JP2007129630A - Mobile communication terminal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a CDMA-type mobile communication terminal device which is capable of acquiring a diversity gain, reducing a current consumption when in use, and keeping the stability in receiving quality. <P>SOLUTION: The mobile communication terminal device 100 is equipped with a first receiving system provided with an antenna 110, a receiving signal processing unit 130, and a rake combination unit 140 and a second receiving system provided with an antenna 112, a receiving signal processing unit 132, and a rake combination unit 142. When either of the first receiving system and the second receiving system or both of them have excellent receiving quality, a receiving control unit 190 stops the operation of the receiving signal processing unit (130 or 132) corresponding to either of the receiving systems determined in accordance with a prescribed reference. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a mobile communication terminal apparatus used in a CDMA (Code Division Multiple Access) type mobile communication system that performs reception combining diversity.

  Conventionally, as a mobile communication terminal device used in a CDMA mobile communication system that performs reception combining diversity, there is one described in Patent Document 1.

  FIG. 6 is a circuit block diagram showing a configuration of a mobile communication terminal apparatus described in Patent Document 1 using a conventional radio control method.

  The mobile communication terminal device of Patent Document 1 includes a first receiving system including an external antenna 1, a duplexer (DUP) 3, a first diversity branch (BR1) 6, and a first rake receiver (RAKE1) 8. And a second receiving system including a built-in antenna 2, a bandpass filter (BPF) 5, a second diversity branch (BR2) 7, and a second rake receiver (RAKE2) 9. In diversity reception by these two receiving systems, when the combined output of the symbol combining circuit (COMB) 10 has a predetermined reception quality, the signal quality determination circuit (QLTY) 11 includes the second diversity branch 7 and the second rake. The operation of the receiver 9 is stopped. For this reason, the mobile communication terminal apparatus receives only by the first receiving system. Thereafter, when the predetermined reception quality cannot be obtained only by the first reception system, the signal quality determination circuit 11 restarts the operations of the second diversity branch 7 and the second rake receiver 9, Diversity reception is performed in the receiving system.

With the configuration described above, the mobile communication terminal apparatus disclosed in Patent Document 1 can reduce current consumption during use while obtaining a desired diversity gain.
JP 2000-252896 A

  However, the mobile communication terminal device of Patent Document 1 has a problem that the reception quality is not stable when the reception quality of the first reception diversity branch 6 is significantly deteriorated compared to the reception quality of the second diversity branch 7.

  That is, under the above conditions, when the second diversity branch 7 is operating, the reception quality of the combined output exceeds the predetermined reception quality, so the signal quality determination circuit 11 performs the operation of the second diversity branch 7. Stop. However, if the operation of the second diversity branch 7 is stopped, the reception quality of the combined output falls below the predetermined reception quality, so the signal quality determination circuit 11 immediately performs the operation of the second diversity branch 7. Let it resume. Thus, under the above conditions, the operation of the second diversity branch 7 is repeatedly stopped and restarted, so that the reception quality is not stable.

  The present invention has been made in view of the above points, and is a CDMA (Code Division Multiple Access) type mobile communication terminal device that reduces current consumption during use and has stable reception quality while obtaining diversity gain. The purpose is to provide.

  The CDMA mobile communication terminal of the present invention includes a first received signal processing means for converting a radio frequency signal received through a first antenna shared for transmission and reception into a first baseband signal, and dedicated for reception. A second received signal processing means for converting a radio frequency signal received through the second antenna to be used into a second baseband signal; and a first for rake combining a multipath signal included in the first baseband signal. Rake combining means, second rake combining means for rake combining multipath signals included in the second baseband signal, and first reception for measuring reception quality of output signals of the first rake combining means Quality measurement means, second reception quality measurement means for measuring the reception quality of the output signal of the second rake combining means, and the first reception quality measurement means. Measured by the first reception quality determination means for determining whether the reception quality of the output signal of the first rake combining means is equal to or higher than a predetermined first reception quality threshold, and the second reception quality measurement means. A second reception quality judgment means for judging whether or not the reception quality of the output signal of the second rake combining means is equal to or higher than a predetermined second reception quality threshold, and the first reception quality judgment means Based on the determination result and the determination result of the second reception quality determination means, reception of at least one of the output signal of the first rake combining means and the output signal of the second rake combining means A reception control means for stopping the operation of the reception signal processing means corresponding to one of the reception systems determined in accordance with a predetermined criterion when it is determined that the quality is equal to or higher than a corresponding reception quality threshold; A configuration that.

