JP2008005454A - Modulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a modulator capable of generating a waveform through digital signal processing, without having to depend on the carrier wave frequency and on the modulation system in a modulator, used for multimode/multiband available transmitters for radio communications systems. <P>SOLUTION: The modulator comprises a baseband signal generation unit 11 for generating a baseband signal constituted by superimposing a carrier wave corresponding to a system; a carrier wave signal processing unit 12 for extracting the amplitude and a phase for each carrier wave cycle, based on the baseband signal; a digital signal processing unit 14 for generating a digital signal corresponding to the baseband signal, by specifying a one-bit signal sequence corresponding to the carrier wave for each cycle, based on the amplitude and the phase for each carrier wave cycle extracted by the carrier wave signal processing unit. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a modulator applied to a transmitter compatible with multimode and multiband used in a wireless communication system.

  For example, in a transmission amplifier used in an audio band, a digital amplifier that converts an input signal into a digital pulse and amplifies the signal may be used. Further, for example, in a transmitter / receiver that supports multiband and multimode, an IC may be provided for each communication system to be transmitted (see, for example, Patent Document 1, Non-Patent Documents 1 and 2).

  FIG. 12 is a configuration diagram of a first conventional modulator, which is described in Patent Document 1. In FIG. This modulator converts a PCM (Pulse Code Modulation) multi-bit signal into a PWM (Pulse Width Modulation) signal, amplifies the PWM signal with a switching amplifier, and outputs the amplified signal.

  Specifically, the conventional first modulator includes an analog signal input terminal 101, a PCM data generation unit 111, a digital interface receiver 112, a digital attenuator 113, a noise shaver 114, a PWM converter 115, a switching amplifier, and the like. An output amplification stage 116, a low-pass filter 117, and an output terminal 102 are included.

  As shown in FIG. 12, the digital attenuator 113, the noise shaver 114, and the PWM converter 115 constitute a digital signal processing unit (DSP).

  Next, the operation will be described. First, an analog signal such as audio sound input from the analog signal input terminal 101 is digitally encoded by the PCM data generation unit 111 to generate a PCM multi-bit. Next, the digital interface receiver 112 demodulates the PCM multi-bit signal and performs oversampling processing on the demodulated signal.

  Next, the digital attenuator 113 and the noise shaver 114 shift the level adjustment and the quantization noise to the high frequency side. Next, the PWM converter 115 converts the input signal into a PWM signal. The converted PWM signal is amplified by the output amplification stage 116, then the high-frequency component is removed by the low-pass filter 117, and output from the output terminal 118 as an analog waveform.

  As described above, the conventional first modulator is driven by the on / off control of the switching element, and therefore generally operates with higher efficiency and generates less heat than the analog amplifier. Is possible.

  FIG. 13 is a configuration diagram of a conventional second modulator, and shows a configuration including a digital amplifier in which the concept of the ΔΣ modulation algorithm described in Non-Patent Document 1 is introduced. Specifically, the conventional second modulator includes an analog signal input terminal 101, a digital attenuator 113, a noise shaver 114, a 1-bit signal converter 119, an output amplification stage 116 including a switching amplifier, a low-pass filter 117, And an output terminal 102.

  As shown in FIG. 13, the digital attenuator 113, the noise shaver 114, and the 1-bit signal converter 119 constitute a digital signal processing unit (DSP).

  Next, the operation will be described. An analog signal such as audio sound input from the analog signal input terminal 101 is subjected to level adjustment and noise processing by a digital attenuator 113 and a noise shaver 114. Thereafter, the signal is converted into a 1-bit signal sequence by a 1-bit signal converter 119 using a ΔΣ modulation technique. The 1-bit signal sequence is amplified by the output amplification stage 116, then the high-frequency component is removed by the low-pass filter 117, and output from the output terminal 102 as an analog waveform.

  As described above, the conventional second modulator is driven by the on / off control of the switching element, similarly to the conventional first modulator shown in FIG. Since it operates with high efficiency and generates less heat, it can be downsized.

  Further, FIG. 14 is a configuration diagram of a conventional third modulator, and shows a configuration of a multimode IC described in Non-Patent Document 2. Specifically, the conventional third modulator includes baseband signal input terminals 103 and 104, a W-CDMA transmission / reception IC 121, a band-pass filter 122, an output amplification stage 123, a GSM transmission / reception IC 124, a low-pass filter 125, An output amplification stage 126, a switch module 127, and an output terminal 102 are included.

  Next, the operation will be described. Signals input from baseband signal input terminals 103 and 104 are input to W-CDMA transmission / reception IC 121 and GSM transmission / reception IC 124, which are different communication system ICs, respectively. The output signal of the W-CDMA transceiver IC 121 is amplified by the output amplification stage 123 via the band-pass filter 122 and then input to the switch module 127.

  On the other hand, the output signal of the GSM transceiver IC 124 is amplified by the output amplification stage 126 via the low-pass filter 125 and then input to the switch module 127. A signal input to the switch module 127 is output from the output terminal 102.

JP 2004-128662 A Sharp Technical Report (No. 77, August 2000, P67-72) SANYO TECHNIC REVIEW (No. 36 December 2004, P114-123)

  However, the prior art has the following problems. In the above-described multimode IC in the prior art, when a signal of a different communication system is to be transmitted, it is necessary to prepare an IC corresponding to each system. Therefore, there is a problem that the communication system to be transmitted cannot be arbitrarily changed.

  Further, the above-described conventional modulator has a problem in that digital processing is overloaded because signal processing is not performed for each carrier frequency. Furthermore, these conventional techniques are only examples in which the digital encoding technique is applied to an amplifier, and application to other circuits has not been considered.

