JP4840205B2 - Portable terminal device, communication control method, and program - Google Patents

Description

  The present invention relates to a mobile terminal device, a communication control method, and a program.

  At present, the number of components increases with the enhancement of the functions of the mobile terminal device, and the miniaturization of the mobile terminal device is also a proposition, so mounting components in a finite mounting area has become an issue. To solve this problem, downsizing of parts is one of the solutions. Therefore, it is necessary to shrink the conventional circuit.

  Particularly, in a conventional portable terminal device having a wireless communication function, when a device receives power at a high input in order to ensure a certain level of wireless blocking characteristics or BER (Bit Error Rate) characteristics, an LNA (Low Noise Amplifier) A bypass circuit has been used to prevent distortion of the component. However, this means has a problem that the circuit becomes large because the bypass circuit is used.

  Another solution has been to improve the P1dB characteristic of the LNA and increase the bias current so as not to be distorted by high-level power input, but this means that it is necessary to increase the current flowing through the LNA. There is a problem that the reception current of the entire apparatus increases.

As a prior art example of a portable terminal device having a wireless communication function as described above, frequency band switching control in a multiband wireless device is efficiently performed without increasing the interface line for control between the wireless unit and the CPU. (For example, refer to Patent Document 1).
JP 2006-80671 A

  The present invention has been made in view of the above circumstances, and as a new control method for an antenna switch used in a wireless circuit unit of a conventional portable terminal device, a frequency band not used internally in the antenna switch. In order to realize control that inputs power to the LNA component with low input power even when the device receives power at a high input by turning on the path of the circuit, the circuit is not increased and the current is reduced. It is an object of the present invention to provide a mobile terminal device, a communication control method, and a program that can solve the above-described problems by adding software control of an antenna switch without increasing the number.

In order to achieve such an object, a first aspect of the present invention is a portable terminal device including an antenna, an antenna switch circuit, and a plurality of frequency band circuits, wherein a transmission path and a reception path of the frequency band circuit The antenna switch circuit compares the received power received by the antenna with the previous received power received by the antenna before receiving the received power, and the received power is the previous received power. A first determination is made to determine whether the received power is equal to or greater than the first threshold value when the received power is not equal to or higher than the previous received power as a result of the first determination. A second determination is made, and if the reception power is equal to or higher than the previous reception power as a result of the first determination, a third determination is made as to whether the reception power is equal to or lower than a predetermined second threshold Make a decision and receive as a result of the second decision If the power is not less than or equal to the first threshold, or if the received power is less than or equal to the second threshold as a result of the third determination, the received power is sent as it is to the frequency band circuit in use, and the second If the received power is equal to or lower than the first threshold as a result of the determination, or if the received power is not lower than the second threshold as a result of the third determination, the difference between the received power and the second threshold is obtained. The difference is transmitted to a frequency band circuit in use .

According to a second aspect of the present invention , there is provided a communication control method performed in a terminal device including an antenna, an antenna switch circuit, and a plurality of frequency band circuits, wherein the terminal device transmits and receives a transmission path of the frequency band circuit. When the path has the same configuration, the antenna switch circuit compares the received power received by the antenna with the received power received by the antenna before receiving the received power. The first determination is made to determine whether the received power is equal to or higher than the received power, and if the received power is not equal to or higher than the previous received power as a result of the first determination, the received power is equal to or lower than a predetermined first threshold value. A second determination is made to determine whether or not the received power is equal to or lower than a predetermined second threshold when the received power is equal to or higher than the previous received power as a result of the first determination. Make a third decision and make a second decision As a result, if the received power is not less than or equal to the first threshold, or if the received power is less than or equal to the second threshold as a result of the third determination, the received power is sent as it is to the frequency band circuit in use, If the received power is less than or equal to the first threshold as a result of the second determination, or if the received power is not less than or equal to the second threshold as a result of the third determination, the difference between the received power and the second threshold And the difference is transmitted to the frequency band circuit in use .

