JPH1093475A - Composite system shared terminal equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio equipment shaped by a plurality of systems with a small size and simple configuration that has provision for systems where modulation system, transmission speed, access system, radio frequency and signal band differ from each other. SOLUTION: In the terminal equipment, a reference carrier wave signal from a 1st signal generator 110 to be provided to a reception mixer pair 103 and a transmission mixer pair 109 is made variable so as to allow the terminal equipment to have provision for a plurality of radio frequencies and a frequency from a 2nd signal generator 111 to be fed to a digital system 112 including an A/D converter 105 and a D/A converter 107 is made variable to have provision for different transmission speeds and different channel band signals. Furthermore, the frequency characteristics of analog filters 104, 108 is made variable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a portable telephone and a PHS
The present invention relates to a wireless communication terminal used in a wireless communication system such as the above, and particularly to a complex system shared terminal that can be shared by a plurality of wireless communication systems.

[0002]

2. Description of the Related Art In recent years, PHS (Personal Ha) has been developed.
ndyphone System), PDC (Pers
Services of a plurality of mobile communication systems such as an online digital cellar (PC) and a pager are provided. In the future, demand for terminals (multimedia terminals) that can be shared by these multiple systems is expected to increase. These systems use different modulation schemes, transmission speeds, access schemes, radio frequencies, and signal bands, so that the hardware of the corresponding radios is also different.

For example, the PHS employs a transmission speed of 384 kbps and a radio frequency band of 1.9 GHz, and the PDC employs a transmission speed of 21 kbps and a radio frequency band of 1.5 GHz. As shown in FIG. 15, it is assumed that the wireless terminals that can communicate with the plurality of wireless systems separately incorporate the respective systems.

FIG. 16 shows a specific example of an assumed complex system shared terminal (two systems shared in this example). Here, the receiving system is shared with the low-noise amplifier 1 for reception, and the subsequent stage is an RF filter 3, a second mixer 7 for down-converting an RF signal to an intermediate frequency, and a mixer 7 as a receiving system used in the first system. It comprises a filter 11 for removing signals in unnecessary bands from the output, and a second mixer 20 for further down-converting the output signal of the filter 11 to a frequency that can be handled by the digital signal processing unit 18. The receiving system used for the second system is composed of the RF filter 4, the mixer 8, the filter 12, and the second mixer 14, similarly to the receiving system used for the first system.

[0005] One transmission system shares the transmission power amplifier 2 in the last stage, and the preceding stage, as a transmission system used in the first system, increases the output signal of the digital signal processing unit 18 to the first intermediate frequency. It comprises a mixer 21 for converting, a filter 19 for removing a signal of an unnecessary band from the output of the mixer 21, a mixer 9 for up-converting an IF signal into an RF signal, and a transmission RF filter 5. Second
Similarly to the transmission system used in the first system, the mixer 15, the filter 13, and the mixer 1
0, a transmission RF filter 6.

[0006] The first synthesizer 22 supplies a local signal to the mixers 7 and 9. The second synthesizer 16 supplies a local signal to the mixers 8, 10. The third synthesizer 17 includes mixers 20, 14,
A local signal is supplied to 21 and 15. The digital signal processing unit 18 demodulates the received signal whose frequency has been converted to a low frequency, modulates the transmission signal, and outputs a modulated signal.

Next, the operation of the conventional complex system shared terminal configured as described above will be described.

In a conventional complex system shared terminal,
Two systems are prepared in advance for the two systems, one for the transmission system and the other for the reception system, and the switches are switched according to the system to be used so as to correspond to each system. For example, here, the first system is a PHS (1.9 GHz band), and the second system is a digital cellular phone (1.5 GHz band).
z band). PHS is a TDD system, and the transmission frequency and the reception frequency are the same. The mobile phone uses the FDD system, and the transmission frequency and the reception frequency are detuned by about 50 MHz. When the PHS is used, a desired signal is obtained by operating the first synthesizer 22 to supply a signal of, for example, 1.65 GHz to the reception mixer 7 and the transmission mixer 9. The received signal is frequency-converted again by the mixer 20 through the filter 11, input to the digital signal processing unit 18 and demodulated.

In the transmission system, the signal modulated by the digital signal processing unit 18 is frequency-converted to an intermediate frequency by a mixer 21 and input to a mixer 9 through a filter 19. The third synthesizer 17 includes the mixers 20 and 2
By supplying a local signal to 1, 2 in the receiving system
The 50 MHz IF signal is converted into a 10 MHz signal, and the transmission system converts the 10 MHz modulated signal into a 250 MHz IF signal. On the other hand, when a mobile phone is used, a desired signal is obtained by operating the synthesizer 16 and supplying a signal of, for example, 1.2 GHz to the reception mixer 8 and the transmission mixer 10. The received signal is frequency-converted again by the mixer 14 through the filter 12, input to the digital signal processing unit 18, and demodulated. The signal modulated by the digital signal processing unit 18 is frequency-converted to an intermediate frequency by the mixer 15, and is input to the mixer 10 through the filter 13. The third synthesizer 17 includes the mixer 14
By supplying a local signal to the signals 15 and 15, the receiving system converts the 250 MHz IF signal into a 40 MHz signal, and the transmitting system converts the 10 MHz modulated signal into a 250 MHz IF signal.

Here, focusing on the transmission power amplifier 2, the problem of the conventional complex system shared terminal will be described.

[0011] The transmission power amplifier 2 in the complex system shared terminal
When using the same frequency band with the same output, it is possible to cope by adjusting the band of the matching circuit. However, when the output power of the first system is different from the output power of the second system, it is necessary to adjust the power so that the output power is within a predetermined standard value. At this time, adding an attenuator lowers the power efficiency. In addition, the transmission output defines the unnecessary radiation power inside and outside the band according to the system specifications,
There are cases where the amplifier is used under different bias conditions such as linear operation and saturation operation based on the specifications. Therefore, it is generally difficult to use the transmission power amplifier 2 according to other system specifications.

