 and delay retainer 626 have constituted phase imbalance detector and output phase imbalance values When signal imbalance detects the unbalance detection signal of controller 610 output startups, $\widehat{\mathrm{\&alpha;}}\left(k\right)=\widehat{\mathrm{\&alpha;}}(k-1)+{\mathrm{\&mu;}}_1\left(k\right)\&times;{\tilde{I}}^{\&prime;}\left(k\right)\&times;{\tilde{Q}}^{\&prime;}\left(k\right);$ When 610 outputs of signal imbalance detection controller stop unbalance detection signal, $\widehat{\mathrm{\&alpha;}}\left(k\right)=\widehat{\mathrm{\&alpha;}}(k-1).$

When signal imbalance detects controller 610 output startup amplitude imbalance detection signals, the output amplitude error d (k) of selector 646 output multipliers 644, when 610 outputs of signal imbalance detection controller stop the amplitude imbalance detection signal, selector 646 output constants 0; When signal imbalance detected controller 610 output startup amplitude imbalance detection signals, absolute value maker 641, absolute value maker 642, adder 643, multiplier 644, selector 646, adder 647 and delay retainer 648 constituted phase imbalance detector and output amplitude imbalance values

When detecting controller 610 outputs, signal imbalance starts unbalance detection signal, $\widehat{\mathrm{\&gamma;}}\left(k\right)=\widehat{\mathrm{\&gamma;}}(k-1)+{\mathrm{\&mu;}}_2\left(k\right)\&times;\left(\right|{\tilde{I}}^{\&prime;}\left(k\right)|-|{\tilde{Q}}^{\&prime;}\left(k\right)\left|\right);$ When 610 outputs of signal imbalance detection controller stop unbalance detection signal, $\widehat{\mathrm{\&gamma;}}\left(k\right)=\widehat{\mathrm{\&gamma;}}(k-1).$

Compensating parameter update controller 660 is sent phase place according to the control needs and is upgraded and the amplitude update signal.Update signal can be upgraded for output always, phase imbalance value of every output this moment

Amplitude imbalance values

Imbalance values is upgraded by trigger 603,604 in the capital

And

, promptly $\widehat{\mathrm{\&alpha;}}=\widehat{\mathrm{\&alpha;}}\left(k\right),$ $\widehat{\mathrm{\&gamma;}}=\widehat{\mathrm{\&gamma;}}\left(k\right),$ In addition, also can be periodically or the phase place of sending on aperiodicity ground upgrade and the amplitude update signal.At this moment, by appropriate design its update time, can effectively overcome because the influence of the undesirable evaluated error of bringing of signal short time statistics.

Phase imbalance compensator 630 is made of multiplier 631 and adder 632, according to the phase imbalance value With the Q channel signal is the phase imbalance of benchmark compensation I channel signal.

Amplitude imbalance compensation device 650 is made of multiplier 651, according to amplitude imbalance values

With the Q channel signal is the amplitude imbalance of benchmark compensation I channel signal.

μ among Fig. 6 ₁(k) and μ ₂(k) can also can be variable for constant.

Update controller 660 among Fig. 6, trigger 604 and 603 have constituted imbalance values updating device of the present invention.

In addition, though shown in Figure 6 be as reference signal the I channel signal to be compensated with the Q channel signal, it will be appreciated by those skilled in the art that and can compensate the Q channel signal as reference signal with the I channel signal.

Should be noted that, the technical scheme of the technical scheme of Fig. 6 and technical scheme of the present invention shown in Figure 3 and prior art illustrated in figures 1 and 2 is compared, the technical scheme of Fig. 6 has outstanding characteristics, is to carry out at the input signal of not going the same way the detection of signal imbalance value (comprising phase imbalance value and amplitude imbalance values) with compensation to signal imbalance value (comprising phase imbalance value and amplitude imbalance values) promptly.Promptly, as shown in Figure 6, described input signal is divided into two-way input signal (every road input signal all comprises I road signal and Q road signal), phase imbalance detects and the amplitude imbalance detection is shown at wherein road signal and carried out, and to phase imbalance with to the compensation of amplitude imbalance another road signal is carried out.This also is an outstanding feature of the present invention.