  The present invention has been made to solve the above-described problems. In a modulator used for a multimode and multiband transmitter for a wireless communication system, a carrier frequency and a modulation method are obtained by digital signal processing. An object of the present invention is to obtain a modulator that enables waveform generation without depending on the above.

  The modulator according to the present invention includes a baseband signal generation unit that generates a baseband signal configured by superimposing a carrier wave corresponding to a system, and a carrier wave that extracts an amplitude and phase for each carrier period based on the baseband signal Based on the amplitude and phase of each carrier period extracted by the signal processing unit and the carrier signal processing unit, a 1-bit signal sequence corresponding to the carrier for each period is specified, and a digital signal corresponding to the baseband signal is generated And a digital signal processing unit.

  According to the present invention, by extracting a carrier wave for each period from a baseband signal, extracting an amplitude and a phase, and generating a waveform modulated based on a 1-bit signal sequence corresponding to the extracted amplitude and phase, thereby enabling wireless communication. In a modulator used for a multimode and multiband transmitter for a system, a modulator capable of generating a waveform regardless of a carrier frequency and a modulation method can be obtained by digital signal processing.

Hereinafter, preferred embodiments of the modulator of the present invention will be described with reference to the drawings.
The modulator according to the present invention is characterized by performing digital modulation by performing signal processing for each carrier period of a baseband signal, and as a result, can output an arbitrary modulated carrier wave. A modulator suitable for a transmitter corresponding to a band is realized.

Embodiment 1 FIG.
FIG. 1 is a block diagram of a modulator according to Embodiment 1 of the present invention. The modulator 10 includes a baseband signal generator 11, a carrier signal processor 12, a digital signal processor 14 including a 1-bit signal generator 13, an output amplifier stage 15 including a switching amplifier, a low-pass filter 16, and an output terminal. 1 is composed.

  Next, the operation will be described. Here, a modulator used for a transmitter corresponding to a plurality of systems is considered. The baseband signal generation unit 11 determines a carrier frequency based on baseband signals corresponding to a plurality of systems. Next, the carrier wave signal processing unit 12 extracts amplitude and phase data for each cycle of the carrier wave.

  Next, the 1-bit signal generation unit 13 specifies a 1-bit signal sequence corresponding to the waveform of each cycle of the carrier wave based on the extracted amplitude and phase data, and each specified 1-bit signal sequence Are combined to generate a digital signal corresponding to the waveform of the carrier wave. Further, the digital signal composed of the 1-bit signal sequence is amplified by the output amplification stage 15, the high frequency component is removed by the low-pass filter 16, and output from the output terminal 1 as a modulated carrier wave.

  The output amplification stage 15 is configured by, for example, a switching amplifier in which MOSFETs are push-pull connected. A voltage obtained by subtracting the saturation voltage of the MOSFET from the power supply voltage of the output amplification stage 15 is applied to the output of the output amplification stage 15. Accordingly, the output power value can be changed by controlling the power supply voltage value.

  The 1-bit signal generation unit 13 can perform level adjustment and noise processing by providing functions of a digital attenuator and a noise shaver.

  FIG. 2 is a diagram schematically showing signals at respective parts a to d shown in FIG. 1 in the first embodiment of the present invention. 2A is a signal at point a in FIG. 1, FIG. 2B is a signal at point b in FIG. 1, FIG. 2C is a signal at point c in FIG. 1, and FIG. Respectively show signals at point d in FIG.

  As shown in the upper part of FIG. 2A, the baseband signal generated by the baseband signal generation unit 11 is configured by superposing carrier waves corresponding to the system. Then, the carrier wave signal processing unit 12 extracts a carrier wave for each period from such a baseband signal, and extracts the amplitude and phase corresponding to each carrier wave. FIG. 2A illustrates a case where two continuous carriers are extracted from the baseband signal for each period and the corresponding amplitude and phase are extracted.

  Next, the 1-bit signal generation unit 13 combines the 1-bit signal series corresponding to the carrier wave for each period based on the amplitude and phase extracted for each carrier wave period, thereby generating a digital signal corresponding to the baseband signal. Is generated. FIG. 2B shows each 1-bit signal sequence corresponding to the two carrier waves illustrated in FIG.

  For example, the 1-bit signal generation unit 13 stores in advance a 1-bit signal sequence corresponding to various combinations of amplitude and period as a table in a storage unit not shown in FIG. The unit 12 can identify a 1-bit signal sequence corresponding to the amplitude and phase extracted for each carrier period. The 1-bit signal sequence specified in this way includes the amplitude and phase information included in the carrier wave for one period.

  Next, the output amplification stage 15 amplifies the digital signal composed of the combination of the 1-bit signal series generated by the 1-bit signal generation unit 13. FIG. 2C shows a state where the two 1-bit signal sequences exemplified in FIG. 2B are amplified. Finally, the low-pass filter 16 shapes the waveform of the digital signal amplified by the output amplification stage 15 to generate a carrier wave modulated in accordance with the baseband signal as shown in FIG. Obtainable.

  As described above, according to the first embodiment, the carrier wave for each period is extracted from the baseband signal to extract the amplitude and phase, and the clock signal having a frequency sufficiently higher than the carrier wave for each period is used to deal with the amplitude and phase. A modulated waveform is generated based on the 1-bit signal sequence. As a result, an arbitrary modulated carrier wave can be output, which is effective as a modulator used in a transmitter compatible with multimode and multiband.

  Furthermore, it is possible to optimize the dynamic range and the carrier frequency corresponding to the clock frequency of the carrier according to the system. Further, by using an output amplification stage using a switching amplifier, it is possible to realize low current consumption as a transmitter.

