JPH10190514A - Radio communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a packaging area and to miniaturize an equipment by providing a filter means for eliminating the unrequited waves of transmission intermediate frequency signals and reception frequency signals. SOLUTION: In reception, signals received through an antenna 1 are band- limited by an RF filter 2 and supplied to a mixer 4. The output signals of the RF filter 2 are mixed with local signals from a UHF frequency synthesizer 3 in the mixer 4 and converted into reception IF signals. The reception IF signals are supplied through a changeover switch 5 to an IF filter 6 and the unrequired waves are eliminated there. Further, they are supplied through the changeover switch 5 to a quadrature demodulator 8 and quadrature demodulated by the signals from a VHF frequency synthesizer 7 and demodulation signals are outputted to the circuit of a poststage. A timing control part 13 controls the changeover swtich 5 so as to connect the mixed 4 and the IF filter 6 and controls the changeover swtoich 12 so as to connect the IF filter 6 and the quadrature demodulator 8 in reception.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication apparatus, and more particularly, to a TDMA (Time Division M).
The present invention relates to a wireless communication device of a multiple access (multiple access) system.

[0001]

2. Description of the Related Art As a conventional TDMA wireless communication device, there is a wireless communication device shown in FIG. In FIG. 5, the wireless communication device includes RF filters 40 and 41, a mixer 4
2 and 43, oscillators 44 and 45, IF filter 4
6 and 47, a demodulator 48 and a modulator 49.

[0002] A received signal received through an antenna (not shown) is subjected to noise removal by an RF filter 40 and mixed with a local signal from an oscillator 44 by a mixer 42 to be converted into an intermediate frequency (IF) signal. . The IF signal passes through an IF filter 46 and is demodulated by a signal from an oscillator 45 by a demodulator 48.

On the other hand, a modulated signal modulated by a signal from an oscillator 45 by a modulator 49 is converted to an RF signal by a local signal from an oscillator 44 by a mixer 43 via an IF filter 47. The RF signal is transmitted from the antenna via an RF filter.

In such a wireless device, two mixers must be used, which hinders miniaturization and cost reduction of the device.

Therefore, in the TDMA system, the technique of stopping the signal processing of the transmission system at the time of reception and stopping the signal processing of the reception system at the time of transmission is considered.
For example, it is described in Japanese Unexamined Patent Publication No. Hei.

FIG. 6 is a block diagram showing the configuration of a TDMA wireless communication apparatus described in this document.

In FIG. 6, a radio communication apparatus includes an antenna 51, a transmission / reception switching circuit 52, amplifiers 53 and 60, an RF
It comprises filters 54 and 59, a mixer 55, a local oscillator 56, a demodulator 57, a modulator 58, and changeover switches 61 and 62.

[0008] The basic operation of this radio communication apparatus is the same as that of the radio communication apparatus shown in FIG. 5, and a description thereof will be omitted, and only different operations will be described below.

When the RF signal a is input from the RF filter 54, the IF signal c output from the mixer 55 is guided to the demodulator 57. On the other hand, when the IF signal d is input from the modulator 58, the IF signal c is output from the mixer 55. To the RF filter 59.

That is, when the changeover switch 61 selects the modulator 58 side, the changeover switch 62 sets the RF filter 5
When the switch 9 is selected and the changeover switch 61 selects the RF filter 54 side, the changeover switch 62 selects the demodulator 57 side.

[0011]

However, in the above-mentioned conventional wireless communication device, it is necessary to use two IF filters having the same pass frequency band, so that the circuit scale becomes large, and the size or weight of the device is reduced. I can't do it.

Further, it is impossible to achieve high integration and to simplify the device configuration.

An object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide an improved wireless communication device.

Another object of the present invention is to solve the above-mentioned problems and to provide a wireless communication device capable of reducing a circuit mounting area.

Still another object of the present invention is to provide a wireless communication apparatus which solves the above-mentioned problems, reduces the mounting area of the circuit, and enables the whole apparatus to be downsized.