According to a third aspect of the present invention , there is provided a program executed by a terminal device including an antenna, an antenna switch circuit, and a plurality of frequency band circuits, wherein the terminal device includes a transmission path and a reception path of the frequency band circuit. , The antenna switch circuit compares the received power received by the antenna with the received power received by the antenna before receiving the received power, and the received power is the previous received power. When the reception power is not equal to or higher than the previous reception power as a result of the first determination processing for determining whether the power is equal to or higher than the power, the reception power is equal to or lower than a predetermined first threshold value. When the received power is equal to or higher than the previous received power as a result of the second determining process and the first determined process, it is determined whether the received power is equal to or lower than a predetermined second threshold value. The third judgment process and the second If the received power is not less than or equal to the first threshold as a result of the determination process, or if the received power is less than or equal to the second threshold as a result of the third determination process, the received frequency is used as it is. As a result of the first transmission process and the second determination process to be transmitted to the receiver, the received power is not less than the first threshold or as a result of the third determination process, the received power is not less than the second threshold. In this case, a difference between the received power and the second threshold value is obtained, and a second transmission process for transmitting the difference to the frequency band circuit in use is executed .

  According to the present invention, the LNA output is distorted by high-level power input from the antenna and the BER is prevented from deteriorating, thereby eliminating the bypass circuit as compared with the conventionally widely used method of bypassing the LNA circuit. Therefore, it is possible to contribute to miniaturization of LNA parts, and as a conventional method, the bias current is increased so as not to be distorted by high level power input by improving the P1dB characteristic of LNA. However, even if compared with this method, it is possible to cope without increasing the current.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.

The present invention is characterized by preventing the BER from being deteriorated by distorting the LNA output due to the high level power input from the antenna by the new control method of the component antenna switch used in the wireless circuit unit of the conventional portable terminal device. To do. Accordingly, the present invention prevents the LNA output from being distorted by the high-level power input and BER deterioration, and therefore, the bypass circuit is eliminated as compared with the conventional method of bypassing the LNA (Low Noise Amplifier) circuit widely used. Therefore, it is possible to contribute to miniaturization of the LNA component. In addition, as a conventional method, a method of increasing the bias current so as to prevent distortion by high-level power input by improving the P1dB characteristic of the LNA has been taken. It becomes possible to cope with it.
Each embodiment of the present invention that exhibits the above effects will be described below.

A description will be made based on a CDMA (Code Division Multiple Access) system that is currently the mainstream system of mobile terminal devices.
The configuration of a conventional CDMA radio circuit unit is shown in FIG. FIG. 9 shows a transmission / reception circuit in two frequency bands, f1 band and f2 band. For each band, transmission and reception branches on the RFIC circuit 7 side from the duplexers 3 and 4. In the configuration shown in FIG. 9, the acquired waveform data is compared with the waveform data stored in advance in the memory 11, and LNA control is performed.

  FIG. 10 and FIG. 11 show circuit configurations in the antenna switch circuit and the LNA circuit in the conventional CDMA radio circuit unit. FIGS. 10A and 10B show the operation state when the mobile terminal device is close to the base station and receives strong power (at the time of high input), and the mobile terminal device is far from the base station. 11 (a) and 11 (b) show the operation state when weak power is received (at the time of low input).

  As shown in FIGS. 10A and 11A, the antenna switch circuit 2 functions as a transmission / reception band changeover switch regardless of whether the input is high or low. On the other hand, in the LNA circuit (low noise amplifier in the Rx circuit 6) 61, the bypass circuit is changed as shown in FIG. 10B when the input is high, and the weak power is amplified as shown in FIG. 11B when the input is low. Then, transmission to the RFIC circuit 7 is performed. The reason for passing the bypass circuit at the time of high input is that no distortion occurs in the LNA and there is no need to amplify the power. This control is performed by a logic unit (logic circuit) in the LNA circuit 61.

  FIG. 1 shows a configuration of a CDMA radio circuit unit according to the present invention in contrast to the conventional configuration as described above. 2 and 3 show circuit configurations in the antenna switch circuit and the LNA circuit of the present invention. Unlike the conventional configuration described above, in the configuration of the present invention, the acquired waveform data is compared with the waveform data stored in the memory 11 in advance, and antenna switch control is performed.

  The operation state at the time of high input is shown in FIGS. 2 (a) and 2 (b), and the operation state at the time of low input is shown in FIGS. 3 (a) and 3 (b). In the present invention, the configuration of the antenna switch circuit 2 is not changed from the conventional one, and the bypass circuit of the LNA circuit 61 is removed so that only the amplifier circuit is provided, thereby realizing miniaturization of components that do not require a logic unit (logic circuit). It has a configuration. That is, the present invention eliminates the bypass circuit of the LNA circuit 61 in the Rx circuit 6 by realizing a new control method of the antenna switch circuit 2 between the antenna 1 and the duplexers 3 and 4 in the block of FIG. Therefore, the LNA circuit 61 can be reduced in size.