  Furthermore, since an arbitrary modulated carrier wave can be output, it is not necessary to prepare circuits corresponding to different communication systems, and it is possible to reduce the size of the module.

Embodiment 2. FIG.
In the second embodiment, a case where a sine wave is used as a carrier wave in the same modulator as in the first embodiment will be described. The block diagram of modulator 10 in the second embodiment is the same as that in FIG. 1 in the first embodiment. Further, the signal waveforms of the respective parts are the same as those in FIG. 2 in the first embodiment except that the carrier wave is a sine wave.

  By using a sine wave as a carrier wave, the DSP used in the 1-bit signal generation unit 13 can be made into a dedicated IC.

  As described above, according to the second embodiment, by limiting the carrier wave waveform to a sine wave, it is possible to make the DSP unit a dedicated IC, and in addition to the effects of the first embodiment, digital processing is easy. Thus, the processing speed can be increased.

Embodiment 3 FIG.
FIG. 3 is a block diagram of a modulator according to Embodiment 3 of the present invention. The modulator 10a includes a baseband signal generation unit 11, carrier signal processing units 12a and 12b, digital signal processing units 14a and 14b including 1-bit signal generation units 13a and 13b, an output amplification stage 15a including a switching amplifier, 15 b, low-pass filters 16 a and 16 b, a combiner 17, and an output terminal 1.

  The modulator 10a in FIG. 3 in the third embodiment has two systems from the carrier signal processing unit 12 to the low-pass filter 16 as compared with the modulator 10 in FIG. 1 in the first embodiment. In addition, the difference is that a synthesizer 17 is further provided.

  In FIG. 3, the two systems are shown as separate configurations. For example, the functions of the two systems of the carrier signal processing units 12 a and 12 b can be configured as one carrier signal processing unit 12. It is. In this case, the carrier signal processing unit 12a corresponds to the first carrier signal processing unit, and the carrier signal processing unit 12b corresponds to the second carrier signal processing unit.

  Next, the operation will be described. Each circuit portion denoted by the same reference numeral as in FIG. 1 in the first embodiment has the same function. The baseband signal generated by the baseband signal generation unit 11 is divided into a positive potential signal and a negative potential signal, and each of them is processed in parallel by two subsequent circuits. The output signals of the two systems are finally combined by the combiner 17 to obtain a desired modulated carrier wave.

  As described above, according to the third embodiment, even when a modulator having two systems is used, the same effect as in the first embodiment can be obtained. Furthermore, by processing the positive potential output signal and the negative potential output signal in parallel using two systems, it is possible to reduce the load on the digital circuit unit and realize further speedup.

Embodiment 4 FIG.
In the fourth embodiment, a case will be described in which a half wave of a sine wave is used as a positive potential output signal and a negative potential output signal which are carrier waves in the same modulator as in the third embodiment. The block diagram of modulator 10a in the fourth embodiment is the same as that in FIG. 3 in the third embodiment.

  Here, the modulator 10a according to the fourth embodiment is characterized in that each carrier wave processed by the carrier wave signal processing units 12a and 12b is a half wave of a sine wave. By using a half wave of a sine wave as a carrier wave, the DSP used in the 1-bit signal generation units 13a and 13b can be made into a dedicated IC as in the second embodiment.

  As described above, according to the fourth embodiment, by limiting the carrier wave waveform to a half wave of a sine wave, it is possible to make the DSP unit a dedicated IC, and in addition to the effects of the third embodiment, Processing can be facilitated and processing speed can be increased.

Embodiment 5. FIG.
In the fifth embodiment, a case where the modulator 10 shown in the first and second embodiments or the modulator 10a shown in the third and fourth embodiments is connected in parallel will be described. FIG. 4 is a block diagram of a modulator according to the fifth embodiment of the present invention, which is composed of two modulators 10 or 10a connected in parallel, a synthesizer 17, and an output terminal 1.

  Next, the operation will be described. Each of the two modulators 10 / 10a connected in parallel performs a modulation operation on the I signal and Q signal of the baseband signal. The analog waveforms output from each are combined by the combiner 17 and output from the output terminal 1. By adopting such a parallel configuration, the modulator of the fifth embodiment can function as a quadrature modulator.

  As described above, according to the fifth embodiment, the effects of the first to fourth embodiments are achieved by performing the modulation operation on the I signal and the Q signal of the baseband signal using the modulators connected in parallel. In addition, it can have the same function as a quadrature modulator. As a result, it is possible to realize a modulator that can obtain a desired modulation signal even for a multiple phase modulation system.

Embodiment 6 FIG.
In the sixth embodiment, the case where the modulators 10 and 10a described in the first to fifth embodiments are applied to a transmitter will be described. FIG. 5 is a block diagram of a transmitter including a modulator according to the sixth embodiment of the present invention. This transmitter includes a digital data input terminal 2, a modulator 21, an oscillator 22 that determines a carrier frequency, a high-power amplifier 23, a bandpass filter 24, and an output terminal 1. Here, the modulator 21 corresponds to the modulator 10 or the modulator 10a in the first to fifth embodiments.

  The oscillator 22 can determine a desired carrier frequency and provide it to the modulator 21 according to different communication systems. The baseband signal generation unit in the modulator 21 can generate a baseband signal based on a desired carrier frequency given by the modulator 21. As a result, the modulator 21 can support any communication system.

  As described above, according to the sixth embodiment, in a transmitter compatible with multimode and multiband, circuits corresponding to different communication systems are prepared by combining an oscillator with the modulator of the present invention. There is no need, and a transmitter that realizes downsizing of the module can be obtained.

