JP2003258707A - Mobile communication terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform the ON/OFF control of a transmission power source without deteriorating the quality of a received signal. <P>SOLUTION: A control circuit 17A has a PE bit detecting function 17a and a transmission power source timing control function 17b. A PE bit is respectively detected from packet data received in a receiving slot just before and just after a transmitting slot and during such a PE bit period, the supply of a transmission power source voltage Vtx to a transmission circuit 5 is turned on/off. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to mobile communication terminals such as DAs (Personal Digital Assistants), and more particularly to mobile communication terminals having a packet data communication function.

[0002]

2. Description of the Related Art In recent years, mobile communication terminals represented by mobile phones have rapidly become popular. These terminals use a battery as a power source, and the size of the battery greatly affects the size of the terminal. Therefore, various measures have been taken to reduce the power consumption in order to reduce the size of the battery, and one of them is a battery saving function.

For example, in the case of transmission, the battery saving function is to prevent power consumption by turning on the power supply of the transmission circuit immediately before the transmission slot and turning it off immediately after the transmission slot. However, when the power supply of the transmission circuit is turned on / off, the local oscillation frequency of the frequency synthesizer fluctuates due to the influence of the fluctuation of the battery voltage accompanying it. This is not a problem when transmitting and receiving are performed in different time zones such as voice communication, but may be a problem when performing a packet transmitting / receiving operation.

FIG. 9 is a timing chart for explaining this problem. As shown in the figure, as one of the operation modes for transmitting and receiving packet data, all three slots Rm1 to Rm3 of one frame are used to receive packet data, and at the same time, one slot Tm1 is used. And then send it. In this state, when the power supply to the transmission circuit is turned on / off at any timing before and after the transmission slot T1, the receiving local oscillation frequency fluctuates as shown by the influence of the on / off of the transmission power supply.
The packet data reception operation may become unstable, resulting in bit errors.

On the other hand, some mobile communication terminals are provided with two antennas including a main antenna and a sub-antenna, and have a function of selectively using these antennas for receiving antenna diversity. For example, as shown in FIG. 10, this function is performed by sequentially switching between the main antenna and the sub-antenna and measuring the received electric field strengths in a preamble period called an LM period immediately before the reception slot, and based on the measurement result. In addition, it is realized by connecting the antenna on the side with high received electric field strength to the transmission / reception circuit.

However, as described above, when the packet data is received by using all the three reception slots Rm1 to Rm3, the LM period cannot be set and the antenna switching is performed during the reception of the packet data. Measurement operation and connection switching operation must be performed. Therefore, the received signal level fluctuates greatly as shown in the figure during the antenna switching control period, and as a result, an error may occur in the packet data.

[0007]

As described above, in the conventional mobile communication terminal, when the packet data is received by using the plurality of receiving slots, the power supply to the transmitting circuit is turned on / off and the receiving operation is performed. In the antenna switching control period for antenna diversity, the local oscillation frequency of the reception and the level of the reception signal fluctuate, and as a result, reception data error occurs.

The present invention has been made in view of the above circumstances, and a first object thereof is to provide a mobile communication terminal capable of performing on / off control of a transmission power supply without deterioration of quality of a received signal. That is.

A second object is to provide a mobile communication terminal capable of performing control for receiving antenna diversity without degrading the quality of received signals.

[0010]

In order to achieve the above object, a first invention is a mobile communication terminal which performs wireless transmission / reception by a transmission circuit and a reception circuit according to a time division multiple access system, and a transmission assigned to the own terminal. In addition to a transmission power supply circuit that supplies power to the transmission circuit during a period including a slot and stops power supply to the transmission circuit during other periods, a redundant bit detection unit and a transmission power supply control unit are newly added. Is equipped with.

Then, the detecting means detects a predetermined redundant bit period from the packet data received by the receiving circuit, and turns on / off the power supply to the transmitting circuit within the detected redundant bit period. In order
The control means controls the transmission power supply circuit.

