JP2003209477A - Automatic gain control device and automatic gain control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic gain control device in which an initial convergence time can be shortened by setting the initial value of a gain suitable for obtaining a desired received signal level. <P>SOLUTION: When starting a communication, the received signal level is predicted from present location information measured by using a GPS system and a distance to a communicating party station, and in a variable gain amplifier 101, a predictive gain for obtaining the desired received signal level is defined as an initial value. Thus, even when fluctuating a received electric field level in a short period of time by phasing or the like in the case of starting the next communication, the initial value of the gain suitable for obtaining the desired received signal level can be set when starting the communication. <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 an automatic gain control device and an automatic gain control method suitable for use in a mobile station such as a mobile phone in a mobile communication system and a base station that wirelessly communicates with the mobile station.

[0002]

2. Description of the Related Art Conventionally, in a mobile station such as a mobile phone in a mobile communication system or a base station which performs radio communication with this mobile station, an automatic gain control of an amplifier is automatically controlled so that a received signal level becomes a desired level. A gain control device is provided. The automatic gain control device requires the initial value of the gain of the variable gain amplifier at the start of communication such as when the power of the device main body is turned on, when intermittent reception is performed, or when the reception frequency is switched. As a conventional automatic gain control device having a function of setting the initial value of the gain, there is one disclosed in, for example, Japanese Patent Laid-Open No. 59-204306. The automatic gain control device disclosed in this publication holds the previous gain value of the variable gain amplifier and sets the value as the next initial value to shorten the time required for initial convergence at the start of communication. ing.

[0003]

However, in the conventional automatic gain control apparatus, the time until the gain converges by holding the previous gain value of the variable gain amplifier and setting that value as the next initial value. However, if the received electric field level fluctuates in a short time due to fading at the start of the next communication, it is difficult to obtain a desired gain in the initial state.

The present invention has been made in view of the above points, and an automatic gain control device and an automatic gain control method capable of setting an appropriate initial value of gain for obtaining a desired received signal level at the start of communication. The purpose is to provide.

[0005]

An automatic gain control device according to a first aspect of the present invention is a variable gain amplifying means capable of gain control, and a level of a received signal amplified by the variable gain amplifying means reaches a desired level. The predictive reception signal level is calculated from the control means for controlling the gain of the amplifying means and the distance information indicating the distance between the communication partner station immediately after the start of communication, and the calculated prediction reception signal level is obtained. The configuration includes a gain calculating means for calculating a predicted gain of the gain amplifying means, and a setting means for setting the calculated predicted gain as an initial value of the variable gain control means.

With this structure, the gain for obtaining the desired received signal level in the variable gain amplifying means can be predicted and set as the initial value immediately after the wireless communication device starts communication. Therefore, even when the received electric field level fluctuates in a short time at the start of communication next time due to fading or the like, an appropriate initial value of gain for obtaining a desired received signal level can be set at the start of communication.

An automatic gain control method according to a second aspect of the present invention is an automatic gain control method for controlling the gain of a variable gain amplifier for amplifying a received signal, wherein the current position is acquired immediately after the start of communication with a communication partner. The predicted signal level for predicting the received signal level from the acquired distance information indicating the distance between the current position and the communication partner station is used as the initial value of the variable gain amplifier.

According to this method, similarly to the above, the radio communication apparatus can predict the gain for obtaining the desired received signal level in the variable gain amplifier immediately after the start of communication and use it as the initial value. Therefore, even when the received electric field level fluctuates in a short time at the start of communication next time due to fading or the like, an appropriate initial value of gain for obtaining a desired received signal level can be set at the start of communication.

According to a third aspect of the present invention, there is provided a radio communication device, wherein the gain controllable variable gain amplifying means and the gain of the amplifying means are set so that the level of the received signal amplified by the variable gain amplifying means becomes a desired level. Control means for controlling the current position, current position acquisition means for acquiring its own current position, recording means for recording the position of the communication partner station in advance, and distance calculation means for calculating the distance between the communication partner station A gain calculating means for calculating a predicted received signal level from the calculated distance, and a predicted gain of the variable gain amplifying means for obtaining the calculated predicted received signal level; and a variable gain control for calculating the calculated predicted gain. And a setting unit which is an initial value of the unit.

