CN100431273C - Method and system for continuously compensating for phase variations introduced into a communication signal by automatic gain control adjustments - Google Patents

Abstract

A communication system (100) including an automatic control (AGC) circuit (105), a receiver (110), an analog to digital (ADC) converter (115) and an insertion phase variation compensation module (120). The AGC circuit receives and amplifies communication signals (150). The gain of the AGC circuit is adjusted. The AGC circuit outputsan amplified signal (145) to the receiver which, in turn, outputs an analog complex signal to the ADC (115). The ADC outputs a digital complex signal to the insertion phase variation compensation module (120) which counteracts the effects of phase offsets introduced into the communication signal due to the continuous gain adjustments associated with the AGC circuit.

Description

Continuous Compensation gets involved the communicator of the phase variation of signal of communication

Technical field

The relevant wireless communication system that the present invention is total.Say that more specifically the present invention is about a kind of Digital Signal Processing (DSP) technology that is used for compensating the phase variation relevant with automatic gain control (AGC) adjustment.

Background technology

In a traditional phase sensitivity communication system, a receiver uses automatic gain control (AGC) to come automatically gain to be adjusted to the function of the amplitude of a radio frequency (RF) and/or intermediate frequency (IF) signal of communication.A value of real part gain coefficient that is produced by this AGC is added to this signal of communication.In simulation field, the amplitude of signal of communication is maintained in the pre-defined signal amplitude scope and converts thereof into a digital signal by an analog-digital converter (ADC) then, and this transducer is the restricting signal amplitude range also.The purpose of AGC is that the input to ADC is maintained a firm power position standard.

When AGC was adjusted, a phase deviation got involved and makes the degradation of this phase sensitivity communication system in this signal of communication.Therefore expect that a kind of method and system is in order to offset because of adjusting the signal of communication phase deviation that this AGC causes.

Summary of the invention

The invention provides a kind of communicator, it comprises: an automatic gain control circuit, and its reception is also adjusted the gain of one first signal of communication and is produced a second communication signal, and this automatic gain control circuit is controlled by a gain control signal; One receiver, it is electrically coupled to this automatic gain control circuit, and this receiver is in order to receive this second communication signal and output analog in-phase and quadrature signal component from this automatic gain control circuit; One analog-digital converter, it is electrically coupled to this receiver, and this analog-digital converter is in order to receive this analog in-phase and quadrature signal component and this analog in-phase and quadrature signal component are converted to digital homophase and quadrature signal component; One inserts the phase variation compensating module, it is electrically coupled to this analog-digital converter, it is that the effect that gets involved the phase deviation in this signal of communication because of this automatic gain control circuit is offseted on the basis continuously that this insertion phase variation compensating module is used for this gain control signal, should insert wherein that the phase variation compensating module receives from the homophase of this numeral homophase of this automatic gain control circuit and quadrature component and output change and quadrature component and as the function of this gain control signal, the homophase of this change has different phase characteristics with quadrature component compared to this numeral homophase and quadrature component; One modulator-demodulator, it is electrically coupled to this insertion phase variation compensating module and this automatic gain control circuit, this modulator-demodulator is used for receiving from this insertion phase variation compensating module the homophase and the quadrature signal component of change, this modulator-demodulator comprises a processor that produces this gain control signal, and wherein how much power this processor has calculated and be input to this automatic gain control circuit; An and look-up table, it is communicated by letter with this processor and this insertion phase variation compensating module, and wherein this look-up table receives this gain control signal and provides the phase deviation estimated value with the function as this gain control signal to this insertion phase variation compensating module from this processor.

The estimated value that provides comprises a Sin function and the Cos function of a phase deviation x.This insertion phase variation compensating module can have real part (Re) input and one and one Q signal component relevant imaginary part (Im) input relevant with a digital I signal component, and according to the estimated value that is provided by this LUT, the I signal component and that this insertions phase variation compensating module exportable one has a phase place of having adjusted according to function [Cos (x) * Re]-[Sin (x) * Im] has one according to the Q signal component of the phase place of function [Sin (x) * Re]+[Cos (x) * Im] adjustment.

Description of drawings

Explanation by a following preferred embodiments of giving an example can allow the people more understand the present invention with reference to accompanying drawing, in the accompanying drawing:

Fig. 1 is a calcspar according to communication system of the present invention, and this system comprises a payment gets involved the phase deviation in the signal of communication because of an agc circuit insertion phase variation compensating module;

Fig. 2 inserts an example configuration of phase variation compensating module for Fig. 1; And

Fig. 3 is a method flow diagram, and it comprises implementation gets involved the effect of the phase deviation in the signal of communication because of the agc circuit of Fig. 1 with continuous payment step.

