JP3410661B2 - Multimode wireless device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-mode portable telephone terminal for supporting multiple standards in a cellular mobile telephone system.

[0002]

2. Description of the Related Art With the rapid spread of personal computers, mobile phones, the Internet, etc., it is expected that there will be a growing need for full-scale multimedia services even in the mobile environment. For the 21st century, it is necessary to introduce a next-generation mobile communication system that can handle various and comprehensive contents such as voice, data, and video.

Wideband code division multiplexing (CDMA)
sion multiplex access (hereinafter, referred to as wideband CDMA) system is drawing attention. Wideband CDMA system adopts spread spectrum communication system, resistant to multipath fading, capable of high-speed data transmission, good communication quality, good frequency utilization efficiency, communication cost, subscriber capacity, confidentiality, communication Due to its excellent diversification, it is one of the promising communication systems for the next generation mobile communication system and multimedia wireless communication. International standardization activities for next-generation mobile communication systems are mainly conducted by the International Telecommunications Union (ITU).
lecommunication Union). It is necessary to use the same frequency on a global scale so that it can be commonly used anywhere in the world. Therefore, 1992
In the World Wide-Area Communications Conference held at WARC-92 held in 1980
The 25 MHz and 2110-2200 MHz frequency bands were assigned. Among them, 1982-2010 MHz and 217
It was also decided that the 0 to 2200MHz frequency band could be used in systems using satellites. Therefore, considering the common use with the satellite communication system, the reception frequency band of the wideband CDMA is the 60 MHz bandwidth of 2110 to 2170 MHz, and the transmission frequency band is 1920 to 1 considering the pair band.
This is a 60 MHz bandwidth of 980 MHz.

As a wideband CDMA radio link, the 2 GHz band has a spreading bandwidth of 1.25 / 5/10/20 MHz. FIG. 3 shows the configuration of the radio unit when two synthesizers are used as the local oscillator of the radio unit. The receiving system includes a first branch 47 and a second branch 55. Each branch is connected to the internal antenna 45 and the external antenna 53, respectively. The receiving system will be described by taking the first branch 47 as an example. The received signal from the internal antenna 45 is a low noise amplifier 46 (LNA: Low Noise Amplifier).
The signal that is input to and amplified by the bandpass filter 48
(BPF: Band Pass Filter) removes interference signals outside the reception band, and frequency down converter 49
Converted to an intermediate frequency of MHz, 1.25 / 5/10 / 20M
Adjacent channel interference signals are removed by the bandpass filter 50 of Hz bandwidth, and the signals are supplied to the quadrature demodulator 52 via the AGC amplifier 51, and the quadrature demodulator 52 generates I / Q phase baseband signals. It is supplied to the signal processing unit. The operation principle of the second branch 55 is the same as that of the first branch 47, and the operation description is omitted.

The baseband signals of the first and second branches are combined by the baseband signal processing section. As a transmission system, the baseband I / Q signal supplied by the baseband signal processing unit is first input to the quadrature modulator 65, and
Converted to an intermediate frequency of 80MHz, transmit power control amplifier 7
3 and the transmission intermediate frequency band pass filter 72, is input to the up converter 71, is converted into a required transmission frequency by the up converter 71, and is transmitted band band pass filter 70, driver amplifier 69, power amplifier 68, isolator. After passing through 67 and DUP 54, a transmission wave is sent by the external antenna 53.

A desired local frequency is generated by the first local oscillator 57, and the frequency down converter 49 of the receiving system is used.
And the up-converter 71 of the transmission system generates a reception intermediate frequency of 190 MHz and a required transmission frequency from the transmission intermediate frequency of 380 MHz.

The second local oscillator 66 generates a local frequency of 380 MHz and supplies it to the quadrature modulator / demodulators 52 and 65. The quadrature modulator 65 converts the baseband I / Q signal to an intermediate frequency of 380 MHz from the local frequency of 380 MHz. On the other hand, the ½ frequency divider inside the quadrature demodulator
Generates MHz local signal and receives intermediate frequency of 190MHz
A baseband signal is generated by mixing with the signal. With such a configuration, it is possible to configure the local oscillator of the wireless system with the two synthesizers.