Therefore, according to the first aspect of the invention, the transmission power supply is turned on and off by utilizing the redundant bit period which is not necessarily received in the received packet data. Therefore, it is possible to prevent the fluctuation of the reception local oscillation frequency caused by turning on / off the transmission power source from affecting the necessary data portion in the reception packet data. As a result, it is possible to prevent the quality of received data from deteriorating even if the transmission battery saving function is used during packet communication.

On the other hand, according to a second aspect of the invention, in a mobile communication terminal which performs wireless transmission / reception by a transmission circuit and a reception circuit according to a time division multiple access system, first and second antennas which are arranged apart from each other, In addition to an antenna switching circuit that selectively switches between the first and second antennas and connects to the transmitting circuit and the receiving circuit, a redundant bit detecting means and an antenna switching control means are newly provided.

The predetermined redundant bit period of the packet data received by the receiving circuit is detected by the detecting means, and the first and second antennas are alternately switched within the detected redundant bit period. Each of them to measure the reception quality of each antenna, select one of the first and second antennas based on the measurement result, and control the antenna switching circuit by the control means so that the antenna is connected to the transmitting circuit and the receiving circuit. I'm trying to control.

Therefore, according to the second aspect of the invention, the antenna switching control is performed by utilizing the redundant bit period which is not necessarily received in the received packet data. Therefore, it is possible to prevent the fluctuation of the reception level caused by the antenna switching control from affecting the necessary data part in the reception packet data. By this means, it is possible to prevent the quality of received data from deteriorating even if antenna switching is performed during packet communication.

[0016]

(First Embodiment) FIG. 1 is a block diagram showing a circuit configuration of a mobile communication terminal according to a first embodiment of the present invention. This mobile communication terminal uses time division multiple access (TDMA) as a radio access method.
Ion Multiple Access) method is used.

In FIG. 1, a radio carrier signal sent from a base station (not shown) via a radio channel is received by an antenna 1 and then input to a receiving circuit (RX) 3 via an antenna duplexer (DUP) 2. To be done. In the reception circuit 3, the received radio carrier signal is mixed with the reception local oscillation signal output from the frequency synthesizer (SYN) 4 and frequency-converted into a reception intermediate frequency signal. The received intermediate frequency signal is sampled by the A / D converter 6 including a low pass filter and then input to the digital demodulation circuit (DEM) 7.

The digital demodulation circuit 7 establishes frame synchronization and bit synchronization for the digital received intermediate frequency signal, and then performs digital demodulation processing. The baseband digital demodulated signal obtained by this demodulation processing is input to a time division multiple access circuit (TDMA) 8, where the time slot destined for itself is separated and extracted for each transmission frame. The frame synchronization and bit synchronization information obtained in the digital demodulation circuit 7 is notified to the control circuit 17.

The digital demodulated signal output from the TDMA circuit 8 is subsequently subjected to an error correction code decoding circuit (CH-
COD) 9 and undergoes error correction decoding processing. In this error-correction-decoded digital demodulated signal,
Depending on the communication mode at that time, there are information data such as mail and call voice data. Of these, the call voice data is input to the voice code decoding circuit (SP-COD) 10 and subjected to voice decoding processing, whereby a digital received signal is reproduced. This digital reception signal is converted into an analog reception signal by the D / A converter 11 and then output from the speaker 12 via a reception amplifier (not shown). Information data such as received mail and received download data is stored in the control circuit 1.
7 and the control circuit 17A controls the memory (M
EM) 20 and is decrypted while being stored in the display unit 22.
Is displayed in.

On the other hand, the voice transmitted by the speaker is the microphone 1
The sound is collected by 3 and converted into a transmission signal, further amplified by a transmission amplifier (not shown) to a predetermined level, and then A
It is input to the / D converter 14. Then, the A / D converter 14 samples the signal at a predetermined sampling period, thereby converting it into a digital transmission signal composed of a sample pulse train. After the acoustic echo is canceled by an echo canceller (not shown), the digital transmission signal is input to the voice code decoding circuit (SP-COD) 10 and is voice coded here.

