JP2003258927A - Radio communication device, radio processor, and modulation and demodulation processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an outdoor unit (ODU) that can be shared by indoor units (IDU) using different modulation systems. <P>SOLUTION: An IDU 2 sends out a modulation system signal corresponding to its modulation system as a subcarrier signal by a supervisory control part 24. An ODU 1 recognizes the modulation system of the IDU 2 according to the modulation system signal sent out by the IDU 2, sets the attenuation factor of an attenuator 15 arranged in the pre-stage of a power amplifier 131 according to the recognized modulation system, and then sets the operation point of the power amplifier 131 to a value corresponding to the modulation system of the IDU 2. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device, and more particularly to a wireless communication device, a wireless processing device, and a modulation / demodulation processing device which are composed of an outdoor device and an indoor device and are used in a wireless access system or the like.

[0002]

2. Description of the Related Art Generally, in a wireless communication device used in a wireless access system, a wireless processing device installed outdoors is called an ODU (Out Door Unit), and a modulation / demodulation processing device installed indoors is an IDU (In Door Unit). Door Unit) is called. The ODU and IDU are connected by a coaxial cable by an intermediate frequency signal (IF signal) or the like.

Then, the ODU performs the frequency conversion of the IF signal transmitted from the IDU into a radio signal, amplifies the power with a power amplification circuit (output amplifier), and transmits the power, and the radio signal received by the antenna. It is composed of a function of a receiving system that frequency-converts an IF signal and sends it to the IDU.

By the way, in the above radio processing apparatus,
The back-off amount of the output amplifier of the DU is set appropriately in accordance with the modulation method adopted in the IDU.

That is, as the IDU modulation system becomes multi-level modulation, the amount of information increases, and low distortion characteristics are required. Therefore, in the ODU output amplifier, the backoff amount is increased in order to cope with this. Therefore, the high linearity region of the output amplifier must be used.

For example, the IDU modulation method is QPSK (Qu
adrature phase shift keying), the output amplifier of the ODU needs to be operated by backing off at least 4 dB from P1 dB (1 dB compression point), and the IDU modulation method is 16Q.
In the case of AM (Quadrature Amplitude Modulation), it is necessary to operate the output amplifier of the ODU by backing off from P1 dB by at least about 7 dB.

Therefore, in the conventional radio processing apparatus,
Since the back-off amount of the output amplifier of the ODU was individually set according to the modulation system of the IDU, the ODU corresponding to the different modulation system of the IDU is needed. Therefore, the modulation of the IDU It was necessary to manufacture a plurality of types of ODU corresponding to the system.

Therefore, for example, when the IDU is exchanged in order to change the modulation method of the IDU, it is necessary to exchange the ODU even though it has the same radio frequency.

[0009]

As described above, in the wireless communication device used in the conventional wireless access system and the like, a plurality of types of ODUs having different backoff amounts of output amplifiers are manufactured corresponding to the IDU modulation method. Therefore, there is a problem in that the complexity of management in manufacturing increases, and as a result, the manufacturing cost of the entire device increases.

In view of the above, the present invention makes it possible to share ODUs for a plurality of types of IDUs having different modulation systems, thereby reducing management complexity during manufacturing and reducing costs. An object is to provide a wireless processing device and a modulation / demodulation processing device.

[0011]

In order to achieve the above-mentioned object, a wireless communication apparatus of the present invention includes a wireless processing apparatus for performing transmission / reception processing of a wireless signal and a modulation / demodulation processing for performing modulation / demodulation processing on a transmission / reception signal of a user terminal apparatus. In the wireless communication device configured by connecting to the device, the modulation / demodulation processing device includes a modulation method notifying unit that notifies the modulation processing method of the modulation / demodulation processing device to the wireless processing device. A backoff amount varying means for varying the backoff amount of the transmission power amplification circuit of the wireless processing device based on the modulation system of the modulation / demodulation processing device notified by the modulation system notification device from the modulation / demodulation processing device. Characterize.

Here, the back-off amount varying means is arranged in the preceding stage of the transmission power amplifier circuit, and is based on the modulation system of the modulation / demodulation processing device notified by the modulation system notifying device from the modulation / demodulation processing device. It is characterized by comprising an attenuator for varying an attenuation amount of an input signal input to the transmission power amplifier circuit.

