JP2010004515A - Relay sending-receiving apparatus and mobile communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a relay sending-receiving apparatus and a mobile communication system, transmitting a signal amplified by always adequate relay gain, to a base station even if an intensity level of a signal transmitted from a mobile terminal is fluctuated. <P>SOLUTION: The relay sending-receiving apparatus 10 is a relay sending-receiving apparatus to relay a radio transmission and reception conducted between the mobile terminal 3 and the base station 1, and is provided with: a base station side receiving AGC amplifier 105 to amplify a signal from the base station 1 to gain variation; and a base station side receiving level detecting circuit 112 to detect the intensity level of the amplified signal. It is also provided with a terminal side receiving AGC amplifier 205 to amplify the signal from the mobile terminal 3 to the gain variation. The relay sending-receiving apparatus controls the gain brought from the terminal side receiving AGC amplifier 205 according to the intensity level detected by the base station side receiving level detecting circuit 112. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a relay transmission / reception apparatus that relays radio transmission / reception performed between a mobile station and a base station, and a mobile communication system.

  The relay transmitting / receiving apparatus is installed between the base station and the mobile station, and amplifies the signals with an appropriate gain (hereinafter also referred to as a relay gain) when relaying bidirectional signals. The operation of automatically amplifying the signal is called an AGC (Automatic Gain Control) operation. For example, even if there is a mobile station in a shadowing area such as indoors where zone reduction or call quality degradation occurs, the relay transmission / reception device amplifies the signal between the base station and the mobile station with an appropriate gain, The base station and the mobile station can perform good communication with each other.

  In the relay transmitting / receiving apparatus described in Patent Document 1, the line status for detecting line status information such as the number of downlink and uplink communication lines and the call level from the outputs of the output side couplers of the downlink amplification unit and the uplink amplification unit A detection unit is provided. The downlink control unit and the uplink control unit are configured to change the saturation output by switching and controlling the number of amplification stages and the combination of the amplification units according to the detection. In Patent Document 2, a booster dedicated to uplink signals is provided for each zone into which the service area is divided.

Japanese Patent Laid-Open No. 10-22895 Japanese Patent Laid-Open No. 10-56415

  However, in an NGN (Next Generation Network) mobile system using CDMA (Code Division Multiple Access) or OFDMA (Orthogonal Frequency Division Multiplexing Access) for access control, a plurality of mobile stations transmit radio waves of different strength levels via relay transmission / reception devices. Send to the same time. Therefore, the mobile station side AGC control circuit of the relay transmitting / receiving apparatus controls the relay gain to amplify the signal to be transmitted to the base station based on the strength level (reception level) of the signal from the mobile station in the uplink. However, there is a problem that amplification cannot be performed with an appropriate relay gain.

  Further, in a mobile communication system including a relay transmission / reception device, when the base station performs uplink transmission power control for each mobile station, the mobile station AGC circuit of the relay transmission / reception device receives the uplink reception. If the relay gain control is performed based on the level, there is a problem in that the transmission power control performed by the base station does not work correctly and the uplink channel quality is degraded.

  In order to avoid these problems, a method is conceivable in which the AGC operation is stopped and the relay gain to be amplified is manually set. However, the setting requires specialized knowledge and the average electric field strength at the installation location, which is very complicated. In addition, there is also a problem that a radio failure occurs when an erroneous setting is made and an uplink signal is transmitted to the base station with a transmission power more than necessary.

  The present invention has been made to solve the above-described problems. Even when the reception level of a signal transmitted from a mobile station fluctuates, the signal always amplified with an appropriate relay gain is transmitted to the base station. It is an object of the present invention to provide a relay transmitting / receiving apparatus and a mobile communication system capable of transmitting.

  A relay transmission / reception apparatus according to the present invention is a relay transmission / reception apparatus that relays radio transmission / reception performed between a mobile station and a base station, and a downlink reception variable gain amplifier that amplifies a signal from the base station in a variable gain A downlink reception level detection circuit for detecting the intensity level of the signal amplified by the downlink reception variable gain amplifier. A downlink reception gain control unit for controlling a gain of the downlink reception variable gain amplifier according to the intensity level detected by the downlink reception level detection circuit; and an uplink reception for amplifying a signal from the mobile station in a variable manner. And a variable gain amplifier. Then, the relay transmitting / receiving apparatus controls the gain by the uplink reception variable gain amplifier according to the intensity level detected by the downlink reception level detection circuit.