This speech-coded digital transmission signal is input to an error correction code decoding circuit (CH-COD) 9 and is error correction coded there. In addition, the control circuit 17
The image data output from A and information data such as transmission mail are also input to the error correction code decoding circuit 9 and error correction coded. The digital transmission signal output from the error correction code decoding circuit 9 is input to the TDMA circuit 8. In the TDMA circuit 8, time division multiple access (TD
A transmission frame corresponding to the (MA) system is generated, and a process for inserting the digital transmission signal in the time slot assigned to the own device in the transmission frame is performed.

The digital transmission signal output from the TDMA circuit 8 is subsequently supplied to a digital modulation circuit (MOD).
15 is input. In the digital modulation circuit 15, a transmission intermediate frequency signal digitally modulated by the digital transmission signal is generated, and the transmission intermediate frequency signal is D / A.
After being converted into an analog signal by the converter 16, it is input to the transmission circuit (TX) 5. As a digital modulation method, for example, π / 4 shift DQPSK (π / 4 shif
ted, differentially encoded quadrature phase shift
keying) method is used.

In the transmission circuit 5, the modulated transmission intermediate frequency signal is mixed with the transmission local oscillation signal output from the frequency synthesizer 4, and is thereby converted into a radio carrier frequency corresponding to a radio communication channel. Then, this transmission radio carrier signal is controlled to a predetermined transmission power level by a transmission power amplifier (not shown), and then transmitted from the antenna 1 to the base station (not shown) via the antenna duplexer 2.

The key input section 21 is provided with various keys necessary for communication such as a call key, an end key, a plurality of function keys and a dial key.

The display 22 is, for example, a liquid crystal display (LC
D: Liquid Crystal Display) is used to display the display data output from the control circuit 17A. The display data includes not only management data such as a telephone directory and transmission / reception history, data representing the operating state of the apparatus, but also transmission / reception mail and image data.

The memory 20 is composed of, for example, a RAM or a flash memory, and stores mails, download data, sent mails, etc. received from a telephone directory, a terminal of a communication partner or an information site.

The power supply circuit 19 is based on the output voltage of the battery 18, which is a secondary battery, and the power supply voltage Vcc necessary for the operation of each circuit of the mobile communication terminal and the transmission power supply voltage necessary for the operation of the transmission circuit 5. Generate Vtx.

The transmission power supply circuit 23 controls the supply of the transmission power supply voltage Vtx to the transmission circuit 5 according to the on / off timing of the transmission power supply instructed by the control circuit 17A.

The control circuit 17A includes, for example, a microcomputer as a main control unit, and has a PE bit detection function 17a and a transmission function in addition to a normal control function such as a radio access control function, a call control function or a packet communication control function. And a power supply timing control function 17b.

The PE bit detection function 17a is a function for detecting the PE bit portion of the packet data received by the mobile communication terminal during packet communication. Figure 5
It is a slot configuration of a physical channel for packet communication. Of the collision control bits (E bits), I / B and R / N must be received, but partial echo (PE bit) is a bit that does not necessarily need to be received unless data is transmitted immediately before. And PE bit detection function 17
a detects this PE bit.

The transmission power supply timing control function 17b performs the transmission power supply on / off operation based on the battery saving function when performing transmission simultaneously while receiving packet data using the multi-slot, and the PE bit detection function 17a.
This is a function of controlling the on / off timing of the transmission power source, as is performed within the PE bit detected by.

A data transmission / reception operation in the mobile communication terminal configured as described above will be described.

FIG. 2 is a flow chart showing a control procedure and its contents when the mobile communication terminal receives data. When a communication request is generated by making or receiving a call, the control circuit 17
A shifts from step 2a to step 2b and determines whether the communication mode is the single-slot communication mode or the multi-slot communication mode. Then, in the case of the single slot communication mode, in step 2c, a communication process using one slot is executed for both normal transmission and reception.

On the other hand, in the multi-slot communication mode, the control circuit 17A first sets a plurality of slots to be received in step 2d. When the communication is started, the control circuit 17A extracts the received packet data from each of the set receiving slots in step 2f, and stores the extracted packet data in the memory 20 in step 2g. The control circuit 17A repeats this control until the end of communication is detected in step 2e. Then, the received data is displayed on the display unit 22 in step 2h according to the user's operation after the communication is completed.

