JP4649054B2 - transceiver - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radio device that includes a plurality of antennas, and that appropriately selects one of these antennas and that receives a signal appropriately.
[0002]
[Prior art]
A wireless device (mobile communication terminal) such as a mobile phone sets up a wireless communication line using radio waves with a base station, and communicates by transmitting and receiving voice, data, and the like wirelessly. Therefore, there are multiple propagation paths from the base station to the mobile communication terminal due to the influence of buildings, etc. existing near the propagation path between the base station and the mobile communication terminal, and radio waves propagated through these paths interfere. This causes fading. Some portable communication terminals employ a diversity scheme to cope with fading due to multipath. The diversity method is a method in which a reception state (reception field strength, RSSI) of a plurality of antennas is appropriately checked and a call is performed using an antenna having a better reception state (reception field strength is stronger). is there.
[0003]
[Problems to be solved by the invention]
However, although the diversity mobile communication terminal can cope with fading, it cannot overcome the obstacle caused by the sudden interference wave coming from a specific direction. The reception sensitivity is suppressed by this interference wave, and there is a problem that the call state deteriorates.
[0004]
The present invention has been made in view of such problems, and an object of the present invention is to provide a radio device that maintains good reception quality.
[0005]
[Means for Solving the Problems]
A first aspect of the present invention is a diversity-type radio that receives a signal by one of the first antenna (A) or the second antenna (B) that has good reception, and the data of the received signal As a result of detecting an error, if the error rate of the data is out of an allowable range, directivity is provided by the first antenna (A) and the second antenna (B) so that the error of the received data is small. Even if the signal is received with the directivity selected and the error rate of the data is outside the allowable range, if the difference in the strength of the received signal of each antenna is large, reception is performed by the diversity method.
[0006]
The second invention includes a first antenna (A), a second antenna (B), and a receiving unit (8, 9), and the first antenna (A) or the second antenna. (B) Diversity-type radio equipment that receives a signal by appropriately selecting one having better reception and connecting to the receiving unit, wherein the first antenna (A) and the second antenna ( B) receiving means for receiving a signal, detecting means for detecting an error in the data of the received signal, and the first antenna (A) or the second antenna depending on the strength of the received signal (B) Diversity receiving means for deciding which antenna to receive a signal to receive, and directivity in a direction in which errors in received data are reduced, and the first antenna (A) and the above With the second antenna (B) The beam receiving means for receiving the data and the detected error rate of the data outside the allowable range, received by the beam receiving means, even if the data error rate is outside the allowable range, Control means for controlling the diversity reception means to receive when the difference in the intensity of the received signal of each antenna is large.
[0016]
Operation and effect of the invention
In the first invention, as a result of detecting an error in the data of the received signal, if the error rate of the data is out of the allowable range, directivity is provided by the first antenna and the second antenna, and the received data When the signal is received by selecting the directivity in the direction in which the number of errors is small, and the error rate of the data is out of the allowable range, if the difference in the received signal strength of each antenna is large, the diversity Because it receives with the method,Appropriate reception can be performed by switching the presence / absence of directivity with respect to an interference wave coming from a specific direction. This maintains the quality of reception.
[0017]
In the second invention, the receiving means for receiving the signal by the first antenna and the second antenna, the detecting means for detecting an error in the data of the received signal, and the intensity of the received signal, Diversity receiving means for receiving a signal by determining which of the first antenna and the second antenna receives the signal, and directivity in a direction in which errors of received data are reduced When the detected error rate of the data is out of an allowable range, the beam receiving unit receives the received data and the error rate of the data is less than the allowable range. Even if it is outside the allowable range, if the difference in the strength of the received signal of each antenna is large, control is performed so that the diversity receiving means receives the signal. And detecting the data error of the received signal, determining whether to receive diversity or to receive with directivity (beam reception), and to perform appropriate reception The reception quality can be kept good.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram illustrating the configuration of a mobile communication terminal (an example of a wireless device) according to this embodiment. The mobile communication terminal is provided with two antennas A and B. As the antenna A and the antenna B, a whip antenna, an inverted F antenna, or a chip antenna in which the inverted F antenna is miniaturized can be used. In this embodiment, a configuration in which directivity is generated using a plurality of antennas originally provided for diversity reception will be described.
