CN101375575A - Multi-mode modulation apparatus - Google Patents

Abstract

The present invention relates to a multi-mode modulation apparatus and a method of modulating a carrier signal by a baseband signal in at least two modulation modes. The phase of the carrier signal is modulated in response to a first control signal derived from the baseband signal to obtain a first phase-modulated signal, and the phase of the carrier signal is additionally modulated in response to a second control signal derived from the baseband signal to obtain a second phase-modulated signal, wherein combination of the first and second phase-modulated signals is controlled to select one of the at least two modulation modes. Thereby, information of different components (e.g. phase and envelope) of the baseband signal can be phase-modulated and combined in a suitable manner, so that over- sampling and highly linear triangular or saw-tooth signals are no longer required. Moreover, the controlled combination provides a flexible multi-mode modulation scheme.

Description

Multi-mode modulation apparatus

Technical field

The present invention relates to a kind of multi-mode modulation apparatus and method of under at least two modulating modes, coming modulated carrier signal by baseband signal.

Background technology

The known modulation system is used for coming modulated carrier signal based on baseband signal, for example, comes modulated RF (RF) carrier wave based on the information that will transmit in cellular communication system.

Because to the demand growth of spectrum efficiency, it is more and more universal that variable envelope modulation methods has become.Yet the shortcoming of variable envelope modulation methods is, conventional power amplifier (PA) may cause in the transmitter apparatus (being specially the hot property limited devices of similar terminal equipment) heat and/or operation time problem.In order to alleviate these problems, having developed switching mode PA increases power efficiency.Yet these switching modes PA is extremely nonlinear, and may therefore cause distortion to increase.

D.C.Cox, ＂ Linear Amplification with Non-linear Components ＂, IEEE Transactions on Communications, COM-22, pp.1942 to 1945, December 1974 has described a kind of variable envelope modulated system, this system utilizes switching mode PA as LINC (linear amplification with non-linear element) system, wherein, represent any bandpass signal of not only having changes in amplitude but also have phase change by two signals that have constant amplitude and only have a phase change.Can use the power efficient non-linear amplifier to amplify this two angle-modulated signals separately.Then, the output of making up these amplifiers by sum unit is to produce the variable amplitude signal of expectation.The problem of this system is the combination of two incoherent amplifying signals.

In pulse-width modulation (PWM) system, primary signal is encoded to two level signals of pulse with varying width.The average of this two level signal depends on the output signal of expectation, and can extract by filtering.Pulse density modulated (PDM) is the alternate ways that is used to realize same task.Enable another pulse modulation method that is similar to the said PWM system by the sigma-delta modulating system.Can adopt the logical sigma-delta modulator of band that modulated sinusoidal carrier is converted to two level signals.

In addition, in polar-modulation system, at PA punishment other places reason and combination amplitude modulation (AM) component and phase modulation (PM) component.Some kinds of modes that have control PA.The existing polar modulation scheme of one class is the scheme of adding the AM component by the supply voltage of modulating PA therein.In order to realize high power efficiency, should carry out this supply voltage modulation via efficient switch DC-to-DC (DC-DC) transducer.Yet it is difficult realizing the high modulation bandwidth and breaking away from the switch fluctuation.The existing polar modulation scheme of second class is that to utilize two level PWM signals to come the scheme of the input of driving switch PA, this two level PWMs signal therein be by being that triangle (or sawtooth) signal of carrier frequency twice compares and produces at least with AM and PM modulated carrier signal and fundamental frequency.This scheme has caused high PA switching frequency (over-sampling) and for the serious linearisation requirement of triangle (or sawtooth) signal.In addition, before carrying out the PWM conversion, should carry out linear AM modulation to carrier wave.The existing polar modulation scheme of the 3rd class is to utilize the two level pulse density signals of being with logical sigma-delta transducer to be produced to come the scheme of the input of driving switch PA therein.Yet this scheme needs even higher PA switching frequency, and therefore needs significant oversampling ratio.

