JPH11112382A - Dual-band radio communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a circuit small-sized by switching 1st radio communication which uses signals of transmission and reception of respective frequencies of 1st transmission and 1st reception and 2nd radio communication which uses signals of transmission and reception of frequencies of 2nd transmission and 2nd reception. SOLUTION: A base band part 111 outputs a control signal 127 for switching between both systems of the 800 MHz band and 1900 MHz band to switches 102, 105, 113, and 117. A 1st frequency conversion part is used in common for transmission and reception of the 800 MHz band and 1900 MHz band, but performs up and down conversion of the frequencies by a PLL 1:109 and a PLL 2:116 since the frequency difference of the transmission and reception of the 800 MHz band is different from those of respective IFs and performs up and down conversion only by the PLL 1:109 since the difference of the transmission and reception frequencies of the 1900 MHz band is equal to the difference in frequency of transmitting and receiving IFs. A 2nd frequency conversion part converts 800 MHz-band transmitting signals to the 1900 MHz band and 1900 MHz-band receive signals to 800 MHz-band receive signals by a PLL 2:116.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual-band radio communication apparatus in a plurality of systems using two frequency bands, each of which uses a different frequency bandwidth.

[0002]

2. Description of the Related Art In recent years, various wireless communication devices such as portable telephones have become widespread. These wireless communication devices have a plurality of different communication systems depending on the standard. For example,
The communication system is U.S.
ADC (North American Digital Cellular) system and US PCS (Personal Co.
mmunications Services) system or digital 800
PDC (Personal Dig) using the MHz and 1500 MHz bands
There are standards such as the ital Cellular) system.

[0003] Normally, a wireless communication device is compatible with any one standard, but recently, a dual band wireless communication device compatible with two different frequency band standards has been desired. FIG. 6 is a block diagram showing a configuration of a conventional dual band wireless communication device. In the figure, a dual-band wireless communication apparatus is an 800 MHz band NADC system (for example, IS-
95A standard CDMA system, hereinafter abbreviated as 800MHz band system)
And 1900MHz band PCS system (for example, J-STD-008 standard C
DMA system (hereinafter abbreviated as 1900 MHz band system).

[0004] Specifically, in an 800 MHz band system, transmission and reception radio frequency bands are 824 to 8 respectively.
49 MHz, 869-894 MHz. For 1900MHz band system, 1850-1910MHz, 1930 ~
1990 MHz. 800MHz band system, 1900MHZ
The channel spacing of the z-band system is 30 kHz, 5
It is 0 kHz.

[0005] Switching between the 800 MHz band system and the 1900 MHz band system is performed by switching the switching SWs (switches) 202, 208, and 216 in accordance with a control signal 227 output from a BB (baseband) unit 211. That is, SW202, 2
When all 08 and 216 are switched to the a side, the dual band wireless communication apparatus operates in the 800 MHz band system,
When all of W202, 208, and 216 are switched to the b side, it operates in the 1900 MHz band system.

[0006] The dual-band wireless communication apparatus shown in FIG.
The 00 MHz band system and the 1900 MHz band system are independently configured. The frequency difference between the BPF 209 and the BPF 217 is adjusted to the frequency difference between the transmission frequency and the reception frequency of the 1900 MHz band system.
At 3, the transmission signal and the reception signal are frequency-converted. 800
The frequency difference between the transmission frequency and the reception frequency of the MHz band system is different from the frequency difference between the BPF 209 and the BPF 217. Therefore, in the 800 MHz band system, PLL1207
And PLL2215 for frequency conversion.

Therefore, the dual-band wireless communication apparatus shown in FIG. 1 requires three PLLs. FIG. 7 is a block diagram of a dual band wireless communication device having a second conventional configuration. In FIG. 7, a PLL 1307 is a transmission / reception common RF frequency synthesizer in the 800 MHz band, and generates RX / TXLO (transmission / reception common local signal) in a 25 MHz frequency band of 694 to 719 MHz and a 30 kHz frequency interval.