In technical scheme shown in Figure 6, the road input signal that carries out unbalance detection is carried out high-pass filtering.

Thereby, the invention provides a kind of signal imbalance compensation arrangement, this signal imbalance compensation arrangement is transfused to the identical input signal of two-way, this signal imbalance compensation arrangement comprises: signal imbalance detector 620 and 640 is used for detecting the signal imbalance value of the identical input signal of described two-way one road input signal; Signal imbalance compensator 630 and 650 is used for according to the detected signal imbalance value of described signal imbalance detector another road input signal in the identical input signal of described two-way being compensated.

That is to say in a kind of scheme of the present invention, can have signal imbalance and detect controller, also can not have signal imbalance and detect controller.

Similarly, the invention provides a kind of signal imbalance compensation method, this signal imbalance compensation method is handled the identical input signal of two-way of input, wherein, this signal imbalance compensation method comprises: signal imbalance detects step, is used for detecting the signal imbalance value of the identical input signal of described two-way one road input signal; The signal imbalance compensation process is used for according to the detected signal imbalance value of described signal imbalance detector another road input signal in the identical input signal of described two-way being compensated.

Those of ordinary skills can know clearly how to realize above method and apparatus after having read the application in conjunction with Fig. 6 of the present invention.

When input signal possesses some characteristics (very little as input signal), through digital to analog converter 306 as shown in Figure 3,307 back major parts are quantified as 0, the change curve of phase place and amplitude imbalance actual value, estimated value when Fig. 7 is quantified as 0 for surpassing 90% sampling point.

Fig. 7 A shows phase imbalance estimated value and the actual value that adopts after conventional method shown in Figure 2 is estimated phase imbalance, and Fig. 7 B shows amplitude imbalance estimation value and the actual value that adopts after conventional method shown in Figure 2 is estimated amplitude imbalance; Fig. 7 C shows phase imbalance estimated value and the actual value that adopts after the present invention estimates phase imbalance, and Fig. 7 D shows amplitude imbalance estimation value and the actual value that adopts after the present invention estimates amplitude imbalance.This shows effect of the present invention.

Fig. 8 shows the quadrature demodulator under the situation that input that signal imbalance detects controller 821 is the signal after phase compensation, the amplitude compensation.As shown in Figure 8, during signal after input that signal imbalance detects controller 821 is phase compensation, amplitude compensation, compare, after the input signal that its difference is signal imbalance is detected controller compensates through phase place and amplitude with Fig. 3

And

, still adopt the control method identical with Fig. 3.

In addition, should be noted that as mentioned above, can the amplitude imbalance detector and the phase imbalance detector of prior art simply be changed, realize last phase imbalance value output unit of the present invention and last amplitude imbalance values output unit.But this is exemplary, is not limitation of the present invention, the phase imbalance signal that can adopt the whole bag of tricks to export the amplitude imbalance signal of not change and do not change.For example can adopt phase imbalance value in the other register holds register 516 and the amplitude imbalance values in the register 538, utilize switching device shifter then, detect the signal of controller according to signal imbalance, between described other register and register 516, switch, and between described other register and register 538, switch.During value in output register 516 and register 538, upgrade the value in the described other register synchronously, during value in not output register 516 and register 538, do not upgrade the value in the described other register.Again for example, can utilize switching device, the signal that detects controller according to signal imbalance disconnect or conducting e (k) to the input of adder 515.In a word, it may occur to persons skilled in the art that the method and apparatus of last phase imbalance value of various outputs and amplitude imbalance values.