On the other hand, in recent years, the number of subscribers of mobile phones has been rapidly increasing mainly in developed countries. Although mobile phones have been widely used until now, services have started using the analog method, but due to the situation that it is not possible to meet the rapidly increasing demand, digital services such as time division multiplexing method using a new band have become available. Was started. In that case, there are two frequency bands, a conventional analog frequency band and a new service digital frequency band. Therefore, there is a demand for a wireless mobile phone terminal which has different frequency intervals for transmission and reception and which can be used in two frequency bands. As an example,
Japan domestic 800MHz band time division multiplexing mobile phone (PD
C: Personal Digital Cellular System) requires calls in two frequency bands as shown in Table 1.

[0009]

[Table 1]

Generally, the wireless configuration of the mobile phone terminal which can be used in the above two frequency bands employs three synthesizers. A method that employs two synthesizers has already been proposed because of its small size, light weight, and low power consumption. The configuration of the wireless unit is shown in FIG.

As the receiving system 76, the receiving antennas 75 and 99 are selected by the switch 86, the received signals from the antennas are input to the LNA 77, and the digital receiving band bandpass filter 78 corresponding to the receiving band shown in Table 1 is received.
Alternatively, it passes through the analog type reception band band pass filter 79 and is input to the first frequency down converter 81. In the case of digital reception band, the first frequency down converter 81 receives a reception signal of 810 to 828 MHz and
When the first local oscillator frequency signal of 1.1 to 699.1 MHz is input and in the analog reception band, the first frequency down converter 81 receives the reception signal of 870 to 885 MHz and the first local frequency of 741.1 to 756.1 MHz. The oscillator frequency signal is input and frequency conversion is performed. The first intermediate frequency component of 128.9 MHz is output to the output of the first frequency down converter 81.

Adjacent channel interference is removed from the first intermediate frequency signal by the first intermediate frequency band pass filter 82 and the signal is sent to the second frequency down converter 83. The first intermediate frequency signal of 128.9 MHz and the signal of the second local oscillator 98 of 257.6 MHz / 2 are input to the second frequency down converter 83, and 100 kHz is obtained by frequency conversion.
To generate a second intermediate frequency signal component of The second intermediate frequency signal is sent to the baseband signal processing section as a second intermediate frequency signal of 100 kHz by the amplifying and amplitude limiter 85 after further removing adjacent channel interference by the second intermediate frequency bandpass filter 84.

On the other hand, in the transmission system 108, the I / Q baseband signal sent from the baseband signal processing unit is converted into a transmission band frequency by the quadrature modulator 107, and the transmission bandpass filter 106 and the transmission power control amplifier 10 are provided.
5, it is sent to the external antenna 99 by the driver amplifier 104, the power amplifier 103, the isolator 102, the low-pass filter 101, and the transmission / reception switch 100. The first local oscillator 87 has a range of 741.1 to 756.1 MHz or 6 depending on an analog or digital band selection control.
In addition to generating the signal of the first local oscillator 87 of 81.1 to 699.1 MHz and supplying the signal of the first local oscillator 87 to the receiving system 76, it is also connected to the mixer 93.

Further, the second local oscillator 98 performs transmission / reception mode switching control in addition to analog or digital band selection control. Fast frequency switching is performed as shown in Table 2.

[0015]

[Table 2]

The signal of the second local oscillator 98 is also connected to the mixer 93 in addition to being supplied to the receiving system 76, similarly to the signal of the first local oscillator 87. The mixer 93 is the first local oscillator 8
7 and the signal of the second local oscillator 98 are frequency-converted to generate frequency components 925 to 940 MHz and 940
.About.958 MHz is supplied to the quadrature modulator 107. Table 3 shows the frequency conversion relationship of the wireless unit.