The PLL 2322 is a transmission / reception common RF frequency synthesizer in the 1900 MHz band, like the 223 of the PLL 3 in FIG. 6, and generates RX / TXLO in a 60 MHz frequency band of 1720 to 1780 MHz and at a frequency interval of 50 kHz.
FIG. 7 shows the reception IF when receiving in the 800 MHz band system.
Becomes 175 MHz, and the reception IF differs from 210 MHz at the time of reception in the 1900 MHz band system. Therefore, the reception IFBPF of each system is BPF308 and BPF323.
Is required separately, and the filter output is switched by SW3
The selection is switched at 09.

[0009]

However, in the above-mentioned prior art, there is a problem that the two systems need to have independent radio circuit parts, and the circuit scale becomes large. Specifically, in the case of FIG. 6, the RFPLL has two PLL1207s and two PLL2215s for the 800 MHz band,
One PLL 3223 for the 1900 MHz band is required, for a total of three. As the number of PLLs increases, the number of control signals supplied from the BB unit 11 to each PLL for frequency setting increases, which leads to a problem of wiring space and an increase in the number of pins allocated to control signals of ICs used in the BB unit. Become.

In the case of FIG. 7, the BPF at the reception IF is a BPF 308 for the 800 MHz band and a BPF 323 for the 1900 MHz band.
Requires two separate filters. Normally, the lower the frequency, the larger the shape of the filter for maintaining the same characteristics, and therefore the smaller the number of filters in the IF unit, the better. Therefore, there is a problem that the circuit space also becomes large in FIG.

The present invention has been made in view of the above problems, and has as its object to provide a dual-band wireless transmission device capable of downsizing a circuit.

[0012]

In order to solve the above-mentioned problems, a first transmission frequency selected from a first frequency band and a first transmission frequency are selected.
A first wireless communication using a reception frequency; a second transmission frequency selected from a second frequency band higher than the first frequency band;
What is claimed is: 1. A dual-band wireless communication device for performing second wireless communication using a reception frequency, comprising: first transmission conversion means for converting a transmission signal of a transmission intermediate frequency into a transmission signal of a first transmission frequency; A first reception conversion unit for converting the reception signal of the first transmission frequency into a reception signal of an intermediate frequency for reception, a second transmission conversion unit for converting a transmission signal of the first transmission frequency into a transmission signal of a second transmission frequency, A second reception converting means for converting the received signal of the first reception frequency into a reception signal of the first reception frequency;
A first wireless communication using the transmission signal of the transmission frequency and the reception signal of the first reception frequency;
Switching means for switching between the second wireless communication using the reception signal of the reception frequency.

The first transmission conversion means includes a first local oscillator for generating a first local signal, and a first transmission frequency for converting a transmission intermediate frequency to a first transmission frequency using the first local signal. A first localization unit that generates a second local signal; and a first localization unit that frequency-converts the first reception frequency to a reception intermediate frequency using the second local signal. A reception frequency conversion unit,
The second transmission conversion unit has a second transmission frequency conversion unit that converts the first transmission frequency to a second transmission frequency using one of the first local signal and the second local signal. And a second reception frequency conversion unit configured to convert the second reception frequency to the first reception frequency using the one local signal.

When the intermediate frequency for reception is RIF, the intermediate frequency for transmission is TIF, the first reception frequency is f1R, the first transmission frequency is f1T, the second reception frequency is f2T, and the second transmission frequency is f2R, The frequency difference | f2R-f2T | is the frequency difference | f1R-f
1T | and RIF and TIF are | RIF−TIF | = |
f1R−f1T | or | RIF−TIF | = | f2R−f2T |.

[0015] The switching means switches to supply a second local signal to the first reception frequency conversion unit during the first wireless communication and a first local signal during the second wireless communication. The input / output of the antenna is such that the transmission signal of the first transmission frequency and the reception signal of the first reception frequency are transmitted and received, and the transmission signal of the second transmission frequency and the reception signal of the second reception frequency are transmitted and received during the second wireless communication. And an antenna switch unit for switching between them.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 is a block diagram showing a configuration of a dual band wireless communication apparatus according to a first embodiment of the present invention. In this example, a configuration example of a dual-band wireless communication apparatus that supports a 800 MHz band NADC system in the United States (for example, CDMA system of IS-95A standard) and a 1900 MHz band PCS system (for example, CDMA system of J-STD-008 standard) is shown. Is shown.