Next, when focusing on the synthesizer,
The conventional complex system shared terminal has the following disadvantages.

That is, two synthesizers are required, a first synthesizer for operating the first system and a second synthesizer for operating the second system. Synthesizer 1 for generating a third second local
7 can be shared by the first and second systems, but the first local oscillation frequency is the frequency difference between the two systems (in the example, the frequency difference between the PHS and the mobile phone).
2 synthesizers for each system
You need one. Also, to avoid such problems,
By using different frequencies for the first IF in the two systems, it is possible to use one synthesizer that oscillates the first local. However, in this case, the oscillating frequency of the synthesizer that oscillates the second local is different. Therefore, two systems of the second local synthesizers are required for the two systems, and the same problem occurs.

Conventionally, as shown in Japanese Patent Application Laid-Open No. 61-236204, a direct conversion system is used only on the receiving side. There was an example of trying to support the system. However, in the above invention, only the configuration of the receiving system is given,
Further, the mere change of the digital filter band and the clock speed cannot cope with a plurality of wireless communication systems having different transmission speeds. That is, an analog filter for preventing aliasing is required after and before the A / D converter and the D / A converter, and the band characteristics also need to be variable.

[0015]

As described above,
The conventional complex system shared terminal has various problems. Therefore, when trying to receive the services of a plurality of wireless communication systems, the user must have as many wireless devices as the number of systems, which is not practical from the viewpoint of portability.

The present invention has been made in view of such conventional problems, and has as its object to cope with systems having different modulation schemes, transmission speeds, access schemes, radio frequencies, and signal bands. An object of the present invention is to provide a small-sized and simple-structured radio for multiple system use.

Specifically, a composite system shared terminal capable of solving the following problems is provided. That is, when designing a complex system shared terminal, in the circuit design of the radio unit, there is a problem that the current consumption is increased and the design becomes difficult by reducing the volume.

An object of the present invention is to provide a complex system shared terminal which can be designed relatively easily and consumes low power.

Further, in the conventional multi-system shared terminal, there is a problem that the terminal itself is enlarged by mounting a radio unit for transmission and reception for each of a plurality of systems.
Further, there is a problem that when the transmission power is low for each system when the transmission power is different for each system by using a common power amplifier, the transmission must be performed in a situation where the power efficiency is poor. Also, due to the problem of distortion of the amplifier, when amplifying with the first-stage amplifier and the next amplifier, the amplification is performed in the next stage, including the power that generated the same distortion as in direct transmission in the first stage, resulting in large distortion. There was a problem.

The present invention eliminates the above-mentioned drawbacks of the prior art and provides a means for sharing an amplifier while maintaining linearity for a plurality of systems and efficiently amplifying the amplifier itself according to the system. It is the purpose.

Further, from the viewpoint of sharing a synthesizer, the first system must be used to support two systems.
Two synthesizers for Cull are required. Alternatively, there is a problem that two synthesizers for generating the second local are required. This has resulted in increasing the power consumption of the terminal and increasing the volume of the terminal.

In the complex system shared terminal according to the present invention,
It is an object of the present invention to provide a complex system shared terminal capable of supporting two systems without increasing the number of synthesizers.

[0023]

In order to solve the above-mentioned conventional problems, a complex system common use terminal according to the present invention comprises a receiving mixer for mixing a reference signal and converting a received signal into a baseband signal; A variable-bandwidth receiving filter that allows the baseband signal to pass therethrough, and a baseband signal that has passed through the receiving filter is converted to a digital signal and demodulated while operating in response to an operation clock; Digital signal processing means for generating an analog signal and converting the signal to an analog signal, a transmission filter capable of passing the analog signal with a variable pass bandwidth, and transmitting the analog signal mixed with the reference signal and passing through the transmission filter. Depending on the transmission mixer that converts to a signal and the radio frequency, signal band, and transmission speed of the wireless communication system used, The reference signal, the pass bandwidth, and means for setting the operating clock.

According to another aspect of the present invention, there is provided a multi-system shared terminal, comprising: a clock generating means for generating first and second reference signals; and a reception signal in a first frequency band mixed with the first reference signal. A first transmission / reception system comprising: a reception mixer that converts the signal into a baseband signal; and a transmission mixer that mixes with the first reference signal to convert the baseband signal into a transmission signal in a first frequency band. A first-stage reception mixer that mixes the received signal in the second frequency band into an intermediate frequency signal by mixing with the first reference signal; and mixes the intermediate frequency signal into a predetermined frequency signal by mixing with the second reference signal. A second-stage receiving mixer for converting, a first-stage transmitting mixer for mixing with the second reference signal to convert a predetermined frequency signal to an intermediate frequency signal, and a first-stage transmitting mixer for mixing with the first reference signal; In the second round ; And a second transceiver system having a second-stage transmission mixer for converting the number band transmission signal.

More specifically, the present invention relates to a complex system shared terminal used in a plurality of wireless communication systems having at least different radio frequencies, signal bands, and transmission speeds,
A pair of reception mixers for directly converting a reception signal into a baseband band by a reference carrier having substantially the same frequency as the radio frequency of the reception signal, and a reception baseband for removing a high-frequency component of an output of the mixer pair A filter, an A / D converter for converting the analog signal output from the baseband filter into a digital signal, a digital signal processing unit for demodulating the output of the A / D converter to generate a digital modulation signal, D for converting the digitally modulated signal into an analog baseband signal
A / A converter, a transmission baseband filter for removing high frequency components of the analog baseband signal output from the D / A converter, and a reference carrier having substantially the same frequency as the radio frequency. A pair of transmission mixers for directly converting the frequency to a transmission signal in a radio frequency band, and a first frequency variable signal generator for supplying a reference carrier having substantially the same frequency as the radio frequency to the transmission and reception mixers; A second variable frequency signal generator for supplying a sampling clock to the digital signal processing unit, wherein the oscillation frequency of the first variable frequency signal generator is The oscillation frequency of the second frequency-variable signal generator is variable following the transmission / reception signal frequency, The transmission and reception baseband filters are variable in accordance with the data transmission rate of the communication system, and the transmission and reception baseband filters are variable in accordance with the transmission / reception signal band or the sampling clock frequency supplied from the second frequency variable signal generator. Is set so that

In a preferred embodiment of the invention described above,
The reference signals supplied to the first variable frequency signal generator and the second variable frequency signal generator are supplied from a common reference signal generator.