  According to the relay transmission / reception apparatus of the present invention, the gain by the uplink reception variable gain amplifier is controlled according to the intensity level detected by the downlink reception level detection circuit. Thereby, even if the intensity level of the signal transmitted from the mobile station fluctuates, it is possible to always transmit a signal amplified with an appropriate relay gain to the base station.

<Embodiment 1>
FIG. 1 is a diagram showing a configuration of a mobile communication system according to the present embodiment. As shown in the figure, the mobile communication system includes a base station 1, mobile terminals 2, 3 a, 3 b, and a relay transmitting / receiving apparatus (hereinafter also referred to as a repeater) 10. The mobile terminal 2 is a mobile terminal under the base station 1. The relay transmitting / receiving apparatus 10 according to the present embodiment relays wireless transmission / reception performed between the mobile terminals 3a, 3b in the shadowing area (shadowing area) 4 and the base station 1. Hereinafter, when there is no need to distinguish between the mobile terminals 3a and 3b, the mobile terminal 3 may be described.

  The repeater 10 receives a radio signal having a frequency f1 transmitted from the base station 1 (downlink reception), converts the signal into, for example, another frequency f2, and transmits the signal to the mobile terminal 3 (downlink transmission). Further, the repeater 10 receives the signal of the frequency f2 transmitted from the mobile terminal 3 (uplink reception), converts the signal to the frequency f1 and transmits it to the base station 1 (uplink transmission). In the downlink (downlink), downlink reception and downlink transmission are performed, and in the uplink (uplink), uplink reception and uplink transmission are performed.

  FIG. 2 is a diagram showing the configuration of the repeater 10 according to the present embodiment. As shown in the figure, the repeater 10 includes a base station (terminal) side antenna 11 (21), a base station (terminal) side antenna filter 101 (201), and a base station (terminal) side TDD switch 102 (202). , Base station (terminal) side LNA 103 (203), base station (terminal) side down converter 104 (204), base station (terminal) side receiving AGC amplifier 105 (205), base station (terminal) side HPA 106 ( 206), base station (terminal) side up-converter 107 (207), base station side transmission baseband amplifier 108, base station (terminal) side local oscillation circuit (synthesizer) 109 (209), and adjacent channel removal filter 111 (211), a base station (terminal) side reception level detection circuit 112 (212), a base station side AGC control circuit 113, and a base station side transmission skeleton Includes a circuit 151, a terminal-side transmitting AGC amplifier 251, a frame synchronization control circuit 301, the relay gain calculation table 351, and a gain notifying unit 401.

  First, parts common to the configuration for performing uplink and the configuration for performing downlink will be described. In the present embodiment, the base station (terminal) side TDD switch 102 (202) switches the downlink / uplink in a time division manner. This method is called a TDD (Time Division Duplex) method. In addition, although this Embodiment demonstrates the case where switching with a downlink / uplink is switched by a TDD system, the FDD (Frequency Division Duplex) system divided | segmented with a frequency may be sufficient.

  The signal received from the base station 1 (mobile terminal 3) passes through the base station (terminal) side LNA 103 (203) from the base station (terminal) side antenna 11 (21), and is then the base station (terminal) side down converter 104 ( 204) is down-converted to a baseband signal. The down converter is also called a quadrature detector. A signal from the base station (terminal) side down converter 104 (204) is output to the base station (terminal) side reception AGC amplifier 105 (205).

  Base station side reception AGC amplifier 105 which is a downlink reception variable gain amplifier according to the present embodiment amplifies a signal received from base station 1 in a variable gain. Similarly, terminal-side reception AGC amplifier 205 which is an uplink reception variable gain amplifier according to the present embodiment amplifies a signal received from mobile terminal 3 in a variable gain. The adjacent channel removal filter 111 (211) suppresses an adjacent channel component of a desired signal among signals amplified by the base station (terminal) side reception AGC amplifier 105 (205).

  In the above, the part common to the structure which performs an uplink, and the structure which performs a downlink was demonstrated. Next, a description will be given of parts unique to the configuration for performing downlink. The terminal-side transmission AGC amplifier 251 amplifies the signal amplified by the base station-side reception AGC amplifier 105 via the adjacent channel removal filter 111 in a variable gain. The terminal-side upconverter 207 upconverts the signal amplified by the terminal-side transmission AGC amplifier 251 to the transmission frequency. A signal from the terminal side upconverter 207 is transmitted to the mobile terminal 3 via the terminal side HPA 206 and the terminal side antenna 21.