[0023]
The antenna A and the antenna B in FIG. 1 are used for signal reception, and in particular, the antenna B is also used for signal transmission. First, a conventional configuration related to transmission will be described. The portable communication terminal is provided with a transmitter 12, and an acoustic signal is converted into an audio signal here. The audio signal is sent to the audio processing unit 10 and is encoded under the control of the control unit 11 to generate a baseband signal. The baseband signal is then sent to the radio unit 3. Specifically, the baseband signal is sent to the transmission unit 5 of the wireless unit 3 to generate a high frequency signal. At the time of transmission, the switch 4 connects the antenna B and the transmission unit 5, and a high frequency signal is emitted from the antenna B as a radio signal.
[0024]
Next, components related to reception will be briefly described. The antenna A is connected to the tuning circuit 7. The antenna B is switched by the switch 4 and is connected to the transmitter 5 at the time of transmission and to the tuning circuit 6 at the time of reception as described above. A receiving circuit 8 and a receiving circuit 9 are connected to the subsequent stage of the tuning circuit 6 and the tuning circuit 7, respectively. The tuning circuit 6 and the tuning circuit 7 are controlled by the control unit 11 and take the following three states.
[0025]
(1) Connect the antenna and the receiving circuit.
(2) -L Increase the electrical length of the antenna.
(2) -H Shorten the electrical length of the antenna.
[0026]
Since the three states can be selected as described above, the portable communication terminal according to the present embodiment can use both the diversity method in which each antenna is selectively used and the beam method in which directivity is generated by each antenna. Can be switched. The feature of the portable communication terminal of the present embodiment is that the two systems are configured to be switchable. Here, the beam system refers to a system in which the antenna A and the antenna B constitute one directional antenna and directivity is generated in the one antenna to perform reception. For example, by adjusting the electrical length of one of the antennas A and B and using the antenna as a reflector or a director, directivity can be imparted to the set of antennas. Hereinafter, two methods will be described.
[0027]
When diversity system reception is performed, the received signal strength (RSSI) of each of antenna A and antenna B is detected during the antenna switching diversity level measurement time before the reception slot. First, the tuning circuit 6 and the tuning circuit 7 are set to the state {circle around (1)} by the control unit 11. Then, the two high frequency signals transmitted from the antenna A and the antenna B are input to the receiving unit 8 and the receiving unit 9, respectively. The receiving unit 8 and the receiving unit 9 receive signals transmitted from the base station. Further, the receiving unit 8 and the receiving unit 9 respectively amplify and frequency convert the extracted high frequency signal to generate a baseband signal.
[0028]
The control unit 11 receives the received signal strengths of the antenna A and the antenna B from the receiving unit 9 and the receiving unit 8, respectively. And the control part 11 gives the instruction | indication to the audio | voice processing part 10 so that it may receive by a higher received signal strength among the antenna A or the antenna B in the reception slot after the antenna switching diversity level measurement time. The voice processing unit 10 receives a baseband signal from the receiving unit 8 and the receiving unit 9 corresponding to the designated antenna (designated receiving unit), generates a voice signal, and sends it to the receiving unit 13 (speaker). give. Then, an acoustic signal is generated in the receiver 13 and the sound is reproduced. In diversity system reception, the above processing is repeated for each slot.
[0029]
Diversity reception is effective because the received signal strength varies temporally with movement due to the spatial variation of the received signal strength of the signal (received wave) transmitted from the base station, and the antenna A This is a case where there is a difference in received signal strength between the antenna B and the antenna B. Therefore, when such a condition is not satisfied, the diversity system cannot receive well. For example, this is a case where the reception state of both antenna A and antenna B deteriorates due to a sudden disturbance wave coming from a specific direction. That is, it is located in the service area, the electric field strength is uniformly high, and the difference between the received signal strengths of the antenna A and the antenna B is small, but the received signal has an error due to an interference wave or the like. This is when reception fails.