US 2004/0246060 A1 discloses a kind of modulating system, and this modulating system provides the modulation that is suitable for by the expectation of switching mode PA amplification to two level signals.This prior art is from such thought: can be with the redesign of known LINC system for two level constant envelope signal are provided.Be encoded as two control signals by the information (for example amplitude of analog control signal and/or phase place) that final modulation is represented, these two control signal controls are by two modulation that constant envelope modulator applied.This modulation can comprise: in the phase modulated of exporting under the situation that constant envelope signals is a sinusoidal signal, and in the modulation of exporting the transit time under the situation that constant envelope signals is a pulse signal.Then, these two constant envelope signals are combined as single two level constant envelope signal.Therefore, take to use the form of two level signals that single nonlinear amplifier (for example switching mode amplifier) amplifies that single constant envelope signals is provided.Thus, can avoid the non-coherent power combination of traditional LINC system.In addition, opposite with the delta-sigma modulation, the width of the pulse of generation does not disperse, thereby can reduce quantizing noise.

Summary of the invention

The purpose of this invention is to provide a kind of multi-mode modulation apparatus and method,, different modulation types (for example PWM modulation and linear modulation) can be provided, and need not over-sampling and Linear Triangular signal or serrated signal by described multi-mode modulation apparatus and method.

The present invention is limited by independent claims.Dependent claims has been described advantageous embodiments.Correspondingly, optionally make up phase modulation output, to obtain the modulation of predefined type or pattern based on two oscillator arrangements of first control signal that derives from baseband signal and the control of second control signal.This provides following advantage: the over-sampling and high Linear Triangular signal or the serrated signal that do not need to be generally used for producing pwm signal.Only need an additional controlled oscillation apparatus to produce phase modulated.

In addition, make up the serviceability that provides as the high flexible of multi-mode modulator by selectivity.Can add up by the linearity of sine wave signal or sinusoidal voltage controlled oscillator (VCO) signal and produce traditional AM-PM RF carrier wave, and polarization modulation even when only the RF carrier wave being carried out phase modulation and directly envelope component or range weight are presented power supply to PA, also be possible.Under the situation of phase-modulated signal, can use the amplitude modulation(PAM) of the fundamental frequency of phase modulation pwm signal is controlled as power.Can pass through the power supply of adaptive PA simply, the traditional approach of controlling in conjunction with any power uses this power control scheme.The dynamic range that this combination will produce even higher power is controlled.

Adopt two phase modulation output signals of being advised, even can set up PA thought based on the LINC technology.In this case, two phase modulation (constant envelope) signal is fed to two switch P A, can makes up the output signal of these two switch P A, to produce phase-modulated signal and amplitude-modulated signal.

This composite set (for example can comprise gate, or door, with door, NOR gate or the like or its combination in any), be used for logically the binary system square-wave signal that is produced according to the first and second phase modulation output signals respectively being made up, to obtain modulated output signal according to pulse-width modulation as first modulating mode in described at least two modulating modes.In addition, this composite set can comprise adder, is used for the first and second phase modulation output signals are added up, to obtain modulated output signal according to the linear modulation as second modulating mode in described at least two modulating modes.Thus, can use very simple composition element to obtain the output signal of PWM and linear modulation.

According to concrete example, described at least one gate can comprise: NOR gate and with door, be used for for example under the switch operational pattern of two level modulation patterns (for example PWM modulating mode), logically each binary system square-wave signal is made up, to obtain to be used for the push-pull signal of balanced power amplifier.In addition, this composite set can comprise: inverter apparatus is used for for example making under the linear operation pattern of linear modulation mode that described modulated output signal is anti-phase, to obtain to be used for the push-pull signal of balanced power amplifier.Provide the advantage of this balance PWM output signal to be, realized cleaner spectrum in output place of balanced power amplifier.

This control device can comprise: switching device, be used for or door and each output signal of adder between switch.In addition, can obtain multi-mode modulation flexibly in simple mode by between each output signal of composite set, switching.