[0017]

[Table 3]

By controlling the frequency selection of the analog or digital system band of the second local oscillator 98, switching the transmission / reception high-speed frequency, and installing the mixer 93, the local oscillator of the radio unit can be constituted by the two synthesizers.

As mentioned above, wideband CDMA is
Strong multipath fading, can speed up the data transmission, etc. may feature communication quality is good and the frequency utilization efficiency, so that voice calls in the year 2000 prospects, high-speed data communication services such as image transmission is started, Device development and testing are in progress.

However, at the present time, the number of subscribers of digital mobile phones such as PDC tends to increase yearly,
It is deeply penetrating into social activities. When the wideband CDMA system is in service, the wideband CDMA / PD is used during the transitional period of the old and new transitions such as infrastructure maintenance and service area expansion.
The C dual-mode mobile phone terminal is considered essential. Like the current PDC mobile phone service, 10
It is assumed that the user wants a terminal with a small size, light weight, and low power consumption of about 0 cc / 100 g. Wideband CDMA /
FIG. 5 shows the configuration of the wireless unit of the PDC dual-mode mobile phone terminal.

The antenna switch 134 and the voltage controlled oscillator (VCO) of the first local oscillator 124 are
ator) 119, 120 and voltage controlled oscillators 130, 131 of the second local oscillator 126 have been added for dual mode switching. The basic operation principle is the same as in FIGS.
When the switch 121 is connected to the voltage controlled oscillator 119, the first local oscillator 124 generates a local frequency of 2 GHz band, and conversely, the switch 121 causes the voltage controlled oscillator 120 to generate.
Connected to the first local oscillator 124 is 925-95
A local frequency of 8MHz band is generated. Switch 129
Is connected to the voltage-controlled oscillator 130, the second local oscillator 126 generates a local frequency of 380 MHz, and conversely, when the switch 129 is connected to the voltage-controlled oscillator 131, the second local oscillator 127 is 183.9 to 258. .9 MH
A z-band local frequency is generated.

However, as mentioned above, a broadband CD
MA transmission / reception band is 2 GHz band, PDC is 800 MHz
Since it is different from the band, the shared portion of the wireless part of the wideband CDMA / PDC dual-mode mobile phone terminal is small, and downsizing, weight reduction, and power consumption reduction are important issues.

[0023]

However, in the configuration shown in FIG. 5, there is little shared portion of the radio part of the wideband CDMA / PDC dual-mode mobile phone terminal, and the transmission system has two complete systems, which is small and lightweight. It is extremely difficult to reduce power consumption. The present invention provides a simplified configuration of a radio unit in which a part of a transmission system is shared and a mode changeover switch of a second local oscillator and one voltage controlled oscillator are deleted.

In the present invention, a mode switch is provided at the input of the quadrature modulator of the transmission system of the wideband CDMA / PDC dual mode mobile telephone terminal, the quadrature modulator and the power control amplifier are shared, and the mode is set at the output of the power control amplifier. A switch is provided to supply signals to the transmission system circuits of different modes.

On the other hand, a ½ divider circuit is provided between the output of the second local oscillator and the input of the quadrature modulator, and the operating state of this ½ divider circuit is set so that it can be controlled by mode switching. With this 1/2 frequency divider with mode switching, the frequency control range of the voltage-controlled oscillator of the second local oscillator can be narrowed, the voltage-controlled oscillator switching of the second local oscillator becomes unnecessary, and a simplified radio unit can be realized. Can be configured.

[0026]