Further, the radio processing apparatus of the present invention is connected to a modulation / demodulation processing apparatus for performing modulation / demodulation processing on a transmission / reception signal of a user terminal apparatus, and in the radio processing apparatus for performing transmission / reception processing of a radio signal, transmission from the modulation / demodulation processing apparatus is performed. And a modulation method information receiving means for receiving modulation method information indicating a modulation method of the modulation / demodulation processing device, and a backoff for varying the backoff amount of the transmission power amplifier circuit based on the modulation method information received by the modulation method information receiving means. And an amount changing means.

Here, the back-off amount varying means is arranged in the preceding stage of the transmission power amplification circuit and varies the attenuation amount of the input signal input to the transmission power amplification circuit based on the modulation method information. It is characterized by including.

Further, the modulation / demodulation processing apparatus of the present invention is connected to a radio processing apparatus for transmitting / receiving a radio signal, and transmits to the radio processing apparatus in the modulation / demodulation processing apparatus for performing a modulation / demodulation processing on a transmission / reception signal of a user terminal apparatus. Modulation method information generating means for generating modulation method information indicating a modulation method of a transmission signal, and modulation for superimposing the modulation method information generated by the modulation method information generating means on the transmission signal and transmitting it to the wireless processing device. A method information transmission means is provided.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a wireless communication device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an example of the configuration of a wireless communication apparatus according to the present invention.

In FIG. 1, the wireless communication device is an outdoor unit (ODU) 1 which is connected to an unillustrated transmitting / receiving antenna and mainly comprises a high frequency circuit for transmitting / receiving a wireless signal.
The indoor unit (IDU) 2 includes an analog / digital circuit that performs modulation / demodulation processing of a communication signal from a user terminal. The ODU1 and the IDU2 are connected by a single coaxial cable 3.

In such a radio communication device, the radio wave received by the antenna (not shown) is passed through the duplexer (DUP) 11 of the ODU 1 and the low noise amplifier (LNA) 1
It is amplified by 21, converted into an intermediate frequency (IF) by the down converter 122, sent out onto the coaxial cable 3 via the splitter (SP) 14, and supplied to the IDU 2.

The intermediate frequency (IF) signal supplied from the ODU1 to the IDU2 is demodulated by the demodulator (DEM) 222 via the splitter 23, and an interface including a LAN interface 10Base-T interface, a USB interface, or the like. Department (INF) 2
1 is supplied to a user terminal (not shown).

A communication signal from the user terminal (hereinafter referred to as a user signal) is input to the IDU 2 from the interface section 21, modulated by the modulator (MOD) 221, sent from the splitter 23 to the coaxial cable 3, and supplied to the ODU 1. To be done.

Here, the supervisory control unit (CON of the IDU 2
T) 24 performs frequency multiplexing processing of a transmission signal (user signal) and a reception signal, a DC power supply to ODU1, and a control signal between IDU2 and ODU1. Further, the monitoring controller 24 multiplexes a signal (modulation method signal) carrying information on the modulation method of the IDU 2 with the above various signals and sends the signal to the ODU 1.

FIG. 2 shows an example of the modulation method signal.

In FIG. 2, the modulation method signal is carried as a 2-bit quaternary modulation method signal fm in a frame subsequent to the reception frequency fR in the control signal frame transmitted by the monitor control unit 24. This modulation method signal fm has QPSK (Quadrature Phase Shift) at “00”.
Keying method, 16QAM (QuadratureAmp) in "01"
64QAM system is associated with the "10".

In the ODU1 splitter 14, the IDU2
The above various signals are separated and extracted from the frequency-multiplexed signal input from the up converter 13 to extract the user signal.
2 and sends the modulation method signal to the monitoring controller 17. Further, the DC power source is sent to the DC / DC converter 18 and used as a power source for each unit.

The monitor control unit (CONT) 17 generates an attenuation rate setting signal for setting the attenuation rate of the attenuator 15 based on the input modulation method signal fm, and outputs this attenuation rate setting signal to D / It is sent to the attenuator (ATT) 15 via the A converter 16. As a result, the attenuation rate of the attenuator (ATT) 15 is set to a value according to the modulation system of the IDU 2.

Here, a method of adjusting the attenuation rate of the attenuator 15 will be described with a specific example.

Generally, in a wireless device, it is desirable to increase the transmission output as much as possible because the transmittable distance can be increased. However, when operating in the saturation region of the amplifier, fixed deterioration occurs. For example, in the case of the QPSK system, P1dB
It is necessary to operate by backing off at least 4 dB from (1 dB compression point). However, this backoff amount needs to be large enough for multi-level modulation, and in the case of 16QAM, for example, backoff must be performed by at least about 7 dB (see FIG. 3).