  According to the present invention, it is possible to reduce current consumption during use and stabilize reception quality while obtaining diversity gain.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
1 is a block diagram showing a configuration of a diversity receiver of a mobile communication terminal apparatus according to Embodiment 1 of the present invention.

  The mobile communication terminal apparatus 100 includes a first antenna 110, a second antenna 112, an antenna duplexer 120, a transmission circuit 124, a bandpass filter 122, a first received signal processing unit 130, a second Received signal processing section 132, first rake combining section 140, second rake combining section 142, diversity combining section 150, first received quality measuring section 160, and second received quality measuring section 162. A first reception quality determination unit 170, a second reception quality determination unit 172, a reception control unit 190, and a storage unit 180.

  The first antenna 110 radiates the transmission radio frequency signal input from the transmission circuit 124 through the antenna duplexer 120 to the space, and receives the received radio frequency signal through the antenna duplexer 120 through the first reception signal processing unit. To 130.

  The second antenna 112 outputs the received radio frequency signal received through the bandpass filter 122 to the second received signal processing unit 132.

  The antenna duplexer 120 enables the first antenna 110 to be shared between the transmission system and the reception system.

  The bandpass filter 122 passes only signals in a predetermined frequency range and attenuates signals of other frequencies.

  The transmission circuit 124 generates a transmission signal and outputs it.

  The first received signal processing unit 130 converts the radio frequency signal received through the first antenna 110 into a first baseband signal. The first baseband signal is output to the first rake combining unit 140.

  The second received signal processing unit 132 converts the radio frequency signal received through the second antenna 112 into a second baseband signal. The second baseband signal is output to the second rake combining unit 142.

  The first rake combining unit 140 performs rake combining on the multipath signal included in the first baseband signal. The rake combined signal is output to diversity combining section 150 and first reception quality measuring section 160.

  The second rake combining unit 142 performs rake combining on the multipath signal included in the second baseband signal. The rake combined signal is output to diversity combining section 150 and second reception quality measuring section 162.

  Diversity combining section 150 diversity combines the signals rake combined by first rake combining section 140 and second rake combining section 142. The synthesized output signal is input to a subsequent error correction circuit (not shown).

  First reception quality measuring section 160 measures the reception quality of the output signal from first rake combining section 140. The measurement result is output to first reception quality determination section 170.

  Second reception quality measuring section 162 measures the reception quality of the output signal from second rake combining section 142. The measurement result is output to the second reception quality determination unit 172.

  The first reception quality determination unit 170 determines whether the measurement result of the reception quality by the first reception quality measurement unit 160 exceeds the reception quality threshold. The determination result is output to the reception control unit 190.

  The second reception quality determination unit 172 determines whether or not the reception quality measurement result by the second reception quality measurement unit 162 exceeds the reception quality threshold. The determination result is output to the reception control unit 190.

  The reception control unit 190 operates the first reception signal processing unit 130 and the second reception signal processing unit 132 based on the determination results of the first reception quality determination unit 170 and the second reception quality determination unit 172. Stop or resume.

  The storage unit 180 stores a predetermined reception quality threshold value. It is desirable that the reception quality threshold set here has a sufficient margin from the minimum quality level required by the service and has hysteresis. This is because, when the reception quality of any one of the output signals from the two rake combining units 140 and 142 exceeds the reception quality threshold, the reception operation performed by the two reception units is performed by one reception unit. This is because a slight decrease in the S / N ratio is expected because of the transition.

  FIG. 2 is a flowchart showing an operation of the diversity receiver of the mobile communication terminal apparatus according to Embodiment 1 of the present invention.