  In addition, although the circuit block as a transmitter was shown in Embodiment 6, the receiver may be incorporated and the same effect can be acquired.

Embodiment 7 FIG.
In the seventh embodiment, a case will be described in which the modulators 10 and 10a described in the first to fifth embodiments are applied to a transmitter capable of increasing the carrier frequency. FIG. 6 is a block diagram of a transmitter including a modulator according to the seventh embodiment of the present invention. This transmitter is different from the transmitter in the sixth embodiment in that a frequency converter 25 is further provided between the modulator 21 and the high-power amplifier 23.

  Next, the operation will be described. The frequency converter 25 converts the output signal of the modulator 21 to a frequency corresponding to the system based on a desired carrier frequency determined by the oscillator 22 according to a different communication system. The frequency-converted signal is amplified by the high output amplifier 23 and further output from the output terminal 1 via the band pass filter 24.

  As described above, according to the seventh embodiment, in a transmitter compatible with multimode and multiband, by combining an oscillator and a frequency converter with the modulator of the present invention, circuits corresponding to different communication systems can be provided. There is no need to prepare the transmitter, and a transmitter that realizes downsizing of the module can be obtained. Furthermore, by changing the output frequency of the modulator using a frequency converter, the carrier frequency can be increased, and multibanding is facilitated.

  In the seventh embodiment, a circuit block as a transmitter is shown. However, a receiver may be built in, and the same effect can be obtained.

Embodiment 8 FIG.
FIG. 7 is a block diagram of a modulator according to the eighth embodiment of the present invention. The modulator 10b includes a baseband signal generation unit 11, a LOG function amplitude compression unit 18, a carrier signal processing unit 12, a digital signal processing unit 14 including a 1-bit signal generation unit 13, an output amplification stage 15 including a switching amplifier, An EXP function amplitude expansion amplifying unit 19, a low-pass filter 16, and an output terminal 1 are included.

  7 according to the eighth embodiment further includes a LOG function amplitude compression unit 18 and an EXP function amplitude expansion amplification unit 19 as compared with the modulator 10 of FIG. 1 according to the first embodiment. The point is different. Here, the LOG function amplitude compression unit 18 corresponds to an amplitude compression unit, and the EXP function amplitude expansion amplification unit 19 corresponds to an amplitude expansion amplification unit.

  Next, the operation will be described. Each circuit portion denoted by the same reference numeral as in FIG. 1 in the first embodiment has the same function. Here, a modulator used for a transmitter corresponding to a plurality of systems is considered. The baseband signal generation unit 11 determines a carrier frequency based on baseband signals corresponding to a plurality of systems. Next, the LOG function amplitude compression unit 18 compresses the amplitude of the carrier wave. Next, the carrier signal processing unit 12 extracts amplitude and phase data for each cycle of the carrier wave compressed by the LOG function amplitude compression unit 18.

  Next, the 1-bit signal generation unit 13 specifies a 1-bit signal sequence corresponding to the waveform of each cycle of the carrier wave based on the extracted amplitude and phase data, and each specified 1-bit signal sequence Are combined to generate a digital signal corresponding to the waveform of the carrier wave.

  Further, the digital signal composed of the 1-bit signal sequence is amplified by the output amplification stage 15, the amplitude is expanded by the EXP function amplitude expansion unit 19, the high frequency component is removed by the low pass filter 16, and modulated from the output terminal 1. Is output as a carrier wave.

  In the modulator 10b according to the eighth embodiment, the length of the 1-bit signal sequence is determined by the ratio between the minimum amplitude and the maximum amplitude of the signal. For example, when the minimum amplitude is 1, the maximum amplitude is 100. In this case, when the minimum amplitude is represented by one 1-bit signal, the maximum amplitude is represented by 100 1-bit signals. On the other hand, if the amplitude is LOG function compressed with a base of 10, if the minimum amplitude is represented by one 1-bit signal, the maximum amplitude can be represented by three 1-bit signals.

  Accordingly, the number of 1-bit signals generated by the 1-bit signal generation unit 13 is limited to three, and the processing amount of the 1-bit signal generation unit 13 is reduced. Further, since the clock frequency can be kept low by reducing the number of 1-bit signals, the load on the output amplification stage 15 whose processing speed depends on the clock frequency is also reduced. Then, since the amplitude of the signal is expanded by the EXP function amplitude expansion amplifying unit 19, a desired modulation signal can be obtained.

  In the eighth embodiment, the amplitude compression is a LOG function and the amplitude expansion is an EXP function. However, the present invention is not limited to this, and an arbitrary amplitude compression / amplitude expansion function may be used. For example, a function in which the amplitude of the output signal is 1 / N of the input may be used as the amplitude compression function, and a function in which the amplitude of the output signal is the Nth power of the input as a function of amplitude expansion.

  As described above, according to the eighth embodiment, the carrier wave for each period is extracted from the baseband signal to extract the amplitude and phase, and the clock signal having a frequency sufficiently higher than the carrier wave for each period is used to cope with the amplitude and phase. A modulated waveform is generated based on the 1-bit signal sequence. As a result, an arbitrary modulated carrier wave can be output, which is effective as a modulator used in a transmitter compatible with multimode and multiband.

  Furthermore, it is possible to optimize the dynamic range and the carrier frequency corresponding to the clock frequency of the carrier according to the system. Further, by using an output amplification stage using a switching amplifier, it is possible to realize low current consumption as a transmitter.

  Furthermore, since an arbitrary modulated carrier wave can be output, it is not necessary to prepare a circuit corresponding to each different communication system, and it is possible to reduce the size of the module.