According to claim 1 of the present invention , a wideband CDMA mode and a PD are used as operation modes.
C analog band transmission mode and PDC digital band
Multimode having a transmission mode and a PDC reception mode
In the radio device, the reference frequency output from the reference frequency oscillator is input, the first local oscillator that outputs a predetermined frequency, the reference frequency output from the reference frequency oscillator, and the mode control signal are input. A second local oscillator that outputs a predetermined frequency based on the operation mode, a quadrature modulator that quadrature modulates a baseband signal by the output from the second local oscillator, an output from the first local oscillator, and A transmission RF up converter that generates a transmission signal from an output from a quadrature modulator, a reception RF down converter that converts a reception signal to a first intermediate frequency, an output from the RF down converter, and the second local oscillator. A second frequency converter for converting the first intermediate frequency to a second intermediate frequency by mixing the output from
An output from the F downconverter, mixing the output from the second local oscillator, a quadrature demodulator for converting the first intermediate frequency to a baseband signal, the second local oscillator and the quadrature modulator And a first frequency divider that is provided between the first frequency divider and the mode control signal and that changes the frequency division number according to the mode control signal .
However, if the operation mode is the PDC analog band transmission mode,
The PDC digital band
1/2 round in transmission mode and wideband CDMA mode
The above problem is solved by stopping the frequency division operation .

According to claim 2 of the present invention, a second frequency divider is provided between the second local oscillator and the quadrature demodulator, and between the second local oscillator and the second frequency converter. The problem is solved by providing it.

According to a third aspect of the present invention, the second frequency divider is provided at the output of the second local oscillator, and the output of the second frequency divider is the quadrature demodulator and the second local oscillator. The above problem is solved by switching to any of the frequency converters.

According to a fourth aspect of the present invention, the second frequency divider is provided in each of the quadrature demodulator and the second frequency converter, and each of the second frequency dividers is provided by the mode control signal. The above problem is solved by determining whether or not to operate the container.

According to a fifth aspect of the present invention, the above-mentioned problems are solved by changing the frequency division number of the first frequency divider so that the oscillation frequency range of the second local oscillator is within 1.5 times. Solve.

[0031]

1 is a block diagram of a wideband CDMA / PDC dual-mode mobile phone terminal radio section showing an embodiment of the present invention. FIG. 2 is a block diagram showing the relationship between the components. In the wideband CDMA mode, the reception system is 2
System is required. Although one receiving branch in the wideband CDMA mode is not shown in FIG. 1, it is similar to the conventional method shown in FIG.

In the wideband CDMA mode, the received signal is input from the external antenna 8, supplied to the antenna duplexer 11 by the mode switch 9, and passed through the LNA 12, the up-converter 13 and the AGC amplifier 14 to the baseband signal by the quadrature demodulator 15. It is demodulated and is supplied to the baseband signal processing unit. The baseband transmission signal from the baseband signal processing unit is input to the quadrature modulator 33 by the mode switches 34 and 39, converted into a transmission intermediate frequency of 380 MHz, and transmitted through the transmission power control amplifier 32 and the mode switch 30 to the wideband CDMA mode. Transmission circuit 2
Sent to 9.

In the PDC mode, the mode switch 9 is connected to the mode switch 10, and the received signal is input from the external antenna 8 or the internal antenna 1 by the mode switch 2 and input to the PDC mode receiving system 7 and the PDC mode receiving system. A second intermediate frequency signal of 7 to 100 kHz is output.

On the other hand, the baseband transmission signal from the baseband signal processing section is transmitted through the PDC through the common transmission circuit 40 including the mode switches 35 and 39, the quadrature modulator 33 and the transmission power amplifier 32 as in the wideband CDMA mode.
It is sent to the mode transmission circuit 36.

Next, the local oscillators 21 and 26 of the wideband CDMA / PDC dual-mode mobile phone terminal will be described. As shown in Fig. 1, the VCTCXO25 (Voltage
Control Temperature Compensation X-tal Oscillato
r) oscillates at 14.4 MHz, and the reference frequency of 14.4 MHz is input to the PLL circuit 23 of the second local oscillator of the second local oscillator 26. On the other hand, the voltage controlled oscillator 22 of the second local oscillator 26 has a frequency of 367.8 MHz depending on the operation mode.
It oscillates at frequencies of 257.6 MHz, 258.9 MHz and 380 MHz and inputs it to the PLL circuit 23 of the second local oscillator.

In the case of 380 MHz and 257.6 MHz, the internal partial frequency of the PLL23 of the second local oscillator is 400 kHz.
In case of 367.8MHz, 258.9MHz, 300KHz
Choose. In order to satisfy the transmission / reception band frequencies of the wideband CDMA system and the PDC system, the frequency allocation of Table 4 is proposed.

