JP4858373B2 - Gain adjustment circuit and radio communication apparatus - Google Patents

Description

  The present invention relates to a gain adjustment circuit for a wireless communication device used in a broadband mobile wireless communication system and the like, and a wireless communication device.

In recent years, as a communication system capable of covering a wide area wirelessly and providing a high-speed broadband service, for example, a broadband mobile wireless communication system (Broadband Wireless Access System) called “WiMAX” defined in IEEE 802.16, Hereinafter, the BWA system) is attracting attention.
The BWA system includes a base station apparatus and a mobile terminal that establishes wireless communication with the base station apparatus, and the base station apparatus provides a broadband wireless communication service to the mobile terminal. I will provide a.
In general, in a wireless communication system, the signal level of a received signal transmitted from a base station apparatus and received by a mobile terminal varies greatly depending on the position of the mobile terminal with respect to the base station and the surrounding environment. For this reason, a so-called automatic gain adjustment circuit is incorporated in the receiver of the mobile terminal. Such an automatic gain adjustment circuit includes a circuit that adjusts the gain so that the received signal level falls within the dynamic range of the AD converter incorporated in the mobile terminal, and is obtained by detecting the envelope of the received signal. The gain is adjusted based on the detected voltage (see, for example, Patent Document 1).

JP-A-9-130342

On the other hand, the BWA system employs a TDD (Time Division Duplex) communication method that divides uplink communication and downlink communication on the time axis. A mobile terminal based on this TDD communication system receives a signal in the time slot of the downlink communication frame, but does not receive a signal in the time slot of the uplink communication frame, so the power level when the received signal is envelope-detected is For example, as shown in the lower diagram in FIG. 3, periodic fluctuations occur.
For this reason, depending on the timing at which the detection voltage is taken in, the value of the detection voltage varies even with the same reception signal power. Therefore, it is difficult to accurately measure the reception signal power with the conventional automatic gain adjustment circuit. There is a risk that stable gain adjustment cannot be performed.
Further, in the automatic gain adjustment circuit of the conventional example, gain adjustment may be performed during reception of an area in which a synchronization signal is stored, for example, in a downstream frame, and the accuracy when demodulating the reception signal is increased. There was also a risk that it would decrease.

  As described above, when the conventional automatic gain adjustment circuit is applied to a TDD communication wireless communication apparatus, stable gain adjustment can be performed due to the division of uplink communication and downlink communication on the time axis. Had no problem.

  The present invention has been made in view of such circumstances, and provides a gain adjustment circuit and a wireless communication apparatus capable of performing stable gain adjustment while suppressing a decrease in demodulation accuracy of a received signal. Objective.

In order to achieve the above object, the present invention switches between a transmission signal and a reception signal using a time division duplex method and communicates, and transmits and receives a transmission / reception switching time based on a synchronization signal stored in the reception signal. A gain adjustment circuit used in a wireless communication device including a switching signal generation unit that generates a switching signal, the detection unit detecting a detection voltage detected from a reception signal received by the wireless communication device, and the detection voltage A gain adjusting unit for adjusting the gain of the received signal based on the transmission / reception switching signal, setting a detection time referring to the detection voltage based on the transmission / reception switching signal, taking in the detection voltage at the detection time, and the gain adjusting unit Is set to adjust the gain of the received signal, and control is performed to cause the gain adjustment unit to perform gain adjustment at the adjustment time based on the detected detection voltage. And a control unit, wherein the adjustment time, the in the signal reception time period the wireless communications device receives a reception signal, is set in a time zone other than the time zone information radio communication apparatus used is stored It is characterized in that there.

  According to the gain adjustment circuit configured as described above, the control unit sets the detection time for detecting the detection voltage and the adjustment time for performing gain adjustment based on the transmission / reception switching signal generated by the switching signal generation unit. Therefore, the timing for detecting the detection voltage and adjusting the gain can be suitably set.