According to another aspect of the present invention, there is provided a composite system shared terminal used in a plurality of wireless communication systems having different transmission speeds, wherein the transmission system baseband signal processing system has the maximum transmission speed. And a low-pass filter using an oversampling D / A converter using a sampling clock based on the wireless communication system. The present invention is a slightly simplified version of the clock system of the above invention. That is, the clock input to the D / A converter is:
A clock frequency is determined by determining an oversampling ratio based on the higher of the transmission rate of the first system and the transmission rate of the second system. Therefore, regardless of which system is selected, the clock frequency can be fixed and shared. For this reason, the same filter cutoff frequency can be used regardless of the system connected to the subsequent stage of the D / A converter. Therefore, it is possible to realize a filter without selecting a filter or using a variable filter, and it is possible to simplify the design.

According to another aspect of the present invention, there is provided a multi-system common terminal in which different radio system terminals are multiplied by multiplying a first frequency and a first frequency different from the first frequency including DC. And generating a local signal.

In a preferred embodiment of the present invention, the first frequency and the first different frequency obtained as a result of multiplying the multiplied local signal by the first frequency and the first different frequency including direct current are added. The number of band-pass filters that pass the set frequencies is input to filters connected in parallel by the number of different systems, and the output is input to the modulator.

In a preferred embodiment of the present invention, a power amplifier and an antenna prepared for each different radio communication system are used.

In a preferred embodiment of the present invention, a power amplifier and an antenna to be used are selected based on a conduction / shutoff operation of a power supply of the power amplifier. Another invention of a complex system shared terminal according to the present invention is a complex system shared terminal used in two wireless communication systems having different terminal transmission outputs, wherein the first wireless communication system has the lowest terminal transmission output. Corresponding first
And a first power amplifier having a gain over the band of the second wireless communication system, and a second wireless amplifier outputting a second output level greater than the first output level. And a power amplifier having a gain with respect to the band of the communication system, wherein the output of the first power amplifier can be taken out between the first and second power amplifiers. In the present invention, an amplifier is shared by a plurality of systems, and a high-efficiency multiple-system transmission unit is provided. In addition, the input power of the shared amplifier is adjusted according to each system, thereby realizing an amplifier with less distortion for a linear system. Therefore, there is an effect that a complex system shared terminal with low power consumption can be realized.

Another aspect of the present invention is a composite system shared terminal used in two wireless communication systems, a wireless communication system having the same transmission / reception frequency and a wireless communication system having a different transmission / reception frequency. The wireless system used in a wireless communication system having the same transmission and reception frequency is a direct conversion system, the wireless system used in a wireless communication system having a different transmission and reception frequency is a superheterodyne system, and the oscillation frequency of the synthesizer is the same as the transmission and reception frequency. The transmission and reception frequencies of the same wireless communication system are set.

[0033]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a multi-system shared terminal according to the present invention.

First, a first embodiment of the complex system shared terminal according to the present invention, that is, an embodiment relating to a radio unit having a simple configuration will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a preferred embodiment of a complex system shared terminal according to the present invention.

First, the configuration and operation principle of the receiving section will be described. The signal received by the transmitting / receiving antenna 101 is transmitted to a duplexer (or a duplexer) 1
After passing through 02, the reference signal having substantially the same frequency as the reception signal supplied from the local oscillator 110 is mixed by the reception mixer 103, and directly frequency-converted into a baseband signal. Here, a phase difference of π / 2 is given to the reference signal supplied to each mixer of the reception mixer pair 103 or the reception signal input to each mixer pair. The I and Q outputs frequency-converted into baseband signals by the reception mixer pair 103 are band-limited by the reception baseband filter pair 104. The filter pair 104 is provided to prevent the A / D converter 105 from being saturated by an interference wave other than the desired wave, and to provide an anti-aliasing function at the preceding stage of the A / D converter 105. The digital signal processing unit 106 performs signal processing such as digital modulation / demodulation processing, channel codec, voice codec, and TDMA processing. Although not shown in FIG. 1, the duplexer 10
A low-noise amplifier and a high-frequency filter may be inserted between the stage of the receiving mixer pair 103 and the receiving mixer 103. The low-noise amplifier, the high-frequency filter, and the duplexer 102 have frequency characteristics that are passbands in the frequency bands of all wireless communication systems handled by the shared terminal.

Next, the configuration and operating principle of the transmitting section will be described. The transmitting section converts the digital I and Q baseband signals generated by the digital signal processing section 106 into analog signals with the D / A converter 107. As the D / A converter 107, a normal D / A converter, a ΔΣ-type oversampling type, or the like is used. D / A converter 107
The latter filter 108 is for removing aliasing noise generated in the D / A converter 107, and may be one having a low-pass characteristic. Generally, if an oversampling type D / A converter is used, the aliasing noise component is reduced to a normal D / A converter.
It is possible to increase the frequency in the high frequency range by the oversampling frequency as compared with the case where the A converter is used. Therefore, if the current consumption of the oversampling type D / A converter is not a problem, the oversampling type D / A converter which can constitute the aliasing noise removing filter 108 with a low order is used in the radio equipment. This is advantageous for miniaturization as a whole. Filter 10
The transmission baseband signal that has passed through 8 is
Are frequency-converted directly from the baseband frequency band to the radio frequency band. Here, although not shown, π between local signals supplied to the mixer pair 109 or between baseband IQ signals.
/ 2 phase difference is given in advance. The transmission signal that has been frequency-converted into the wireless carrier band is radiated from the antenna 101 into the air after passing through the duplexer 102.