On the other hand, in parallel with the reception control of the packet data, the control circuit 17A allocates 1
Data transmission control is performed using the transmission slots. Then, at that time, the supply timing of the transmission power supply voltage Vtx to the transmission circuit 5 is controlled. FIG. 3 is a flowchart showing the control procedure and control contents, and FIG. 4 is a timing chart showing the supply timing of the transmission power supply voltage Vtx.

When the data communication is started, the control circuit 17A
First, from the packet data received in the reception slot immediately before the transmission slot in step 3a, the collision control bit (E
Bit), and further, a partial echo (PE bit) in this E bit is detected. This PE bit is a bit that does not necessarily need to be received when transmission is not performed in the immediately preceding transmission slot.

When the PE bit is detected, the control circuit 17A determines an arbitrary timing during the PE bit reception period, for example, the timing of the first bit as the transmission power-on timing in step 3b, and this is determined in step 3c. The transmission power-on signal is given to the transmission power supply circuit 23 at the transmission power-on timing. The transmission power supply circuit 23 starts to supply the transmission power supply voltage Vtx to the transmission circuit 5 as shown in FIG. 4, when the transmission power supply ON signal is given. Therefore, the transmission circuit 5 becomes ready for the transmission operation. Therefore, in the transmission slot period, the transmission circuit 5 performs the wireless transmission operation of the transmission data.

The control circuit 17A monitors the end of the transmission slot period in step 3d during the transmission operation period. Then, when the transmission slot period ends, step 3
In step e, the E bit is detected from the packet data received in the reception slot immediately after the end of the transmission slot period, and the PE bit in the E bit is detected. When this PE bit is detected, the control circuit 17A
Determines the transmission power off timing at an arbitrary timing during the PE bit reception period, for example, the timing of the first bit in step 3f, and transmits the transmission power off signal at the transmission power off timing determined in step 3g. It is given to the supply circuit 23. The transmission power supply circuit 23 stops the supply of the transmission power supply voltage Vtx to the transmission circuit 5 as shown in FIG. 4 when the transmission power supply off signal is given.

Thereafter, similarly, the control circuit 17A repeats the transmission power supply control for each transmission slot.

As described above, in the first embodiment, the PE bit is detected from the packet data received in the reception slot immediately before and after the transmission slot, and the transmission power supply voltage Vtx for the transmission circuit 5 is detected during this PE bit period.
The power supply is turned on and off.

Therefore, the power supply voltage Vcc of the power supply circuit 19 fluctuates due to the ON / OFF operation of the supply of the transmission power supply voltage Vtx, which causes the reception local oscillation frequency of the frequency synthesizer 4 to fluctuate and the reception operation of the reception circuit 3 to become unstable. However, the PE bit in the received packet data is the only affected portion, and all other important bits in the received packet data are normally received. Therefore, it is possible to perform the transmission battery saving operation while maintaining good reception quality.

(Second Embodiment) FIG. 6 is a block diagram showing a circuit configuration of a mobile communication terminal according to a second embodiment of the present invention. In the figure, the same parts as those in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted.

The mobile communication terminal according to the second embodiment is
The first antenna (main antenna) 1, the second antenna (sub antenna) 24, and these antennas 1, 23
And an antenna switching device 25 for selectively connecting to the antenna duplexer 2.

The control circuit 17B has a reception antenna diversity control function, and by this function, the reception electric field strength (RSS) by the main antenna 1 and the sub antenna 24 is obtained.
I) is detected based on the output of the reception electric field strength detector 26, and the antenna switching unit 25 is switched and controlled based on the detection result to connect the antenna having a good reception electric field strength to the antenna duplexer 2. .

By the way, the control circuit 17B has a new function for realizing the above-mentioned receiving antenna diversity.
It has a PE bit detection function 17a and an antenna switching timing control function 17c.

The PE bit detection function 17a is a function for detecting the PE bit portion of the packet data received by the mobile communication terminal during packet communication. Figure 5
It is a slot configuration of a physical channel for packet communication. Of the collision control bits (E bits), I / B and R / N must be received, but partial echo (PE bit) is a bit that does not necessarily need to be received unless data is transmitted immediately before. And PE bit detection function 17
a detects this PE bit.