In addition, pre-distortion device can be provided, be used for giving the phase place correlated components of described baseband signal and at least one of amplitude correlated components to apply predetermined predistortion in response to described selectivity modulating mode, wherein, by in summing unit, the phase place correlated components being produced first control signal in the Calais mutually with the amplitude correlative, and produce second control signal by in substracting unit, this phase place correlated components and amplitude correlated components being subtracted each other.Thus, this selectivity predistortion provides following advantage: optimize modulated output signal based on selected modulating mode.Particularly, this pre-distortion device can be adapted to be: in response to selected modulating mode, and optionally remove sin (x)/x distortion or produce modulated subcarrier technique.

Can come by each phase-locked loop circuit that is connected to reference oscillator to carry out phase-locked to the first and second controlled oscillation apparatuses.Therefore, can easily change tranmitting frequency or RF frequency by the reference frequency that provides by this reference oscillator is provided simply.

Description of drawings

Now with reference to accompanying drawing, based on preferred embodiment the present invention is described, in the accompanying drawings:

Fig. 1 shows the schematic block diagram according to the PLL multi-mode modulator of preferred embodiment;

Fig. 2 shows the signal waveform of the preferred embodiment that is obtained by the AM component;

Fig. 3 shows the waveform of the symmetrical PWM signal at different sequential place;

Fig. 4 shows the signal waveform of the preferred embodiment that is obtained by the PM component;

Fig. 5 shows the schematic circuit of the alternative example of the signal combination part among the Fig. 1 that is suitable for driven equilibrium PA;

Fig. 6 A shows only at the output spectra under the PWM pattern under the AM situation;

Fig. 6 B show with Fig. 6 A in the corresponding time signal of output spectra;

Fig. 7 only shows the output spectra at the preferred embodiment under the PWM pattern under the situation of PM;

Fig. 8 shows the output spectra at the preferred embodiment under the PWM pattern under the situation of AM and PM;

Fig. 9 A only shows the output spectra at the preferred embodiment under linear model under the situation of AM; And

Fig. 9 B show with Fig. 9 A in the corresponding time signal of output spectra.

Embodiment

Below, to preferred embodiment be described in conjunction with phase-locked loop (PLL) multi-mode modulator, can be with the efficient modulation of this PLL multi-mode modulator applications in realizing transmitter, to be used for wireless lan (wlan), WPAN (Wireless Personal Network), Bluetooth system, OFDM (OFDM) system, global system for mobile communications (GSM), global system for mobile communications (UMTS), code division multiple access (CDMA) system, low power mobile communication equipment or the like.

Fig. 1 shows the schematic block diagram according to the PLL modulating equipment of preferred embodiment.Range weight A (t) and phase component Φ with baseband signal _p(t) offer baseband processing circuitry 10, baseband processing circuitry 10 comprises the selectivity pre-distortion unit 110 by the control signal control of depending on selected modulating mode (for example PWM or linear modulation).In output place of baseband processing circuitry 10, the phase-modulated component Φ that the acquisition amplitude is relevant _M(t) and the relevant phase modulated signal Φ of phase place _p(t), and with the two offer each summing junction 27,37 of two PLL circuit.The PLL circuit comprises that a VCO 26 and the 2nd VCO 36, the one VCO 26 and the 2nd VCO 36 come phase-locked by their PLL circuit separately.The phase modulated signal Φ that phase place is relevant _p(t) directly offer summing junction 27 and 37, simultaneously that amplitude is relevant phase modulated signal Φ _M(t) directly offer first summing junction 27 of a PLL circuit, and provide it to second summing junction 37 of the 2nd PLL circuit via inverter 40.Thus, first summing junction 27 act as: the phase modulated signal Φ that phase place is relevant _p(t) and the relevant phase modulated signal Φ of amplitude _M(t) addition, and second summing junction 37 act as: the phase modulated signal Φ that phase place is relevant _p(t) and the relevant phase modulated signal Φ of amplitude _M(t) subtract each other.