Therefore, for example, when P1 dB of the power amplifier 131 is 21 dBm, the monitor control unit 17
The IDU2 modulation system is recognized based on the input modulation system signal, and when the IDU2 modulation system is QPSK, the attenuation rate of the attenuator 15 is adjusted so that the operating point of the power amplifier 131 becomes 17 dBm, and the IDU2 When the modulation method of 16QAM is 16QAM, the power amplifier 131
The attenuation rate of the attenuator 15 is adjusted so that the operating point of is 14 dBm.

As a result, even if the modulation system of the IDU 2 changes, the operating point of the power amplifier 131 can be automatically adjusted according to the modulation system. One ODU can be shared.

FIG. 4 is a block diagram showing another example of the circuit configuration of the wireless communication apparatus according to the present invention.

In the radio communication apparatus shown in FIG. 2, the digital communication attenuator (ATT) 15 of the radio communication apparatus shown in FIG.
The A converter 16 is omitted. Its function is similar to that shown in FIG.

[0033]

As described above, according to the present invention, the ODU automatically sets the operating point of the output amplifier according to the modulation system of the IDU. One ODU can be shared, the type of ODU can be reduced, and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a configuration of a wireless communication device according to the present invention.

FIG. 2 is a diagram showing an example of a modulation method signal.

FIG. 3 is a diagram illustrating operating characteristics of an amplifier.

FIG. 4 is a diagram showing another example of the configuration of the wireless communication device according to the present invention.

[Explanation of symbols]

1 Outdoor equipment 2 Indoor equipment 3 coaxial cable 11 Duplexer 121 Low noise amplifier 122 Down Converter 131 Power Amplifier 132 up converter 14 Splitter 15 Attenuator 16 D / A converter 17 Monitoring and control unit 18 D / D converter 21 Interface part 222 demodulator 221 modulator 23 Splitter 24 Monitoring and control unit

Claims (5)

[Claims] 1. A wireless communication device configured by connecting a wireless processing device for performing transmission / reception processing of a wireless signal and a modulation / demodulation processing device for performing modulation / demodulation processing on a transmission / reception signal of a user terminal device, wherein the modulation / demodulation processing device comprises: The modulation / demodulation processing apparatus is provided with a modulation method notifying unit for notifying the radio processing apparatus of the modulation method of the modulation / demodulation processing apparatus, wherein the radio processing apparatus is the modulation / demodulation processing apparatus notified from the modulation / demodulation processing apparatus by the modulation method notifying unit. A wireless communication device comprising a backoff amount varying means for varying a backoff amount of a transmission power amplifier circuit of the wireless processing device based on a modulation method. 2. The back-off amount varying means is arranged in a preceding stage of the transmission power amplifying circuit, and the transmission power is based on the modulation system of the modulation / demodulation processing device notified by the modulation system notifying device from the modulation / demodulation processing device. The wireless communication device according to claim 1, further comprising an attenuator that varies an attenuation amount of an input signal input to the amplifier circuit. 3. A wireless processing device, which is connected to a modulation / demodulation processing device for performing a modulation / demodulation process on a transmission / reception signal of a user terminal device and performs a transmission / reception process of a wireless signal, wherein the modulation method of the modulation / demodulation processing device transmitted from the modulation / demodulation processing device. And a backoff amount varying means for varying the backoff amount of the transmission power amplifier circuit based on the modulation method information received by the modulation method information receiving means. A wireless processing device. 4. The back-off amount varying means comprises an attenuator, which is arranged in front of the transmission power amplification circuit and varies the attenuation amount of an input signal input to the transmission power amplification circuit based on the modulation method information. The wireless processing device according to claim 3, wherein: 5. A modulation / demodulation processing apparatus which is connected to a wireless processing apparatus for transmitting / receiving a wireless signal and performs a modulation / demodulation processing for a transmission / reception signal of a user terminal apparatus, the modulation indicating a modulation method of a transmission signal to be transmitted to the wireless processing apparatus. Modulation method information generating means for generating method information, and modulation method information transmitting means for superimposing the modulation method information generated by the modulation method information generating means on the transmission signal and transmitting it to the wireless processing device. A modulation / demodulation processing device characterized by.