According to this structure, immediately after the start of communication, it is possible to predict the gain for obtaining the desired received signal level in the variable gain amplifying means and set it as the initial value. Therefore, even when the received electric field level fluctuates in a short time at the start of communication next time due to fading or the like, an appropriate initial value of gain for obtaining a desired received signal level can be set at the start of communication.

The mobile station of the invention according to claim 4 is the mobile station according to claim 1.
The invention is provided with an automatic gain control device.

According to this configuration, an appropriate initial value of gain for obtaining a desired received signal level is set even if the received electric field level fluctuates in a short time due to fading at the start of communication. A stable received signal level can be obtained from the beginning.

The base station of the invention according to claim 5 is the base station according to claim 1.
The invention is provided with an automatic gain control device.

According to this structure, a stable received signal level can be obtained from the start of communication as in the above.

The mobile station of the invention according to claim 6 is the mobile station according to claim 3.
A configuration including the wireless communication device according to the invention is adopted.

According to this structure, a stable received signal level can be obtained from the start of communication as in the above.

The base station of the invention according to claim 7 is the base station according to claim 3.
A configuration including the wireless communication device according to the invention is adopted.

According to this structure, a stable received signal level can be obtained from the start of communication as in the above.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The essence of the present invention is to predict a received signal level from its own current position and a distance between a communication partner station, and use a variable gain amplifying means for predicting a gain for obtaining the predicted received signal level. The initial value of is to shorten the time required to converge to a desired received signal level at the start of communication.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of an automatic gain control apparatus according to Embodiment 1 of the present invention. The automatic gain control device according to the present embodiment is used for various wireless communication devices in addition to mobile stations and base stations in mobile communication systems, but the configuration of the wireless communication device main body is omitted.

In this figure, the automatic gain control device of the present embodiment comprises a variable gain amplifier 101 and an automatic gain control circuit 100. The automatic gain control circuit 100 is
It includes a power detection circuit 102, a gain control circuit 103, an initial value setting circuit 104, and a received power prediction circuit 105. The power detection circuit 102 detects the power of the received signal and inputs it to the gain control circuit 103. Gain control circuit 103
Outputs a control signal for controlling the gain of the variable gain amplifier 101 so that the received signal has a desired power level using the power value of the received signal detected by the power detection circuit 102. The variable gain amplifier 101 is an automatic gain control circuit 100.
The gain is set based on the control signal from the gain control circuit 103.

FIG. 2 is a block diagram showing the configuration of the received power prediction circuit 105. The reception power prediction circuit 105 includes a communication distance calculation circuit 206 and a distance / gain conversion circuit 207. The current position information and the position information of the communication partner station are input to the communication distance calculation circuit 206 at the start of communication. The current position information is obtained by a GPS (Global Positioning System) not shown.
em) Obtained from the system. Communication distance calculation circuit 206
Calculates the communication distance from the current position and the position information of the known communication partner station, and inputs the result to the distance / gain conversion circuit 207.

The distance / gain conversion circuit 207 predicts the gain of the variable gain amplifier 101 that obtains a desired received signal level using the communication distance information from the communication distance calculation circuit 206,
It is output to the gain control circuit 103 as an initial value. The gain control circuit 103 starts controlling the variable gain amplifier 101 using the initial value from the initial value setting circuit 104. By this operation, the gain of the variable gain amplifier 101 that can obtain a desired received signal level is predicted and set as an initial value. Variable gain amplifier 1 capable of obtaining a desired received signal level
By setting the initial value close to the gain of 01, the received signal level can be converged to the desired received signal level in a short time.

As described above, according to the automatic gain control apparatus of the present embodiment, the received signal level is predicted and varied from the current position information measured using the GPS system at the start of communication and the distance to the communication partner station. Since the predicted gain for obtaining the desired received signal level in the gain amplifier 101 is set as the initial value, the initial value of the gain of the variable gain amplifier 101 is brought close to the gain for obtaining the desired received signal level, and the initial convergence time is shortened. Can be realized. That is, even when the reception electric field level fluctuates in a short time at the start of communication next time due to fading or the like, it is possible to set an appropriate initial value of gain for obtaining a desired reception signal level at the start of communication. A stable received signal level can be obtained from.

In the above embodiment, the GPS system is used to acquire the current position, but any other device capable of measuring the current position may be used.