  Furthermore, by using the amplitude compression unit and the amplitude expansion amplification unit, the length of the 1-bit signal sequence corresponding to the maximum amplitude can be suppressed, and the processing amount of the 1-bit signal generation unit 13 can be reduced. Furthermore, by reducing the number of 1-bit signals, the clock frequency can be kept low, and the load on the output amplification stage whose processing speed depends on the clock frequency can be reduced. Furthermore, since the amplitude of the signal is expanded by the amplitude expansion amplification unit, a desired modulation signal can be obtained.

Embodiment 9 FIG.
In the ninth embodiment, a case where a sine wave is used as a carrier wave in the same modulator as in the previous eighth embodiment will be described. The block diagram of modulator 10b in the ninth embodiment is the same as that in FIG. 7 in the previous eighth embodiment.

  By using a sine wave as a carrier wave, the DSP used in the 1-bit signal generation unit 13 can be made into a dedicated IC.

  As described above, according to the ninth embodiment, by limiting the carrier wave waveform to a sine wave, the DSP unit can be made into a dedicated IC, and in addition to the effects of the previous eighth embodiment, digital processing is facilitated. Thus, the processing speed can be increased.

Embodiment 10 FIG.
FIG. 8 is a block diagram of the modulator according to the tenth embodiment of the present invention. The modulator 10c includes a baseband signal generation unit 11, an amplitude error adjustment unit 20, a LOG function amplitude compression unit 18, a carrier signal processing unit 12, a digital signal processing unit 14 including a 1-bit signal generation unit 13, a switching amplifier, and the like. The output amplification stage 15, the EXP function amplitude expansion amplification unit 19, the low-pass filter 16, and the output terminal 1. The modulator 10c of FIG. 8 in the tenth embodiment is different from the modulator 10b of FIG. 7 in the previous eighth embodiment in that it further includes an amplitude error adjusting unit 20.

Next, the operation will be described. Each circuit portion to which the same reference numeral as in FIG. 7 in the previous embodiment 8 has the same function. Assuming that the carrier wave for one cycle in the previous second embodiment is Asint, the carrier wave for one cycle in the previous eighth embodiment is the function of the LOG function amplitude compression unit 18 and the EXP function amplitude expansion amplification unit 19. The following formula.
exp (logAsin t) = B ₁ sin t + B ₂ sin ² t +.

The harmonic component is removed by a low-pass filter, but a difference occurs in the amplitude of the carrier wave. Therefore, the amplitude error adjustment unit 20 in the tenth embodiment corrects the amplitude so that B ₁ sin t becomes Asin t. Thereby, also in the modulator using the LOG function amplitude compression unit 18 and the EXP function amplitude expansion amplification unit 19, the carrier for one period is set to the same as the carrier generated by the baseband signal generation unit 11. be able to.

  As described above, according to the tenth embodiment, in addition to the effect of the previous eighth embodiment, even when a LOG function amplitude compression unit and an EXP function amplitude expansion amplification unit are added, the same amplitude as that when not added is obtained. A modulated wave can be obtained.

Embodiment 11 FIG.
In the eleventh embodiment, a case where a sine wave is used as a carrier wave in the same modulator as in the tenth embodiment will be described. The block diagram of modulator 10c in the eleventh embodiment is the same as FIG. 8 in the previous tenth embodiment.

  By using a sine wave as a carrier wave, the DSP used in the 1-bit signal generation unit 13 can be made into a dedicated IC.

  As described above, according to the eleventh embodiment, by limiting the carrier wave waveform to a sine wave, it is possible to make the DSP unit a dedicated IC, and in addition to the effects of the tenth embodiment, digital processing is facilitated. Thus, the processing speed can be increased.

Embodiment 12 FIG.
FIG. 9 is a block diagram of a modulator according to the twelfth embodiment of the present invention. The modulator 10d includes a baseband signal generation unit 11, a LOG function amplitude compression unit 18, carrier signal processing units 12a and 12b, and 1-bit signal generation units 13a and 13b, digital signal processing units 14a and 14b, switching amplifiers, and the like. Output amplification stages 15a and 15b, EXP function amplitude expansion amplification sections 19a and 19b, low-pass filters 16a and 16b, a combiner 17 and an output terminal 1.

  The modulator 10d in FIG. 9 in the twelfth embodiment has two circuits from the carrier signal processing unit 12 to the low-pass filter 16 as compared with the modulator 10b in FIG. 7 in the previous eighth embodiment. In addition, the difference is that a synthesizer 17 is further provided.

  In FIG. 9, the two systems are shown as separate configurations, but for example, the functions of the two systems of the carrier signal processing units 12 a and 12 b can be configured as one carrier signal processing unit 12. It is. In this case, the carrier signal processing unit 12a corresponds to the first carrier signal processing unit, and the carrier signal processing unit 12b corresponds to the second carrier signal processing unit.

  Next, the operation will be described. Each circuit unit to which the same reference numerals as those in FIG. 3 in the previous third embodiment and FIG. 7 in the previous eighth embodiment have the same functions. The baseband signal generated by the baseband signal generation unit 11 is subjected to LOG function amplitude compression by the LOG function amplitude compression unit 18, divided into a positive potential signal and a negative potential signal, and processed in parallel by two circuits in the subsequent stage. The The output signals of the two systems are finally combined by the combiner 17 to obtain a desired modulated carrier wave.

  As described above, according to the twelfth embodiment, even when a modulator having two systems is used, the same effects as those of the eighth embodiment can be obtained. Furthermore, by processing the positive potential output signal and the negative potential output signal in parallel using two systems, it is possible to reduce the load on the digital circuit unit and realize further speedup.