[0037]

[Table 4]

In FIG. 1, the fixed frequency divider 24 is commonly connected to the second frequency converter 5 and the quadrature demodulator 15 for easy understanding of frequency allocation, but in the case of an actual circuit configuration, the wideband CDMA mode is used. At this time, the output frequency (190 MHz) of the fixed frequency divider 24 is the first reception intermediate frequency (19 MHz).
Since it is equal to 0 MHz), the reception sensitivity is deteriorated when it wraps around the input terminal of the quadrature demodulator 15 .

In order to reduce the inter-circuit interference, as shown in FIG. 7, separate frequency dividers are provided for the second frequency converter 5 and the quadrature demodulator 15, and the frequency dividers provided separately. Is switched according to the mode control signal 35, and the frequency dividers 24 and 41 are connected to the second frequency converter 5 and the quadrature demodulator 1.
There is a way to place it near 5. Further, a method of incorporating the frequency divider 24 in the quadrature demodulator 15 can be considered.

FIG. 6 shows a basic configuration obtained by simplifying FIG. 1 in order to clarify the frequency relationship of the wideband CDMA / PDC dual-mode mobile phone terminal according to the present invention.

Voltage controlled oscillator 22 of second local oscillator 26
Depending on each operation mode, 380MHz (wideband CDMA mode), 367.8MHz (PDC analog band transmission mode), 258.9MHz (PDC digital band transmission mode)
And 257.6 MHz (PDC reception mode) are output.

In the case of the PDC analog band transmission mode, 3
The local frequency signal of 67.8 MHz is divided by 1/2.
And the mode control signal 35 from the baseband signal processing unit is input to the 1/2 frequency divider 31.

When the mode control signal 35 is in the PDC analog band transmission mode, the ½ frequency divider 31 performs ½ frequency division operation and performs ½ division of the local frequency signal of 367.8 MHz by 183. It outputs a local frequency signal of 9MHz. The output local frequency signal of 183.9 MHz performs quadrature modulation with the baseband signal in the quadrature modulator 33, and outputs 183.9 MHz from the output of the quadrature modulator 33.
The modulated signal having the transmission intermediate frequency of is output.

The modulation signal of 183.9 MHz is converted to the first local frequency signal of 741.1 MHz to 756.1 MHz from the first local oscillator 21 by frequency conversion, and 925 MHz to 9
A 40 MHz transmission signal is generated and sent to the external antenna 8.

In the PDC digital band transmission mode, 2
The local frequency signal of 58.9 MHz is divided by 1/2.
When the mode control signal 35 is in the PDC digital band transmission mode, the ½ frequency divider 31 stops the ½ frequency division operation and directly passes it, and the local frequency signal of 258.9 MHz is 1 as it is. It is output from the 1/2 frequency divider 31. The output local frequency signal of 258.9 MHz is used to perform quadrature modulation with the PDC mode baseband signal in the quadrature modulator 33.
A modulated signal having a transmission intermediate frequency of 58.9 MHz is output.

The modulation signal of 258.9 MHz is converted to 9 by the frequency conversion with the PDC mode first local frequency signal of 681.1 MHz to 699.1 MHz from the first local oscillator 21.
A transmission signal of 40 MHz to 958 MHz is generated and sent to the external antenna 8.

In the case of PDC analog and digital band reception modes, 25 generated by the second local oscillator 26.
The 7.6 MHz local frequency signal is divided by 1/2 by the 1/2 fixed frequency divider 24, and the 128.8 MHz local frequency signal is supplied to the PDC mode receiving unit 7, and the PDC mode receiving unit 7 causes the PDC mode receiving unit 7 to perform PDC. Mode reception first intermediate frequency 12
The PDC mode reception second intermediate frequency of 100 kHz is generated by the received signal of 8.9 MHz and the frequency conversion, and is supplied to the PDC baseband signal processing unit after amplification, filtering and amplitude limitation.