  The base station side reception level detection circuit 112 which is a downlink reception level detection circuit according to the present embodiment detects the intensity level of the signal amplified by the base station side reception AGC amplifier 105. The base station side AGC control circuit 113 which is a downlink reception gain control unit according to the present embodiment has a base station side reception AGC amplifier 105 according to the strength level (reception level) detected by the base station side reception level detection circuit 112. To control the gain.

  The relay gain calculation table 351 provided in the relay transmission / reception apparatus (repeater) 10 according to the present embodiment includes a gain for amplifying a downlink signal transmitted from the base station 1 to the mobile terminal 3, and the mobile station 3 to the base station. 1 is stored in advance in association with the gain to amplify the uplink signal transmitted to 1. Hereinafter, the above gain stored in the relay gain calculation table 351 may be referred to as a relay gain. In this embodiment, the gain of the uplink signal stored in relay gain calculation table 351 is set higher than the gain of the downlink signal stored in relay gain calculation table 351. In addition, the relay gain calculation table 351 according to the present embodiment associates the distance between the base station 1 and the repeater 10 with the uplink signal gain and the downlink signal gain (relay gain) in advance. Stored.

  The repeater 10 according to the present embodiment calculates the above-mentioned distance from the intensity level (reception level) detected by the base station side reception level detection circuit 112, and the appropriate relay corresponding to the distance from the relay gain calculation table 351. Calculate the gain. Here, the above-mentioned distance is calculated from the reception level detected by the base station side reception level detection circuit 112. However, the distance is not limited to this, and it is temporarily determined from the control amount in the base station side AGC control circuit 113. The above-described distance may be calculated. Since the control amount in the base station side AGC control circuit 113 corresponds to the reception level detected by the base station side reception level detection circuit 112, even in this configuration, the same operation as the above configuration is performed.

  The repeater 10 controls the gain by the terminal-side reception AGC amplifier 205 based on the relay gain (uplink signal gain) stored in the relay gain calculation table 351. In this way, the relay transmitting / receiving apparatus (repeater) 10 according to the present embodiment has a terminal-side reception AGC amplifier that is an uplink reception variable gain amplifier in accordance with the strength level (reception level) detected by the base station-side reception level detection circuit 112. The gain by 205 is controlled. Similarly, repeater 10 according to the present embodiment controls the gain by terminal side transmission AGC amplifier 251 according to the reception level detected by base station side reception level detection circuit 112.

  The frame synchronization control circuit 301 controls frame synchronization based on a signal from the base station 1. The frame synchronization control circuit 301 according to the present embodiment detects timing from a signal from the base station 1 and controls the base station (terminal) side TDD switch 102 (202) described above. Thereby, the base station (terminal) side TDD switch 102 (202) switches the uplink / downlink to the TDD system.

  Although the part specific to the configuration performing the downlink has been described above, the part specific to the configuration performing the uplink will be described next. The base station side transmission baseband amplifier 108 which is an uplink transmission variable gain amplifier according to the present embodiment amplifies the signal amplified by the terminal side reception AGC amplifier 205 in a variable gain. The base station side upconverter 107 upconverts the signal amplified by the base station side transmission baseband amplifier 108 to a transmission frequency. A signal from the base station side upconverter 107 is transmitted to the base station 1 via the base station side HPA 106 and the base station side antenna 11.

  The terminal-side reception level detection circuit 212 which is an uplink reception level detection circuit according to the present embodiment detects the intensity level (reception level) of the signal amplified by the terminal-side reception AGC amplifier 205. The base station side transmission squelch circuit 151 which is an uplink transmission gain control unit according to the present embodiment controls the gain by the base station side transmission baseband amplifier 108 according to the frame synchronization state by the frame synchronization control circuit 301. In the present embodiment, the base station side transmission squelch circuit 151 controls the gain by the base station side transmission baseband amplifier 108 to zero until frame synchronization by the frame synchronization control circuit 301 is established. Note that the control by the base station side transmission baseband amplifier 108 to make the gain zero corresponds to the fact that no signal is transmitted from the relay transmitting / receiving apparatus 10 to the base station 1. This is the same in the following.