  First, in step S1000, the reception control unit 190 instructs the first reception signal processing unit (BR1) 130 and the second reception signal processing unit (BR2) 132 to operate together. Perform the receive operation.

  In step S 1100, the first reception quality determination unit 170 stores the reception quality of the output signal from the first rake combining unit 140 measured by the first reception quality measurement unit 160 in the storage unit 180. It is determined whether the reception quality threshold is exceeded. When the reception quality of the output signal from the first rake combining unit 140 exceeds the reception quality threshold (S1100: YES), the process proceeds to step S1200. On the other hand, if the reception quality of the output signal from the first rake combining unit 140 does not exceed the reception quality threshold (S1100: NO), the process proceeds to step S1600.

  In step S1200, since the reception quality of the output signal from the first rake combining unit 140 is good, the reception control unit 190 stops the second received signal processing unit 132. That is, the reception operation is performed only by the first reception signal processing unit 130.

  In step S 1300, the first reception quality determination unit 170 stores the reception quality of the output signal from the first rake combining unit 140 measured by the first reception quality measurement unit 160 in the storage unit 180. It is determined whether the reception quality threshold is exceeded. This determination operation is always performed after the second reception signal processing unit 132 is stopped in step S1200, but is not necessarily continuous. When the reception quality of the output signal from the first rake combining unit 140 exceeds the reception quality threshold (S1300: YES), the process proceeds to step S1400. On the other hand, when the reception quality of the output signal from the first rake combining unit 140 is lower than the reception quality threshold (S1300: NO), the process proceeds to step S1500.

  In step S1400, it is determined whether communication has been completed. While the communication continues (S1400: NO), the process proceeds to step S1300. That is, as long as the reception quality of the output signal from the first rake combining unit 140 exceeds the reception quality threshold value and the communication continues, the process substantially remains in step S1300. On the other hand, when the communication is finished (S1400: YES), the operation is finished.

  In step S1500, since the reception quality of the output signal from the first rake combining unit 140 is lower than the reception quality threshold, the reception control unit 190 restarts the operation of the second received signal processing unit 132. That is, the first reception signal processing unit 130 and the second reception signal processing unit 132 are operated together, and reception operations are performed by two reception systems.

  In step S1600, the second reception quality determination unit 172 receives the reception quality of the output signal from the second rake synthesis unit 142 measured by the second reception quality measurement unit 162, stored in the storage unit 180. Determine whether the quality threshold is exceeded. When the reception quality of the output signal from the second rake combining unit 142 exceeds the reception quality threshold value (S1600: YES), the process proceeds to step S1700. On the other hand, if the reception quality of the output signal from the second rake combining unit 142 does not exceed the reception quality threshold (S1600: NO), the process proceeds to step S2100.

  In step S1700, since the reception quality of the output signal from the second rake combining unit 142 is good, the reception control unit 190 stops the first received signal processing unit 130. That is, the reception operation is performed only by the second reception signal processing unit 132.

  In step S 1800, the second reception quality determination unit 172 stores the reception quality of the output signal from the second rake synthesis unit 142 measured by the second reception quality measurement unit 162 in the storage unit 180. It is determined whether the reception quality threshold is exceeded. This determination operation is always performed after stopping the first reception signal processing unit 130 in step S1700, but is not necessarily continuous. If the reception quality of the output signal from the second rake combining unit 142 exceeds the reception quality threshold (S1800: YES), the process proceeds to step S1900. On the other hand, if the reception quality of the output signal from the second rake combining unit 142 is below the reception quality threshold (S1800: NO), the process proceeds to step S2000.

  In step S1900, it is determined whether communication is completed. While the communication continues (S1900: NO), the process proceeds to step S1800. That is, as long as the reception quality of the output signal from the second rake combining unit 142 exceeds the reception quality threshold value and the communication continues, the process substantially remains in step S1800. On the other hand, when the communication is finished (S1900: YES), the operation is finished.

  In step S2000, since the reception quality of the output signal from the second rake combining unit 142 is below the reception quality threshold, the reception control unit 190 restarts the operation of the first received signal processing unit 130. That is, both the first received signal processing unit 130 and the second received signal processing unit 132 are operated, and the receiving operation is performed by the two systems of receiving units.