Specifically, transmission and reception frequency bands in an 800 MHz band NADC system (hereinafter, abbreviated as 800 MHz band system) are 824 to 849 MHz and 869 to 894 MHz, respectively.
And the channel interval is 30 kHz. Similarly, in PCS systems, 1850-1910 MHz, 1930-1990 MHz
It is 50kHz. The present dual-band wireless communication apparatus includes an antenna 101 for transmitting and receiving a wireless signal, a switch (SW in FIG.
5, 113, 117 and a duplexer (DUP in the figure) 1 which is a filter for separating transmission / reception signals of the same system.
03, 120; low-noise amplifiers (LNA in the figure) 104 and 121 for amplifying the received signal with low noise; high-power amplifiers (PA in the figure) 112 and 124 for amplifying and outputting the transmission signal to a predetermined level; Bandpass filters (BPF in the figure) 106, 108, 11
4, 118, 122, 125, mixers 107, 115, 123, 126 for frequency conversion, and PLL 1109, PLL 211 for generating a local signal as a frequency synthesizer
6, a reception IF unit 110, a transmission IF unit 119, a baseband (BB in the figure) unit 111, and a control signal 127 output from the baseband unit and supplied to a changeover switch to perform switching. 800MHz band NAD
The system is configured to switch between the C system and the 1900 MHz band PCS system.

FIG. 1 can be broadly divided into a baseband section 111, an IF section, a first frequency conversion section, a second frequency conversion section, and an antenna section. <Baseband unit 111> The baseband unit 111
Control signals 127 for switching between the 00 MHz band system and the 1900 MHz band system are transmitted to the switches 102, 105, and 1.
13 and 117. That is, when operating as an 800 MHz band system, the baseband unit 111
Outputs a control signal 127 so that all the switches 102, 105, 113, and 117 are switched to the a side, and when operating as a system in the 1900 MHz band, b
The control signal 127 is output to switch to the side. <IF section> The IF section has a reception IF section 110 and a transmission IF section 119, and mutually converts a baseband signal and an IF signal.

The reception IF is 210 MHz and the transmission IF is 130 M
The frequency is set to Hz because the frequency difference is adjusted to the frequency difference between the transmission frequency and the reception frequency in the 1900 MHz band. <First Frequency Converter> The first frequency converter converts the transmission IF signal into an 800 MHz band transmission signal, and converts the 800 MHz band reception signal into a reception IF signal. The first frequency conversion unit is 8
The transmission and reception in the 00 MHz band and the transmission and reception in the 1900 MHz band are shared, but when transmitting and receiving in the 800 MHz band, the frequency difference between the reception IF and the transmission IF is different from the frequency difference between the transmission frequency and the reception frequency in the 800 MHz band. So, PLL1109, PL
Frequency up-conversion and down-conversion are performed using two of L2116. When transmitting and receiving in the 1900 MHz band, the frequency difference between the reception IF and the transmission IF is 1900 MHz.
Since the frequency difference between the transmission frequency and the reception frequency of the band is the same, up-conversion and down-conversion of the frequency are performed using one PLL 1109.

The RFPLL 1109 covers a wider frequency bandwidth (60 MHz in this case) of the two systems. The RFPLL 2116 covers a narrow system-side frequency bandwidth (25 MHz) and also functions as a fixed oscillator for frequency conversion (1061 MHz fixed oscillation) of the second system. In this case, the total number of local oscillators is 107
Covers MHz frequency bandwidth.

The frequency synthesizers RFPLL1109 and RFPLL2
Since 116 variable steps correspond to 2 systems, 8
1900 in 30kHz frequency step when operating in 00MHz band
During operation in the MHz band system, control is performed by the BB unit 111 to set a frequency step of 50 kHz. Where 800
When operating as a MHz band system, PLL1109 and PLL211
6 are 1079MHz ~ 1104MHz and 954MHz ~
The frequency can be varied in a 25 MHz band up to 979 MHz. The start signal outputs of the PLL 1109 and the PLL 2116 are output as the RX local signal and the TX local signal, respectively.
07 and a switch 117 are input to the transmission mixer 115.