  The base station side transmission squelch circuit 151 controls the gain by the base station side transmission baseband amplifier 108 according to the intensity level (reception level) detected by the terminal side reception level detection circuit 212. In the present embodiment, even if the frame synchronization control circuit 301 maintains the frame synchronization state, if the reception level detected by the terminal-side reception level detection circuit 212 is zero or less than a predetermined value, The base station side transmission squelch circuit 151 controls the gain by the base station side transmission baseband amplifier 108 to be zero.

  The base station side transmission squelch circuit 151 controls the gain by the base station side transmission baseband amplifier 108 according to the intensity level detected by the base station side reception level detection circuit 112. In the present embodiment, when the output value (gain) based on the relay gain calculation table 351 is equal to or less than a certain value, for example, 10 dB or less, the base station side transmission squelch circuit 151 determines that relay is unnecessary, and automatically Thus, control is performed so that the gains by the terminal side reception AGC amplifier 205 and the base station side transmission baseband amplifier 108 are zero.

  The gain notification unit 401 included in the repeater 10 according to the present embodiment notifies the outside, for example, the user of the gain state of the base station side transmission baseband amplifier 108 controlled by the base station side transmission squelch circuit 151. In the present embodiment, gain notifying section 401 has zero gain from base station side transmission baseband amplifier 108 except when there is no output from terminal side reception level detection circuit 212 or when it is below a certain value. The status is displayed as “alarm” using, for example, an LED.

  According to the mobile communication system according to the present embodiment as described above, the gain by the terminal side reception AGC amplifier 205 is controlled according to the reception level detected by the base station side reception level detection circuit 112. Thereby, even if the base station 1 performs transmission power control on the mobile terminal 3 and the reception level of the signal transmitted from the mobile terminal 3 fluctuates, the relay transmitting / receiving apparatus (repeater) 10 always maintains an appropriate relay gain. The signal amplified in step 1 can be transmitted to the base station 1.

  Further, the base station side transmission squelch circuit 151 controls the gain by the base station side transmission baseband amplifier 108 to be zero until the frame synchronization by the frame synchronization control circuit 301 is established. With this control, it is possible to prevent a noise signal generated in a state where an inappropriate gain setting is set due to malfunction due to noise or the like from being transmitted from the repeater 10 to the base station 1. As a result, it is possible to prevent interference of a noise signal with respect to communication of the mobile terminal 2 under the base station 1.

  Also, when the reception level detected by the terminal-side reception level detection circuit 212 is zero or less than a predetermined value, the base station-side transmission squelch circuit 151 sets the gain by the base station-side transmission baseband amplifier 108 to zero. To control. By this control, a signal with a poor S / N ratio transmitted from a mobile terminal outside the relay area is relay-amplified, and a large power in-band noise signal is prevented from being transmitted from the repeater 10 to the base station 1. Can do. As a result, it is possible to prevent interference of a noise signal with respect to communication of the mobile terminal 2 under the base station 1.

  When the output value based on the relay gain calculation table 351 is equal to or smaller than a certain magnitude, the base station side transmission squelch circuit 151 determines that relaying is unnecessary, and automatically performs the terminal side reception AGC amplifier 205 and the base station side. Control is performed so that the gain by the station-side transmission baseband amplifier 108 becomes zero. By this control, it is possible to prevent the repeater 10 from operating in an area where the electric field strength of a predetermined signal relayed and amplified by the repeater 10 is small. As a result, since the signal to be amplified by the repeater 10 can reduce radio wave interference and noise radiation given to other signals, it is possible to prevent the line quality of other signals from deteriorating.

  Further, the gain notification unit 401 is in a state where the gain by the base station side transmission baseband amplifier 108 is zero, except when there is no output from the terminal side reception level detection circuit 212 or when it is below a certain fixed value, For example, an “alarm” is displayed using an LED. Thereby, since the user can know that the repeater 10 is not functioning, the installation environment of the repeater 10 and the communication terminal 3 can be reviewed.

  In the present embodiment, the gain of the uplink signal stored in relay gain calculation table 351 is set higher than the gain of the downlink signal stored in relay gain calculation table 351. Thereby, the range which a signal reaches from the repeater 10 to the base station 1 side can be expanded. As a result, an area where multi-level modulation can be applied to the uplink can be expanded, so that the performance of the entire system can be improved.