  In step S2100, it is determined whether communication has been completed. While the communication continues (S2100: NO), the process proceeds to step S1100. That is, while the communication continues, the above steps S1100 to S2000 are repeated. On the other hand, when the communication is finished (S2100: YES), the operation is finished.

  In the above description, the reception control unit 190 starts its operation from the control based on the determination result of the first reception quality determination unit 170. Of course, the determination result of the second reception quality determination unit 172 You may start operation | movement from the place controlled based on.

  In the above description, the reception quality threshold values stored in the storage unit 180 are not particularly distinguished, but different reception quality threshold values are used for the first reception quality determination unit 170 and the second reception quality determination unit 172. It may be used. In this case, the storage unit 180 stores a plurality of reception quality threshold values.

  Further, in the above description, the criterion is that the threshold is above or below the threshold, but the criterion may include the threshold, that is, may be greater than or less than the threshold.

  By controlling as described above, mobile communication terminal apparatus 100 according to the present embodiment can always use optimal received signal processing sections 130 and 132. Further, even when the reception quality of the signal output via the first rake combining unit 140 is significantly deteriorated than the reception quality of the signal output via the second rake combining unit 142, this In the mobile communication terminal apparatus 100 according to the invention, the reception quality is stable. Furthermore, since the time during which the two received signal processing units 130 and 132 operate simultaneously is reduced as much as possible, the mobile communication terminal apparatus 100 according to the present invention can reduce power consumption compared to the conventional one.

(Embodiment 2)
FIG. 3 is a block diagram showing the configuration of the diversity receiver of the mobile communication terminal apparatus according to Embodiment 2 of the present invention.

  The mobile communication terminal apparatus 200 according to the second embodiment employs substantially the same configuration as the mobile communication terminal apparatus according to the first embodiment. However, when performing HSDPA (High Speed Downlink Packet Access) communication, the reception control unit 210 receives the signal. The difference is that the second received signal processing unit 132 is operated regardless of the quality. That is, when the reception control unit 210 is informed that the HSDPA communication is performed by the communication mode control signal indicating that the HSDPA communication is performed, the second reception unit 210 always receives the second reception regardless of the reception quality during the subsequent HSDPA communication. The signal processing unit 132 is operated. When HSDPA communication is not performed, that is, when normal communication is performed, the same operation as in the first embodiment is performed.

  In the case of HSDPA communication, which is a high-speed data communication that requires high reception quality, the mobile communication terminal configured as described above always operates the second received signal processing unit 132 to perform the operation of the present invention. In addition to the effects of the first embodiment, HSDPA communication can be performed more reliably.

  The above effect can also be obtained by changing the value of the reception quality threshold according to the communication method. For example, in the case of HSDPA communication, the reception quality threshold value may be set higher than in the case of normal communication.

(Embodiment 3)
FIG. 4 is a block diagram showing a configuration of a diversity receiver of the mobile communication terminal apparatus according to Embodiment 3 of the present invention.

  The mobile communication terminal apparatus 300 according to the third embodiment includes a plurality of antennas 310, 312, 314, and 316 (here, instead of the first antenna 110 and the second antenna 112 according to the first or second embodiment). In this example, the number is four) and the antenna selection unit 320 is provided. Other constituent elements are the same as those of the mobile communication terminal apparatus according to the first or second embodiment, and thus will not be described here (see FIG. 1).

  One of the plurality of antennas 310, 312, 314, and 316 is connected to the antenna duplexer 120 by the antenna selection unit 320, and one of the remaining antennas is connected to the bandpass filter 122.

  The antenna connected to the antenna duplexer 120 radiates a transmission radio frequency signal input from the transmission circuit 124 through the antenna duplexer 120 to the space, and receives the received radio frequency signal through the antenna duplexer 120 to the first. It outputs to the received signal processing unit 130. That is, it operates as the first antenna.

  The antenna connected to the band pass filter outputs the received radio frequency signal received through the band pass filter 122 to the second received signal processing unit 132. That is, it operates as a second antenna.