[0016]

In order to achieve the above-mentioned object, a radio communication apparatus according to the present invention comprises a modulating means for converting a signal to be transmitted to a transmission intermediate frequency signal, and a transmitting high frequency signal for transmitting the transmission intermediate frequency signal. First frequency conversion means for converting the signal into a signal, transmission means for transmitting the transmission high-frequency signal, reception means for receiving a high-frequency signal from a base station or another station, and the received high-frequency signal as the transmission intermediate frequency signal. Second for converting to a reception intermediate frequency signal having substantially the same frequency
Frequency conversion means, demodulation means for demodulating the reception intermediate frequency signal, and filter means for removing unnecessary waves of the transmission intermediate frequency signal and the reception frequency signal.

[0017] Preferably, there is provided switching means connected to the filter means for switching between the reception intermediate frequency signal and the transmission intermediate frequency signal and supplying the signal to the filter means.

Further, the radio communication apparatus according to the present invention comprises a modulating means for modulating a signal to be transmitted and outputting a transmission intermediate frequency signal, a demodulation means for demodulating a reception intermediate frequency signal, Filter means for switching and passing a reception frequency signal, first conversion means for converting a transmission intermediate frequency signal passed through the filter means to a transmission high frequency signal, and reception means for receiving a signal from a base station or another device And second converting means for converting the received high-frequency signal received by the receiving means into the received intermediate frequency signal.

The filter means may be the first or second filter means.
A first switching means for connecting to one of the conversion means, a second switching means for connecting the filter means to one of the modulation means or the demodulation means, and a control means for controlling the first and second switching means. Control means for controlling the transmission of either the transmission intermediate frequency signal or the reception intermediate frequency signal.

Preferably, power is supplied to the receiving means when receiving the high-frequency signal, and power is supplied to the transmitting means when transmitting the high-frequency signal.

It is preferable that a frequency synthesizer for supplying a first transmission local signal and a second reception local signal having different frequencies to the first and second frequency conversion means is provided.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a structural block diagram showing a preferred embodiment of the present invention.

In FIG. 1, a radio communication apparatus includes an antenna 1, RF filters 2 and 11, a UHF frequency synthesizer 3, mixers 4 and 10, and changeover switches 5 and 1.
2, IF filter 6, VHF frequency synthesizer 7, quadrature demodulator 8 and quadrature modulator 9, timing controller 13
Consists of

At the time of reception, a signal received via the antenna 1 is band-limited by the RF filter 2 and supplied to the mixer 4. The output signal of the RF filter 2 is mixed by the mixer 4 with the local signal from the UHF frequency synthesizer 3 and converted into a reception IF signal. The received IF signal is supplied to an IF filter 6 via a changeover switch 5, where unnecessary waves are removed.
Is supplied to the quadrature demodulator 8 through The received IF signal supplied to the quadrature demodulator 8 is quadrature-demodulated by a signal from the VHF frequency synthesizer 7, and the demodulated signal is output to a subsequent circuit (not shown).

On the other hand, at the time of transmission, the signal to be transmitted is modulated by the signal from the VHF frequency synthesizer 7 in the quadrature modulator 9 and the modulated signal, that is, the transmission IF
The signal is filtered by an IF filter 6 through a changeover switch 12 to remove unnecessary waves.
Supplied to The transmission IF signal is frequency-converted by the local signal from the UHF frequency synthesizer 3 in the mixer 10, band-limited by the RF filter 11, and then transmitted from the antenna 1.

The timing control unit 13 controls the changeover switch 5 to connect the mixer 4 and the IF filter 6 during reception, and controls the changeover switch 12 to connect the IF filter 6 and the quadrature demodulator 8. On the other hand, at the time of transmission, the changeover switch 5 is controlled so as to connect the mixer 10 and the IF filter 6, and the changeover switch 12 is controlled so as to connect the IF filter 6 and the quadrature modulator 9.

Further, the timing control section 13 controls the frequency of the oscillation local signal of the UHF frequency synthesizer 3 such that the frequency of the reception IF signal and the frequency of the transmission IF signal at the time of reception and transmission are in the same frequency band. .

The operation of the changeover switches 5 and 12 by the timing control unit 13 will be described with reference to FIG.

In FIG. 2, changeover switches 5 and 12
Is a three-point switch, terminals a and b are movable contacts, and terminal c is a fixed contact.

FIG. 2A shows a receiving state. In the changeover switch 5, the fixed contact c connected to the IF filter 6 is shown.
Is connected to the movable contact a connected to the receiving mixer 4. On the other hand, the movable contact b connected to the transmission-side mixer 10 is opened.