In the complex system shared terminal, the radio frequency, the signal bandwidth, the transmission speed, and the like need to be variable corresponding to a plurality of different systems.

In this complex system shared terminal, it is assumed that the antenna 101, the duplexer 102, and the receiver mixer pair 103 have wideband characteristics and can be used in a plurality of wireless communication systems included in these bands. ing.

In order to support a plurality of radio frequencies, a transmission and reception frequency converter, that is, a reception mixer pair 10
3. First signal generator 1 to be supplied to transmission mixer pair 109
The reference carrier signal from 10 needs to be variable. Since the transmission / reception system of the complex system common terminal uses the direct conversion method, the oscillation frequency of the local oscillator 110 may be set to the same frequency as the radio frequency. In order to support different transmission speeds and different channel band signals, the A / D converter 105 and the D / A converter 107
, The frequency of the second signal generator 111 to be supplied to the digital system 112, that is, the reference clock frequency needs to be variable.

Next, referring to FIG. 2, a first signal generator 110 and a second signal generator 111 whose oscillation frequencies are variable.
Will be described.

FIG. 2 is a diagram for explaining a more detailed configuration of the first signal generator 110 and the second signal generator 111. In FIG. 2, portions surrounded by dotted lines are the first signal generator 110 and the second signal generator 1 shown in FIG.
It corresponds to 11. In this configuration example, each signal generator is
It has an L synthesizer configuration. That is, the first signal generator 110 divides the frequency of the signal of the VCO (voltage controlled oscillator) 203 by the frequency divider 204 and compares the phase with the reference signal generator 201 by the phase comparator 205. Phase comparison period 2
The high-frequency component of the 05 output is removed by the loop filter 206 and becomes the control signal of the VCO 203. The operation principle is completely the same for the second signal generator 111. Here, the frequency division ratio of the frequency divider 210 is determined by the first signal generator 110.
By setting a different value from that of the frequency divider 204 and by making the frequency of the reference signal generator 201 variable, both the first signal generator 110 and the second signal generator 111 can set a desired oscillation frequency. Obtainable. Note that FIG.
In the example shown in (2), assuming that the signal transmission speed is high and the clock frequency of the second signal generator 111 is relatively high, the second signal generator 111 is also configured as a PLL synthesizer. However, if the clock frequency of the second signal generator is low and the oscillation frequency is such that it can run by a general crystal oscillator, there is no need to adopt a PLL configuration. In this case,
The reference signal generator 201 in FIG. 2 may be used as the reference signal generator 111 as it is, and the second signal generator 111 in FIG. 2 may be deleted. In this case, the large volume VCO 209 for the second signal generator 111 can be omitted. Also at this time, by making the clock speed of the reference signal generator 201 that supplies the clock, ie, 111, variable, it is possible to cope with a variable signal band and a variable transmission speed.

As a radio device to which the direct conversion method is applied, a conventional radio device is disclosed in Japanese Patent Application Laid-Open No. 61-23620.
As disclosed in Japanese Patent Application Publication No. 4 (1999) -1992, there is no conventional example in which a direct conversion system is used only on the receiving side, and in particular, the band and clock speed of a digital filter are made variable in a digital signal processing section to cope with a plurality of systems. Was.

On the other hand, in the complex system common use terminal according to the present invention, not only the receiving unit but also the transmitting unit is configured to be compatible with a plurality of systems. Further, the receiving side A / D converter 105 and Transmission side D / A converter 107
The analog filters 104 and 108 for aliasing removal on each input side and output side of the above also include an element that makes the frequency characteristics variable. Therefore, there is an advantage that it is possible to flexibly cope with a plurality of systems without deteriorating the performance of the wireless device. That is, in the receiving system, even when a strong electric field level interference wave other than the desired wave exists in the clock frequency component supplied to the A / D converter 105, the aliasing of the aliasing is performed by the frequency variable baseband filter 104. It is possible to provide a composite system shared terminal having excellent reception sensitivity without any influence. Also, regarding the transmission system, a high-frequency aliasing component generated by the D / A converter 107 is deleted by the frequency variable filter 107 to provide a transmission system excellent in modulation accuracy and out-of-band radiation characteristics. It becomes possible.

Next, a second embodiment of the complex system common terminal according to the present invention, that is, an embodiment relating to a reduction in power consumption of the radio section will be described in detail with reference to the drawings.

FIG. 3 shows a different wireless system SYSTEM.
1 is a diagram showing an example of a complex system sharing terminal sharing SYSTEM2. This is the SYSTE shown in FIG.
A composite of M1 and SYSTEM2 is shown.
For example, SYSTEM1 is PHS and SYSTE
M2 is a PDC. When the wireless systems are combined in this manner, not only do the wireless frequencies differ in each wireless communication system, but also the band and transmission speed differ, so that wireless circuits, filters, oscillators, frequency converters, etc., suitable for each system are provided. is necessary. Therefore, as described above, in a complex system shared terminal, a direct conversion system that does not depend on an intermediate frequency and has only a baseband signal and an RF signal is practical.

FIG. 4 is a diagram for explaining a preferred embodiment of the transmission system of the complex system shared terminal employing the direct conversion system according to the present invention. First, the operation principle of the transmission system in FIG. 4 will be described. SYSTE
Baseband signal generator 410 for M1 and SYSTEM
The baseband signal generator 411 for 2 is connected to the ROM 412 via SW1 (switching switch) 427.
Here, Ich data and Qch data are extracted from the R0M 412 by an input signal, and are input to the sigma-delta (ΣΔ) modulation oversampling D / A converter 413.