The operation of the first embodiment of the present invention will be described. Here, consider an example of receiving power in the f1 band.
In the antenna switch circuit 2, in the case of a high input shown in FIG. 2A, the logic unit 21 determines whether to turn each switch ON or OFF based on the information on the strength of the power. As a result, the switch 22 on the f1 band circuit side is turned off, and the switch 23 on the f2 band circuit side is turned on. By the ON / OFF control of this switch, most of the strong power is shunted to the non-functioning f2 band radio circuit, while the f1 band radio circuit in the OFF state is weak due to coupling at the switch section. Power is transmitted to the duplexer. Due to the effect of shunting, the f1 band wireless circuit is in the same state as when the input is low before passing through the LNA circuit 61 of FIG. The LNA circuit 61 shown in FIG. 2B performs the same operation as in the conventional low input. The divided power to the f2 band radio circuit is transmitted to the RFIC circuit 7 side, but is absorbed as it is.
In the case of the low input shown in FIG. 3A and when the f1 band is used, the logic unit 21 turns on the switch 22 on the f1 band circuit side, which is the used band, and the unused band. The switch 23 on the f2 band circuit side is turned OFF.

FIG. 7 shows a control flowchart. As shown in the timing chart of FIG. 8, two threshold values (X value and Y value) are defined, and control for reducing received power at the time of high input is realized. Assume that the power actually received by the apparatus is P1 (t) and the power after control is P2 (t).
In step S1, if P1 (t) ≧ P1 (t−1) (step S1 / YES), the process proceeds to step S3.
If P1 (t) ≧ P1 (t−1) is not satisfied in step S1 (step S1 / NO), the process proceeds to step S2.
If P1 (t) ≦ X value in step S2 (step S2 / YES), the process proceeds to step S5.
In step S2, when P1 (t) ≦ X value is not satisfied (step S2 / NO), the process proceeds to step S4.
In step S3, if P1 (t) ≦ Y value (step S3 / YES), the process proceeds to step S4.
If P1 (t) ≦ Y value is not satisfied in step S3 (step S3 / NO), the process proceeds to step S5.
In step S4, P2 (t) = P1 (t) is set, and the process returns to step S1.
In step S5, P2 (t) = P1 (t) −Y is set, and the process returns to step S1.

  In the above, the reason why two threshold values (X value, Y value) are provided is that, in the case of one, after the high input power is dropped, the operation of returning to the original power level is performed, and control is performed at the threshold boundary. This is to prevent this from flapping. Further, in order to perform the above control, a storage device for storing the values of P1 (t) and P2 (t) is necessary. This is realized by storing in the memory 11 in FIG.

  In the case of the CDMA system, the transmission / reception path is the same on the antenna side than the duplexer. Therefore, when the above control is performed by the antenna switch circuit at the time of high input, the transmission power from the mobile terminal device to the base station also passes through the path in the switch OFF state. It is transmitted from the antenna as weak power. However, when the input is high, the mobile terminal device is close to the base station, so there is no need to amplify the power.

A description will be given based on a TDMA (Time Division Multiple Access) method used in GSM.
FIG. 4 shows the configuration of the TDMA radio circuit unit. FIG. 4 shows a transmission / reception circuit in two frequency bands, f1 band and f2. Unlike the CDMA system described above, the transmission and reception paths for the f1 band and f2 band are different, but a switch (see FIG. 5) for changing the path is required. The transmission / reception path from this switch to the RFIC side has the same configuration as that of the CDMA system. By combining the antenna switch circuit and the low noise amplifier (LNA circuit) in the Rx circuit, the size of the LNA circuit can be reduced.

  The configuration in the antenna switch circuit is shown in FIG. FIG. 5 shows a case where only the f1 band is taken as an example, but the present invention can be similarly applied to a circuit in the f2 band. Under the control of the logic unit 21, the switch 24 switches between transmission and reception at regular time intervals, so that transmission and reception are not performed simultaneously. On the other hand, since the LNA circuit is the same as that described in the CDMA system, description thereof is omitted here.

The operation of the second embodiment of the present invention will be described.
In the TDMA wireless circuit unit used in PDC and GSM, unlike the CDMA method, the transmission / reception unit is a separate path (FIG. 4). Therefore, the transmission power does not become weak at the time of high input unlike the CDMA system. Since the operation of the antenna switch circuit is different from that of the CDMA system, it will be described below.