Embodiment

The present invention proposes a kind of payment and adjusts the method and system of getting involved the phase difference in a RF or the IF signal of communication (that is data streaming) because of carrying out AGC.

Preferable, disclosed method and system is embodied in the wireless transmitter/receiver unit (WTRU).Hereinafter, the non-limitation of a WTRU comprises user's equipment, a portable base station, a holding or portable subscriber unit, calling set or any other types of devices that can operate in a wireless environment.Feature of the present invention can be embodied in the integrated circuit (IC) or by planning and comprise in the circuit of a large amount of interconnecting assemblies one.

The present invention can be applicable to adopt time division duplex (TDD), frequency division duplexing (FDD), demal is multidirectional closely connects the communication system of (CDMA), CDMA 2000, timesharing synchronization CDMA (TDSCDMA), orthogonal frequency division multitasking (OFDM) or similar techniques.

Fig. 1 is a calcspar according to the communication system 100 of the present invention running.Communication system 100 comprises an agc circuit 105, a receiver 110, an analog-digital converter (ADC) 115, an insertion phase variation compensating module 120 and a modulator-demodulator 125.Agc circuit 105 and ADC 115 can be merged in the receiver 110.Agc circuit 105 can comprise one pass gain or multistage gain.In addition, inserting phase variation compensating module 120 can incorporate in the modulator-demodulator 125.

Modulator-demodulator 125 comprises one and calculates the processor 130 how much power is defeated by ADC 115.Modulator-demodulator 125 receives compound I and Q signal component 135,140 from inserting phase variation compensating module 120, and via 130 pairs of agc circuits of processor, 105 outputs, one gain control signal 145.Gain control signal 145 comprises one and is used for setting the gain coefficient of the amplitude of a RF and/or IF signal of communication 150 by agc circuit 105.Gain control signal 145 is also exported to a look-up table (LUT) 155 from processor 130, and this look-up table utilizes 145 pairs of gain control signals to insert phase variation compensating module 120 a phase deviation estimated value that gets involved in the signal of communication 150 is provided.Another selection can adopt a predefined multinomial or any other method to replace LUT 155 that the phase deviation estimated value is provided.

When the gain level of the gain stage of agc circuit 105 changed at every turn, a dependent phase deviation (that is phase place rotation) may get involved in the signal of communication 150.Therefore, the phase deviation estimated value (x) of a function of the gain that provided of agc circuit 105 can be judged in a continuity mode by any other method that access LUT 155, one pre-defined multinomial or the full breadth of AGC value that can be relevant with agc circuit 105 are mapped across a phase deviation estimated value.

Fig. 2 is for inserting an example configuration of phase variation compensating module 120, this module serves as that the basis rotates from the I of a digital complex signal of ADC 115 output and the phase characteristic of Q signal component, so that payment gets involved the effect of the phase deviation in the signal of communication 150 because of agc circuit 105 with gain control signal 145.Therefore, modulator-demodulator 125 is not influenced by these phase deviations, and the performance of communication system 100 can variation.Different gain level can make different gain deviations get involved in the signal of communication 150.

As shown in Figure 2, insert phase variation compensating module 120 and comprise multiplier 205,210,215,220 and adder 225 and 230.Inserting phase variation compensating module 120 receives a real part (Re) I signal components 250 and imaginary part (jIm) Q signal component 260 and the phase place of signal component Re and jIm is rotated x degree (e shown in following equation 1 from ADC 115 ^Jx):

(Re+jIm) * e ^Jx=(Re+jIm) * [Cos (x)+jSin (x)] equation 1

The result of real part output

Shown in following equation 2:

$\hat{R}e=[\mathrm{Cos}\left(x\right)\&times;\mathrm{Re}]+[{\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="C20048001533900091.png"\; state="\{\{state\}\}">j</figure-callout>}}^2\&times;\mathrm{Sin}\left(x\right)\&times;\mathrm{Im}]=[\mathrm{Cos}\left(x\right)\&times;\mathrm{Re}]-[\mathrm{Sin}\left(x\right)\&times;\mathrm{Im}]$ Equation 2

It is also noted that if x approaches zero, then Cos (x)=1.0 and Sin (x)=x, shown in following equation 3:

$\hat{R}e=\mathrm{Re}-\mathrm{Im}\&times;x$ Equation 3

The result of imaginary part output

Shown in following equation 4:

$\hat{I}m=[\mathrm{Sin}\left(x\right)\&times;\mathrm{Re}]+[\mathrm{Cos}\left(x\right)\&times;\mathrm{Im}]$ Equation 4