[0030]
Therefore, in order to cope with such a situation, the control unit 11 in FIG. 1 grasps how much error has occurred in the received signal. The control unit 11 receives redundant information (for example, an error correction code) added to the signal from the reception unit 8 or the reception unit 9 and obtains a bit error rate (hereinafter referred to as BER) of the signal based on the redundant information. When a failure occurs in reception due to an interference wave or the like, the received signal strength (RSSI) of the desired wave is good, but the BER is high. Therefore, by knowing the BER, it is possible to estimate the occurrence of an interference wave or the like.
[0031]
The mobile communication terminal according to the present embodiment is configured to switch to the beam method when reception is not successful in the diversity method, which is a feature. That is, the influence of the interference wave is avoided by switching to reception with directivity directed to avoid the interference wave. How switching is determined will be described in detail later with reference to FIG.
[0032]
When beam-type reception is performed, the tuning circuit 6 and the tuning circuit 7 can take any of the states (1), (2) -L, and (2) -H. The control unit 11 performs control such that one of the antennas A and B having a good reception state is connected to the reception unit and used as a feeding element, and the other is used as a reflector or a director to generate directivity. Do. In order to realize such a configuration, the tuning circuit 7 and the tuning circuit 6 may be configured as illustrated in FIGS. 2 and 3, for example.
[0033]
2 and 3 are schematic diagrams illustrating circuit configurations of the tuning circuit 7 and the tuning circuit 6, respectively. The tuning circuit 7 and the tuning circuit 6 have the same configuration, and the difference is that the connection destination is different and that the control is performed independently. Therefore, first, the tuning circuit 7 will be described with reference to FIG. 2, and the tuning circuit 6 will be described later with a focus on the difference from the tuning circuit 7 with reference to FIG.
[0034]
As illustrated in FIG. 2, the tuning circuit 7 is provided with a switching element SWA, and either the receiving unit 9 (switch position 1 side) or the electrical length switching circuit 20A (switch position 2 side) and the antenna A Are configured to be connected. In the electrical length switching circuit 20A, a coil having one end connected to the switch position 2 side is inserted, and a plurality of electrical elements connected in parallel to each other are connected in series to the other end. A resonance circuit is configured by these components.
[0035]
The part of the resonant circuit where the electrical elements are connected in parallel is composed of a coil and a current-cut capacitor connected in series, and a variable capacitor for changing the resonant frequency (in this example, a varicap diode). And a capacitor for securing the capacity of the resonance circuit even when the capacity of the variable capacitor is reduced, is connected in parallel. One end of these circuit elements is grounded, and a resistor is connected to the other end in addition to the coil described above. The other end of the resistor serves as a terminal of the electrical length switching circuit 20A, and two voltages can be applied by a voltage source such as a D / A converter controlled by the control circuit 11.
[0036]
The two kinds of voltages are an “H” level voltage (for example, 4 V) having a higher value than a reference voltage (for example, 2.5 V) and a low value “L” level voltage (for example, 1 V). By changing the magnitude of the applied voltage in two ways, the capacitance of the variable capacitor changes, thereby changing the resonance frequency of the resonance circuit. When the antenna A is connected to the position 2 side of the switching element SWA, the resonance frequency of the antenna A changes, and the electrical length of the antenna at the reception frequency changes.
[0037]
Specifically, when an H level voltage is applied to the terminal TA, the capacitance of the variable capacitor is reduced, the electrical length of the antenna A is shortened, and the antenna A functions as a waveguide for the antenna B. To do. On the other hand, when an L level voltage is applied, the capacity of the variable capacitor increases, the electrical length of the antenna A becomes longer, and the antenna A functions as a reflector for the antenna B.