Fig. 9 shows the flow chart according to the signal imbalance compensation method of one embodiment of the present invention.As shown in Figure 9, at first in the scope whether the I tributary signal and the Q tributary signal of step 901 judgement input are being scheduled to, if (step 901 in predetermined scope, be), then start the phase imbalance detection signal and start the amplitude imbalance detection signal in step 902 output, and in step 904 pair current phase place and amplitude imbalance values renewal, promptly $\widehat{\mathrm{\&alpha;}}\left(k\right)=\widehat{\mathrm{\&alpha;}}(k-1)+{\mathrm{\&mu;}}_1\left(k\right)\&times;{\tilde{I}}^{\&prime;}\left(k\right)\&times;{\tilde{Q}}^{\&prime;}\left(k\right),$ $\widehat{\mathrm{\&gamma;}}\left(k\right)=\widehat{\mathrm{\&gamma;}}(k-1)+{\mathrm{\&mu;}}_2\left(k\right)\&times;\left(\right|{\tilde{I}}^{\&prime;}\left(k\right)|-|{\tilde{Q}}^{\&prime;}\left(k\right)\left|\right).$ If the I tributary signal of input and Q tributary signal be (step 901 in predetermined scope not, not), then stop the phase imbalance detection signal and stop the amplitude imbalance detection signal, and in step 905, export original phase place and amplitude imbalance values, promptly in step 903 output $\widehat{\mathrm{\&alpha;}}\left(k\right)=\widehat{\mathrm{\&alpha;}}(k-1),$ $\widehat{\mathrm{\&gamma;}}\left(k\right)=\widehat{\mathrm{\&gamma;}}(k-1).$ Here the control of phase place and amplitude detection can adopt identical controlled condition also can adopt different controlled condition respectively.Afterwards, judged whether the timing that compensates at phase place and amplitude imbalance values in step 906, if, then in step 907, current phase/amplitude imbalance values is upgraded with imbalance values compensation, that is, make $\widehat{\mathrm{\&alpha;}}=\widehat{\mathrm{\&alpha;}}\left(k\right),$ $\widehat{\mathrm{\&gamma;}}=\widehat{\mathrm{\&gamma;}}\left(k\right).$ If not, then continue to keep when using phase place and amplitude imbalance values

With

Constant.

In addition, should be noted that in the execution mode more than the present invention, phase place and amplitude have all been adopted compensation arrangement of the present invention and method, but the present invention can only be applied to phase compensation or only be applied to the amplitude compensation.

Signal imbalance detector of the present invention has comprised phase imbalance detector and amplitude imbalance detector or one of them.Signal compensator of the present invention has comprised phase imbalance compensator and amplitude imbalance compensation device or one of them.Accordingly, signal imbalance detection controller of the present invention can be divided into phase imbalance detection controller that only detection is controlled to phase imbalance and the amplitude imbalance detection controller that only detection is controlled to amplitude imbalance.That is, signal imbalance of the present invention detects controller and comprises that phase imbalance detects controller and amplitude imbalance detection controller or one of them.

According to the abovementioned embodiments of the present invention, can prevent the performance degradation that the I channel signal that causes because of defective quadrature demodulator and the phase place between the Q channel signal and/or amplitude imbalance cause.

Need to prove that scope of the present invention also comprises and is used to the computer readable recording medium storing program for performing carrying out the computer program of above-mentioned phase place and amplitude compensation method and record this program.As recording medium, the readable floppy disk that can use a computer here, hard disk, semiconductor memory, CD-ROM, DVD, magneto optical disk (MO) and other medium.

Although below only selected preferred embodiment to come illustration the present invention, those skilled in the art are easy to carry out variations and modifications according to content disclosed herein under the situation that does not break away from the invention scope that is defined by the following claims.The explanation of the foregoing description only is exemplary, and does not constitute the restriction by claims and the invention that equivalent limited thereof.