It is also noted that if x approaches zero, then Cos (x)=1.0 and Sin (x)=x, shown in following equation 5:

$\hat{I}m=\mathrm{Im}+\mathrm{Re}\&times;x$ Equation 5

Therefore, shown in equation 2, real signal component 250 is taken advantage of by LUT 155 a specified Cos (x) functions 280 via multiplier 215, and imaginary signal component 260 is that LUT 155 a specified Sin (x) functions 270 are taken advantage of via multiplier 210 equally, is subtracted the output of multiplier 210 by this with the output of multiplier 215 by adder 225.In addition, shown in equation 4, real signal component 250 is taken advantage of by LUT 155 a specified Sin (x) functions 270 via multiplier 205, and imaginary signal component 260 is that LUT 155 a specified Cos (x) functions 280 are taken advantage of via multiplier 220 equally, by adder 230 output of multiplier 220 is added the output of multiplier 205 by this.

Fig. 3 is the flow chart of a method 300, and it comprises implementation gets involved the effect of the phase deviation in the signal of communication 150 that agc circuit 105 received with continuous payment step.In step 305, provide gain control signal 145 to agc circuit 105.In step 310, agc circuit 105 is in response to the gain of gain control signal 145 adjustment one signal of communication 150, and this adjustment causes a phase deviation to get involved in the signal of communication 150.In step 315, provide the phase deviation estimated value of a function of gain control signal 145 to inserting phase variation compensating module 120.In step 320, phase variation compensating module 120 serves as the phase place that signal of communication 150 is adjusted on the basis with provided estimated value.Method 300 repeats in a continuity mode.

Although use literal and description of drawings especially with reference to preferred embodiment, person skilled in the art person obviously can not break away from the above scope of the invention as can be known and make various variation with regard to form and details.

Claims (6)

1. communicator, it comprises:

One automatic gain control circuit, its reception is also adjusted the gain of one first signal of communication and is produced a second communication signal, and this automatic gain control circuit is controlled by a gain control signal;

One receiver, it is electrically coupled to this automatic gain control circuit, and this receiver is in order to receive this second communication signal and output analog in-phase and quadrature signal component from this automatic gain control circuit;

One analog-digital converter, it is electrically coupled to this receiver, and this analog-digital converter is in order to receive this analog in-phase and quadrature signal component and this analog in-phase and quadrature signal component are converted to digital homophase and quadrature signal component; One inserts the phase variation compensating module, it is electrically coupled to this analog-digital converter, it is that the effect that gets involved the phase deviation in this signal of communication because of this automatic gain control circuit is offseted on the basis continuously that this insertion phase variation compensating module is used for this gain control signal, should insert wherein that the phase variation compensating module receives from the homophase of this numeral homophase of this automatic gain control circuit and quadrature component and output change and quadrature component and as the function of this gain control signal, the homophase of this change has different phase characteristics with quadrature component compared to this numeral homophase and quadrature component;

One modulator-demodulator, it is electrically coupled to this insertion phase variation compensating module and this automatic gain control circuit, this modulator-demodulator is used for receiving from this insertion phase variation compensating module the homophase and the quadrature signal component of change, this modulator-demodulator comprises a processor that produces this gain control signal, and wherein how much power this processor has calculated and be input to this automatic gain control circuit; And

One look-up table, it is communicated by letter with this processor and this insertion phase variation compensating module, and wherein this look-up table receives this gain control signal and provides the phase deviation estimated value with the function as this gain control signal to this insertion phase variation compensating module from this processor.

2. communicator as claimed in claim 1 is characterized in that the estimated value that provides comprises a Sin function and the Cos function of a phase deviation x.

3. communicator as claimed in claim 2, it is characterized in that this insertion phase variation compensating module has real part Re input and one and one a quadrature signal component relevant imaginary part Im input relevant with a digital inphase signal component, and according to the estimated value that is provided by this look-up table, this insertions phase variation compensating module output one has an in-phase signal component according to the phase place of function [Cos (x) * Re]-[Sin (x) * Im] adjustment.

4. communicator as claimed in claim 2, it is characterized in that this insertion phase variation compensating module has real part input Re and one and one a quadrature signal component relevant imaginary part input Im relevant with a digital inphase signal component, and according to by the estimated value that this look-up table provided, this insertions phase variation compensating module output one has a quadrature signal component according to the phase place of function [Sin (x) * Re]+[Cos (x) * Im] adjustment.

5. communicator as claimed in claim 1 is characterized in that this communicator is a wireless transmitter/receiver unit.

6. communicator as claimed in claim 1 is characterized in that this communicator is an integrated circuit.

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