Ich output from D / A converter 413
The data and the Qch data are input to the low-pass filter 414, and block noise components that have spread to high frequencies due to oversampling. The modulator 415 performs quadrature modulation by mixing the Ich and Qch data with the local signal via the bandpass filter 421. Although a specific configuration of the modulator is not shown, a quadrature modulator including a general 90-degree phase shift circuit and a DBM (double balance mixer) may be used.

The output of the modulator 415 is the power amplifier 416 for SYSTEM1 and the power amplifier 417 for SYSTEM2.
Is connected to the input terminal. The power amplifier 416 for the SYSTEM1 is driven by the power supply VDD1, and the output of the power amplifier 416 is radiated into the air via the antenna 419 for the SYSTEM1. The power amplifier 417 for the SYSTEM2 is driven by the power supply VDD2, and the output of the power amplifier 417 is output from the antenna 420 for the SYSTEM2.
Radiated through the air.

On the other hand, the local signal generator LO 1 (424) for SYSTEM 2 generates a signal of frequency f 1 [Hz] and supplies it to the frequency converter 425. SYSTEM1
The local signal generator of the oscillation frequency f2 used for the input is input to SW2 (switch) 426. SW2
The other input is connected to a signal generator 423 for supplying a desired direct current (DC) level, and SW2 selects LO2 (42) depending on which SYSTEM is selected.
2) and the DC (423) signal are selected, and the frequency converter 4
Enter 25. The frequency converter 425 is connected to the LO1 (42
4) and LO2 (422) or DC (42
3), and outputs an output signal including the frequency f1 + f2 or f1. The filter 421 calculates f
This is a bandpass filter that passes frequencies of 1 and f1 + f2, and its output is input to the modulator 415. Here, the transmission frequency of SYSTEM1 is f1 + f2 [Hz].
Assuming that the transmission frequency of SYSTEM2 is f1 [Hz], when SW2 selects the LO2 (422) signal, SW1 (427) selects the SYSTEM1 baseband signal generator 410 and SW2 (427). )
Selects the DC (423) signal, SW1 (42
7) is a baseband signal generator 41 for SYSTEM2.
Select 1.

Next, the clock of the transmission system will be described in detail.

The clock fck input to the D / A converter 413 depends on the transmission speed of SYSTEM1 and the speed of SYSTEM2.
The oversample ratio is determined on the basis of the higher one at the transmission speed of, and fck is determined. By doing so, SYS
Regardless of which TEM1 or TEM is selected, fck
Can be shared without changing. Further, the same cutoff frequency can be used for the filter 414 connected downstream of the D / A converter 413 regardless of the system, so that the filter can be realized without selecting a filter or using a variable filter. This filter is a filter for an oversampling signal and can be realized by a filter having a simple RC configuration, so that there is also an advantage that the design can be simplified. Next, the second
An embodiment relating to the configuration of the local oscillator according to the invention will be described.

In the present invention, it is necessary to generate local signals for different wireless communication systems. In the present invention, multiplication of LO1 (424), which is a high-frequency signal, and LO2 (422) or DC (423) is used. According to this configuration, LO2 (422) having an oscillation frequency of f2 [Hz] can be generally realized by a low-frequency local oscillator. Therefore, LO2 (422) can be generated with a simple configuration, and current consumption can be reduced. The filter 421 has f1 [Hz] or f1 + f2 [H
z] is input and any one of them may be selected, so that the center frequency f1 as shown in FIG.
[Hz] band pass filter and center frequency f1 + f2
It can be constituted by a parallel circuit of band filters of [Hz]. According to this configuration, a local signal generator of f1 [Hz], which is a local signal generator of a high frequency signal, and f1
There is no need to manufacture two local signal generators of + f2 [Hz], and power consumption can be reduced. Further, since modulation of a plurality of systems can be performed with the 415-modulators, downsizing of the terminal can be realized.

Next, a configuration example of the power amplifiers (416, 417) and the antennas (419, 420) will be described.

Generally, in different wireless communication systems, the transmission output power and the radio frequency of the terminal are different. In general, an amplifier is designed to maximize efficiency at a desired frequency in order to increase efficiency. Therefore, sharing a power amplifier at different frequencies may increase power consumption. Also, the antenna is similarly designed so as to obtain the maximum gain at a desired frequency. Therefore, if the antenna is shared, the loss tends to increase. In such a case, the power amplifiers (416, 417) and the transmission antennas (419, 42) corresponding to the respective wireless communication systems are used.
The use of (0) is another method of configuring a complex system shared terminal. When such a configuration is adopted, switching between the power amplifiers 416 and 417 and switching between the antennas 419 and 420 are performed by the power supplies VDD1 and VDD supplied to each power amplifier.
2 can be easily performed by turning on and off. Here, the power supplies VDD1 and VDD2 may be changed according to the wireless communication system to be used. However, in general, the higher the power supply voltage is, the higher the efficiency can be. Therefore, the same power supply voltage is used in accordance with the high output power supply. Is also good.

Next, a third embodiment of the complex system common use terminal according to the present invention, that is, an embodiment relating to the configuration of the power amplifier will be described in detail with reference to the drawings. FIG. 5 is a diagram showing a first configuration example of the transmission unit power amplification unit of the present complex system shared terminal. Hereinafter, the composite system shared terminal will be described as supporting two wireless communication systems. However, by increasing the number of components to three or more, in principle, it also supports three or more wireless communication systems. It can be done. In this example, it is assumed that two systems have antennas 501 and 505. The operation of the transmitting unit in FIG. 5 is as follows.