In the wide band CDMA mode, the local frequency signal of 380 MHz generated by the second local oscillator 26 is divided by 1/2 by the 1/2 fixed frequency divider 24 to obtain 19
The local frequency signal of 0 MHz is supplied to the wide band CDMA mode receiving unit 16,
Wide band CDMA mode reception first intermediate frequency 190MHz
A wideband CDMA mode baseband signal (having a bandwidth of DC to about 5 MHz) is generated by the received signal and the quadrature demodulation, and is supplied to the wideband CDMA mode baseband signal processing unit after being amplified and filtered.

On the other hand, the local frequency signal of 380 MHz generated by the second local oscillator 26 is sent to the 1/2 frequency divider 31, which outputs 1 when the mode control signal 35 is in the wide band CDMA mode. The / 2 frequency division operation is stopped, the signal is directly passed, and the local frequency signal of 380 MHz is output from the 1/2 frequency divider 31 as it is.

The output 380 MHz local frequency signal performs quadrature modulation with the wideband CDMA mode baseband signal in the quadrature modulator 33, and the quadrature modulator 33 outputs a modulation signal having a transmission intermediate frequency of 380 MHz. To be done.

The modulated signal of 380 MHz is generated by the first local oscillator 2
1 to 2300MHz to 2360MHz wideband CDMA mode frequency conversion from the first local frequency signal
A transmission signal of 920 MHz to 1980 MHz is generated and sent to the external antenna 8.

The above description is for the frequency relationship shown in Table 4 when the second intermediate frequency of the PDC mode reception is 100 kHz. The present invention can be applied even when the second intermediate frequency of the PDC mode reception is 450 kHz. Table 5 shows the frequency relationship.

[0053]

[Table 5]

Further, the frequency relationship of the present invention can be summarized in the following mathematical formula.

In order to express a general mathematical expression, the following symbols are first defined.

Reception frequency: f _RXn Transmission frequency: f _TXn Reception first intermediate frequency: f _RXn _ _IF1 Transmission first intermediate frequency: f _TXn _ _IF1 Reception second intermediate frequency: f _RXn _ _IF2 Transmission second intermediate frequency: f _TXn _ _IF2 Receive first local oscillator frequency: f _RXn _ _LO1 Transmit first local oscillator frequency: f _TXn _ _LO1 Receive second local oscillator frequency: f _RXn _ _LO2 Transmit second local oscillator frequency: f _TXn _ _LO2 Second local oscillator Oscillator frequency change range: Δf where n is a mode and n = 1,2,3.

Tables 6 and 7 show the relationships between these symbols and the frequencies in Table 4 above.

[0058]

[Table 6]

[0059]

[Table 7]

Transmission / reception first intermediate frequencies f _{RXn _IF1} , f _{TXn _IF1}
Is

[0061]

[Equation 1]

It becomes

On the other hand, the reception first intermediate frequency f _{RXn _IF1} is

[0064]

[Equation 2]

Where a is the frequency division coefficient of the integer frequency divider.

The transmission first intermediate frequency f _{TXn _IF1} is

[0067]

[Equation 3]

It becomes

Summarizing these equations,

[0070]

[Equation 4]

It becomes Therefore, the frequency change range Δf of the second local oscillator is

[0072]

[Equation 5]

It becomes

Δf represents an oscillation frequency variable range of the voltage controlled oscillator of the local oscillator and is one important index of the voltage controlled oscillator. The oscillating frequency variable range of the voltage controlled oscillator is 10 in consideration of easiness of manufacturing in consideration of element variation.
Limited to about%. When a wide frequency coverage is required, there is a method to expand the variable range by switching the oscillation element, but when realizing with a simple oscillation element switching circuit, there is a limit to the oscillation frequency coverage range due to restrictions on oscillation conditions. There is. In consideration of these conditions, if the oscillation frequency variable range Δf is limited to about 1.5 times, a small and easily manufactured voltage controlled oscillator can be realized. For this example,
The frequency division coefficient a of the frequency divider is 1, and when the PDC mode reception second intermediate frequency is 100 kHz, Δf = 380 MHz / 25
7.6 MHz = 1.48, and when the PDC mode reception second intermediate frequency is 450 kHz, Δf = 380 MHz / 259.1 MHz =
Since this is 1.47, the oscillation frequency variable range Δf is a range that can be realized by one voltage controlled oscillator.