(Embodiment 2) FIG.3 is a block diagram showing a configuration of a receiving section of a radio communication apparatus according to Embodiment 2 of the present invention. In this figure, the same parts as those of the automatic gain control device according to the first embodiment described above are designated by the same reference numerals.

In this figure, the wireless communication device 400 is
Amplifier 407, 90 ° phase shifter 408, mixer 409
And 410, a local oscillator 411, two variable gain amplifiers 101, and an automatic gain control circuit 100 provided corresponding to each variable gain amplifier 101.

In such a configuration, the input reception signal is amplified by the amplifier 407 and then converted into a baseband signal by the mixers 409 and 410. Then, the baseband signal is amplified by each variable gain amplifier 101 to a desired received signal level and output. According to this wireless communication device 400, since the automatic gain control circuit 100 of the first embodiment is provided, the same operational effect can be obtained.

(Third Embodiment) Next, a mobile terminal according to a third embodiment of the present invention will be described. However, operations similar to those of the above-described first and second embodiments are omitted. Note that, here, a GPS system is used as an example of a means for acquiring the current position information, and communication between a mobile station and a base station is taken as an example.

FIG. 4 is a block diagram showing the configuration of the mobile communication system. The mobile communication system shown in this figure is
The mobile station 412, the base station 413, and the GPS satellite 414 are provided. The mobile station 412 incorporates the wireless communication device 400 of FIG. 3 in order to obtain a desired received signal level even in an environment where the received signal level fluctuates. Since this wireless communication device 400 includes the automatic gain control circuit 100 of the first embodiment, the same effect can be obtained.

[0032]

As described above, according to the present invention,
At the start of communication, the reception signal level is predicted from the distance between the current position information and the communication partner station, and the variable gain amplification means uses the predicted gain for obtaining the desired reception signal level as the initial value. Even if the received electric field level fluctuates in a short time at the beginning of communication due to fading, etc., an appropriate initial value of gain to obtain the desired received signal level can be set at the start of communication, and stable from the start of communication. The received signal level obtained is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an automatic gain control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a received power prediction circuit that constitutes the automatic gain control device according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a receiving unit of the wireless communication device according to the second embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a mobile communication system according to a third embodiment of the present invention.

[Explanation of symbols]

101 variable gain amplifier 100 Automatic gain control circuit 102 Power detection circuit 103 gain control circuit 104 Initial value setting circuit 105 received power prediction circuit 206 Communication distance calculation circuit 207 Distance / gain conversion circuit 400 wireless communication device 407 amplifier 408 90 ° phase shifter 409,410 mixer 411 Local oscillator 412 mobile station 413 base station 414 GPS satellite

Claims (7)

[Claims] 1. A variable gain amplifying means capable of gain control, a control means for controlling the gain of the amplifying means so that the level of a received signal amplified by the variable gain amplifying means becomes a desired level, and immediately after the start of communication. A gain calculating means for calculating a predicted received signal level from distance information indicating a distance to the communication partner station, and a predicted gain of the variable gain amplifying means for obtaining the calculated predicted received signal level; Setting means for setting a predicted gain as an initial value of the variable gain control means,
An automatic gain control device comprising: 2. An automatic gain control method for controlling the gain of a variable gain amplifier for amplifying a received signal, wherein a current position is acquired immediately after communication with a communication partner is started, and the acquired current position and the communication partner station are acquired. An automatic gain control method, comprising: predicting a received signal level from distance information indicating a distance between the two, and setting a predicted gain for obtaining the predicted received signal level as an initial value in the variable gain amplifier. 3. A variable gain amplifying means capable of gain control, a control means for controlling the gain of the amplifying means so that the level of a received signal amplified by the variable gain amplifying means becomes a desired level, and its own present Current position acquisition means for acquiring the position, recording means for recording the position of the communication partner station in advance,
Distance calculating means for calculating the distance to the communication partner station, and calculating a predicted reception signal level from the calculated distance,
A gain calculating means for calculating a predicted gain of the variable gain amplifying means for obtaining the calculated predicted received signal level; and a setting means for setting the calculated predicted gain as an initial value of the variable gain control means. A characteristic wireless communication device. 4. A mobile station comprising the automatic gain control device according to claim 1. 5. A base station comprising the automatic gain control device according to claim 1. 6. A mobile station comprising the wireless communication device according to claim 3. 7. A base station comprising the wireless communication device according to claim 3.