Embodiment 13 FIG.
In the thirteenth embodiment, a case will be described where, in the same modulator as in the previous twelfth embodiment, half waves of sine waves are used as the positive potential output signal and the negative potential output signal which are carrier waves. The block diagram of modulator 10d in the thirteenth embodiment is the same as FIG. 9 in the previous twelfth embodiment.

  Here, the modulator 10d according to the thirteenth embodiment is characterized in that each carrier wave processed by the carrier wave signal processing units 12a and 12b is a half wave of a sine wave. By using a half wave of a sine wave as a carrier wave, the DSP used in the 1-bit signal generators 13a and 13b can be made into a dedicated IC as in the previous twelfth embodiment.

  As described above, according to the thirteenth embodiment, by limiting the carrier wave waveform to a half wave of a sine wave, the DSP unit can be made into a dedicated IC. In addition to the effects of the previous twelfth embodiment, Processing can be facilitated and processing speed can be increased.

Embodiment 14 FIG.
FIG. 10 is a block diagram of a modulator according to the fourteenth embodiment of the present invention. The modulator 10e includes a digital signal processing unit 14a including a baseband signal generation unit 11, an amplitude error adjustment unit 20, a LOG function amplitude compression unit 18, carrier wave signal processing units 12a and 12b, and 1-bit signal generation units 13a and 13b. , 14b, output amplifier stages 15a and 15b including switching amplifiers, EXP function amplitude expansion amplifying units 19a and 19b, low-pass filters 16a and 16b, a combiner 17 and an output terminal 1. The modulator 10e of FIG. 10 in the fourteenth embodiment is different from the modulator 10d of FIG. 9 in the previous twelfth embodiment in that it further includes an amplitude error adjusting unit 20.

  Next, the operation will be described. Each circuit portion denoted by the same reference numeral as in FIG. 9 in the previous twelfth embodiment has the same function. In addition, the amplitude error adjusting unit 20 has the same function as that shown in the tenth embodiment. That is, also in the modulator using the LOG function amplitude compression unit 18 and the EXP function amplitude expansion amplification units 19a and 19b, the carrier wave for one cycle is assumed to be an Asint equivalent to the carrier wave generated by the baseband signal generation unit 11. can do.

  As described above, according to the fourteenth embodiment, in addition to the effects of the previous twelfth embodiment, even when a LOG function amplitude compression unit and an EXP function amplitude expansion amplification unit are added, the amplitude is the same as when no addition is performed. A modulated wave can be obtained.

Embodiment 15 FIG.
In the fifteenth embodiment, a case will be described in which a half wave of a sine wave is used as a positive potential output signal and a negative potential output signal that are carrier waves in the same modulator as in the previous fourteenth embodiment. The block diagram of modulator 10e in the fifteenth embodiment is the same as FIG. 10 in the previous fourteenth embodiment.

  Here, the modulator 10e according to the fifteenth embodiment is characterized in that each carrier wave processed by the carrier wave signal processing units 12a and 12b is a half wave of a sine wave. By using a half wave of a sine wave as a carrier wave, the DSP used in the 1-bit signal generators 13a and 13b can be made into a dedicated IC as in the case of the previous embodiment 14.

  As described above, according to the fifteenth embodiment, by limiting the carrier wave waveform to a half wave of a sine wave, the DSP unit can be made into a dedicated IC. In addition to the effects of the previous fourteenth embodiment, Processing can be facilitated and processing speed can be increased.

Embodiment 16 FIG.
In the sixteenth embodiment, the modulator 10b shown in the previous eighth and ninth embodiments, the modulator 10c shown in the previous tenth and eleventh embodiments, and the modulator shown in the previous twelfth and thirteenth embodiments. 10d or a case where the modulator 10e shown in the previous fourteenth and fifteenth embodiments is connected in parallel will be described. FIG. 11 is a block diagram of a modulator according to the sixteenth embodiment of the present invention, which includes two modulators 10b / 10c / 10d / 10e, a synthesizer 17, and an output terminal 1 that are connected in parallel.

  Next, the operation will be described. Each of the two modulators 10b / 10c / 10d / 10e connected in parallel performs a modulation operation on the I signal and Q signal of the baseband signal. The analog waveforms output from each are combined by the combiner 17 and output from the output terminal 1. By adopting such a parallel configuration, the modulator of the sixteenth embodiment can function as a quadrature modulator.

  As described above, according to the sixteenth embodiment, the effects of the previous eight to fifteenth embodiments are obtained by performing the modulation operation on the I signal and the Q signal of the baseband signal using the modulators connected in parallel. In addition, it can have the same function as a quadrature modulator. As a result, it is possible to realize a modulator that can obtain a desired modulation signal even for a multiple phase modulation system.

Embodiment 17. FIG.
In the seventeenth embodiment, a case will be described in which the modulators 10b, 10c, 10d, or 10e described in the previous eighth to fifteenth embodiments are applied to a transmitter. The block diagram of the transmitter including the modulator in the seventeenth embodiment is the same as that in FIG. 5 in the sixth embodiment. This transmitter includes a digital data input terminal 2, a modulator 21, an oscillator 22 that determines a carrier frequency, a high-power amplifier 23, a bandpass filter 24, and an output terminal 1. Here, the modulator 21 corresponds to the modulators 10b, 10c, 10d or the modulator 10e in the previous eighth to fifteenth embodiments.