When operating as a 1900 MHz band system, P
LL1109 has 10
The frequency is changed in the band of 60 MHz from 79 to 1139 MHz, and is input to the transmission mixer 115 via the reception mixer 107 and the changeover switch 117. On the other hand, PLL2116
It oscillates at a fixed frequency of 1 MHz and converts the received signal of the 1900 MHz band to 800
The signals are input to the reception mixer 123 and the transmission mixer 126 as fixed local signals for converting the frequency of the transmission signal of the 800 MHz band to the frequency band of 1900 MHz. <Second frequency converter> The second frequency converter is 800 MHz
Band transmission signal to 1900MHz transmission signal, 1900M
PLL2116 converts the received signal in the Hz band to the received signal in the 800 MHz band.
Is converted using. Further, the pass bandwidths of the BPFs 106 and 114 are adjusted to a wider system side (in this case, 60 MHz of the second system) among the used frequency bandwidths of the two systems. <Antenna unit> The antenna unit switches the 800 MHz band received signal input from the antenna 101 to the switch 10.
2 to the duplexer 103, and conversely 800
A transmission signal in the MHz band is transmitted from the output of the duplexer 103 to the antenna 101 via the changeover switch 102. Also, a 1900 MHz band reception signal is input to the duplexer 120 via the changeover switch 102, and conversely, a 1900 MHz band transmission signal is transmitted from the duplexer 120 output from the antenna 101 via the changeover switch 102. (Second Embodiment) FIG. 2 is a block diagram showing a configuration of a dual band wireless communication device of a second embodiment. In the figure, description of the same points as in the configuration of FIG. 1 will be omitted, and only different points will be described below.

FIG. 2 shows that the PLL 2116 of FIG.
3 and 126, except that a fixed oscillator 21 is newly provided instead of also serving as a fixed oscillator. When operating in an 800 MHz band system, PLL1
23 and the PLL 224 to perform frequency conversion, respectively, and operate in a 1900 MHz band system.
The frequency conversion of the transmission signal and the reception signal is performed using only 224.

Note that, instead of FIG. 2, FIG.
2, 25, PLL 123, and PLL 224 are configured to have different values. (Third Embodiment) FIGS. 4 and 5 are block diagrams showing the configuration of a dual-band wireless communication apparatus according to a third embodiment.

FIG. 4 is different from FIG. 2 in that only one PLL is used.
The difference is that two fixed oscillators 42 and 43 are provided. FIG.
Is the PLL for the 1900MHz band system compared to FIG.
Have different variable frequency ranges. 2 is realized by one PLL as compared with FIG. 2, so that the circuit scale can be further reduced as compared with FIG.

[0026]

As is apparent from the above description, the dual-band radio communication device according to the present invention is capable of performing the first radio communication using the first transmission frequency and the first reception frequency selected from the first frequency band. A dual-band wireless communication apparatus for performing second wireless communication using a second transmission frequency selected from a second frequency band higher than the first frequency band and a second reception frequency, the transmission signal having a transmission intermediate frequency. To a transmission signal of a first transmission frequency, a first reception conversion means of converting a reception signal of the first reception frequency to a reception signal of an intermediate frequency for reception, and a transmission signal of the first transmission frequency The second
Second transmission conversion means for converting the transmission signal into a transmission signal having a transmission frequency;
A second reception conversion means for converting a reception signal of the second reception frequency into a reception signal of the first reception frequency, a first wireless communication using the transmission signal of the first transmission frequency and the reception signal of the first reception frequency, Switching means for switching between a transmission signal at the transmission frequency and a second wireless communication using the reception signal at the second reception frequency; Thereby, the first transmission conversion unit and the first reception conversion unit are shared by the first wireless communication and the second wireless communication,
This has the effect of reducing the circuit scale.