  The antenna selection unit 320 selectively switches a plurality of antennas, and selects a specific antenna from them. Specifically, one of the plurality of antennas 310, 312, 314, and 316 is connected to the antenna duplexer 120, and the remaining one is connected to the bandpass filter 122. At this time, the antenna connected to the bandpass filter 122 is selected based on a predetermined criterion from all the remaining antennas not connected to the antenna duplexer 120.

  FIG. 5 is a flowchart showing the operation of the diversity receiver of the mobile communication terminal device according to the third embodiment of the present invention.

  The operation of the diversity receiver of the mobile communication terminal apparatus according to the third embodiment is characterized by antenna selection before starting communication, and the operation after starting communication (step S3500) is the same as that of the first embodiment. Therefore, it will not be described in detail here (see FIG. 2). Also, antenna selection section 320 assumes that one antenna has already been selected as the antenna to be connected to antenna duplexer 120, and the antenna to be connected to bandpass filter 122 is selected from the remaining antennas based on the reception quality. Will be described.

  First, in step S3000, the reception control unit 330 turns on the second reception signal processing unit 132 so that it can operate.

  In step S3100, antenna selection section 320 selects one antenna whose reception quality is not measured from a plurality of antennas not connected to antenna duplexer 120.

  In step S3200, second reception quality measuring section 162 measures the reception quality of the received signal received through the antenna selected in step S3100. The measurement result is passed to the antenna selection unit 320 through the reception control unit.

  In step S3300, antenna selection section 320 determines whether or not measurement of reception quality has been completed for all of the plurality of antennas not connected to antenna duplexer 120. When the measurement of the reception quality of all the antennas for a plurality of antennas not connected to the antenna duplexer 120 is completed (S3300: YES), the process proceeds to step S3400. On the other hand, if there is an antenna whose reception quality has not been measured (S3300: NO), the process proceeds to step 3100. That is, step S3100 to step S3300 are repeated until antenna selection section 320 and second reception quality measurement section 162 measure the reception quality for all antennas that are not used as antenna duplexer 120.

  In step S3400, antenna selection section 320 compares the reception qualities of all antennas measured in step S3200 and selects the antenna with the best reception quality. The selected antenna is connected to a bandpass filter and used as a second antenna in subsequent communications.

  In step S3500, communication is started using the selected antenna.

  As described above, by selecting an antenna having good reception quality from among a plurality of antennas and performing communication using the selected antenna, reception is performed as compared with the mobile communication terminal apparatuses of the first and second embodiments. Quality is improved. As a result, the period during which the operation of the received signal processing unit is stopped is lengthened, so that power consumption can be further reduced.

  In the above description, the case of selecting an antenna to be connected to the bandpass filter has been described. However, for the first antenna, an antenna having good reception quality can be selected using the same method.

  In the above description, reception quality is used as an antenna selection parameter. However, the same effect can be obtained by using RSSI (Received Signal Strength Indicator) indicating received signal strength. Similarly to the first embodiment, when a plurality of transmission power control signal thresholds are provided, the switch configuration is SP3T-SW (Single-Pole Triple-Throw Switch) or DPDT-SW (Double-Pole Double-Throw Switch). The same effect can be obtained even in such cases.

  In this embodiment, the case where there are four antennas has been described as an example. However, the number of antennas is not limited to this. If there are two or more antennas, the same effect can be obtained.

  The mobile communication terminal apparatus according to the present invention has an effect that the received signal processing unit is flexibly controlled according to the reception quality and the communication method, and has the effect that the power consumption can be reduced and can be reduced. This is useful as a reception diversity combining and reception control method for a mobile communication terminal used in a communication system.