The one PLL circuit comprises the PLL loop, will have reference phase θ in the PLL loop _RefReference frequency offer phase detectors 22, in phase detectors 22, the output frequency of a reference frequency and a VCO 26 is compared, first divider circuit 24 has carried out frequency division to the output frequency of a VCO 26.The output of first phase detectors 22 is offered loop filter 28, and loop filter 28 offers a VCO26 with filtered control signal, with the reference phase θ based on reference oscillator 50 _RefControl the phase place of the output signal of a VCO 26.Realize modulation by the 3rd summing junction 25, at the 3rd summing junction 25, with the phase-modulated signal Φ after the summation _p(t) and Φ _M(t) add to give the output of first phase detectors 22, with the phase place of the output signal of controlling a VCO 26.

Similarly, the 2nd PLL circuit comprises: second phase detectors 32, second loop filter 38 and second divider circuit 34.The 2nd PLL circuit is operated in a similar manner, and comprises the 4th summing junction 35, with two phase modulated signal Φ _p(t) and Φ _M(t) difference offers the 4th summing junction 35, and the 4th summing junction 35 is added to this difference the output of second phase detectors 32.

The phase modulation output signal θ 1 of the one VCO 26 ₀Phase modulation output signal θ 2 with the 2nd VCO 36 ₀Be connected to add circuit 70, with the two addition, and offer the first terminal of switch 80 at add circuit 70 places.In addition, with the phase modulation output signal θ 1 of first and second VCO 26,36 ₀With θ 2 ₀Offer symbolic circuit 60, in symbolic circuit 60, sinusoidal signal is converted to and corresponding binary system two level signals of the symbol of sine amplitude.Then, the binary character signal offered or door 62, or door 62 in the binary character signal is carried out logical combination (being logic OR), and provide it to second terminal of switch 80.

If at least one in two incoming symbol signals has first logical value " 1 ", then or the binary output signal of door 62 have first logical value " 1 ".If two incoming symbol signals all have second logical value, i.e. " 0 ", then or door 62 produce logic output valves " 0 ".

Switch 80 can be any electrical switchgear (a for example passive or active semi-conductor switch element), and switch 80 is controlled by the control signal that is used to select modulating mode, and this control signal also is provided for baseband processing circuitry 10.Based on this control signal, select or the output of door 62 and add circuit 70 in one, and with it as modulation output S _RF(t) offer PA 90.Then, can offer for example transmitting antenna via the modulation output of band pass filter after with power amplification.

In the current example of Fig. 1, baseband processing circuitry 10 only comprises a pre-distortion unit 110, is used for predistortion is applied to range weight A (t), so that the relevant phase modulated signal Φ of generation amplitude _M(t).Yet, if desired, suitable predistortion can be offered the relevant phase modulated signal Φ of phase place equally _P(t).

Therefore,, can carry out amplitude modulation(PAM) and phase modulated, be used for the appropriate signals of efficient switch PA 90 with generation the first-harmonic of two level PWM RF output signals according to preferred embodiment.On two that run on the RF frequency phase-locked PLL circuit, baseband envelope and phase information are modulated.Then, AM-PM two level PWM signals two square wave VCO output signals or that generation is wanted in the door computing.For this modulator approach, do not need over-sampling, and do not need to be generally used for producing the high Linear Triangular signal or the serrated signal of pwm signal.Under the situation of two level RF carrier waves, only need an additional PLL circuit to produce phase modulated.In addition, can be by selecting linear modulation and therefore select the linear adder of sinusoidal wave VCO signal to produce traditional AM-PM RF carrier wave, and polarization modulation even when only the RF carrier wave being carried out phase modulated and directly envelope is presented power supply to PA 90, be possible.Under the situation of phase-modulated signal, the amplitude modulation(PAM) to the fundamental frequency of phase modulation pwm signal can be used for power control.