The first transmission conversion means includes a first local oscillator for generating a first local signal, and a first transmission frequency converter for frequency-converting a transmission intermediate frequency to a first transmission frequency using the first local signal. Wherein the first reception conversion means includes: a second local oscillation section for generating a second local signal; and a first reception frequency for converting the first reception frequency to a reception intermediate frequency using the second local signal. A second transmission conversion unit for converting the first transmission frequency to the second transmission frequency using one of the first local signal and the second local signal. The second reception conversion means includes a second reception frequency conversion unit that converts the second reception frequency to the first reception frequency using the one local signal. As a result, one of the first local transmission section and the second local transmission section is used also as the second transmission conversion section and the second reception conversion section, and the circuit scale is further reduced in addition to the same effect as described above. There is an effect that.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a dual band wireless communication device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a dual band wireless communication device according to a second embodiment.

FIG. 3 is a block diagram illustrating another configuration of the dual band wireless communication device according to the second embodiment.

FIG. 4 is a block diagram illustrating a configuration of a dual band wireless communication device according to a third embodiment.

FIG. 5 is a block diagram showing another configuration of the dual band wireless communication device according to the third embodiment.

FIG. 6 is a block diagram showing a configuration of a conventional dual band wireless communication device.

FIG. 7 is a block diagram illustrating another configuration of a conventional dual-band wireless communication device.

[Explanation of symbols]

101 antenna 102, 105, 113, 117 switch 103, 120 duplexer 104, 121 low-noise amplifier 112, 124 transmission power amplifier 106, 108, 114, 118, 122, 125 band-pass filter 107, 115, 123, 126, mixer 109, 116 Frequency synthesizer 110 Receive IF section 119 Transmit IF section 111 Baseband section

Claims (4)

[Claims] 1. A first wireless communication using a first transmission frequency and a first reception frequency selected from a first frequency band, and a second transmission frequency and a second transmission frequency selected from a second frequency band higher than the first frequency band. A dual-band wireless communication device that performs a second wireless communication using a second reception frequency, wherein the first transmission conversion unit converts a transmission signal of a transmission intermediate frequency into a transmission signal of a first transmission frequency; First reception conversion means for converting a reception signal of a reception frequency into a reception signal of an intermediate frequency for reception; second transmission conversion means for converting a transmission signal of the first transmission frequency to a transmission signal of a second transmission frequency; A second reception conversion means for converting a reception signal of the reception frequency into a reception signal of the first reception frequency, a first radio communication using the transmission signal of the first transmission frequency, the reception signal of the first reception frequency, and a second transmission frequency Transmission signal and second reception Dual-band wireless communication device characterized by comprising a switching means for switching the second wireless communication using a reception signal wave number. 2. A first transmission conversion means, comprising: a first local oscillation section for generating a first local signal; and a first transmission frequency for converting a transmission intermediate frequency to a first transmission frequency using the first local signal. A first localization oscillator that generates a second local signal; and a first localization unit that frequency-converts the first reception frequency to a reception intermediate frequency using the second local signal. A second transmission conversion means for converting a first transmission frequency to a second transmission frequency using one of the first local signal and the second local signal. The second reception conversion means has a first reception frequency using the one of the local signals.
The dual-band wireless communication device according to claim 1, further comprising a second reception frequency conversion unit that converts a frequency to a reception frequency. 3. An intermediate frequency for reception is RIF, an intermediate frequency for transmission is TIF, a first reception frequency is f1R, and a first transmission frequency is f1.
T, the second reception frequency is f2T, and the second transmission frequency is f2R, the frequency difference | f2R−f2T | is different from the frequency difference | f1R−f1T |, and RIF and TIF are | RIF-TIF | = | F1R-f1T | or | RIF
3. The dual-band wireless communication apparatus according to claim 2, wherein -TIF | = | f2R-f2T | is determined. 4. A switch unit for switching to supply a second local signal to the first reception frequency conversion unit during the first wireless communication and a first local signal during the second wireless communication, and a first wireless communication unit. The input / output of the antenna is such that the transmission signal of the first transmission frequency and the reception signal of the first reception frequency are transmitted and received, and the transmission signal of the second transmission frequency and the reception signal of the second reception frequency are transmitted and received during the second wireless communication. The dual-band wireless communication device according to claim 2, further comprising an antenna switch unit that switches between the two.