In the case of a high input, the switch 24 is turned OFF (Tx circuit side is ON) from the switch ON / OFF determination in the logic unit 21 based on the information on the strength of power. The Rx circuit side in the OFF state is transmitted as weak power due to coupling at the switch unit. Due to the effect of shunting, the Rx circuit is in the same state as when the input is low before passing through the LNA circuit. On the other hand, the divided power to the Tx circuit is transmitted to the RFIC side, but is absorbed as it is. In the case of low input, the Rx circuit side is turned on (Tx circuit side is turned off) as usual.
By controlling as described above, the input power to the LNA circuit is always weak power, and the LNA performs only the operation of amplifying the power.

An embodiment of a radio circuit having a space diversity receiver will be described.
The configuration of the wireless circuit unit is shown in FIG. As shown in FIG. 6, in addition to the communication methods exemplified in FIGS. 1 and 4, the reception-only radio circuit 12 is included. A receiver other than the CDMA and TDMA receivers is used for decoding separately. By detecting, correcting, and recombining the phase difference of each receiver, it is configured to realize reception with a good S / N ratio even in a multipath environment.

The operation of the third embodiment of the present invention will be described.
In the case of the CDMA system, the transmission / reception circuit is the same path between the antenna and the duplexer, and in the case of the TDMA system, the transmission / reception unit is a separate path. In the case of reception diversity, since there is only the reception circuit 12, the present invention can be applied without causing a problem of the CDMA system.

  When the present invention is applied, a portion corresponding to antenna switch circuit control in the case of the CDMA method may be applied to switching of the receiving antenna.

  As described above, in the first to third embodiments of the present invention, the configuration in which the LNA bypass circuit is deleted by new control in the antenna switch has been mainly described. This means can realize coupling only by an antenna switch, but it is also conceivable to perform another stage of coupling at that location without deleting the LNA bypass circuit. Thereby, the magnitude of the received power can be further adjusted.

  Any two or more of the first to third embodiments may be combined, and control for changing the multiplicity of each control according to the antenna reception level may be performed.

  Although the present invention has been described above, the present invention is not limited to the above description, and various modifications can be made without departing from the scope of the invention.

  The present invention can be applied to a mobile terminal device that includes an LNA and an antenna switch.

1 is a block diagram illustrating a configuration of a CDMA radio circuit unit according to a first embodiment of the present invention. FIG. It is a figure which shows the operation state at the time of the high input in the antenna switch circuit and LNA circuit which concern on Example 1 of this invention. It is a figure which shows the operation state at the time of the low input in the antenna switch circuit and LNA circuit which concern on Example 1 of this invention. It is a block diagram which shows the structure of the radio | wireless circuit part of the TDMA system which concerns on Example 2 of this invention. It is a figure which shows the structure in the GSM antenna switch circuit based on Example 2 of this invention. It is a block diagram which shows the structure of the reception diversity which concerns on Example 3 of this invention. It is a flowchart which shows the control action which concerns on Example 1 of this invention. It is a timing chart which shows the control action which concerns on Example 1 of this invention. It is a block diagram which shows the structure of the radio circuit part of the conventional CDMA system. It is a figure which shows the operation state at the time of the high input in the conventional antenna switch circuit and LNA circuit of a CDMA system. It is a figure which shows the operation state at the time of the low input in the conventional antenna switch circuit and LNA circuit of a CDMA system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antenna 2 Antenna switch circuit 3 f1 band duplexer 4 f2 band duplexer 5 Tx circuit 6 Rx circuit 7 RFIC circuit 8 AD converter 9 AGC control circuit and reception level measurement circuit 10 Comparator 11 Memory 12 Reception-only radio circuit 21 Logic unit 22 , 23, 24 Switch 61 LNA circuit (low noise amplifier)

Claims (12)