[0038]
The tuning circuit 6 in FIG. 3 has the same circuit configuration as the tuning circuit 7 shown in FIG. 2, and the switching element SWB connects the antenna B and either the receiving unit 8 or the electrical length switching circuit 20B. A voltage of H level or L level is applied to the terminal TB of the electrical length switching circuit 20B under the control of the control circuit 11, and the antenna B functions as a director or a reflector for the antenna A.
[0039]
In the example of FIG. 1, the tuning circuit 7, the tuning circuit 6, the receiving unit 9, and the receiving unit 8 are provided for the antenna A and the antenna B, respectively. However, only one tuning circuit and one receiving unit are provided. It may be provided and connected to the antenna A and the antenna B so as to be shared. In this case, a switch for switching the connection of the antenna A and the antenna B to the tuning circuit and the receiving circuit is necessary.
[0040]
In this case, at the time of antenna switching diversity level measurement, antenna A and antenna B are connected in order to the receiving unit to obtain the received signal strength and BER of each antenna, and these are compared by the control circuit 11. When receiving by the beam method, one of the antenna A and the antenna B is connected to the receiving unit to be a power feeding element, and the other is connected to a tuning circuit to change the electrical length.
[0041]
Below, how to set the switching element SWA and the switching element SWB of FIGS. 2 and 3 and the level of the voltage applied to the terminal TA and the terminal TB, the antenna A and the antenna B can be used appropriately. explain.
[0042]
FIG. 4 is a diagram illustrating a specific setting in the diversity scheme and the beam scheme. When performing reception by the diversity method, as illustrated in FIG. 4, both the switching element SWA and the switching element SWB in FIGS. 2 and 3 are set to the position 1 side. As a result, the antenna A and the antenna B are connected to the receiving circuit 9 and the receiving circuit 8, respectively, and diversity system reception is possible.
[0043]
When performing reception using the beam method, four settings are possible. There are two cases in which either antenna A or antenna B is used as the feed element, and in each case, two cases occur depending on whether the remaining one is used as a reflector or a director. Because it becomes street.
[0044]
First, the case where the antenna B is used as a feeding element and the antenna A is used as a reflector will be described as an example. With respect to the antenna B used as the feeding element, the switching element SWB in FIG. 3 is set to the position 1 side and the antenna B is connected to the receiving unit 8. For the antenna A used as a reflector, in order to increase the electrical length, the switching element SWA in FIG. 2 is set to the position 2 side and connected to the electrical length switching circuit 20A, and an L level signal is applied to the terminal TA. give.
[0045]
On the other hand, when the antenna A is used as a director, the signal given to the terminal TA in the above setting may be changed to H level. That is, the switching element SWB is set to the position 1 side and the antenna B is connected to the receiving unit 8. For the antenna A used as a reflector, in order to shorten the electrical length, the switching element SWA is set to the position 2 side to be connected to the electrical length switching circuit 20A, and an H level signal is given to the terminal TA. As a result, the electrical length of the antenna A is shortened, and the antenna A functions as a director.
[0046]
As can be understood from the above description, the switching element may be set on the position 1 side for the antenna serving as the feeding element. For the remaining antennas, the switching element is set to the position 2 side, and the signal level applied to the terminals TA and TB is “L” when used as a reflector, and “ It may be set to “H”.
[0047]
With the configuration described above, the diversity method and the beam method are automatically switched by the control of the control circuit 11 in FIG. 1 according to the reception state. Here, there are various ways of selecting which of the four combinations in the beam system of FIG. For example, the control circuit 11 obtains the BER for all four combinations, and the control circuit 11 can select the combination that gives the minimum BER for reception. In addition, the reception status (BER) is measured for the four combinations in a predetermined order, and when a combination that gives a BER smaller than a value set in advance as a reference is found, this combination is adopted and the rest It is also possible to adopt a method in which the BER is not determined for the combination of the above. As an example, the processing procedure in the latter case will be described below.