According to Fig. 1, by two PLL with first and second VCO 26,36 phase-locked be the same datum frequency.If selected the PWM modulating mode, then two square waves output VCO signals are presented to or door 62, or door 62 produces the unmodulated square-wave output signal with 50% duty ratio.Under the situation of linear modulation mode, with two sinusoidal wave VCO signal plus, this has produced the sine wave that equals reference frequency under the situation that does not have modulation at add circuit 70 places.These two PLL circuit can be equipped with extra frequency divider, in order to the scope of expansion phase detectors 22,32.

Under the situation of modulation, add modulation signals by loop filter circuit 28,38 at two VCO 26,36, VCO 26,36 will become phase modulation.The loop bandwidth of PLL circuit is enough for the phase modulated that employing is injected into the expectation of loop filter 28,38.Under the PWM modulating mode, can produce the carrier wave (two level signals) of the RF modulation that is suitable for switching mode PA thought (D class), and under linear modulation mode, produce the RF signal, to be used for conventional P A thought.

Under the PWM modulating mode, select the respective phase predistortion at pre-distortion unit 110 places, and select in addition or the output of door 62.The phase modulated signal Φ that amplitude after the predistortion is relevant _M(t) (envelope or the amplitude information of its expression baseband signal) produces the amplitude modulation(PAM) of the first-harmonic of pwm signal.Will be with positively-modulated signal+ΔΦ _MCome a VCO 26 is carried out phase modulation, and will be with negatively-modulated signal-ΔΦ _MCome the 2nd VCO 36 is carried out phase modulation.

Fig. 2 shows from the relevant phase modulated signal Φ of amplitude _MThe signal waveform of preferred embodiment (t).The indication of the waveform on top is the modulation output S under zero the situation in the relevant phase modulated of amplitude _RF(t).Second phase modulated signal relevant with the 3rd waveform indicator range changes ΔΦ _MEffect.Change ΔΦ _MThe output signal θ 1 that causes a VCO 26 ₀(t) skew left, and the output signal θ 2 of the 2nd VCO 36 ₀(t) skew to the right.Therefore, by the relevant phase modulated signal Φ of the amplitude after the difference predistortion _M(t) come the first-harmonic of PWM is carried out amplitude modulation(PAM).

Illustrate, can come the first-harmonic of PWM carrier wave is carried out amplitude modulation by the predistortion of duty ratio by removing sin (x)/x distortion.The 4th waveform among Fig. 2 shows the modulation output S at the circuit among Fig. 1 _RF(t), it has the pulsewidth of increase, and the fundamental frequency that therefore has the lower amplitude of this rectangular signal.Duty ratio for 50%, the amplitude of first-harmonic has maximum, and the further increase on pulsewidth will produce the first-harmonic than low amplitude.

Alternative about the exemplary circuit among Fig. 1 can be realized two VCO output signal θ 1 by other gate (for example with door, NOR gate or the like) equally ₀(t) and θ 2 ₀(t) combination.Two curves in bottom among Fig. 2 show respectively by replace with door and NOR gate or door 62 situation under modulation output S _RF(t).Still can obtain suitable AM modulation.

Fig. 3 shows indication very first time t=t ₁With the second time t=t ₂Between the oscillogram of change of pulsewidth of (being between the top wave form and foot waveform among Fig. 2).

Below, the required predistortion at pre-distortion unit 110 places that is used for the PWM modulating mode is described.

If modulating frequency far below carrier frequency, then can be used quasi stationary approach.For the amplitude of the first-harmonic of as shown in Figure 3 pwm signal, use following equation:

$A\left(\mathrm{\&tau;}\right)=\frac{\mathrm{\&tau;}}{{\mathrm{<figure-callout\; id="0"\; label="T"\; filenames="A200680052825E00191.png,A200680052825E00192.png"\; state="\{\{state\}\}">T</figure-callout>}}_0}\frac{\sin \left(2\mathrm{\&pi;}{\mathrm{<figure-callout\; id="0"\; label="f"\; filenames="A200680052825E00191.png,A200680052825E00192.png"\; state="\{\{state\}\}">f</figure-callout>}}_0\frac{\mathrm{\&tau;}}{2}\right)}{2\mathrm{\&pi;}{f}_0\frac{\mathrm{\&tau;}}{2}}$

Wherein, T ₀The cycle of indication pwm signal, f ₀=1/T ₀The expression correspondent frequency.