The signal whose frequency has been converted to a radio frequency band by the mixer 509 passes through a filter 508 and is input to an amplifier 507 shared by each radio communication system. After that, the filter 506 removes a harmonic component generated by the non-linearity of the amplifier 507, and the selection switch 504 switches the transmitting antenna according to a desired system.
When this terminal is used for a system in which the transmission output specified by the system satisfies the shared amplifier 507 output level, the output of the common amplifier 507 is directly radiated from the transmission antenna 505 into the air.

On the other hand, for a system in which a larger output level is specified, after the signal is further amplified by the amplifier 503 at the subsequent stage of the shared amplifier 507, the unnecessary radiation power out of the band is removed by the filter 502, and then the antenna Sent from 501.

Here, the filters in each path need only be able to remove out-of-band unnecessary radiation generated by the non-linearity of each of the amplifiers 507 and 503, and can usually be constituted by low-pass filters. Therefore, when a desired amount of attenuation can be obtained by a matching circuit or the like subsequent to each amplifier, it may be deleted.

Next, FIGS. 6 and 7 show frequency characteristics of the amplifier. Here, the antenna 505 of the transmitter shown in FIG.
Is f2, and the frequency of the signal transmitted from the antenna 501 is f1. FIG. 6 is an example of the frequency characteristic of the amplifier 506 shared by each system. In this example, two systems are using frequencies f1 and f2, and have gain at both frequencies.

FIG. 7 shows an example of the frequency characteristic of the amplifier 503. It has a gain at the frequency f1, but has a small gain at f2, and the gain can be increased because the frequency range to be amplified is narrower by using a dedicated amplifier.

The active element section for amplifying each amplifier may be multistage.

FIG. 8 and FIG. 9 are diagrams showing a second example of the configuration of the transmission power amplifying unit of the present complex system shared terminal.

FIG. 8 shows an example in which the antenna of each system can be shared. In particular, the frequency used by each system is represented by f.
When 1 and f2 are set, when f1 and f2 are separated by more than twice, that is, 2 × f1 <f2 or 2 × f2 <f
This is an example in the case of 1. Hereinafter, 2 × f1 <where f1 <f2
It is assumed that f2 holds, and the transmission power of the system at the frequency f2 is smaller than the transmission power of the system at f1.

First, when a signal having a frequency of f1 or f2 is input to the shared amplifier 807, the filter 806
As a result, a 2 × f2 component of the harmonic output of the common amplifier 807 is removed. This state is shown in FIG.
Here, 1002 is the frequency characteristic of the filter 806. The signal of the frequency f2 is switched by the switch 805 to a path that does not pass through the amplifier 804, and is transmitted from the antenna 801 as it is. When a signal having a frequency of f1 is passed, the path is switched to a path through a dedicated amplifier 804. After amplification by the dedicated amplifier, harmonic components such as 2f1 are removed by a filter 803, and then transmitted from an antenna 801 via a switch 802. I do. Here, 10 in FIG.
01 shows the frequency characteristic of the filter 803.

Next, when the frequency difference between f1 and f2 is within twice (2 × f1> f2 or 2 × f2> f1), the transmitter is configured as shown in FIG. Hereinafter, 2 × f1> f2 holds when f1 <f2, and f2
It is assumed that the transmission power of the system with the frequency f1 is smaller than the transmission power of the system with the frequency f1.

The signal having the frequency f2 is supplied to the shared amplifier 90.
After passing through the path No. 6, the path is switched by the switch 905 and switched to a path not passing the amplifier 904. After passing through the switch 903, the light is radiated from the antenna 901 to the air through the filter 902. On the other hand, the signal of the frequency f1 passes through the shared amplifier 906,
5 through a path with a dedicated amplifier 904 and switch 9
After passing through the filter 03, the light is radiated from the antenna 901 to the air through the filter 902. In this case, the harmonic frequency 2 of f1
Since xf1 is higher than f2, a filter for removing harmonic components of f1 and f2 can be shared by the common low-pass filter 902. The frequency characteristic of the filter 902 at this time is shown by 1003 in FIG. That is,
In this case, there is no need for two filters as in 806 and 803 in FIG.
It is possible to share one.

FIG. 11 is a diagram showing a third configuration example of the transmission unit power amplification unit of the present complex system shared terminal.

In a plurality of wireless communication systems to be used, there are cases where a constant envelope modulation signal and a linear modulation signal are generally mixed. Here, a saturation amplifier can be used for the constant envelope modulation signal, but when the linear modulation signal is saturated and amplified, the signal spectrum is widened. This leads to an increase in out-of-band leakage power and a deterioration in the modulation accuracy of a desired signal. Therefore, it is generally difficult to collectively amplify and saturate all signals of a plurality of systems. Therefore, in order to share the power amplifier with the complex system common terminal, a linear amplifier is generally required. However, if only linear amplifiers are used for signals that can be amplified in saturation, the operating efficiency will be worse,
Problems such as shortening of battery life occur. Therefore, even in the complex system shared terminal, when it is necessary to amplify the constant envelope modulation signal, it is desirable to perform the saturation amplification as much as possible. Therefore, in the example shown in FIG. 11, the shared amplifier 1107 corresponding to the shared amplifier 507 of the transmission unit shown in FIG. 5 has a function of switching between saturation amplification and linear amplification.
Specifically, this can be easily realized by making the bias voltage of the shared amplifier 1107 variable according to the modulation signal, for example, by making the gate applied voltage variable in the FET amplifier.

As another example, as shown in FIG. 12, there is a method in which an attenuator 1211 is provided in a stage preceding the common amplifier 507 of the transmitting section shown in FIG. 5, and the input power to the common amplifier 507 is controlled. In this method, the shared amplifier 507
Instead of making its own operating condition variable, the input power is made variable by the attenuator 1211 and the power amplifier 507
Is used for the saturation amplification and the linear amplification.