[0048]
FIG. 5 is a flowchart illustrating a processing procedure in the mobile communication terminal of this embodiment. As illustrated in the figure, when the power is turned on, in step S101, the control circuit 11 of FIG. 1 uses the antenna A or the antenna B designated in the initial setting as the receiving antenna for the time being. select.
[0049]
Next, in step S102, depending on whether or not the signal from the base station has been received and whether or not the signal from the base station has been received, within the service area within the range where the mobile communication terminal can receive radio waves from the base station. Is determined. If “YES” is determined, it is determined that the mobile communication terminal is in the service area and a call is possible, and the call is started in step S103. On the other hand, if “NO” is determined, the mobile communication terminal is in a range where the radio waves from the base station cannot reach (outside the service area) and cannot make a call, so the mobile communication terminal moves into the service area. In step S102, the process of searching for radio waves from the base station is repeated until a call can be made.
[0050]
In step S104 subsequent to step S103, the received signal levels of antenna A and antenna B are measured during the antenna switching diversity level measurement period. In the subsequent step S105, in order to know whether or not an interfering wave exists, the BER is 10^-3Whether or not this is the case is determined by the control circuit 11. The reason for determining the occurrence of the jamming wave using the BER is that when the jamming wave is generated, the BER is naturally expected to deteriorate even if the received signal strength (RSSI) does not deteriorate. is there. Here, “10^-3"Is set as an example of an upper limit value of error tolerance, and other values can be adopted.
[0051]
If "NO" is determined in the step S105, it is determined that the BER is within the allowable range and a sufficiently high quality call is possible even with the current setting, and the process proceeds to the step S108 without changing the setting. On the other hand, if “YES” is determined, it is determined that the BER is out of the allowable range and the call quality is low in the current setting, and it is necessary to change the setting to an antenna suitable for obtaining a good received signal. If there is, the process proceeds to step S106. When the received signal strength is high but the BER is bad (out of the allowable range), it is assumed that there is an interference wave with respect to the desired wave from the base station, and this interference wave is effectively removed. It is necessary to set the state of the antenna.
[0052]
Even when the generation of the interference wave is estimated in step S105, if the difference in the intensity of the received signal between the antenna A and the antenna B is large, the effect on reception is greater when the radio wave is interrupted due to fading than the interference wave. . In such a case, it is preferable to perform reception using the diversity method instead of the beam method. Therefore, in step S106, it is determined whether or not the reception intensity difference between antenna A and antenna B is 10 dB or more. Again, the value “10 dB” is an example of a guideline for the generation of an interference wave or the like, and other values can be adopted according to convenience. In step S106, it is determined whether the signal is received by the diversity method or the beam method with the directivity depending on the intensity difference of the received signal for each antenna, but the signal is received by the diversity method depending on the received signal strength itself. It may also be determined whether to receive with directivity using the beam method. That is, when the received signal strength is high but the received signal quality is poor (BER is poor), it can be determined that the influence of the interference wave has occurred. Therefore, in order to remove the influence of the interference wave, the antenna has directivity. To receive signals from the base station.
[0053]
If the influence due to fading is dominant, the control circuit 11 determines “YES” in step S106, and the process proceeds to step S107. Under the diversity scheme, the antenna A or the antenna B with the higher received signal strength Is switched so as to be connected to the receiving unit, and reception is performed. On the other hand, if the influence of a directional interference wave or the like is dominant and reception cannot be performed satisfactorily, “NO” is determined in step S106, and the process proceeds to step S110 to perform reception using the beam method.
[0054]
In step S110 and subsequent steps, reception is performed in order using the above-described four combinations of beam methods, the reception quality is confirmed, and a certain standard (BER is 10).^-3The processing is performed in such a manner that the combination is adopted when a satisfying condition is found. Here, for example, there are two combinations of (antenna A, antenna B) = (waveguide, feeding element) or (feeding element, reflector) that give directivity from antenna B to antenna A. There are two combinations that provide directivity suitable for reception. Therefore, in the example of FIG. 5, there is a possibility that the reception quality is better for the combination that should have been tried after the actually selected combination.