  The oscillator 22 can determine a desired carrier frequency and provide it to the modulator 21 according to different communication systems. The baseband signal generation unit in the modulator 21 can generate a baseband signal based on a desired carrier frequency given by the modulator 21. As a result, the modulator 21 can support any communication system.

  As described above, according to the seventeenth embodiment, in a transmitter compatible with multimode and multiband, circuits corresponding to different communication systems are prepared by combining an oscillator with the modulator of the present invention. There is no need, and a transmitter that realizes downsizing of the module can be obtained.

  In addition, although the circuit block as a transmitter was shown in Embodiment 17, the receiver may be incorporated and the same effect can be acquired.

Embodiment 18 FIG.
In the eighteenth embodiment, a case will be described in which the modulator 10b, 10c, 10d, or 10e described in the eighth to fifteenth embodiments is applied to a transmitter capable of increasing the carrier frequency. The block diagram of the transmitter including the modulator in the eighteenth embodiment is the same as FIG. 6 in the previous seventh embodiment. This transmitter is different from the transmitter according to the seventeenth embodiment in that a frequency converter 25 is further provided between the modulator 21 and the high-power amplifier 23.

  Next, the operation will be described. The frequency converter 25 converts the output signal of the modulator 21 to a frequency corresponding to the system based on a desired carrier frequency determined by the oscillator 22 according to a different communication system. The frequency-converted signal is amplified by the high output amplifier 23 and further output from the output terminal 1 via the band pass filter 24.

  As described above, according to the eighteenth embodiment, in a transmitter compatible with multimode and multiband, by combining an oscillator and a frequency converter with the modulator of the present invention, circuits corresponding to different communication systems can be provided. There is no need to prepare the transmitter, and a transmitter that realizes downsizing of the module can be obtained. Further, by changing the output frequency of the modulator using a frequency converter, the carrier frequency can be increased, and multibanding is facilitated.

  Note that although a circuit block as a transmitter is shown in Embodiment 18, a receiver may be built in, and the same effect can be obtained.

It is a block diagram of the modulator in Embodiment 1, 2 of this invention. It is the figure which showed typically the signal of each part of ad shown in FIG. 1 in Embodiment 1, 2 of this invention. It is a block diagram of the modulator in Embodiment 3 and 4 of this invention. It is a block diagram of the modulator in Embodiment 5 of this invention. It is a block diagram of a transmitter including a modulator in Embodiments 6 and 17 of the present invention. It is a block diagram of a transmitter including a modulator in Embodiments 7 and 18 of the present invention. It is a block diagram of the modulator in Embodiment 8 and 9 of this invention. It is a block diagram of the modulator in Embodiment 10, 11 of this invention. It is a block diagram of the modulator in Embodiment 12, 13 of this invention. It is a block diagram of the modulator in Embodiment 14 and 15 of this invention. It is a block diagram of the modulator in Embodiment 16 of this invention. It is a block diagram of the conventional 1st modulator. It is a block diagram of the 2nd conventional modulator. It is a block diagram of the conventional 3rd modulator.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Output terminal 2 Digital data input terminal 10, 10a, 10b, 10c, 10d, 10e Modulator, 11 Baseband signal generation part, 12 Carrier wave signal processing part, 12a Carrier wave signal processing part (1st carrier wave signal processing part ), 12b Carrier wave signal processor (second carrier signal processor), 13, 13a, 13b Bit signal generator, 14 Digital signal processor, 14a Digital signal processor (first digital signal processor), 14b Digital Signal processing unit (second digital signal processing unit), 15, 15a, 15b Output amplification stage (output amplification unit), 16, 16a, 16b Low-pass filter, 17 combiner, 18 LOG function amplitude compression unit (amplitude compression unit) , 19 EXP function amplitude expansion amplification unit (amplitude expansion amplification unit), 20 amplitude error adjustment unit, 21 modulator, 22 oscillator, 2 High power amplifier, 24 a band pass filter, 25 a frequency converter.

Claims (14)