<Embodiment 2>
In relay transmission / reception apparatus 10 of the mobile communication system according to Embodiment 1, when the uplink signal strength level is lower than a predetermined value, the gain for amplifying the uplink signal is zero, that is, relay transmission / reception. Control was performed so that no signal was transmitted from the apparatus 10 to the base station 1. On the other hand, when the mobile terminal 3a exists in the vicinity of the repeater 10, the strength level of the uplink signal is high. In such a case, if the uplink signal is amplified by the base station side HPA 106, the uplink signal is distorted. As a result, there has been a problem that the signal transmitted from the repeater 10 to the base station 1 interferes with the signal of the adjacent channel.

  Thus, the mobile communication system according to the present embodiment aims to solve this problem. The configuration of relay transmission / reception apparatus (repeater) 10 according to the present embodiment is the same as that of relay transmission / reception apparatus (repeater) 10 according to FIG. 2, and the operation of some of the configurations is different. In the following, the same components as those in the first embodiment are denoted by the same reference numerals, and the components not newly described are the same as those in the first embodiment.

  The base station side transmission squelch circuit 151 according to the present embodiment sets the gain by the base station side transmission baseband amplifier 108 to zero when the intensity level detected by the terminal side reception level detection circuit 212 is a predetermined value or more. To control. The predetermined value according to the present embodiment is an intensity level at which the distortion level at the base station side HPA 106 is assumed to reach a specified distortion level. The base station side transmission squelch circuit 151 maintains the above-described control for a certain period sufficient for the mobile terminal 3 and the base station 1 to be directly connected.

  In general, when the mobile terminal 3 is in the vicinity of the repeater 10, the reception level of the signal from the base station 1 at the mobile terminal 3 is substantially equal to the reception level of the signal from the base station 1 at the repeater 10. That is, when the mobile terminal 3 is in the vicinity of the repeater 10, the mobile terminal 3 receives a signal having a strength level sufficient to communicate directly with the base station 1. According to the mobile communication system according to the present embodiment, when the mobile terminal 3 is arranged in an area that does not originally require the repeater 10, the repeater 10 interrupts communication with the mobile terminal 3. The signal from the mobile terminal 3 is not amplified by the base station side HPA 106. As a result, transmission of a distorted signal from the repeater 10 to the base station 1 can be prevented. On the other hand, the mobile terminal 3 in the vicinity of the repeater 10 can be prompted to connect directly to the base station 1.

  Note that the communication capability of the mobile terminal 3 may be inferior to the communication capability of the repeater 10. In this case, even if the mobile terminal 3 in the vicinity of the repeater 10 is prompted to connect directly to the base station 1, the mobile terminal 3 and the base station 1 cannot communicate directly. FIG. 3 shows the configuration of a mobile communication system that solves this problem. The mobile communication system according to FIG. 3 includes a plurality of relay transmitting / receiving apparatuses 10 in the same shadowing area 4. The plurality of relay transmission / reception devices 10a and 10b are provided between one base station 1 and the plurality of mobile terminals 3a and 3b, and the plurality of relay transmission / reception devices 10a and 10b are provided apart from each other.

  Each of the repeaters 10a and 10b included in the mobile communication system according to FIG. 3 detects the strength level of the uplink signal by the terminal side reception level detection circuit 212. When the intensity level detected by the terminal-side reception level detection circuit 212 reaches a value that is equal to or higher than the predetermined value, the base station-side transmission squelch circuit 151 sets the gain by the base station-side transmission baseband amplifier 108 to zero. Control to do.

  Thereby, when the mobile terminal 3a in the vicinity of the repeater 10a transmits a signal (burst signal) having an excessive intensity level to the repeater 10a, the relay function of the frame of the repeater 10a is interrupted. However, in the vicinity of the repeater 10b far from the mobile terminal 3a, the strength level of the signal transmitted from the mobile terminal 3a is lower than the original strength level, so that the repeater function of the repeater 10b for the frame is maintained. As described above, according to the mobile communication system according to FIG. 3, when the mobile terminal 3 cannot communicate directly with the base station 1, it maintains communication with the base station 1 via the repeater 10b. Can do.

<Embodiment 3>
In the mobile communication system according to Embodiment 2, when the strength level detected by the terminal-side reception level detection circuit 212 by the base-station-side transmission squelch circuit 151 is equal to or higher than a predetermined value, the base-station-side transmission baseband amplifier 108 is used. The gain was controlled to zero. That is, the signal is not transmitted from the relay transmitting / receiving apparatus 10 to the base station 1 by the squelch function. This squelch function is effective in terms of preventing interference. However, when the plurality of repeaters 10a and 10b are not used as in the mobile communication system according to FIG. 3, as long as the mobile terminal 3a continues to exist in the vicinity of one repeater 10, the overinput state continues. There is a problem that 10 functions remain interrupted. In addition, when the repeater 10 is installed in an underground mall or the like, there is a problem that the mobile terminal 3a and the base station 1 in the vicinity thereof cannot be directly connected.