[0055]
First, in step S110, BER is obtained in a state where antenna A is set as a reflector and antenna B is set as a feed element. In step S111, the BER is 10^-3It is determined whether or not it is less than the value. If “YES” is determined, it is determined that the reception quality is sufficient, and the process proceeds to step S119 in order to perform reception with this combination. If "NO" is determined, the next combination is tried because the current combination cannot be received satisfactorily.
[0056]
In this way, after step S112, the combination that antenna B is a reflector and antenna A is a feed element (step S112), the combination that antenna A is a director and antenna B is a feed element (step S114), and antenna B is guided. A combination (step S116) in which the waver and the antenna A are the feeding elements is tried in order based on the switching pattern of FIG.^-3The evaluation based on the condition “Steps S113, S115, S117” is repeated. Of course, such an order is merely an example.
[0057]
In this example, for example, antenna A is set as a reflector in step S110, and antenna B is set as a reflector in step S112. That is, the antenna serving as the feeding element and the antenna serving as the reflector or the director are alternated every time one combination is tried. However, by setting one antenna as the feed element and changing the other antenna from the director to the reflector (or from the reflector to the director), the directivity is reversed, and the one that satisfies the evaluation conditions is found. If not, this time, the other antenna may be used as the feeding element, and the same process may be repeated. If the order is set in this way, it is possible to suppress the number of times the switch SWA and the switch SWB are switched, as illustrated in FIG.
[0058]
Further, when there is a difference in antenna gain between the antenna A and the antenna B and a difference in reception sensitivity occurs, for example, when one is a whip antenna and the other is a chip antenna, Therefore, it is preferable to set the one having better reception sensitivity as the power feeding element. This is to improve the quality of the call by making a call with a better sensitivity.
[0059]
In the above processing, “BER <10^-3If no combination satisfying the condition “is found, the process proceeds from step S117 to step S118. In step S118, the combination having the lowest BER among the four combinations tried in the above processing is selected. 1 is selected, and the states of the antenna A and the antenna B are set based on the combination thereof, and such processing is performed by providing the control unit 11 of FIG. It can be realized by doing.
[0060]
In the state where the settings of the antenna A and the antenna B are determined and the directivity is determined as described above, reception by the beam system having directivity is performed in step S119.
[0061]
In the directivity determination procedure (S110 to S118) described above, if the reception quality is better than the predetermined value (BER <10).^-3However, the reception quality may be confirmed for all four combinations, and the one having the best reception quality may be selected.
[0062]
After step S119, step S105, and step S107, it is determined in step S108 whether or not to continue the call. This determination is made based on whether or not an end-call signal has been issued. When the call is continued because the end signal is not generated, “YES” is determined. In order to continue the call, the process returns to step S104, and the reception is performed at the antenna switching diversity level measurement time in the next slot. Measure the level. That is, Steps S104 to S108 correspond to processing for one slot. On the other hand, if “NO” is determined in step S108, the call is ended in step S109. The above is an example of the processing procedure performed by the control circuit 11.
[0063]
Next, an example of attachment positions of a plurality of antennas is shown. FIG. 6 is a perspective view showing an example in which two whip antennas A1 and B1 (solid lines) are mounted side by side with the same polarization plane (the whip antennas A1 and B1 are shown in the mobile communication terminal in the figure). Shown in the stowed state). FIG. 7 is a perspective view showing an example in which two chip antennas A2 and B2 (dotted lines) are mounted side by side with the same plane of polarization. As illustrated, by providing a plurality of antennas along a direction orthogonal to the longitudinal direction of the mobile communication terminal, when the mobile communication terminal is used in a beam system, the directivity by the two antennas is in the horizontal direction. Therefore, it is easy to capture a desired wave coming from the horizontal direction, and it is easy to remove an interference wave coming from the horizontal direction. However, arranging the two antennas in a direction perpendicular to the longitudinal direction is intended to fully demonstrate the effects of the mobile communication terminal of the present embodiment, and must be arranged in this manner. It does not mean that radio waves cannot be captured.