The configuration of the power amplifier according to the present invention for supporting two different wireless communication systems has been described above. It is easy to apply the present invention to three or more wireless communication systems. For example, in the example of FIG. 12, a desired number of systems and antennas may be provided downstream of the switch 505, and the switch 505 may be used for different purposes.

Next, a fourth embodiment of the complex system common terminal according to the present invention, that is, an embodiment relating to the structure of a synthesizer will be described in detail with reference to the drawings. FIG. 13 is a diagram showing a preferred configuration example for simplifying the synthesizer of the present complex system shared terminal. In this example, it is assumed that the complex system shared terminal targets two systems.

First, the overall structure will be described with reference to FIG.

The receiving system is a low-noise amplifier 130 for reception.
1 is shared by the two systems, and the subsequent stage is an RF filter 130 as a receiving system used in the first system.
3. IQ2 system mixer pair 13 for down-converting (direct conversion) an RF signal to a base band
07, a pair of I and Q baseband filters 1311 for removing unnecessary band signals from the output of the mixer pair 1307
Consists of

The receiving system used in the second system has a different configuration from the receiving system used in the first system, and includes an RF filter 1304, a mixer 1308 for down-converting an RF signal to an intermediate frequency, and an unnecessary band from an output of the mixer 1308. Filter 1312 for removing signal, filter 1312
Mixer 1 that further down-converts the output signal of FIG. 1 to a frequency that can be handled by digital signal processing unit 1318
314. On the other hand, the transmission system shares the transmission power amplifier 1302 in the last stage, and
The transmission system used in the first system includes an I and Q two-system mixer pair 1309 for up-converting (direct converting) a baseband signal into an RF signal from an output signal of the digital signal processing unit 1318, and a transmission RF filter 1305. ing.

The transmission system used in the second system has a different configuration from the transmission system used in the first system, and the mixer 1315 for up-converting the output signal of the digital signal processing unit 1318 to the first intermediate frequency and the output from the mixer 1315 A filter 1313 for removing an unnecessary band signal, and a mixer 13 for up-converting the intermediate frequency signal to an RF signal
10. The transmission RF filter 1306.

The first synthesizer 1316 supplies a local signal to the mixers 1307, 1308, 1309, 1310. Second synthesizer 1317
Supplies local signals to the mixers 1314, 1315. Digital signal processing section 1318 demodulates the received signal frequency-converted to a low frequency, modulates the transmission signal, and outputs a baseband modulated signal.

Next, the operation of the terminal configured as described above will be described.

In this example, two systems are prepared for the transmission system and the reception system for each of the two systems, and the switches are switched according to the system to be used. The same is true. The features of this example are
The transmission and reception direct conversion method is adopted for the TDD system, and the transmission and reception superheterodyne method is used for the FDD system. This enables the first local oscillator 1316 to support a plurality of wireless communication systems. It realizes a complex system shared terminal. Hereinafter, a specific example will be described.

In the following example, it is assumed that the present invention deals with two wireless communication systems that are most effective.
That is, it is assumed that one is a TDMA / TDD system and the other is a TDMA / FDD system.

That is, as described in the conventional example,
Assuming that the transmission / reception frequency is the same frequency as the first system, that is, a PHS (radio frequency band: 1.9 GHz) of the TDMA / TDD system, and the transmission / reception frequency is another frequency as the second system, that is, the digital mobile phone of the TDMA / FDD system. Telephone (Radio frequency band: 1.5GH
z).

When used as a PHS terminal, the output signal of the first synthesizer 1316 is input to the mixer pair 1307 of the first system PHS. This mixer pair 1307
In order to perform direct conversion, the output signal frequency of the synthesizer is the same as the carrier frequency of the PHS reception signal (that is, the 1.9 GHz band). The output signal of mixer pair 1307 is converted to a baseband signal, and this signal is input to digital signal processing section 1318.

In the case of transmission, the digital signal processing unit 13
The baseband modulation signal output from 18 is input to mixer pair 1309. Mixer 1309 receives a local signal having the same transmission frequency from the synthesizer, and directly up-converts (modulates) the modulated signal to a carrier frequency in the 1.9 GHz band.

Next, the operation when a mobile phone is used will be described. Synthesizer oscillation signal (frequency: 1.9 GH
z) is input to the mixer 1308 on the receiving side as the first local. The 1.5 GHz band signal input to the mixer 1308 is frequency-converted to a 400 MHz difference frequency band (first intermediate frequency band) by a 1.9 GHz band local signal. This signal is passed through a filter 1312 to the mixer 1
At 314, the frequency is converted to a lower second intermediate frequency band capable of digital signal processing. Specifically, the mixer 131
4 is supplied with a reference signal from a second synthesizer 1317, frequency-converted, input to a digital signal processing unit 1318, and demodulated. Here, assuming that the frequency of the second synthesizer 1307 is 410 MHz, the second intermediate frequency band is about 10 MHz.

Next, the transmission system will be described. The 40 MHz modulated signal output from the digital signal processing unit 1318 is mixed with a 410 MHz local signal by a mixer 1315 and converted to an intermediate frequency of 450 MHz. At this time, the local signal supplied to the mixer 1315, that is, the oscillation frequency of the second synthesizer 1317 may be the same as that for reception. The output of the mixer 1315 is input to the mixer 1310 through the filter 1313. The output of the mixer 1310 receives the output of the first synthesizer 1316, which is the first local signal of the 1.9 GHz band, and converts the frequency of the transmission signal to the 1.45 GHz band.

As described above, in the present multi-system shared terminal, the direct conversion is used for the TDMA / TDD system, and the superheterodyne system is used for the TDMA / FDD system. The first local is set to generate the frequency of the first system, and the second system uses the same local to set the intermediate frequency to the frequency of the first system and the frequency of the second system. And the difference. At this time, it is possible to share the first local by appropriately selecting the frequency of the second local.
Therefore, in the conventional complex system shared terminal, if only two radios are combined, two synthesizers, which are required, can be reduced by one.