The block diagram which shows the structure of Embodiment 1 of the mobile communication terminal device which concerns on this invention. The flowchart which shows operation | movement of Embodiment 1 of the mobile communication terminal device which concerns on this invention. The block diagram which shows the structure of Embodiment 2 of the mobile communication terminal device which concerns on this invention The block diagram which shows the structure of Embodiment 3 of the mobile communication terminal device which concerns on this invention. The flowchart which shows operation | movement of Embodiment 3 of the mobile communication terminal device which concerns on this invention. The block diagram which shows the structure of the conventional mobile communication terminal device

Explanation of symbols

1 External antenna 2 Built-in antenna 3 Duplexer (DUP)
4 Transmitter (TX)
5 Bandpass filter (BPF)
6 First diversity branch (BR1)
7 Second diversity branch (BR2)
8 First rake receiver (RAKE1)
9 Second Rake Receiver (RAKE2)
10 Symbol synthesis circuit (COMB)
11 Signal quality judgment circuit (QLTY)
12 changeover switch 100, 200, 300 mobile communication terminal device 110 first antenna 112 second antenna 120 antenna duplexer 122 band pass filter 124 transmission circuit 130 first received signal processing unit 132 second received signal processing unit 140 First Rake Combining Unit 142 Second Rake Combining Unit 150 Diversity Combining Unit 160 First Reception Quality Measuring Unit 162 Second Reception Quality Measuring Unit 170 First Reception Quality Judging Unit 172 Second Reception Quality Judging Unit 180 Storage unit 190, 210, 330 Reception control unit 310, 312, 314, 316 Antenna 320 Antenna selection unit

Claims (4)

First received signal processing means for converting a radio frequency signal received through a first antenna shared for transmission and reception into a first baseband signal;
Second received signal processing means for converting a radio frequency signal received through a second antenna used exclusively for reception into a second baseband signal;
First rake combining means for rake combining a multipath signal included in the first baseband signal;
Second rake combining means for rake combining multipath signals included in the second baseband signal;
First reception quality measuring means for measuring the reception quality of the output signal of the first rake combining means;
Second reception quality measuring means for measuring the reception quality of the output signal of the second rake combining means;
First reception quality determination means for determining whether the reception quality of the output signal of the first rake combining means measured by the first reception quality measurement means is equal to or higher than a predetermined first reception quality threshold; ,
Second reception quality determination means for determining whether or not the reception quality of the output signal of the second rake combining means measured by the second reception quality measurement means is equal to or greater than a predetermined second reception quality threshold; ,
Based on the determination result of the first reception quality determination means and the determination result of the second reception quality determination means, the output signal of the first rake combining means and the output signal of the second rake combining means When it is determined that the reception quality of at least one of the output signals is equal to or higher than the corresponding reception quality threshold, the operation of the reception signal processing unit corresponding to one of the reception systems determined according to a predetermined criterion is stopped. Reception control means;
A mobile communication terminal apparatus. The reception control means includes
Immediately after the start of communication or after resuming the operation of the first received signal processing means, the first received quality determining means determines that the received quality of the input signal is greater than or equal to a predetermined received quality threshold. While stopping the operation of the second received signal processing means,
After the operation of the second received signal processing means is stopped, when the first received quality determining means determines that the received quality of the input signal is less than a predetermined received quality threshold, Restart the operation of the received signal processing means,
After restarting the operation of the second received signal processing means, while the second received quality determining means determines that the received quality of the input signal is equal to or higher than a predetermined received quality threshold, Stop the operation of one received signal processing means,
After the operation of the first received signal processing means is stopped, when the second received quality determining means determines that the received quality of the input signal is less than a predetermined received quality threshold, To resume the operation of the received signal processing means of
The mobile communication terminal device according to claim 1. The reception control means includes
When a signal indicating that HSDPA communication is performed is input, the first received signal processing means and the second received signal processing means are operated together.
The mobile communication terminal device according to claim 1. Have multiple antennas,
Antenna switching means for selectively switching connection between the plurality of antennas and the first received signal processing means and the second received signal processing means;
A switching parameter measuring means for measuring an antenna switching parameter for each antenna that is not used as the first antenna among the plurality of antennas;
An antenna selection unit that selects the antenna corresponding to the parameter of the optimum value among the parameters measured by the switching parameter measurement unit, and controls the antenna switching unit so that the selected antenna becomes the second antenna;
The mobile communication terminal apparatus according to claim 1, further comprising:

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