The duty ratio of signal is by d (τ)/T ₀Provide, it produces the following expression formula of revising:

$A=d\frac{\sin \left(\mathrm{nd}\right)}{\mathrm{nd}}$ $d\left(\mathrm{\&tau;}\right)=\frac{\arcsin \left(\mathrm{\&pi;A}\left(\mathrm{\&tau;}\right)\right)}{\mathrm{\&pi;}}$

This expression formula provides the expectation amplitude (amplitude modulation(PAM)) of fundamental frequency of pwm signal and the relation between the duty ratio.The maximum level of carrier wave adopts zero phase modulation (duty ratio 50%), and minimum levels adopts 90 ° phase modulated ( duty ratio 0 or 100%).This has produced the following formula that is used for phase-modulated signal:

${\widehat{\mathrm{\&Phi;}}}_M=\frac{\mathrm{\&pi;}}{2}$ ${\mathrm{\&Phi;}}_M\left(t\right)=(1-2d\left(t\right)){\widehat{\mathrm{\&Phi;}}}_M$

The relevant phase modulated signal Φ of phase place of the phase place of expression baseband signal _P(t) effect has caused the direct modulation (commonality schemata) at two loop filters, 28,38 places of the first and second PLL circuit, and this produces the phase modulated of the fundamental frequency of pwm signal.

Fig. 4 shows the signal waveform similar to Fig. 2, but only at the relevant phase modulated signal Φ of phase place _P(t) situation.Here, two output signal θ 1 of first and second VCO 26,36 ₀(t) and θ 2 ₀(t) be offset the relevant amount of phase modulation ΔΦ of phase place in the same direction _P(t), and therefore produce modulation output S _RF(t) phase modulated.

If the selection linear modulation mode is then selected another phase predistortion in pre-distortion unit 110, and is selected the output of linear add circuit 70, to be used for the sine wave output of first and second VCO 26,36.Must change the relevant phase modulated signal Φ of amplitude of the envelope information that is applied to the expression baseband signal _M(t) predistortion is to obtain the outgoing carrier of amplitude modulation.

Can be following the envelope of expression expectation:

A(t)＝a+m ₁sinω _m1t

Can represent normal amplitude-modulated signal by following formula:

s _AM(t)＝A(t)cos(ω ₀t)

Provide the signal that a VCO 26 and the 2nd VCO 36 are produced by following formula:

θ1 ₀(t)＝cos(ω ₀t+Φ _M(t))

θ2 ₀(t)＝cos(ω ₀t-Φ _M(t))

Adding up of two signals produces the carrier wave of amplitude modulation, and it is expressed as followsin:

s ^* _AM(t)＝θ1 ₀(t)+θ2 ₀(t)＝cos(ω ₀t+Φ _M(t))+cos(ω ₀t-Φ _M(t))

s ^* _AM(t)＝2cos(Φ _M(t))cos(ω ₀t)

The signal of expectation and the signal of generation are compared, and do not consider amplitude proportional (factor 2), provided the predistortion of phase modulated, to obtain the carrier wave of amplitude modulation, it can be expressed as followsin:

s ^* _AM(t)=s _AM(t), it provides: Φ _M(t)=arcos (A (t))

Under linear modulation mode, utilize the commonality schemata phase modulated to finish phase modulated, thereby can following expression have the total output signal of first and second VCO 26,36 of amplitude and phase modulated:

θ1 ₀(t)＝cos(ω ₀t+arccos(A(t))+Φ _P(t))

θ2 ₀(t)＝cos(ω ₀t-arccos(A(t))+Φ _P(t))

Two VCO signal θ 1 at add circuit 70 places ₀With θ 2 ₀Linearity add up and produce the AM-PM modulated signal, it can be represented as follows:

s _AM-PM(t)＝θ1 ₀(t)+θ2 ₀(t)＝2A(t)cos(ω ₀t+Φ _P(t))