A baseband signal generation unit that generates a baseband signal configured by superposing carrier waves corresponding to the system;
A carrier signal processor that extracts the amplitude and phase of each carrier period based on the baseband signal;
Based on the amplitude and the phase for each carrier period extracted by the carrier signal processing unit, a 1-bit signal sequence corresponding to the carrier for each period is specified, and a digital signal corresponding to the baseband signal is generated A modulator comprising: a digital signal processing unit. The modulator of claim 1, wherein
The modulator further comprising an output amplifying unit for switching and amplifying the digital signal generated by the digital signal processing unit. The modulator according to claim 1 or 2,
The baseband signal generation unit generates a baseband signal by superimposing a carrier wave that is a sine wave,
The carrier signal processing unit extracts the amplitude and the phase using the carrier wave whose waveform for each carrier period is a sine wave,
The modulator characterized in that the digital signal processing unit specifies the 1-bit signal series based on the carrier wave that is a sine wave. The modulator according to claim 1 or 2,
A synthesizer for synthesizing a plurality of modulated signals;
The baseband signal generation unit outputs the generated baseband signal divided into a positive potential output signal and a negative potential output signal,
The carrier signal processing unit extracts a first carrier wave signal processing unit that extracts an amplitude and a phase for each carrier cycle based on the positive potential output signal, and an amplitude and phase for each carrier cycle based on the negative potential output signal. A second carrier signal processing unit to extract,
The digital signal processing unit generates a first digital signal corresponding to the positive potential output signal based on the amplitude and phase of each carrier cycle extracted by the first carrier signal processing unit. Second digital signal processing for generating a second digital signal corresponding to the negative potential output signal based on the amplitude and phase of each carrier cycle extracted by the signal processing unit and the second carrier signal processing unit And
The synthesizer generates a modulation signal corresponding to the baseband signal by combining a modulation signal based on the first digital signal and a modulation signal based on the second digital signal. . The modulator of claim 4, wherein
The baseband signal generation unit generates a baseband signal by superimposing a carrier wave that is a sine wave, and divides the generated baseband signal into a positive potential output signal and a negative potential output signal that are half waves of a sine wave. Output,
The first carrier signal processing unit and the second carrier signal processing unit in the carrier signal processing unit receive the positive potential output signal and the negative potential output signal in which the waveform for each carrier cycle is a half wave of a sine wave. To extract the amplitude and phase respectively,
The first digital signal processing unit and the second digital signal processing unit in the digital signal processing unit are each a 1-bit signal based on the positive potential output signal and the negative potential output signal which are half waves of a sine wave A modulator characterized by identifying a series. The modulator of claim 2, wherein
An amplitude compression unit that compresses the amplitude of the baseband signal generated by the baseband signal generation unit;
An amplitude expansion amplifying unit that expands the amplitude of the digital signal that is switched and amplified by the output amplification unit, and
The modulator, wherein the carrier signal processing unit extracts an amplitude and a phase for each carrier period based on the baseband signal whose amplitude is compressed by the amplitude compression unit. The modulator of claim 6, wherein
The baseband signal generation unit generates a baseband signal by superimposing a carrier wave that is a sine wave,
The amplitude compression unit compresses the amplitude of the baseband signal generated by the baseband signal generation unit,
The carrier wave signal processing unit extracts the amplitude and the phase using the carrier wave whose waveform for each carrier wave period is a sine wave,
The modulator characterized in that the digital signal processing unit specifies the 1-bit signal sequence based on the carrier wave that is a sine wave. The modulator according to claim 6 or 7,
An amplitude error adjustment unit that corrects the amplitude of the baseband signal so that the amplitude after expansion by the amplitude expansion amplification unit becomes equal to the amplitude of the baseband signal generated by the baseband signal generation unit;
The modulator, wherein the amplitude compression unit compresses the amplitude of the baseband signal corrected by the amplitude error adjustment unit. The modulator of claim 6, wherein
A synthesizer for synthesizing a plurality of modulated signals;
The amplitude compression unit outputs a baseband signal whose amplitude is compressed by dividing it into a positive potential output signal and a negative potential output signal,
The carrier signal processing unit extracts a first carrier wave signal processing unit that extracts an amplitude and a phase for each carrier cycle based on the positive potential output signal, and an amplitude and phase for each carrier cycle based on the negative potential output signal. A second carrier signal processing unit to extract,
The digital signal processing unit generates a first digital signal corresponding to the positive potential output signal based on the amplitude and phase of each carrier cycle extracted by the first carrier signal processing unit. Second digital signal processing for generating a second digital signal corresponding to the negative potential output signal based on the amplitude and phase of each carrier cycle extracted by the signal processing unit and the second carrier signal processing unit And
The output amplifying unit is configured to switch and amplify the first digital signal generated by the first digital signal processing unit, and the first output amplifying unit generated by the second digital signal processing unit. A second output amplifier for switching and amplifying the two digital signals,
The amplitude expansion amplifying unit is switched and amplified by a first amplitude expansion amplifying unit that expands an amplitude of the first digital signal that is switching-amplified by the first output amplification unit, and the second output amplification unit. A second amplitude expansion amplifying unit for expanding the amplitude of the second digital signal;
The synthesizer synthesizes a modulation signal based on the first digital signal output from the first amplitude expansion amplification unit and a modulation signal based on the second digital signal output from the second amplitude expansion amplification unit. To generate a modulation signal corresponding to the baseband signal. The modulator of claim 9, wherein
The amplitude compression unit compresses the amplitude of the baseband signal generated by the baseband signal generation unit, and converts the compressed baseband signal into a positive potential output signal and a negative potential output signal that are half waves of a sine wave. Output separately,
The first carrier signal processing unit and the second carrier signal processing unit in the carrier signal processing unit receive the positive potential output signal and the negative potential output signal in which the waveform for each carrier cycle is a half wave of a sine wave. To extract the amplitude and phase respectively,
The first digital signal processing unit and the second digital signal processing unit in the digital signal processing unit are each a 1-bit signal based on the positive potential output signal and the negative potential output signal which are half waves of a sine wave A modulator characterized by identifying a series. The modulator according to claim 9 or 10,
The amplitude after the expansion by the first amplitude expansion amplification unit and the second amplitude expansion amplification unit in the amplitude expansion amplification unit is equal to the amplitude of the baseband signal generated by the baseband signal generation unit. An amplitude error adjustment unit for correcting the amplitude of the baseband signal;
The modulator, wherein the amplitude compression unit compresses the amplitude of the baseband signal corrected by the amplitude error adjustment unit. A modulator having a configuration in which two modulators according to any one of claims 1 to 11 are connected in parallel,
A synthesizer that synthesizes the output signals of the respective modulators connected in parallel;
The first modulator processes the I signal of the baseband signal,
The second modulator processes the Q signal of the baseband signal,
The synthesizer generates a modulation signal corresponding to the baseband signal by synthesizing a modulation signal from the first modulator and a modulation signal from the second modulator. . The modulator according to any one of claims 1 to 12,
An oscillator that outputs a desired carrier frequency according to the system;
The modulator, wherein the baseband signal generation unit generates the baseband signal based on the desired carrier frequency. The modulator of claim 13.
A modulator further comprising: a frequency converter that converts a modulated output signal into a frequency corresponding to a system based on the desired carrier frequency output from the oscillator.

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