Claims (10)

1, a kind of signal imbalance compensation arrangement, this signal imbalance compensation arrangement comprises:

Signal imbalance detector (311,313) is used to detect the signal imbalance value of input signal;

Signal imbalance compensator (312,314) is used for according to the detected signal imbalance value of described signal imbalance detector, and the signal imbalance of described input signal is compensated;

Judging unit (401), be used to judge described input signal or through described signal imbalance compensator compensates cross through compensating signal whether in preset range;

Signal imbalance detection signal generation unit (402), according to the judged result of described judging unit, output unbalance detection signal of enabling signal or the unbalance detection signal of stop signal;

When the unbalance detection signal of described signal imbalance detection signal generation unit output stop signal, the signal imbalance value of detected input signal before described signal imbalance detector (311, the 313) output.

2, signal imbalance compensation arrangement according to claim 1, it is characterized in that, described judging unit by judge described input signal or described judge through the position of compensating signal on the IQ plane described input signal or described through compensating signal whether in preset range, described preset range refers to that estimation error puts the letter district.

3, signal imbalance compensation arrangement according to claim 1 is characterized in that, described signal imbalance compensation arrangement also comprises the signal update control unit, is used for the renewal of signal is controlled.

4, signal imbalance compensation arrangement according to claim 3 is characterized in that, described signal update control unit comprises:

Signal update controller (660) is used to determine to carry out the timing of signal update,

Trigger (603,604) is used to make described signal imbalance compensator only to carry out the compensation of described input signal in the determined timing of described signal update controller.

5, signal imbalance compensation arrangement according to claim 1 is characterized in that, described signal imbalance detector (311,313) comprising:

The unbalance detector of current demand signal is used to detect the signal imbalance value of current demand signal;

Last signal imbalance follower is used to export the signal imbalance value of previous detected input signal;

Selector, when the unbalance detection signal of described signal imbalance detection signal generation unit output enabling signal, described selector is selected the output of the unbalance detector of described current demand signal, and offers described signal imbalance compensator; When the unbalance detection signal of described signal imbalance detection signal generation unit output stop signal, described selector is selected the output of described last signal imbalance follower, and offers described signal imbalance compensator.

6, signal imbalance compensation arrangement according to claim 1, it is characterized in that, described signal imbalance detector comprises phase imbalance detector and amplitude imbalance detector, described signal imbalance compensator comprises phase imbalance compensator and amplitude imbalance compensation device, and described signal imbalance detection signal generation unit generates different unbalance detection signal of enabling signal or the different unbalance detection signals of stop signal and controls described phase imbalance detector and described amplitude imbalance detector respectively.

7, a kind of signal imbalance compensation method is characterized in that, described signal imbalance compensation method comprises:

Determining step, be used to judge input signal or through the signal of imbalance compensation whether in preset range;

The signal imbalance detection signal generates step, according to the judged result of described determining step, and output unbalance detection signal of enabling signal or the unbalance detection signal of stop signal;

Imbalance values detects step, detects the signal imbalance value of described input signal;

The imbalance compensation step, when described signal imbalance detection signal generates the unbalance detection signal of step output stop signal, compensate according to the signal imbalance of detected signal imbalance value before input signal, when described signal imbalance detection signal generated the unbalance detection signal of step output enabling signal, the signal imbalance value that goes out according to current detection compensated the signal imbalance of input signal.

8, signal imbalance compensation method according to claim 7, it is characterized in that, described method also comprises step along separate routes, described input signal is divided into two paths of signals, wherein said determining step and described imbalance values detect step carries out at road signal in the described two paths of signals, and described imbalance compensation step is carried out at another road signal in the described two paths of signals.

9, signal imbalance compensation method according to claim 8 is characterized in that, described method also comprises the high-pass filtering step, is used for described one road signal is carried out high-pass filtering.

10, a kind of signal imbalance compensation arrangement, this signal imbalance compensation arrangement is transfused to the identical input signal of two-way, and this signal imbalance compensation arrangement comprises:

Signal imbalance detector (620,640) is used for detecting the signal imbalance value of the identical input signal of described two-way one road input signal;

Signal imbalance compensator (630,650) is used for according to the detected signal imbalance value of described signal imbalance detector another road input signal in the identical input signal of described two-way being compensated.

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