A mobile terminal device comprising an antenna, an antenna switch circuit, and a plurality of frequency band circuits,
The transmission path and reception path of the frequency band circuit are configured identically,
The antenna switch circuit is
The received power received by the antenna is compared with the previous received power received by the antenna before receiving the received power, and it is determined whether the received power is equal to or higher than the previous received power. Make a first decision,
As a result of the first determination, when the received power is not equal to or higher than the previous received power, a second determination is performed to determine whether the received power is equal to or less than a predetermined first threshold;
As a result of the first determination, when the received power is equal to or higher than the previous received power, a third determination is performed to determine whether the received power is equal to or lower than a predetermined second threshold;
If the received power is not less than or equal to the first threshold as a result of the second determination, or if the received power is less than or equal to the second threshold as a result of the third determination, the received power is Send it to the frequency band circuit in use,
If the received power is less than or equal to the first threshold as a result of the second determination, or if the received power is not less than or equal to the second threshold as a result of the third determination, A portable terminal device characterized by obtaining a difference from the second threshold value and sending the difference to a frequency band circuit in use . A plurality of switches provided corresponding to each of the plurality of frequency band circuits;
A logic unit that performs control to turn on or off the plurality of switches based on the strength of the received power; and
The logic part is
2. The portable terminal device according to claim 1, wherein when the reception level of the antenna is high, a switch corresponding to a frequency band circuit in use is turned off, and a switch corresponding to an unused frequency band circuit is turned on. . The logic part is
3. The portable terminal device according to claim 2 , wherein when the reception level of the antenna is high, a switch corresponding to the frequency band circuit in use is turned off on the reception path side and turned on on the transmission path side. If the reception level of the antenna is high, the received power, the portable terminal device according to any one of claims 1 to 3, characterized in that it comprises a receive-only circuit that transmits dedicated path shunting. A communication control method performed in a terminal device including an antenna, an antenna switch circuit, and a plurality of frequency band circuits,
When the terminal device has the same configuration of the transmission path and the reception path of the frequency band circuit,
The antenna switch circuit is
The received power received by the antenna is compared with the previous received power received by the antenna before receiving the received power, and it is determined whether the received power is equal to or higher than the previous received power. Make a first decision,
As a result of the first determination, when the received power is not equal to or higher than the previous received power, a second determination is performed to determine whether the received power is equal to or less than a predetermined first threshold;
As a result of the first determination, when the received power is equal to or higher than the previous received power, a third determination is performed to determine whether the received power is equal to or lower than a predetermined second threshold;
If the received power is not less than or equal to the first threshold as a result of the second determination, or if the received power is less than or equal to the second threshold as a result of the third determination, the received power is Send it to the frequency band circuit in use,
If the received power is less than or equal to the first threshold as a result of the second determination, or if the received power is not less than or equal to the second threshold as a result of the third determination, A communication control method characterized by obtaining a difference from the second threshold and sending the difference to a frequency band circuit in use . If the reception level of the antenna is high, and turns off the switch provided corresponding to the frequency band circuit in use, according to claim 5, characterized in that to turn on the switch corresponding to the frequency band circuit of the unused Communication control method. The switch according to claim 6 , wherein when the reception level of the antenna is high, a switch provided corresponding to the in-use frequency band circuit is turned off on the reception path side and turned on on the transmission path side. Communication control method. If the reception level of the antenna is high, the received power, the communication control method according to any one of claims 5 7, characterized in that for transmitting the dedicated path for shunting. A program to be executed by a terminal device comprising an antenna, an antenna switch circuit, and a plurality of frequency band circuits,
When the terminal device has the same configuration of the transmission path and the reception path of the frequency band circuit,
In the antenna switch circuit,
The received power received by the antenna is compared with the previous received power received by the antenna before receiving the received power, and it is determined whether the received power is equal to or higher than the previous received power. A first determination process;
As a result of the first determination process, when the received power is not equal to or higher than the previous received power, a second determination process for determining whether the received power is equal to or lower than a predetermined first threshold;
As a result of the first determination process, when the received power is equal to or higher than the previous received power, a third determination process for determining whether the received power is equal to or lower than a predetermined second threshold;
If the received power is not less than or equal to the first threshold as a result of the second determination process, or if the received power is less than or equal to the second threshold as a result of the third determination process, the reception A first transmission process for transmitting power to a frequency band circuit in use as it is;
If the received power is less than or equal to the first threshold as a result of the second determination process, or if the received power is not less than or equal to the second threshold as a result of the third determination process, the reception Obtaining a difference between the power and the second threshold, and sending the difference to a frequency band circuit in use;
A program characterized by having executed . When the reception level of the antenna is high, a switch provided corresponding to a frequency band circuit in use is turned off, and a process of turning on a switch corresponding to an unused frequency band circuit is executed by a computer. The program according to claim 9 . When the reception level of the antenna is high, the switch provided corresponding to the frequency band circuit in use is made to execute a process of turning off the reception path side and turning on the transmission path side. The program according to claim 10 . The program according to any one of claims 9 to 11 , wherein when the reception level of the antenna is high, a computer is caused to execute a process of transmitting the reception power to a dedicated path for diversion.

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