By the above description, it has been described that the first local oscillator 21 of FIG. 1 is composed of the two voltage controlled oscillators 17 and 18 having the oscillation frequencies shown in Tables 4 and 5 above.

The first local oscillator 21 of FIG. 1 can be realized by one voltage controlled oscillator using a frequency divider and a frequency multiplier. As shown in Table 5, in order to satisfy the relationship between the transmission / reception frequency of each mode and the transmission / reception first intermediate frequency, the first local oscillator 21 has the wideband CDMA mode of 2300 to 2300.
It is necessary to oscillate at a frequency of 2360 MHz and PDC mode of 680 to 755 MHz.

However, three times the oscillation frequency of the PDC mode is (680-755) × 3 = 2040-2265.
It can be seen that the frequency change range Δf of the first local oscillator 21 becomes 2360/2040 = 1.16 times in MHz.
When the frequency variation range Δf is about 1.16 times, the circuit constant of one voltage controlled oscillator is kept constant, that is,
The required variable frequency range can be obtained without switching the resonance inductance or the resonance capacitance.

In the wideband CDMA / PDC dual-mode mobile phone terminal according to the present invention, the first local oscillator 21 uses one voltage controlled oscillator without internal constant switching, and in the PDC mode, at a frequency of 680 to 755 MHz. It oscillates and supplies it to the PDC mode receiving system 7 and the PDC mode transmitting system 36.
80 to 755MHz triple harmonic frequency component 2040 to
Wideband CDMA mode reception system 1 using 2265MHz
6 and wideband CDMA mode transmission system 29.

In the case of the wide band CDMA mode using one voltage controlled oscillator without switching internal constants, 2
Broadband CDM oscillating at a frequency of 300 to 2360 MHz
It is supplied to the A mode reception system 16 and the wide band CDMA mode transmission system 29, and in the case of the PDC mode, 680 to 755 MH
It oscillates at a frequency of 2040 to 2265 MHz which is three times z, and the output of the first local oscillator 21 and the PDC mode receiving system 7 and P
A frequency divider of 1/3 can be inserted between the DC mode transmission system 36 to supply a frequency of 680 to 755 MHz to the PDC mode reception system 7 and the PDC mode transmission system 36. Since the frequency divider is small in size due to the voltage controlled oscillator, it is advantageous for downsizing the dual mode mobile phone terminal as compared with the case of switching between two voltage controlled oscillators.

[0080]

According to the present invention, for a multi-mode portable radio terminal compatible with a plurality of radio systems having different radio frequencies, the present invention limits the oscillation frequency variable range to about 1.5 times and is compact and easy to manufacture. You can use an oscillator,
Since there is no need to switch the voltage-controlled oscillator, a radio device can be configured with two synthesizer oscillators.

In the wide band CDMA / PDC dual mode portable terminal, a frequency divider is provided between the second local oscillator and the quadrature modulator, and the frequency dividing number is changed according to the analog band mode or the digital band mode of the PDC. , The second local oscillator can be simplified. Further, by the means for changing the frequency division number, a part of the dual mode transmitter of the wide band CDMA / PDC can be shared, and the transmission system can be simplified as compared with the conventional system.

A feature of inserting a frequency divider between the second frequency converter and quadrature demodulator for the PDC mode and the wideband CDMA mode, respectively, and the second local oscillator is that the wideband C
In the case of the DMA mode, a quadrature demodulator with a 1/2 frequency divider circuit can be adopted. Furthermore, by inserting a frequency divider between the second frequency converter / quadrature demodulator and the second local oscillator, and adding means for switching the output of the frequency divider between the second frequency converter and the quadrature demodulator. It is difficult for the wideband CDMA mode reception sensitivity to deteriorate due to the second local oscillation frequency.