In the gain adjustment circuit, in the signal reception time zone, a time zone other than a time zone in which information used by the wireless communication device is stored is downlink map information assigned in the communication frame, and uplink User data is not stored in a time zone in which information intervening with map information is not stored, or in a downlink burst area allocated for storing user data in the communication frame It is a time zone.
The control unit may set the pre-Symbol detection time to the band the signal reception time.
In this case, the control unit takes in the detection voltage detected in the signal reception time zone and causes the gain adjustment unit to adjust the gain, so that the gain can be adjusted by the detection voltage based on the current reception signal, Gain adjustment can be performed stably.

In addition, the present invention switches a transmission signal and a reception signal by switching in a time division duplex method, and generates a transmission / reception switching signal indicating a transmission / reception switching time from a synchronization signal stored in the reception signal. A gain adjustment circuit used in a wireless communication device including a generation unit, the detection unit detecting a detection voltage detected from a reception signal received by the wireless communication device, and the reception signal based on the detection voltage Based on the transmission / reception switching signal, a gain adjustment unit for adjusting the gain of the received signal is set based on the transmission / reception switching signal, and the gain adjustment unit is configured to adjust the gain at the adjustment time. and a control unit for controlling to perform the adjustment time, the in the signal reception time period the wireless communications device receives a reception signal, is stored the information that the wireless communication device is used by It is characterized in that it is set in that time zone other than the time zone.

According to the gain adjustment circuit configured as described above, the control unit can set the adjustment time for performing gain adjustment based on the transmission / reception switching signal generated by the switching signal generation unit. The timing to perform can be set suitably.
Further, the control unit can specify a signal transmission time zone in which the wireless communication apparatus transmits a transmission signal based on the transmission / reception switching signal, and set the adjustment time to the signal transmission time zone.

  By setting the adjustment time in the signal transmission time zone as described above, the gain adjustment unit can perform gain adjustment in the signal transmission time zone in which the communication device does not receive the reception signal. That is, since the gain adjustment unit can be set not to perform gain adjustment in the signal reception time zone, it is possible to prevent the reception signal from being disturbed during reception of the reception signal. Therefore, it is possible to suppress a decrease in demodulation accuracy when the received signal is demodulated thereafter.

Further, the control unit specifies a synchronization signal storage time zone in which the synchronization signal used by the wireless communication device is stored based on the transmission / reception switching signal, and sets the adjustment time other than the synchronization signal storage time zone. It may be set to time.
In this case, since the gain adjustment unit does not perform gain adjustment in the synchronization signal storage time zone in which the synchronization signal is stored, it is possible to prevent the reception signal from being disturbed during reception of the information. . Therefore, it is possible to suppress a decrease in demodulation accuracy when the received signal is demodulated thereafter.

Further, the present invention is a wireless communication apparatus comprising a communication unit that switches between a transmission signal and a reception signal by time division duplex communication and a gain adjustment circuit that adjusts the gain of the reception signal, The communication unit includes a switching signal generation unit that generates a transmission / reception switching signal indicating a transmission / reception switching time from a synchronization signal stored in the reception signal, and the gain adjustment circuit is configured to receive the reception signal received by the wireless communication device. A detection unit that detects a detected voltage to be detected; a gain adjustment unit that adjusts the gain of the received signal based on the detection voltage; and a detection time that refers to the detection voltage based on the transmission / reception switching signal. The detection voltage is taken in at this detection time, and the adjustment time for causing the gain adjustment unit to adjust the gain of the received signal is set. Based on the acquired detection voltage, the gain adjustment unit And a control unit for controlling to perform the gain adjustment integer time, the adjustment time, the in the signal reception time period the wireless communications device receives a reception signal, is stored the information that the wireless communication device is used by It is characterized by being set to a time zone other than the current time zone .

  According to the wireless communication device configured as described above, the detection voltage detection and gain adjustment timing can be suitably set as described above, and the gain adjustment can be performed stably.

Further, the present invention is a wireless communication apparatus comprising a communication unit that switches between a transmission signal and a reception signal by time division duplex communication and a gain adjustment circuit that adjusts the gain of the reception signal, The communication unit includes a switching signal generation unit that generates a transmission / reception switching signal indicating a transmission / reception switching time from a synchronization signal stored in the reception signal, and the gain adjustment circuit is configured to receive the reception signal received by the wireless communication device. A detection unit for detecting a detected voltage to be detected; a gain adjustment unit for adjusting a gain of the reception signal based on the detection voltage; and a gain of the reception signal on the gain adjustment unit based on the transmission / reception switching signal. set the adjustment time to carry out the adjustment, and a control unit for controlling to perform the gain adjustment on the gain adjustment unit in this adjustment time, wherein the adjustment time, the wireless communication device receives a received signal signal In Shin time zone, and wherein the information which the wireless communication device is used is set to a time zone other than the time zone stored.

  According to the wireless communication device configured as described above, the timing for performing gain adjustment can be suitably set as described above, and gain adjustment can be performed stably.

  As described above, according to the gain adjustment circuit and the wireless communication apparatus of the present invention, it is possible to stably adjust the gain while suppressing a decrease in demodulation accuracy of the received signal.

[Overall configuration of communication system]
Next, reference examples will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing an overall configuration of a broadband mobile radio communication system (BWA system). This BWA system employs, for example, a wireless communication system called “WiMAX” defined in IEEE 802.16 that supports an orthogonal frequency division multiple access (OFDMA) system in order to realize broadband wireless communication. Base station 10 (hereinafter also referred to as BS10) and mobile terminal 20 (hereinafter also referred to as MS20) that can move.
The BS 10 sets a cell S that is a range in which wireless communication is possible with the MS 20 around the BS 10, and provides high-speed broadband service by wireless communication to the MS 20 located in the cell S. Further, the cells S are set so as to overlap each other with the adjacent cells S, and the entire service area of the present BWA system is configured by these many cells S.
Between the BS 10 and the MS 20 with which communication has been established, information (user data) can be sent and received by placing information (user data) in a predetermined communication frame. Entry into the network becomes possible.

[Configuration of mobile terminal]
Figure 2 is a block diagram showing the configuration of M S20. In the BWA system of this reference example , a so-called TDD (Time Division Duplex) communication method is adopted in which a transmission signal and a reception signal are switched by a time division duplex method based on the WiMAX specification. The MS 20 is also configured corresponding to the TDD communication method.
The MS 20 performs an antenna 21 that transmits and receives a signal for performing wireless communication with the BS 10, a transmission unit 22 that performs processing such as D / A conversion, modulation, and amplification related to the transmission signal, and processing of the reception signal. A receiving unit 23 for performing the operation, a switch 24 connected between the antenna 21 and the transmitting / receiving units 22 and 23, a communication control / baseband processing unit 25 for controlling each unit and performing various processes relating to wireless communication, And an input / output unit 26 for inputting / outputting user data exchanged between the BS 10 and the MS 20 via wireless communication.

The receiving unit 23 includes a band-pass filter 23a connected to the antenna 21 side, and further, an amplifier 23b connected in order from the band-pass filter 23a toward the communication control / baseband processing unit 25, and an automatic The gain adjustment circuit 30, the quadrature demodulator 23c, and the A / D converter 23d are included, and processing such as amplification, demodulation, and A / D conversion related to the received signal is performed.
The automatic gain adjustment circuit 30 adjusts the gain so that the signal level of the reception signal amplified by the amplifier 23b falls within the dynamic range of the A / D converter 23d. The automatic gain adjustment circuit 30 will be described in detail later.

The communication control / baseband processing unit 25 is configured by a microcomputer having a CPU, a memory (RAM), a storage device (hard disk and ROM), and the like, and performs processing for establishing wireless communication with the BS 10 by controlling each unit. User data is extracted from the communication frame of the received signal transmitted from the BS 10 and output to the input / output unit 26, or the user data input to the input / output unit 26 is transmitted on the communication frame. Process.
The communication control / baseband processing unit 25 includes a switching signal generation unit 25a that generates a transmission / reception switching signal that is information indicating a transmission / reception switching time based on a synchronization signal included in the reception signal. The switching signal generation unit 25 a generates a transmission / reception switching signal by acquiring a synchronization signal included in the received signal, and outputs the transmission / reception switching signal to the switching unit 24 to control the switching unit 24.

  The switch 24 is configured so that the connection to the antenna 21 can be switched to either the transmission unit 22 side or the reception unit 23 side. When the MS 20 transmits a signal, the antenna 21 is switched. When connecting to the transmission unit 22 side and receiving a signal from the BS 10, the connection is made to the reception unit 23 side. The switch 24 performs the switching operation based on the transmission / reception switching signal output from the switching signal generation unit 25a.

FIG. 3 is a diagram showing an example of a communication frame configuration of the present system, an output waveform of a transmission signal transmitted by the BS 10, and a detection output waveform by the detection unit 31 corresponding thereto, which will be described later. In the figure, the horizontal axis represents elapsed time.
The communication frame S of this system shown in the upper part of FIG. 3 is composed of a downlink subframe D to which a reception signal received by the MS 20 is allocated and an uplink subframe U to which a transmission signal transmitted by the MS 20 is allocated. The subframes D and U are alternately arranged on the time axis and have a general structure in the TDD communication system.
Necessary for establishing communication such as a previous value signal (Preamble), a frame control header (FCH), downlink map information (DL-MAP), and uplink map information (UL-MAP) in the downlink subframe D After such information, a downlink burst area (Burst) in which user data is stored is allocated.
After that, a gap G1 in which signal transmission / reception is not performed is assigned for a predetermined time in order to divide between the downlink subframe D and the uplink subframe U, and the uplink subframe U is assigned after the gap G1.
In addition, the gap G2 is similarly assigned while switching from the upstream subframe U to the downstream subframe D. These gaps G1 and G2 are assigned between the subframes D and U for switching between transmission and reception.

The switching signal generation unit 25a of the communication control / baseband processing unit 25 uses the gap G1, the communication frame S as one cycle from the information stored in the downlink subframe D and necessary for establishing communication. Information on the time zone for each cycle of G2 or a synchronization signal for synchronizing the operation timing with the BS 10 is acquired, and the switching time for each cycle for switching transmission and reception (for example, switching time t1 in FIG. 3) , T2). Then, a transmission / reception switching signal indicating the switching time is generated and output to the switch 24. Upon receiving the transmission / reception switching signal, the switch 24 performs a switching operation according to the transmission / reception switching signal as described above. Here, when the communication control / baseband processing unit 25 establishes communication with the BS 10, since the operation timing is synchronized with the BS 10, the switch 24 is synchronized with the communication frame S. Switching operation can be performed.
As described above, the MS 20 can perform communication based on the TDD communication method.
Note that the transmission / reception switching signal output at the switching time t1 stores information indicating switching from downlink to uplink, and the transmission / reception switching signal output at the switching time t2 stores information indicating switching from uplink to downlink. .
Next, the automatic gain adjustment circuit 30 included in the receiving unit 23 will be described.

As described above, the automatic gain adjustment circuit 30 adjusts the gain so that the signal level of the received signal received by the MS 20 is within the dynamic range of the A / D converter 23d. A detection unit 31 that detects a detection voltage from the signal, a gain adjustment unit 32 that adjusts the gain of the reception signal amplified by the amplifier 23b based on the detection voltage detected by the detection unit 31, and a control unit that controls each unit 34.
The control unit 34 is connected to the switching signal generation unit 25a of the communication control / baseband processing unit 25, and is configured to receive a transmission / reception switching signal output from the switching signal generation unit 25a. The control unit 34 is configured to control the gain adjustment unit 32 based on the input transmission / reception switching signal. Specifically, when it is determined that the gain adjustment is to be performed, the control unit 34 transmits a gain adjustment signal in which parameters necessary for gain adjustment are stored to the gain adjustment unit 32 at the time of the gain adjustment. The gain adjustment unit 32 that has received the gain adjustment signal performs gain adjustment based on this signal.
The contents of control of the gain adjusting unit 32 will be described later.
The detection unit 31 is configured to detect the detection voltage by performing envelope detection on the reception signal received by the MS 20. Here, the detection voltage detected by the detection unit 31 will be described.

[About detection voltage]
Referring to FIG. 3, the middle stage in the figure shows the output waveform of the transmission signal of BS 10 corresponding to the communication frame configuration of the system in the upper stage, and the lower stage shows the detection output waveform of detection unit 31. The elapsed time is shown.
Since the transmission signal transmitted from the BS 10 is assigned to the downlink subframe D in the communication frame S, the output waveform A is transmitted in the time zone of the downlink subframe D as shown in the middle stage of FIG. Since a transmission signal is not output in the time zone of the uplink subframe U that is output and assigned to the transmission of the MS 20, the shape is periodically uneven. In the drawing, for the output waveform A, the unit of the vertical axis is “dBm” for easy understanding.

Furthermore, the detection output waveform B when the MS 20 receives the above-described signal transmitted from the BS 10 and the detection unit 31 detects the received signal by envelope detection is as shown in the lower part of FIG. For the detection output waveform B, the unit of the vertical axis is indicated as “V”. Since this detection output waveform B receives the transmission signal from the BS 10 assigned to the downlink subframe D in the time zone d of the downlink subframe D, it shows a substantially constant detection voltage. On the other hand, in the time zone of the uplink subframe U, since the signal is not received as described above, the detection voltage is gently lowered. Thereby, the detection output waveform B becomes a waveform which fluctuates periodically according to both subframes D and U. Note that the detection unit 31, smoothing circuit is integrated, is smoothed by a predetermined condition, it is gradually changing waveform shown in FIG obtained.
From this detection output waveform B, in the time zone d of the downstream subframe D, the MS 20 receives a signal from the BS 10, so that a detection voltage based on the current received signal is obtained, and in the time zone u of the upstream subframe U, Since the MS 20 does not receive a signal, it can be seen that a detection voltage lower than the level of the current received signal can be obtained.
Next, the control contents of the detection unit 31 and the gain adjustment unit 32 performed by the control unit 34 will be described.

[About control contents of the control unit]
Based on the detection voltage detected by the detection unit 31 over time based on the transmission / reception switching signal output from the switching signal generation unit 25a, the control unit 34 detects the detection time at which the control unit 34 refers to the detection voltage, and the gain. The adjustment unit 32 has a function of setting an adjustment time at which the gain of the received signal is adjusted, taking in the detection voltage at the detection time, and controlling the gain adjustment unit 32 to perform gain adjustment at the adjustment time. .
That is, the control unit 34 can grasp from the transmission / reception switching signal the switching times t1 and t2 at which the communication control / baseband processing unit 25 (switching signal generation unit 25a) switches between transmission and reception, and the MS 20 receives the reception signal. The time zone d of the downlink subframe D that is a signal reception time zone to be transmitted and the time zone u of the uplink subframe U that is a signal transmission time zone in which the MS 20 transmits a signal can be specified.
The control unit 34 sets the detection time t3 at which the control unit 34 takes in the detection voltage to the time zone d of the downstream subframe D based on the information related to the identified both subframes D and U. Thereby, the control part 34 can take in the detection voltage based on the present received signal which MS20 is actually receiving detected in the time slot | zone d of the downlink sub-frame D. FIG.
In addition, the control unit 34 sets the adjustment time t4 when the gain adjustment unit 32 adjusts the gain of the received signal to the time zone u of the uplink subframe U.

According to the gain adjustment circuit 30 and the MS 20 configured as described above, the control unit 34 detects the detection voltage based on the transmission / reception switching signal generated by the switching signal generation unit 25a, and the gain adjustment. Since the adjustment time for performing detection can be set, the detection voltage detection and gain adjustment timing can be set appropriately.
That is, as described above, the control unit 34 can specify the time zone d of the downlink subframe D in which the MS 20 receives the received signal based on the transmission / reception switching signal, and can set the detection time to the time zone u. .
In this case, the control unit 34 takes in the detection voltage detected in the time zone u and causes the gain adjustment unit 32 to adjust the gain, so that the gain adjustment can be performed by the detection voltage based on the current received signal, Gain adjustment can be performed stably.

Moreover, since the control part 34 can set the adjustment time which the gain adjustment part 32 performs a gain adjustment based on a transmission / reception switching signal as mentioned above, it can set the timing which performs a gain adjustment suitably. .
Furthermore, the control unit 34 can specify the time zone u of the uplink subframe U based on the transmission / reception switching signal and set the adjustment time to the time zone u. In this case, the gain adjustment unit 32 can perform gain adjustment in a time zone u when the MS 20 is not receiving a reception signal. That is, since the gain adjustment unit 32 can be set not to perform gain adjustment in the time zone d of the downlink subframe D, it is possible to prevent the reception signal from being disturbed during reception of the reception signal. . As a result, it is possible to suppress a decrease in demodulation accuracy when the received signal is demodulated thereafter.
As described above, according to the gain adjustment circuit 30 and the MS 20 of this reference example , it is possible to stably perform gain adjustment while suppressing a decrease in demodulation accuracy of the received signal.

Further, in the above reference example , the control unit 34 sets the adjustment time t4 for performing gain adjustment of the gain adjustment unit 32 based on the transmission / reception switching signal acquired from the switching signal generation unit 25a. In addition to the switching signal from the switching signal generation unit 25a, adjustment is performed for obtaining map information regarding information stored in the communication frame S and performing gain adjustment of the gain adjustment unit 32 based on the switching signal and the map information. Time t4 may be set.
In contrast to the above-described reference example, the gain adjustment circuit 30 according to the present invention is different from the above-described reference example in the following points. That is, the control unit 34 of the gain adjustment circuit 30 according to the present invention includes information (Preamble, FCH, DL-MAP, UL-MAP) necessary for the MS 20 to establish communication within the communication frame S, and the user. Specify a time zone in which information used by the MS 20 such as a downlink burst area (Burst) in which data is stored and a synchronization signal for synchronizing the operation timing with the BS 10 is stored, and an adjustment time other than that time zone Can be set to time zone.
For example, the control unit 34 can specify a synchronization signal storage time zone in which the synchronization signal is stored, and set the adjustment time to a time other than the synchronization signal storage time zone.

As the time period other than the time zone information the MS20 is used is stored, if example embodiment, the upper communicating frame S in FIG. 3, the information that is interposed between the DL-MAP and UL-MAP stores For example, a time zone e corresponding to Empty which is not performed, a time zone where user data is not stored in the downlink burst region, and the like.
Even in this case, the gain adjustment unit 32 according to the present invention does not perform gain adjustment in the time zone in which the information used by the MS 20 is stored in the communication frame S, so that the received signal is received during reception of the information. Disturbance can be prevented. As a result, it is possible to suppress a decrease in demodulation accuracy when the received signal is demodulated thereafter.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the case where the gain adjustment circuit of the present invention is applied to a mobile terminal has been illustrated, but the present invention can also be applied to the base station apparatus side.

It is a figure which shows the whole structure of a broadband mobile radio | wireless communications system (BWA system). Is a block diagram showing the configuration of the M S. It is the figure which showed an example of the communication frame structure of this system, the output waveform of the transmission signal which BS transmits, and the detection output waveform by the detection part corresponding to this.

Explanation of symbols

10 BS (base station) 20 MS (mobile terminal, wireless communication device)
21 Antenna 22 Transmitter 23 Receiver
23a Band pass filter 23b Amplifier 23c Quadrature demodulator
23d A / D converter 24 switch 25 communication control / baseband processing unit 25a switching signal generation unit 26 input / output unit 30 automatic gain adjustment circuit 31 detection unit 32 gain adjustment unit 34 control unit D downlink subframe S communication frame U uplink Subframe d Time zone e Time zone u Time zone t1 Switching time t2 Switching time t3 Detection time t4 Adjustment time

Claims (6)

A transmission signal and a reception signal are switched and communicated by a time division duplex method, and a switching signal generation unit is provided that generates a transmission / reception switching signal indicating a transmission / reception switching time based on a synchronization signal stored in the reception signal. A gain adjustment circuit used in a wireless communication device,
A detection unit for detecting a detection voltage detected from a reception signal received by the wireless communication device;
A gain adjustment unit that adjusts the gain of the received signal based on the detection voltage;
Based on the transmission / reception switching signal, set a detection time with reference to the detection voltage, capture the detection voltage at the detection time, and set an adjustment time for the gain adjustment unit to perform gain adjustment of the received signal, A control unit that controls the gain adjustment unit to perform gain adjustment at the adjustment time based on the detected detection voltage ; and
The gain is characterized in that the adjustment time is set in a time zone other than a time zone in which information used by the radio communication device is stored in a signal reception time zone in which the radio communication device receives a reception signal. Adjustment circuit. The time zone other than the time zone in which the information used by the wireless communication device is stored in the signal reception time zone is between the downlink map information allocated in the communication frame and the uplink map information. A time zone in which no intervening information is stored, or a time zone in which no user data is stored in a downlink burst area allocated for storing user data in the communication frame. 2. The gain adjustment circuit according to 1. Wherein the control unit, gain control circuit according to claim 1 or 2 to set the pre-Symbol detection time to the band the signal reception time. A radio having a switching signal generation unit that switches between a transmission signal and a reception signal by time division duplex communication and generates a transmission / reception switching signal indicating a transmission / reception switching time from a synchronization signal stored in the reception signal A gain adjustment circuit used in a communication device,
A detection unit for detecting a detection voltage detected from a reception signal received by the wireless communication device;
A gain adjustment unit that adjusts the gain of the received signal based on the detection voltage;
A control unit configured to set an adjustment time for causing the gain adjustment unit to perform gain adjustment of the reception signal based on the transmission / reception switching signal, and to perform control for causing the gain adjustment unit to perform gain adjustment at the adjustment time; Prepared ,
The gain is characterized in that the adjustment time is set in a time zone other than a time zone in which information used by the radio communication device is stored in a signal reception time zone in which the radio communication device receives a reception signal. Adjustment circuit. A wireless communication apparatus comprising a communication unit that switches between a transmission signal and a reception signal by time division duplex communication and a gain adjustment circuit that adjusts the gain of the reception signal,
The communication unit includes a switching signal generation unit that generates a transmission / reception switching signal indicating a transmission / reception switching time from a synchronization signal stored in the reception signal,
The gain adjustment circuit includes:
A detection unit for detecting a detection voltage detected from a reception signal received by the wireless communication device;
A gain adjustment unit that adjusts the gain of the received signal based on the detection voltage;
Based on the transmission / reception switching signal, set a detection time with reference to the detection voltage, capture the detection voltage at the detection time, and set an adjustment time for the gain adjustment unit to perform gain adjustment of the received signal, A control unit that controls the gain adjustment unit to perform gain adjustment at the adjustment time based on the detected detection voltage ; and
The adjustment time is set in a time zone other than a time zone in which information used by the radio communication device is stored in a signal reception time zone in which the radio communication device receives a reception signal. Communication device. A wireless communication apparatus comprising a communication unit that switches between a transmission signal and a reception signal by time division duplex communication and a gain adjustment circuit that adjusts the gain of the reception signal,
The communication unit includes a switching signal generation unit that generates a transmission / reception switching signal indicating a transmission / reception switching time from a synchronization signal stored in the reception signal,
The gain adjustment circuit includes:
A detection unit for detecting a detection voltage detected from a reception signal received by the wireless communication device;
A gain adjustment unit that adjusts the gain of the received signal based on the detection voltage;
A control unit configured to set an adjustment time for causing the gain adjustment unit to perform gain adjustment of the reception signal based on the transmission / reception switching signal, and to perform control for causing the gain adjustment unit to perform gain adjustment at the adjustment time; Prepared ,
The adjustment time is set in a time zone other than a time zone in which information used by the radio communication device is stored in a signal reception time zone in which the radio communication device receives a reception signal. Communication device.

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