[0064]
Furthermore, the two chip antennas in the example of FIG. 7 are arranged side by side on the widest plane (rear) side among the six side surfaces inside the main body of the mobile communication terminal. It is also possible to adopt a configuration in which chip antennas are attached one by one along the left side surface facing this. Here, in the examples of FIGS. 6 and 7, the two antennas are arranged so that the planes of polarization are the same, but this is intended to maximize the effect by making them the same. is there. The effect can be obtained if the antennas are arranged so that the planes of polarization are aligned to the extent that the desired wave can be received.
[0065]
6 and FIG. 7, two antennas are attached to each other, but it is naturally possible to attach three or more antennas. When receiving with the beam method, when there are only two antennas, only two directions on a single direction can be selected as directivities. However, it is possible to set the directivity along a plurality of directions by disposing all three or more antennas so that they do not exist on the same straight line. Even if the user changes the angle at which the mobile communication terminal is held, it can be handled by changing the combination, and it is possible to always realize a call with good quality.
[0066]
In such a case, when receiving with the diversity method, the antenna with the highest received signal strength is selected, and when receiving with the beam method,_nP₂A combination that can be satisfactorily received is selected from the combinations (the number of permutations in which two out of n are extracted by distinguishing the order, and n is an integer equal to or greater than 2 that is the total number of antennas).
[0067]
In the above example, one antenna is used as a director or a reflector in the beam method in which the antenna has directivity, but directivity is generated by the antenna A and the antenna B without such setting. It is possible. For example, antenna A and antenna B can be used as a set of adaptive antennas. In this case, the control circuit 11 adjusts the phase difference between the tuning circuit 6 and the tuning circuit 7 so that a signal having a desired frequency can be extracted. By adjusting the difference value, the directivity can be selected.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a mobile communication terminal.
FIG. 2 is a circuit diagram illustrating the configuration of a tuning circuit 7;
FIG. 3 is a circuit diagram illustrating a configuration of a tuning circuit 6;
4 is a diagram illustrating a combination of settings of tuning circuit 7 and tuning circuit 6 in FIGS. 6 and 7, respectively. FIG.
FIG. 5 is a flowchart illustrating a processing procedure of the mobile communication terminal.
FIG. 6 is a perspective view showing a first example of attachment of an antenna.
FIG. 7 is a perspective view showing a second example of mounting an antenna.
[Explanation of symbols]
6,7 Tuning circuit
8,9 Receiver
11 Receiver
A, B antenna
Steps S101 to S119
SWA, SWB Switching element

Claims (2)

A diversity-type radio that receives a signal from a first antenna or a second antenna that has better reception,
As a result of detecting an error in the data of the received signal, if the error rate of the data is out of an allowable range , directivity is provided by the first antenna and the second antenna, and the error of the received data is small. Select the directionality and receive the signal ,
Even if the error rate of the data is outside the allowable range, if the difference in the strength of the received signal of each antenna is large, reception is performed using the diversity method .   A signal having a first antenna, a second antenna, and a receiving unit, and appropriately selecting one of the first antenna and the second antenna that has good reception and connecting to the receiving unit Diversity radios that receive
  Receiving means for receiving signals by the first antenna and the second antenna;
  Detecting means for detecting an error in data of the received signal;
  Diversity receiving means for deciding which antenna to receive a signal from among the first antenna and the second antenna according to the strength of the received signal,
  Beam receiving means for performing reception by causing the first antenna and the second antenna to generate directivity in a direction in which errors in received data are reduced; and
  When the detected error rate of the data is outside the allowable range, the beam reception unit receives the data, and even if the data error rate is outside the allowable range, the difference in the received signal strength of each antenna is large. In this case, a radio device comprising: control means for controlling to receive by the diversity receiving means.

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