  Thus, the mobile communication system according to the present embodiment aims to solve this problem. FIG. 4 is a diagram showing a configuration of relay transmission / reception apparatus (repeater) 10 according to the present embodiment. As shown in the figure, the relay transmitting / receiving apparatus 10 according to the present embodiment includes a base station side AGC control circuit 161 instead of the base station side transmission squelch circuit 151, and instead of the base station side transmission baseband amplifier 108. The base station side transmission AGC amplifier 171 is different.

  Base station side transmission AGC amplifier 171 which is an uplink transmission variable gain amplifier according to the present embodiment amplifies the signal amplified by terminal side reception AGC amplifier 205 in a variable manner. The base station side AGC control circuit 161 which is an uplink transmission gain control section according to the present embodiment controls the gain by the base station side transmission AGC amplifier 171 according to the strength level detected by the terminal side reception level detection circuit 212. . In the present embodiment, when the strength level detected by the terminal-side reception level detection circuit 212 is equal to or higher than a predetermined value, the base station-side AGC control circuit 161 reduces the gain by the base station-side transmission AGC amplifier 171. Control. The predetermined value according to the present embodiment is an intensity level at which the distortion level at the base station side HPA 106 is assumed to reach a specified distortion level.

  In the present embodiment, base station side AGC control circuit 161 reduces the gain by base station side transmission AGC amplifier 171 so that the distortion level at base station side HPA 106 falls within an allowable level. In addition, the base station side AGC control circuit 161 according to the present embodiment returns the gain by the base station side transmission AGC amplifier 171 to the original gain after a lapse of a predetermined time from the time when the gain by the base station side transmission AGC amplifier 171 is reduced. return.

  In the present embodiment, the base station side AGC control circuit 161 controls the gain of the base station side transmission AGC amplifier 171 so that the relay gain is gradually recovered to the original relay gain every short time of one to several frames. To do. Even during the control to recover the relay gain, the terminal-side reception level detection circuit 212 detects the strength level of the uplink signal from the mobile terminal 3. When the strength level is equal to or higher than the predetermined value, the base station side AGC control circuit 161 again transmits the base station side AGC amplifier so that the distortion level at the base station side HPA 106 falls within the prescribed distortion level. Control to reduce the gain by 171 is performed. After a predetermined time has elapsed, the base station side AGC control circuit 161 again increases the gain of the base station side transmission AGC amplifier 171 so that the relay gain is gradually recovered to the original relay gain every short time within one frame. Control.

  In the mobile communication system according to the present embodiment as described above, the original gain is restored again after a lapse of a predetermined time from the time when the relay gain for the uplink signal is reduced. Therefore, even if the mobile terminal 3a continues to exist in the vicinity of the repeater 10, it can be avoided that the function of the repeater 10 remains interrupted. In this way, it is possible to avoid a state in which a mobile terminal far from the repeater 10 cannot communicate in a suppressed environment for a long period of time. Note that the repeater 10 may reduce the relay gain of the downlink signal by a value that reduces the relay gain of the uplink signal. As described above, when the relay gain of the uplink signal and the relay gain of the downlink are controlled simultaneously, it is possible to prevent an error from occurring in the power control of the line while the gain is being reduced.

1 is a diagram showing a configuration of a mobile communication system according to Embodiment 1. FIG. 1 is a diagram illustrating a configuration of a relay transmission / reception device according to Embodiment 1. FIG. FIG. 3 is a diagram showing a configuration of a mobile communication system according to a second embodiment. FIG. 11 is a diagram illustrating a configuration of a relay transmission / reception device according to a third embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Base station, 2, 3, 3a, 3b Mobile terminal, 4 Shadowing area | region, 10, 10a, 10b Relay transmission / reception apparatus, 11 Base station side antenna, 21 Terminal side antenna, 101 Base station side antenna filter, 102 Base station side TDD switch, 103 Base station side LNA, 104 Base station side down converter, 105 Base station side reception AGC amplifier, 106 Base station side HPA, 107 Base station side up converter, 108 Base station side transmission baseband amplifier, 109 Base station side Local oscillation circuit, 111, 211 Adjacent channel removal filter, 112 Base station side reception level detection circuit, 113, 161 Base station side AGC control circuit, 151 Base station side transmission squelch circuit, 171 Base station side transmission AGC amplifier, 201 Terminal side Antenna filter, 202 Terminal side TDD switch , 203 terminal side LNA, 204 terminal side down converter, 205 terminal side reception AGC amplifier, 206 terminal side HPA, 207 terminal side up converter, 209 terminal side local oscillation circuit, 212 terminal side reception level detection circuit, 301 frame synchronization control circuit 351 Relay gain calculation table 401 Gain notification unit.

Claims (11)

A relay transmission / reception device that relays wireless transmission / reception performed between a mobile station and a base station,
Downlink reception variable gain amplifier that amplifies the signal from the base station variably,
A downlink reception level detection circuit for detecting the intensity level of the signal amplified by the downlink reception variable gain amplifier;
A downlink reception gain control unit for controlling a gain by the downlink reception variable gain amplifier according to the intensity level detected by the downlink reception level detection circuit;
An uplink reception variable gain amplifier for amplifying a signal from the mobile station in a variable gain,
According to the intensity level detected by the downlink reception level detection circuit, the gain by the uplink reception variable gain amplifier is controlled.
Relay transmission / reception device. A relay transmission / reception device that relays wireless transmission / reception performed between a mobile station and a base station,
An upstream reception level detection circuit for detecting an intensity level of a signal from the mobile station;
An uplink transmission variable gain amplifier that variably amplifies a signal to be transmitted to the base station;
An uplink transmission gain control unit that controls gain by the uplink transmission variable gain amplifier according to the intensity level detected by the uplink reception level detection circuit;
Relay transmission / reception device. A relay transmission / reception device that relays wireless transmission / reception performed between a mobile station and a base station,
A frame synchronization control circuit for controlling frame synchronization based on a signal from the base station;
An uplink transmission variable gain amplifier that variably amplifies a signal to be transmitted to the base station;
An uplink transmission gain control unit for controlling a gain by the uplink transmission variable gain amplifier according to a frame synchronization state by the frame synchronization control circuit;
Relay transmission / reception device. A relay transmission / reception device that relays wireless transmission / reception performed between a mobile station and a base station,
A downlink reception level detection circuit for detecting the intensity level of the signal from the base station;
An uplink transmission variable gain amplifier that variably amplifies a signal to be transmitted to the base station;
An uplink transmission gain control unit that controls gain by the uplink transmission variable gain amplifier according to the intensity level detected by the downlink reception level detection circuit;
Relay transmission / reception device. A gain notification unit for notifying externally the gain state of the uplink transmission variable gain amplifier controlled by the uplink transmission gain control unit;
The relay transmission / reception apparatus according to any one of claims 2 to 4. The uplink transmission gain controller is
When the intensity level detected by the uplink reception level detection circuit is equal to or lower than a predetermined value, the gain by the uplink transmission variable gain amplifier is controlled to be zero.
The relay transmission / reception apparatus according to claim 2. The uplink transmission gain controller is
When the intensity level detected by the downlink reception level detection circuit is less than or equal to a predetermined value, the gain by the uplink transmission variable gain amplifier is controlled to be zero.
The relay transmission / reception apparatus according to claim 4. The uplink transmission gain controller is
When the intensity level detected by the uplink reception level detection circuit is equal to or higher than a predetermined value, the gain by the uplink transmission variable gain amplifier is controlled to be reduced or zero.
The relay transmission / reception apparatus according to claim 2. The uplink transmission gain controller is
After a predetermined time has elapsed from when the gain by the uplink transmission variable gain amplifier is reduced, the gain by the uplink transmission variable gain amplifier is returned to the original gain.
The relay transmission / reception apparatus according to claim 8. A gain for amplifying a downlink signal transmitted from the base station to the mobile station and a gain for amplifying an uplink signal transmitted from the mobile station to the base station are stored in association with each other. A relay gain calculation table;
The gain of the uplink signal stored in the relay gain calculation table is higher than the gain of the downlink signal stored in the relay gain calculation table,
The relay transmission / reception apparatus according to claim 1. A mobile communication system comprising a plurality of relay transmission / reception devices according to claim 8 or 9,
The plurality of relay transmission / reception devices are provided apart from each other,
Mobile communication system.

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