In the above embodiment, the signal having the second intermediate frequency of about 40 MHz is directly input to the digital signal processing unit.
In some cases, the signal of 40 MHz is once again frequency-converted to a lower frequency for digital signal processing. At this time, one more synthesizer is required, but this is the same in the conventional example, and the effect of the present invention is not lost.

For the same reason, another synthesizer (or fixed oscillator) may need to be prepared in the second local in order to lower the second intermediate frequency in some cases. But because it is the same,
The effect of the present invention is not lost at all.

In this embodiment, the dual mode radio corresponding to two systems in which one is the TDD system and the other is the FDD system has been described. However, other systems, such as triple mode radios corresponding to three systems, one being the TDD system and the other two being the FDD system, or one being the TDD system and the other being the FDD system
It is apparent that the same effect can be obtained in a multimode radio corresponding to a plurality of systems such as a system.

[0090]

As described above, according to the first aspect, not only the receiving unit but also the transmitting unit uses the direct conversion system so as to be applicable to a plurality of systems. Further, an analog filter for aliasing removal on the input side and output side of each of the reception side A / D converter and the transmission side D / A converter also has an element for making the frequency characteristics variable. Therefore, there is an advantage that it is possible to flexibly cope with a plurality of systems without impairing the performance of the wireless device, that is, the reception sensitivity, the modulation accuracy, and the out-of-band radiation characteristics.

In the second invention, for example, when one system is a TDMA / TDD system and the other system is a TDMA / FDD system, the TDMA. T
By using the direct conversion method as the DD method and adjusting the oscillation frequency of the synthesizer to the TDMA / TDD method, the number of synthesizers can be reduced. For this reason, there is an effect that the cost can be significantly reduced, the size of the terminal can be reduced, and the power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a preferred embodiment of a complex system shared terminal according to the present invention.

FIG. 2 is a diagram showing a configuration of a first signal generator and a second signal generator shown in FIG.

FIG. 3 is a diagram showing an example of a complex system shared terminal sharing different wireless systems.

FIG. 4 is a diagram for explaining a preferred embodiment of a transmission system of a complex system shared terminal employing a direct conversion method according to the present invention.

FIG. 5 is a diagram illustrating a first configuration example of a transmission unit power amplification unit of the complex system common use terminal according to the present invention.

FIG. 6 is a diagram illustrating a frequency characteristic of the amplifier illustrated in FIG. 5;

FIG. 7 is a diagram illustrating a frequency characteristic of the amplifier illustrated in FIG. 5;

FIG. 8 is a diagram illustrating a second configuration example of the transmission unit power amplification unit of the complex system shared terminal according to the present invention.

FIG. 9 is a diagram illustrating a second configuration example of the transmission unit power amplification unit of the complex system shared terminal according to the present invention.

FIG. 10 is a diagram illustrating frequency characteristics of the filters illustrated in FIGS. 8 and 9;

FIG. 11 is a diagram illustrating a third configuration example of the transmission unit power amplification unit of the complex system shared terminal according to the present invention.

12 is a diagram illustrating another configuration example of the transmission unit power amplification unit illustrated in FIG. 11;

FIG. 13 is a diagram showing a preferred configuration example for simplifying a synthesizer of a complex system shared terminal according to the present invention.

FIG. 14 is a configuration example of two signal generators according to the present invention.

FIG. 15 is a schematic configuration diagram of a conventional complex system shared terminal including two different wireless communication systems.

FIG. 16 is a configuration diagram of a radio unit of a conventional complex system shared terminal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Antenna for transmission / reception 102 Transmission / reception duplexer 103 Reception mixer 104 Filter 105 A / D converter 106 Digital signal processing part 107 D / A converter 108 Filter 109 Mixer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Yoshida 1 Toshiba R & D Center, Komukai Toshiba-cho, Kawasaki-shi, Kanagawa Prefecture (72) Inventor Hiroyuki Kayano Sachi-ku, Kawasaki-shi, Kanagawa No. 1 Muko Toshiba Town Toshiba R & D Center

Claims (2)

[Claims] 1. A receiving mixer for mixing a reference signal to convert a received signal to a baseband signal, a receiving filter capable of changing a passband width and passing the baseband signal, and operating according to an operation clock. Digital signal processing means for converting a baseband signal passed through the reception filter into a digital signal, demodulating the signal, and generating a digitally modulated signal to convert the signal into an analog signal; A transmission filter that allows a signal to pass therethrough; a transmission mixer that mixes the reference signal with the reference signal to convert an analog signal that has passed through the transmission filter into a transmission signal; depending on a radio frequency, a signal band, and a transmission rate of a radio communication system to be used. Means for setting the reference signal, the pass band width, and the operation clock, respectively. Complex system shared terminal. 2. A clock generating means for generating first and second reference signals, a reception mixer for mixing the first reference signal and converting a received signal in a first frequency band into a baseband signal, Mixing the baseband signal with the first reference signal to form a first signal;
A first transmission / reception system including a transmission mixer that converts the signal into a transmission signal in a frequency band of the first frequency band, and a first stage that converts the reception signal in the second frequency band into an intermediate frequency signal by mixing with the first reference signal A receiving mixer;
A second-stage reception mixer for mixing the intermediate frequency signal into a predetermined frequency signal by mixing with the second reference signal;
A first-stage transmission mixer that mixes a predetermined frequency signal into an intermediate frequency signal by mixing with a reference signal of the second type; and converts the intermediate frequency signal into a transmission signal of the second frequency band by mixing with the first reference signal. A second stage transmission mixer
A shared system shared terminal comprising: