JP2001186069A - Mobile wireless terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile wireless terminal that can sufficiently enhance the diversity effect. SOLUTION: A high frequency signal received by an antenna 5 projected externally is given via an antenna multicoupler 4 to a low noise amplifier 7, where the signal is power-amplified. The high frequency signal received by a built-in antenna 6 is given to a low noise amplifier 10, which amplifies the power by the same gain as that of the low noise amplifier 7 and where the signal is power-amplified, and the amplified signal is given to a low noise amplifier 11. Then the low noise amplifier 11 amplifies the power of the signal at a gain equivalent to the gain difference between the externally projected antenna 5 and the built-in antenna 6. Furthermore, a delay circuit 17 gives a delay to the received signal passing through a reception IF filter 16 in a way that the delay has at least a time of one chip time of a spread code or over used for the inverse spread processing at a post-stage to the received signal passing through a reception IF filter 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile radio terminal device of a mobile radio communication system such as an automobile telephone system or a mobile telephone system, which employs a code division multiple access (CDMA) system.

[0002]

2. Description of the Related Art A diversity receiving circuit used in a conventional mobile radio terminal apparatus aims at improving communication quality in a so-called weak electric field area where a distance from a base station is long and a receiving electric field is weak. .

On the other hand, in a CDMA mobile phone system recently introduced, a mobile radio terminal is close to a base station,
Diversity control is performed even in an area where the reception electric field is sufficiently strong.

In a CDMA mobile phone system, communication traffic is large, and in an area with many base stations,
Although the level of a signal mainly from a base station that communicates fluctuates due to fading, a composite wave of a signal from many other base stations that becomes an interference wave is almost constant in many cases.

[0005] Therefore, even when a signal from a base station that mainly communicates can be received at a sufficiently strong level, an interference wave ratio (C / I) fluctuates due to level fluctuation due to fading, and communication quality deteriorates. Resulting in.

The multipath causing the fading can be dealt with, for example, by RAKE reception. However, for that purpose, a delay time difference between the multipath signals needs to be equal to or more than a specified value (1 Chip time). In an area close to a simple base station, the delay time between multipath signals is small, and RAKE reception often does not function effectively.

However, even in an area close to the base station and having a small delay time between multipath signals,
The above diversity (antenna diversity) is effective.

[0008] Diversity suitable for a mobile radio terminal device that requires small size, light weight and low power consumption includes (1) IF combining diversity and (2) antenna switching (selection) diversity. When applying antenna diversity to a mobile wireless terminal device, a built-in antenna is often adopted as one of the antennas for the reason of appearance.

However, the gain of the built-in antenna is lower than that of the external antenna, and the built-in antenna is easily affected by the human body.
When worn on the human body, a gain difference from the external antenna may be about 10 dB.

When there is a gain difference between the two antennas as described above, there is a disadvantage that it is difficult to obtain a diversity effect. In other words, the IF combining diversity of (1) provides better performance than (2) when there is no gain difference between the two antennas, but its effect decreases as the gain difference between the antennas increases.

The antenna switching diversity of (2) is effective when there is no gain difference between the two antennas. However, when the gain difference is large, the built-in antenna having a small gain cannot be used effectively, and the diversity effect is reduced. There is a problem that it cannot be obtained.

[0012]

In the conventional mobile radio terminal device, when a diversity receiving circuit is used, there is a problem that the diversity effect is not sufficiently exhibited because there is a gain difference between two antennas used for diversity. The present invention has been made to solve the above-described problem, and has as its object to provide a mobile wireless terminal device capable of sufficiently exhibiting a diversity effect.

[0013]

In order to achieve the above object, the present invention has a first amplifying means for amplifying a signal received by a first antenna, and a gain difference from the first antenna. A second amplifying signal received by the second antenna
A delay means for delaying the signal amplified by the second amplification means, and a synthesis means for synthesizing the signal amplified by the first amplification means and the signal delayed by the delay means. A mobile wireless terminal device for wirelessly communicating with a wireless base station connected to a communication network, comprising: a first amplifying means;
Gain between the first antenna and the second antenna
The antenna is configured to correct a gain difference with the antenna.

Further, according to the present invention, the first amplifying means for amplifying the signal received by the first antenna and the second amplifying means for amplifying the signal received by the second antenna having a gain difference from the first antenna. 2, one of the signal amplified by the first amplifier and the signal amplified by the first amplifier is used as a signal for reproducing received data. Selecting means for selecting, and switching control means for controlling the selecting means to switch the signal selected by the selecting means when the reception quality of the signal selected by the selecting means has deteriorated below a predetermined reference level. A mobile wireless terminal device, comprising: a wireless communication device that wirelessly communicates with a wireless base station connected to a communication network, wherein a gain difference between a first amplifying means and a second amplifying means causes a first antenna and a second To compensate for the gain difference with the antenna Form was.

In the mobile radio terminal having the above-described configuration, a gain difference between the first amplifying means and the second amplifying means is given.
Thereby, the gain difference between the first antenna and the second antenna is corrected.

Therefore, according to the mobile radio terminal having the above configuration, the gain difference between the first antenna and the second antenna can be corrected, so that the diversity effect can be sufficiently exhibited.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a diversity receiving circuit of a mobile radio terminal according to a first embodiment of the present invention.

The high-frequency transmission signal generated by the transmission circuit 1 is power-amplified by the power amplifier 2 and then radiated into space from the outside antenna 5 via the isolator 3 and the antenna duplexer (DUP) 4. .

A high-frequency reception signal received from a base station (not shown) by the outside antenna 5 is input to the low-noise amplifier 7 via the antenna duplexer 4 and power-amplified here.

From the power-amplified high-frequency reception signal, an unnecessary band signal is removed by a band-pass filter 8.
Only the reception signal in the reception frequency band is output to down converter 13.

In the down-converter 13, the local signal generated by the synthesizer (not shown) is mixed with the received signal passed through the band-pass filter 8, and the received signal is down-converted to an intermediate frequency. From the down-converted received signal, unnecessary waves are removed by the reception IF filter 15, and only the desired wave is output to the combiner 18.

On the other hand, a high-frequency reception signal received by the built-in antenna 6 passes through a band-pass filter 9 that allows a high-frequency signal in a reception frequency band to pass therethrough, and then performs a low-noise amplifier that performs power amplification equivalent to that of the low-noise amplifier 7. After power amplification at 10, the signal is input to the low noise amplifier 11.

The low-noise amplifier 11 amplifies power with a gain corresponding to the gain difference between the external antenna 5 and the built-in antenna 6, and amplifies the power of the received signal that has been amplified by the low-noise amplifier 10. , To the band-pass filter 12.

From the power-amplified high-frequency reception signal, an unnecessary band signal is removed by a band-pass filter 12, and only the reception signal in the reception frequency band is converted by the down-converter 1.
4 is output.

The down-converter 14 mixes a local signal generated by a synthesizer (not shown) with a received signal that has passed through the band-pass filter 12, and down-converts the received signal to an intermediate frequency. Unwanted waves are removed from the down-converted reception signal by the reception IF filter 16 and only the desired wave is output to the delay circuit (τ) 17.

The delay circuit 17 delays the received signal that has passed through the reception IF filter 16, and the delayed received signal is output to the combiner 18. Note that the delay time given here is at least one chip time of the spread code used in the despreading process at the subsequent stage between the received signal passed through the receive IF filter 15 and the received signal passed through the receive IF filter 16. That is all.

The combiner 18 combines the reception signal passed through the reception IF filter 15 with the reception signal delayed by the delay circuit 17 and outputs the result to the reception IF circuit 19. Receive I
The F circuit 19 performs predetermined signal processing such as despreading processing on the synthesized signal input from the synthesizer 18,
KE reception is performed, and reception data is extracted and reproduced.

With the above configuration, in the diversity receiving circuit according to the first embodiment, the low noise amplifier 11
Accordingly, power amplification corresponding to the gain difference between the outside antenna 5 and the built-in antenna 6 is performed on the signal received by the built-in antenna 6.

Further, the delay circuit 17 adds at least one chip time or more of the spread code used in the subsequent despreading process between the signal received by the outside antenna 5 and the signal received by the built-in antenna 6. A delay time difference is provided.

Therefore, according to the diversity receiving circuit having the above structure, the gain difference between the two antennas 5 and 6 is eliminated by the low-noise amplifier 11, and the received signals are combined, so that the diversity effect can be sufficiently exhibited. it can.
In addition, since a delay time longer than a specified value required for RAKE reception is given between signals received by the two antennas 5 and 6, RAKE reception can be performed.

Next, a description will be given of a diversity receiving circuit of a mobile radio terminal according to a second embodiment of the present invention. FIG. 2 shows the configuration. Transmission circuit 1
The high-frequency transmission signal generated by the power amplifier 2 is power-amplified by the power amplifier 2 and then radiated to the space from the outside antenna 5 via the isolator 3 and the antenna duplexer (DUP) 4.

A high-frequency received signal received from a base station (not shown) by the outside antenna 5 is input to the low-noise variable amplifier 20 via the antenna duplexer 4 and power-amplified here.

From the power-amplified high-frequency reception signal, an unnecessary band signal is removed by a band-pass filter 8.
Only the reception signal in the reception frequency band is output to down converter 13.

The down converter 13 mixes a local signal generated by a synthesizer (not shown) with a received signal that has passed through the band-pass filter 8, and down-converts the received signal to an intermediate frequency. From the down-converted received signal, unnecessary waves are removed by the reception IF filter 15, and only the desired wave is output to the combiner 18.

On the other hand, a high-frequency reception signal received by the built-in antenna 6 passes through a band-pass filter 9 for passing a high-frequency signal in a reception frequency band, is power-amplified by a low-noise variable amplifier 21, and is then band-passed. Output to the filter 12.

The gains of the low noise variable amplifiers 20 and 21 are based on the gain difference between the external antenna 5 and the built-in antenna 6, and are the sum of the gain of the external antenna 5 and the gain of the low noise variable amplifier 20. However, the gain of the built-in antenna 6 and the gain of the low noise variable amplifier 21 are set to be equal to the sum.

From the high-frequency reception signal power-amplified by the low-noise variable amplifier 21, unnecessary band signals are removed by the band-pass filter 12, and only the reception signal in the reception frequency band is output to the down converter 14.

The down-converter 14 mixes a local signal generated by a synthesizer (not shown) with the received signal that has passed through the band-pass filter 12, and down-converts the received signal to an intermediate frequency. Unwanted waves are removed from the down-converted reception signal by the reception IF filter 16 and only the desired wave is output to the delay circuit (τ) 17.

The delay circuit 17 delays the reception signal that has passed through the reception IF filter 16, and the delayed reception signal is output to the combiner 18. Note that the delay time given here is at least one chip time of the spread code used in the despreading process at the subsequent stage between the received signal passed through the receive IF filter 15 and the received signal passed through the receive IF filter 16. That is all.

The combiner 18 combines the reception signal passed through the reception IF filter 15 with the reception signal delayed by the delay circuit 17, and outputs the result to the reception IF circuit 19. Receive I
The F circuit 19 performs predetermined signal processing such as despreading processing on the synthesized signal input from the synthesizer 18,
KE reception is performed, and reception data is extracted and reproduced.

With the above configuration, in the diversity receiving circuit according to the second embodiment, the external antenna 5 and the built-in antenna 6 are controlled by the low noise variable amplifiers 20 and 21.
The power is amplified with a gain that eliminates the gain difference between.

Further, the delay circuit 17 adds at least one chip time or more of the spread code used in the subsequent despreading process between the signal received by the outside antenna 5 and the signal received by the built-in antenna 6. A delay time difference is provided.

Therefore, according to the diversity receiving circuit having the above-described configuration, the received signals are synthesized by amplifying so as to eliminate the gain difference between the received signals by the two antennas 5 and 6, so that the diversity effect can be sufficiently exhibited. Can be.
In addition, since a delay time longer than a specified value required for RAKE reception is given between signals received by the two antennas 5 and 6, RAKE reception can be performed.

Next, a description will be given of a diversity receiving circuit of a mobile radio terminal according to a third embodiment of the present invention. FIG. 3 shows the configuration. Transmission circuit 1
The high-frequency transmission signal generated by the power amplifier 2 is power-amplified by the power amplifier 2 and then radiated to the space from the outside antenna 5 via the isolator 3 and the antenna duplexer (DUP) 4.

A high-frequency received signal received from a base station (not shown) by the outside antenna 5 is input to the low-noise variable amplifier 22 via the antenna duplexer 4, where the power is amplified. The gain of the low noise variable amplifier 22 is controlled by a CPU 241 described later.

From the high-frequency reception signal power-amplified by the low noise variable amplifier 22, unnecessary band signals are removed by the band-pass filter 8, and only the reception signal in the reception frequency band is output to the down converter 13.

The down converter 13 mixes the local signal generated by the synthesizer (not shown) with the received signal that has passed through the band-pass filter 8, and down-converts the received signal to an intermediate frequency. From the down-converted received signal, unnecessary waves are removed by the reception IF filter 15, and only the desired wave is output to the combiner 18.

On the other hand, the high-frequency reception signal received by the built-in antenna 6 passes through a band-pass filter 9 for passing a high-frequency signal in a reception frequency band, and then passes through a low-noise amplifier
, And is output to the band-pass filter 12. The low-noise amplifier 23 includes a CPU 241 described later.
ON / OFF control.

From the high-frequency reception signal power-amplified by the low-noise amplifier 23, an unnecessary band signal is removed by the band-pass filter 12, and only the reception signal in the reception frequency band is output to the down converter 14.

The down converter 14 is connected to a CPU 2
At the time of operation, a local signal generated by a synthesizer (not shown) and a received signal that has passed through the band-pass filter 12 are mixed, and the received signal is down-converted to an intermediate frequency. This down-converted received signal is output to the reception IF
Unwanted waves are removed by the filter 16 and only the desired waves are output to the delay circuit (τ) 17.

The delay circuit 17 delays the reception signal that has passed through the reception IF filter 16, and the delayed reception signal is output to the synthesizer 18. Note that the delay time given here is at least one chip time of the spread code used in the despreading process at the subsequent stage between the received signal passed through the receive IF filter 15 and the received signal passed through the receive IF filter 16. That is all.

The combiner 18 combines the reception signal passed through the reception IF filter 15 with the reception signal delayed by the delay circuit 17 and outputs the result to the reception IF circuit 19. Receive I
The F circuit 19 performs predetermined signal processing such as despreading processing on the synthesized signal input from the synthesizer 18,
KE reception is performed, and reception data is extracted and reproduced.

The CPU 241 monitors the reception signal strength mainly from the connected base station in the reception IF circuit 19, and according to this strength, as shown in FIG. ON / OFF control of the noise amplifier 23 and the down converter 14 (diversity control)
And to do.

That is, as shown in FIG. 4, when the distance from the connected base station is short and the signal strength is strong, the CPU 241 sets the gain of the low noise variable amplifier 22 to G
Control to _L.

[0055] In this case, CPU 241, for the low-noise amplifier 23, and ON control, as well as the G ₀ which is set the gain in advance, also the down-converter 14 O
N control is performed, and diversity reception is performed.

Note that the gain G _L of the low noise variable amplifier 22 is
And the gain G ₀ of the low-noise amplifier 23 is based on the gain difference between the outside antenna 5 and the built-in antenna 6, and the sum of the gain of the outside antenna 5 and the gain _GL of the low-noise variable amplifier 22 is equal to the built-in antenna 5. 6 and the gain G of the low noise amplifier 23
It is set to be equal to the sum of ₀ .

On the other hand, as shown in FIG. 4, when the distance is far from the base station to be connected and the signal strength is weak, C
The PU 241 sets the gain of the low noise variable amplifier 22 to G _H (>
G _L ).

In this case, the CPU 241 controls the low-noise amplifier 23 to turn off and stops the operation, and also controls the down converter 14 to turn off.
Diversity reception is stopped.

With the above configuration, in the diversity receiving circuit according to the third embodiment, when the distance to the base station is short and a strong received signal is obtained, the low noise variable amplifier 22 and the low noise amplifier are used. 23, amplification is performed so as to eliminate the gain difference between the outside antenna 5 and the built-in antenna 6, and diversity reception is performed.

Further, the delay circuit 17 adds at least one chip time of the spread code used in the subsequent despreading process between the signal received by the outside antenna 5 and the signal received by the built-in antenna 6. A delay time difference is provided.

When the distance from the base station is long and only a weak received signal can be obtained, the operation of the receiving system by the built-in antenna 6 is stopped, and reception is performed only by the receiving system by the outside antenna 5.

Therefore, according to the diversity receiving circuit having the above configuration, when the distance from the base station is short, amplification is performed so as to eliminate the gain difference between the signals received by the two antennas 5 and 6, and the received signals are combined. Therefore, the diversity effect can be sufficiently exhibited. In addition, since a delay time longer than a specified value required for RAKE reception is given between signals received by the two antennas 5 and 6, RAKE reception can be performed.

When the distance from the base station is long, the diversity effect cannot be expected so much. Therefore, the operation of the receiving system of the built-in antenna 6 is stopped. Can be extended.

Next, the diversity receiving circuit of the mobile radio terminal according to the fourth embodiment of the present invention will be described. FIG. 5 shows the configuration. Transmission circuit 1
The high-frequency transmission signal generated by the power amplifier 2 is power-amplified by the power amplifier 2 and then radiated to the space from the outside antenna 5 via the isolator 3 and the antenna duplexer (DUP) 4.

A high-frequency reception signal received from a base station (not shown) by the outside antenna 5 is input to the low-noise amplifier 7 via the antenna duplexer 4 and power-amplified here. It is output to 25 first input terminals.

On the other hand, a high-frequency reception signal received by the built-in antenna 6 passes through a band-pass filter 9 for passing a high-frequency signal in a reception frequency band, and then performs a low-noise amplifier that performs power amplification equivalent to that of the low-noise amplifier 7. The power is amplified at 10 and then input to the low noise amplifier 11.

The low-noise amplifier 11 performs power amplification with a gain corresponding to the gain difference between the external antenna 5 and the built-in antenna 6, and amplifies the power of the received signal that has been power-amplified by the low-noise amplifier 10. To the second input terminal of the changeover switch 25.

The changeover switch 25 is controlled by the CPU 242 to selectively output one of the reception signals input to the first input terminal and the second input terminal to the bandpass filter 8. Bandpass filter 8
Removes an unnecessary band signal from the received signal input from the changeover switch 25 and outputs only the received signal in the received frequency band to the down converter 13.

The down converter 13 mixes the local signal generated by the synthesizer (not shown) with the received signal that has passed through the band-pass filter 8, and down-converts the received signal to an intermediate frequency. Unwanted waves are removed from the down-converted reception signal by the reception IF filter 15, and only the desired wave is output to the reception IF circuit 19.

The reception IF circuit 19 performs predetermined signal processing such as despreading processing on the reception signal input from the reception IF filter 15, performs RAKE reception, extracts received data, and reproduces the received data.

The CPU 242 monitors the reception quality of the reception IF circuit 19, and when the reception quality is deteriorated and falls below a predetermined reference value, controls the changeover switch 25 to switch over.
This controls the switching of the system used for reception.

With the above configuration, in the diversity receiving circuit according to the fourth embodiment, the low noise amplifier 11
Accordingly, power amplification corresponding to the gain difference between the outside antenna 5 and the built-in antenna 6 is performed on the signal received by the built-in antenna 6.

Therefore, according to the diversity receiving circuit having the above configuration, the gain difference between the two antennas 5 and 6 is eliminated by the low noise amplifier 11. For this reason, the NF (noise figure) of the built-in antenna 6 system can be improved, and communication can be performed using the system having the better reception quality from the two systems, so that the area where diversity is effective can be expanded.

The present invention is not limited to the fourth embodiment. For example, the present invention is applicable to the case where the antenna switching diversity is employed in the diversity receiving circuits shown in FIGS.

Next, a diversity receiving circuit of the mobile radio terminal according to the fifth embodiment of the present invention will be described. FIG. 6 shows the configuration. Transmission circuit 1
The high-frequency transmission signal generated by the power amplifier 2 is power-amplified by the power amplifier 2 and then radiated to the space from the outside antenna 5 via the isolator 3 and the antenna duplexer (DUP) 4.

The high-frequency reception signal received from the base station (not shown) by the outside antenna 5 is input to the low-noise amplifier 26 via the antenna duplexer 4, where the signal is amplified.

The high-frequency reception signal power-amplified by the low-noise amplifier 26 is input to the low-noise variable amplifier 27 and further power-amplified. The gain of the low noise variable amplifier 27 is controlled by a CPU 243 described later.

From the high-frequency reception signal power-amplified by the low-noise variable amplifier 27, unnecessary band signals are removed by the band-pass filter 8, and only the reception signal in the reception frequency band is output to the down converter 13.

In the down-converter 13, the local signal generated by the synthesizer (not shown) and the received signal that has passed through the band-pass filter 8 are mixed, and the received signal is down-converted to an intermediate frequency. From the down-converted received signal, unnecessary waves are removed by the reception IF filter 15, and only the desired wave is output to the combiner 18 and the RSSI measurement circuit (RSSI 1) 30.

On the other hand, the high-frequency reception signal received by the built-in antenna 6 passes through a band-pass filter 9 for passing a high-frequency signal in a reception frequency band, and then a low-noise amplifier 28
, And then input to the low-noise variable amplifier 29 and further power-amplified. The low-noise variable amplifier 2
The gain of 9 is controlled by a CPU 243 described later.

From the high-frequency signal power-amplified by the low-noise variable amplifier 29, an unnecessary band signal is removed by the band-pass filter 12, and only the reception signal in the reception frequency band is output to the down converter 14.

The down-converter 14 mixes a local signal generated by a synthesizer (not shown) with the received signal that has passed through the band-pass filter 12, and down-converts the received signal to an intermediate frequency. Unwanted waves are removed from the down-converted reception signal by the reception IF filter 16 and only the desired wave is output to the delay circuit (τ) 17.

The delay circuit 17 delays the received signal that has passed through the reception IF filter 16, and the delayed received signal is combined with the combiner 18 and the RSSI measurement circuit (RSSI measurement circuit).
2) Output to 31.

Note that the delay time given here corresponds to at least the spreading code of the spreading code used in the subsequent despreading process between the reception signal passed through the reception IF filter 15 and the reception signal passed through the reception IF filter 16. It is one chip time or more.

The combiner 18 combines the reception signal passed through the reception IF filter 15 with the reception signal delayed by the delay circuit 17 and outputs the result to the reception IF circuit 19. Receive I
The F circuit 19 performs predetermined signal processing such as despreading processing on the synthesized signal input from the synthesizer 18,
KE reception is performed, and reception data is extracted and reproduced.

The RSSI measurement circuit 30 detects the reception electric field strength of the reception signal that has passed through the reception IF filter 15 and notifies the CPU 243 of the detection result. Similarly, RSS
The I measurement circuit 31 detects the reception electric field strength of the reception signal delayed by the delay circuit 17 and outputs the detection result to the CPU 243.
Notify.

The CPU 243 includes the RSSI measurement circuit 30,
The received electric field strength detected at 31 is monitored, and the low-noise variable amplifier 27 and 27 are adjusted so that the received electric field strength detected at the RSSI measurement circuits 30 and 31 becomes equal according to the received electric field strength.
29 to perform the gain control.

With the above configuration, in the diversity receiving circuit according to the fifth embodiment, the gain difference between the antennas 5 and 6 that changes every moment due to the use environment (influence with the human body) is determined by the RSSI measurement circuit. Low-noise variable amplifier 2 so that the reception electric field strengths detected at 30 and 31 become equal.
The gain is controlled at 7, 29 to correct the gain.

Further, the delay circuit 17 adds at least one chip time of the spread code used in the subsequent despreading process between the signal received by the outside antenna 5 and the signal received by the built-in antenna 6. A delay time difference is provided.

Therefore, according to the diversity receiving circuit having the above configuration, even if the gain difference between the antennas 5 and 6 changes every moment depending on the usage environment, the low noise variable amplifier 2
Since the gain can be corrected by the gain control of 7, 29, the diversity effect can be sufficiently exhibited. In addition, since a delay time longer than a specified value required for RAKE reception is given between signals received by the two antennas 5 and 6, RAKE reception can be performed.

The present invention is not limited to the above embodiment. It goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0092]

As described above, according to the present invention, the first
The gain difference between the amplifying means and the second amplifying means is given in advance, so that the gain difference between the first antenna and the second antenna is corrected.

Therefore, according to the present invention, since the gain difference between the first antenna and the second antenna can be corrected, it is possible to provide a mobile radio terminal capable of sufficiently exhibiting the diversity effect. .

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing a configuration of a first embodiment of a mobile wireless terminal device according to the present invention.

FIG. 2 is a circuit block diagram showing a configuration of a second embodiment of the mobile wireless terminal device according to the present invention.

FIG. 3 is a circuit block diagram showing a configuration of a third embodiment of the mobile wireless terminal device according to the present invention.

FIG. 4 is a diagram for explaining the operation of the mobile wireless terminal device shown in FIG. 3;

FIG. 5 is a circuit block diagram showing a configuration of a fourth embodiment of the mobile wireless terminal device according to the present invention.

FIG. 6 is a circuit block diagram showing a configuration of a fifth embodiment of the mobile wireless terminal device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transmission circuit 2 ... Power amplifier 3 ... Isolator 4 ... Antenna duplexer (DUP) 5 ... Outgoing antenna 6 ... Built-in antenna 7 ... Low noise amplifier 8, 9 ... Bandpass filter 10, 11 ... Low noise amplifier 12 ... Band Pass filters 13, 14 Down converter 15, 16 IF filter 17 Delay circuit (τ) 18 Synthesizer 19 Receive IF circuit 20, 21 Low noise variable amplifier 22 Low noise variable amplifier 23 Low noise amplifier 241 , 242, 243 CPU 25 changeover switch 26 28 low noise amplifier 27 29 low noise variable amplifier 31 31 RSSI measurement circuit

Claims (4)

[Claims] 1. A first amplifying means for amplifying a signal received by a first antenna, and a second amplifying means for amplifying a signal received by a second antenna having a gain difference from the first antenna. Means, delay means for delaying the signal amplified by the second amplifying means, and combining means for combining the signal amplified by the first amplifying means and the signal delayed by the delay means With
A mobile wireless terminal device that wirelessly communicates with a wireless base station connected to a communication network, wherein a gain difference between the first amplifying unit and the second amplifying unit causes a difference between the first antenna and the second antenna. A mobile wireless terminal device for correcting a gain difference between the mobile wireless terminal device and the antenna. 2. A reception quality detection means for detecting reception quality based on a signal synthesized by the synthesis means, wherein the reception quality detection means uses only the signal amplified by the first amplification means. The mobile radio terminal device according to claim 1, further comprising: a power control unit that stops power supply to the second amplifying unit when detecting that a predetermined reception quality is obtained. 3. An electric field intensity detector for detecting an electric field intensity of a signal amplified by the first amplifier and an electric field intensity of a signal amplified by the second amplifier, respectively. On the basis of the detection result of the detection means, to correct the electric field strength difference between the signal amplified by the first amplification means and the signal amplified by the second amplification means,
2. The mobile radio terminal device according to claim 1, further comprising a gain control unit that variably controls both gains of the first amplification unit and the second amplification unit. 4. A first amplifier for amplifying a signal received by a first antenna, and a second amplifier for amplifying a signal received by a second antenna having a gain difference from the first antenna. Means for selecting one of a signal amplified by the first amplifying means and a signal amplified by the first amplifying means as a signal for reproducing received data. And a switching control unit that controls the selection unit to switch the signal selected by the selection unit when the reception quality of the signal selected by the selection unit is deteriorated below a predetermined reference level. A mobile wireless terminal device that wirelessly communicates with a wireless base station connected to a communication network, wherein a gain difference between the first amplifying unit and the second amplifying unit includes An antenna and the second antenna Mobile radio terminal apparatus characterized by correcting the gain difference.