In the changeover switch 12, the fixed contact c connected to the IF filter 6 is connected to the movable contact a connected to the quadrature demodulator 8. On the other hand, the movable contact b connected to the quadrature modulator 9 is opened.

In this state, the received IF signal from the mixer 4 is supplied from the changeover switch 5 to the changeover switch 12 via the IF filter 6 and further to the quadrature demodulator 8.

FIG. 2B shows a transmission state. In the changeover switch 5, the fixed contact c connected to the IF filter 6 is set.
Is connected to the movable contact b connected to the transmission-side mixer 10. On the other hand, the movable contact a connected to the receiving mixer 4 is opened.

In the change-over switch 12, the fixed contact c connected to the IF filter 6 is connected to the movable contact b connected to the quadrature modulator 9, and the movable contact a connected to the quadrature demodulator 8 is opened.

In this state, the transmission I from the quadrature modulator 9
The F signal is supplied from the changeover switch 12 to the changeover switch 5 via the IF filter 6, and further supplied to the transmission-side mixer 10.

In the above-described embodiment, the quadrature demodulation and the quadrature modulation are applied to the demodulator and the modulator. However, the present invention is not limited to this.

Further, it is preferable that the above-mentioned wireless communication device is a portable telephone device.

FIG. 3 is a block diagram showing the configuration of the portable telephone device of the present invention. 3, components having the same functions as those in FIG. 1 are denoted by the same reference numerals.

In FIG. 3, the portable telephone device includes an antenna 1, a UHF frequency synthesizer 3, mixers 4 and 1
0, changeover switches 5 and 12, IF filter 6, VH
It comprises an F-frequency synthesizer 7, a quadrature demodulator 8 and a quadrature modulator 9, a timing controller 13, a receiver 20 and a transmitter 21.

The receiving section 20 has at least an amplifier 15 for amplifying a received signal and an RF filter 2 for removing unnecessary waves. In addition, the transmission unit 21 has at least the RF filter 11 that removes unnecessary waves of the transmission RF signal from the mixer 10 and the amplifier 18 that amplifies the RF signal.

At the time of reception, a signal received by the receiver 20 via the antenna 1 is amplified by the amplifier 15, band-limited by the RF filter 2, and supplied to the mixer 4. The output signal of the receiving unit 20 is
The signal is mixed with the reception local signal from the HF frequency synthesizer 3 and converted into a reception IF signal. The received IF signal is supplied to an IF filter 6 via a changeover switch 5, where unnecessary waves are removed, and further supplied to a quadrature demodulator 8 via a changeover switch 12. The received IF signal supplied to the quadrature demodulator 8 is quadrature-demodulated by a signal from the VHF frequency synthesizer 7, and the demodulated signal is output to a subsequent circuit (not shown).

On the other hand, at the time of transmission, the signal to be transmitted is modulated by the signal from the VHF frequency synthesizer 7 in the quadrature modulator 9 and the modulated signal, that is, the transmission IF
The signal is filtered by an IF filter 6 through a changeover switch 12 to remove unnecessary waves.
Supplied to The transmission IF signal is frequency-converted by the transmission local signal from the UHF frequency synthesizer 3 in the mixer 10, the unnecessary wave is removed and amplified by the transmission unit 21, and then transmitted from the antenna 1.

The timing control section 22 turns on the receiving section 20 at the timing of receiving a signal from a base station (not shown). That is, a switch for supplying power to the receiving unit 20 is turned on. On the other hand, at this time, the transmission unit 21 is turned off.

Conversely, at the timing of transmitting a signal to the base station, the transmitting unit 21 is turned on and the receiving unit 20 is turned off.

The timing control section 22 controls the changeover switch 5 to connect the mixer 4 and the IF filter 6 at the reception timing, and sets the changeover switch 12 to connect the IF filter 6 and the quadrature demodulator 8 at the reception timing. Control. On the other hand, at the transmission timing, the changeover switch 5
Control is performed to connect the F filter 6, and the changeover switch 12 is controlled to connect the IF filter 6 and the quadrature modulator 9.

Further, the timing control section 22 controls the frequency of the oscillation local signal of the UHF frequency synthesizer 3 so that the frequency of the reception IF signal and the frequency of the transmission IF signal at the time of reception and transmission are in the same frequency band. .

FIG. 4 is a diagram for explaining a signal format in GSM applied to a communication system using a portable telephone device and ON / OFF timing of a transmission / reception unit.

In FIG. 4A, communication between the base station and the portable telephone device is composed of a plurality of frames, and each frame is divided into eight time slots TS0 to TS7.
In each telephone device, transmission and reception timings are determined in advance, and in this embodiment, as shown in FIG. 4B, a time slot TS0 is assigned to reception, and a time slot TS3 is assigned to transmission. I have.

In the timing control section 22 shown in FIG.
As shown in FIG. 4C, the receiving unit 20 is turned on in the time slot TS0, and the transmitting unit 21 is turned on in the time slot TS3 as shown in FIG. 4D.

The power is turned on prior to the start time of the reception and transmission time slots in consideration of the stability of each circuit when the power is changed from off to on and the time from the start of oscillation of the frequency synthesizer to the stabilization. Is preferred.

Further, it is preferable that the receiving unit is turned off only during the period when the transmitting unit is turned on.

[0053]

An advantage of the present invention is that the number of IF filters can be reduced. As a result, the circuit mounting area can be reduced, and the overall size of the portable wireless device can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of a preferred embodiment of the present invention.

FIG. 2 is a view for explaining the operation of the changeover switch shown in FIG. 1;

FIG. 3 is a configuration block diagram showing another preferred embodiment of the present invention.

FIG. 4 is a view for explaining a switching operation of a transmission unit and a reception unit shown in FIG. 3;

FIG. 5 is a configuration block diagram showing a conventional example.

FIG. 6 is a configuration block diagram showing another conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 antenna 2, 11 RF filter 3 UHF frequency synthesizer 4, 10 mixer 5, 12 selector switch 6 IF filter 7 VHF frequency synthesizer 8 quadrature demodulator 9 quadrature modulator 13, 22 timing control unit 15, 18 amplifier

Claims (7)

[Claims] A modulator for converting a signal to be transmitted into a transmission intermediate frequency signal; a first frequency converter for converting the transmission intermediate frequency signal into a transmission high frequency signal; and a transmission unit for transmitting the transmission high frequency signal. Receiving means for receiving a high-frequency signal from a base station or another station; second frequency converting means for converting the received high-frequency signal into a reception intermediate frequency signal having substantially the same frequency as the transmission intermediate frequency signal; A wireless communication device comprising: a demodulation unit that demodulates an intermediate frequency signal; and a filter unit that removes unnecessary waves of the transmission intermediate frequency signal and the reception frequency signal. 2. The wireless communication apparatus according to claim 1, further comprising a switching unit connected to the filter unit, for switching between the reception intermediate frequency signal and the transmission intermediate frequency signal and supplying the signal to the filter unit. . 3. A modulating means for modulating a signal to be transmitted to output a transmission intermediate frequency signal, a demodulation means for demodulating a reception intermediate frequency signal, and switching between the transmission intermediate frequency signal and the reception frequency signal to pass therethrough. Filter means for converting, a first conversion means for converting a transmission intermediate frequency signal having passed through the filter means to a transmission high frequency signal, a reception means for receiving a signal from a base station or another device, and a reception means for receiving the signal. And a second converter for converting the received high-frequency signal into the received intermediate frequency signal. 4. A first switching means for connecting the filter means to one of the first or second conversion means, and a second switching means for connecting the filter means to one of the modulation means or the demodulation means. Means, and control means for controlling the first and second switching means to control any one of the transmission intermediate frequency signal and the reception intermediate frequency signal to pass therethrough. The wireless communication device according to claim 3, wherein: 5. The apparatus according to claim 3, wherein power is supplied to said reception means when receiving said reception high-frequency signal, and power is supplied to said transmission means when transmitting said transmission high-frequency signal. The wireless communication device according to claim 1. 6. The radio communication apparatus according to claim 3, wherein the transmission intermediate frequency signal and the reception intermediate frequency signal have substantially the same frequency. 7. The radio according to claim 6, further comprising a frequency synthesizer for supplying a first transmission local signal and a second reception local signal having different frequencies to the first and second frequency conversion means. Communication device.