Fig. 5 shows and is used for making up VCO output signal θ 1 according to the mode that is suitable for driving the PA 90 that is in balanced arrangement now ₀With θ 2 ₀The schematic circuit of alternative example of built-up section of Fig. 1.In order to realize this circuit, the push-pull signal s1 (t) and the s2 (t) that must will have opposite phases (linear modulation mode) basically or logic state (PWM modulating mode) are applied to each right control terminal of balanced transistor (for example base terminal), obtain the balance PWM output signal between each right lead-out terminal of transistor (for example collector terminal) simultaneously thus.Such balance PWM output signal provides following advantage: eliminated all even harmonicses of the fundamental carrier with its sideband, thus the cleaner spectrum that has realized in output place of balance PA 90.

Under the PWM modulating mode, can be for example by by the NOR gate 63 after the symbolic circuit 60 and with the combination of door 64 come in the alternate figures 1 or door 62 realize the opposite logic state of push-pull signal s1 (t) and s2 (t).Then, switch 80 optionally is connected to each control terminal of balance PA 90 concurrently with NOR gate 63 with each lead-out terminal of door 64.

Under linear modulation mode, can be for example realize that by add inverter circuit 72 in output place of the add circuit 70 of Fig. 1 push-pull signal s1 (t) and s2's (t) is anti-phase.Then, switch 80 optionally is connected to each lead-out terminal of add circuit 70 and inverter circuit 72 each control terminal of balance PA 90 concurrently.

Certainly, can provide other suitable logic OR linear combination circuit, be used for making up the VCO output signal, to obtain one or more appropriate driving signal of PA 90 in the mode of expectation.

Below, the simulation result at PWM modulating mode and linear modulation mode by the circuit acquisition of Fig. 1 is described.Following simulation result is based on the zoom version (factor pi) of the envelope that uses in above equation.

Fig. 6 A is illustrated under the PWM modulating mode output spectra under the situation of amplitude modulation(PAM) only.Article three, the center spectral line shows carrier wave and two sideband frequencies of typical amplitude modulation, and the harmonic wave that rectangular shape caused of carrier signal starts from higher sideband frequency place.

Fig. 6 B shows corresponding time signal, and it has envelope A (t), RF carrier wave (RF), duty ratio (DC) and predistortion phase modulated (PM).

Fig. 6 shows at the output spectra under the situation of phase modulated only under the PWM modulating mode.This spectrum obviously is similar to typical phase modulation spectrum.

Fig. 8 shows at the output spectra under the situation of amplitude and phase modulated combination under the PWM modulating mode.

At last, Fig. 9 A and Fig. 9 B relate to the situation of the linear modulation mode that only is used for amplitude modulation(PAM).In Fig. 9 A, arbitrarily harmonic wave lack the amplitude modulation(PAM) of all representing to have sinusoidal carrier signal (can as seen) from Fig. 9 B, in Fig. 9 B, show envelope A (t), RF carrier wave (RF) and the predistortion phase modulated (PM) of PLL circuit.

It should be noted that the present invention is intended to be subject to preferred embodiment described above, but can realize that wherein, at least the first and second pierce circuits are controlled by each component of baseband signal, to obtain the output signal of each phase modulation with any modulating equipment.In addition, the combination of the output signal of phase modulation is not to be intended to be subject to logic OR combination and linear adder computing.In addition, can adopt any appropriate combination of two phase-modulated signals to realize the modulating mode of expecting.

In a word, multi-mode modulation apparatus and method by the baseband signal modulated carrier signal have been described under at least two modulating modes.In response to the phase place of coming modulated carrier signal from first control signal of baseband signal derivation, and in response to coming the additionally phase place of modulated carrier signal from second control signal of baseband signal derivation, wherein, with first with the Combination Control of described second phase-modulated signal for selecting in described at least two modulating modes.Thus, can come the information of different components (for example phase place and envelope) to carry out phase modulated and combination according to suitable manner, thereby not need over-sampling and high Linear Triangular signal or serrated signal baseband signal.In addition, controlled combination provides multi-mode modulation scheme flexibly.