The present invention also relates to wideband CDMA / PDC.
When applied to the dual-mode mobile phone terminal, it is advantageous in reducing the size, weight and power consumption of the terminal.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of an embodiment of the present invention.

FIG. 2 is a block diagram showing a relationship of each configuration in the embodiment of the present invention.

FIG. 3 is a block diagram of a wideband CDMA mobile phone terminal wireless unit.

FIG. 4 is a block diagram of a wireless unit of a PDC mobile phone terminal.

FIG. 5 is a block diagram of a wireless unit of a dual mode mobile phone terminal of a conventional wideband CDMA / PDC.

FIG. 6 is a simplified block diagram showing an embodiment of the present invention.

FIG. 7 is a block diagram of wideband CDMA mode reception sensitivity deterioration prevention.

[Explanation of symbols]

1 Internal Antenna 2, 9, 10, 30, 34, 39 Mode Switch 7 PDC Mode Receiver 8 External Antenna 11 Wideband CDMA Mode Antenna Duplexer 16 Wideband CDMA Mode Receiver 21 First Local Oscillator 22 Wideband CDMA Mode Second Voltage controlled oscillator 23 for local oscillator 23 PLL circuit 24 for second local oscillator 24 1/2 fixed sub-cycle 25 Reference frequency oscillator 26 Second local oscillator 29 Wideband CDMA mode transmitter 31 Mode 1/2 sub-cycle 32 Transmission power control amplifier 33 Quadrature modulator 35 Mode control signal 36 PDC mode transmitter 40 Dual mode transmission shared circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-316873 (JP, A) JP-A-9-284166 (JP, A) JP-A-9-261106 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H04B 1/38-1/58

Claims (5)

(57) [Claims] 1. A wideband CDMA mode as an operation mode.
Mode, PDC analog band transmission mode, and PDC
It has a digital band transmission mode and a PDC reception mode
In a multimode wireless device, a reference frequency output from a reference frequency oscillator is input, a first local oscillator that outputs a predetermined frequency, a reference frequency output from the reference frequency oscillator, and a mode control signal are input. , a second local oscillator for outputting a predetermined frequency based on the operation mode, a quadrature modulator for quadrature modulating a baseband signal by an output from the second local oscillator, the output from the first local oscillator, A transmission RF up converter that generates a transmission signal from the output from the quadrature modulator, a reception RF down converter that converts the reception signal to a first intermediate frequency, an output from the RF down converter, and the second local unit. A second frequency converter for mixing the output from the oscillator and converting the first intermediate frequency to a second intermediate frequency; An output from the down converter, by mixing the output from the second local oscillator, a quadrature demodulator for converting the first intermediate frequency to a baseband signal, the second local oscillator and said quadrature modulator It is provided between the inputs and the mode control signal, while and a first frequency divider for varying a frequency division number by the mode control signal, the first frequency divider, the operation mode is PDC analog Band
In the transmission mode, the 1/2 frequency division operation is performed and the PD
C digital band transmission mode and wideband CDMA mode
At this time, the multi-mode wireless device is characterized in that the 1/2 frequency division operation is stopped . 2. A second frequency divider is provided between the second local oscillator and the quadrature demodulator, and between the second local oscillator and the second frequency converter, respectively. The multimode wireless device according to claim 1. Wherein the second frequency dividing the output of the previous SL second local oscillator
Only set a vessel, the multi-mode wireless device of claim 1, wherein the output of said second frequency divider is switched to one of the second frequency converter and the quadrature demodulator. Wherein only each set second frequency divider to prior Kijika交復modulator and said second frequency converter, whether to operate the respective said second frequency divider by the mode control signal multi-mode wireless device of claim 1, wherein the determining. 5. The frequency division number of the first frequency divider is changed so that the oscillation frequency range of the second local oscillator is 1.5 times or less. The multi-mode wireless device as described above.