At last, but also be important, should note, when term " comprises " in the specification that is used to comprise claims, be intended to specify the existence of feature, device, step or the assembly stated, but do not get rid of the existence or the interpolation of one or more further feature, device, step, assembly and set thereof.In addition, in the claims, the speech before element " " or " one " do not get rid of the existence of a plurality of this elements.In addition, Reference numeral does not limit the scope of the claims arbitrarily.

Claims (11)

1. a multi-mode modulation apparatus is used for coming modulated carrier signal to obtain modulated output signal by baseband signal, and described equipment comprises:

The first controlled oscillation apparatus (26) is used in response to the phase place of modulating described carrier signal from first control signal of described baseband signal derivation;

The second controlled oscillation apparatus (36) is used in response to the phase place of modulating described carrier signal from second control signal of described baseband signal derivation;

Composite set (60,62,70; 60,63,64,70,72), be used to make up first phase modulation output signal of the described first controlled oscillation apparatus and the second phase modulation output signal of the described second controlled oscillation apparatus, to produce described modulated output signal; And

Control device (80) is used to control the combination function of described composite set, with one at least two modulating modes selecting described multi-mode modulation apparatus.

2. equipment as claimed in claim 1, wherein, described composite set comprises: at least one gate (62; 63,64), be used for logically each binary system square-wave signal that is produced according to the described first phase modulation output signal and the described second phase modulation output signal is made up, to obtain described modulated output signal according to pulse-width modulation as first modulating mode in described at least two modulating modes.

3. equipment as claimed in claim 2, wherein, described at least one gate comprise NOR gate (63) and with door (64), be used for logically described each binary system square-wave signal being made up, to obtain to be used for the push-pull signal of balanced power amplifier (90).

4. any described equipment in the claim as described above, wherein, described composite set comprises: adder (70), be used for described first phase modulation output signal and the described second phase modulation output signal addition, to obtain described modulated output signal according to linear modulation as second modulating mode in described at least two modulating modes.

5. equipment as claimed in claim 4, wherein, described composite set comprises: inverter apparatus (72) is used to make that described modulated output signal is anti-phase, to obtain to be used for the push-pull signal of balanced power amplifier (90).

6. any described equipment in the claim as described above, wherein, described control device comprises: switching device (80) is used for switching between each output signal of described composite set (62,70).

7. any described equipment in the claim as described above, also comprise: pre-distortion device (110), be used for giving the phase place correlated components of described baseband signal and at least one of amplitude correlated components to apply predetermined predistortion in response to described selectivity modulating mode, wherein, by in summing unit (27), described phase place correlated components being produced described first control signal in the Calais mutually with the amplitude correlated components, and produce described second control signal by in substracting unit (37,40), described phase place correlated components and amplitude correlated components being subtracted each other.

8. equipment as claimed in claim 7, wherein, described pre-distortion device (110) is adapted to be: in response to described selectivity modulating mode, optionally remove sin (x)/x distortion or produce modulated subcarrier technique.

9. any described equipment in the claim as described above, wherein, by being connected to each phase-locked loop circuit (22,24 of reference oscillator (50), 28,25,32,34,38,35) come to carry out phase-locked to the described first controlled oscillation apparatus and the second controlled oscillation apparatus (26,36).

10. a transmitter apparatus comprises as any described multi-mode modulation apparatus in the claim 1 to 9.

11. a method of being come modulated carrier signal under at least two modulating modes by baseband signal said method comprising the steps of:

In response to the phase place of modulating described carrier signal from first control signal of described baseband signal derivation, to obtain first phase-modulated signal;

In response to the phase place of modulating described carrier signal from second control signal of described baseband signal derivation, to obtain second phase-modulated signal; And

Control is to the combination of described first phase-modulated signal and described second phase-modulated signal, to select in described at least two modulating modes.

Images