Antenna switching timing control function 17c
Is P detected by the PE bit detection function 17a.
In the E bit period, the main antenna 1 and the sub antenna 24
Alternately switch, and measure the received electric field strength of each,
And the antenna to be used is selected based on the measurement result. Then, an antenna switching signal ASW for connecting the selected antenna to the antenna duplexer 2 is generated and given to the antenna switching device 25.

Next, the receiving antenna diversity control operation by the mobile communication terminal configured as described above will be explained. FIG. 7 is a flowchart showing the control procedure and control contents, and FIG. 8 is a timing chart showing the switching operation timing.

When packet communication in the multi-slot mode is started, the control circuit 17B first detects the PE bit from the packet data received in the first receiving slot of the frame in step 7a. Then, in step 7b, the antenna switching control period is set within the detected PE bit period as shown in FIG. Then, in step 7c, the antenna switching signal ASW is given to the antenna switching device 25 within the set control period to switch the main antenna 1 and the sub-antenna 24 alternately, whereby the received electric field strengths of the antennas 1 and 24 ( RSSI)
Are measured respectively.

Next, based on the above measurement results, RSSI
The antenna on the better side is selected in step 7d, and the antenna switching signal ASW for connecting the selected antenna to the antenna duplexer 2 is given to the antenna switching device 25 (step 7e). Therefore, the selected antenna is connected to the antenna duplexer 2, and thereafter the receiving operation is started by this antenna.

For example, if the RSSI of the main antenna 1 is higher, the main antenna 1 is connected to the antenna duplexer 2, while if the RSSI of the sub antenna 24 is higher, the sub antenna 24 is connected to the antenna duplexer 2. . Here, as the main antenna 1, for example, a rod antenna or a helical antenna protruding outside the housing of the terminal is used, while as the sub-antenna 24, a planar antenna housed in the housing is used. Therefore, the main antenna 1 is used for both reception and transmission, while the sub antenna 2
4 is used only for reception.

When the antenna switching control is completed and the reception operation period starts, the control circuit 17B subsequently determines in step 7f whether the currently connected antenna is the main antenna 1 or the sub antenna 24. To do. The currently connected antenna is the sub antenna 24.
If so, control is performed to switch to the main antenna 1 because it cannot be used during the transmission slot period.

That is, the control circuit 17B uses the step 7g.
The PE bit is detected from the packet data received in the reception slot immediately before the transmission slot. Then, during the detected PE bit period, as shown in FIG. 8, an antenna switching signal ASW for switching the sub antenna 24 to the main antenna 1 is generated and given to the antenna switching device 25 (step 7h). Therefore, thereafter, the transmission circuit 5 and the reception circuit 3 are connected to the main antenna 1, so that the reception operation and the transmission operation can be performed.

On the other hand, if the result of determination in step 7f is that the currently connected antenna is the main antenna 1, the main antenna 1 is for both transmission and reception, and therefore reception is directly performed by this main antenna 1 without switching. Performs operation and transmission operation.

Thereafter, the switching control of the antenna is performed for each frame.

As described above, in the second embodiment, the PE bit is detected from the packet data received in the first reception slot for each frame, and the main antenna 1 and the sub antenna 24 are alternately switched during this PE bit period. Then, the RSSI is measured respectively and the antenna on the higher RSSI side is selected based on the measurement result and connected to the antenna duplexer 2.

Therefore, even if the received signal level fluctuates as shown in FIG. 8 due to the antenna switching control, the affected portion is P in the received packet data.
Only E bits are received, and all other important bits in the received packet data are normally received. Therefore, it is possible to perform reception antenna diversity control while maintaining good reception quality.

(Other Examples) In the second embodiment,
The case where the antenna switching control period is set within the PE bit period in the received packet data has been described as an example on the premise of the multi-slot communication mode, but the antenna switching control can be similarly performed in the single communication mode. is there. Note that it is of course possible to execute the antenna switching control using the LM period shown in FIG. 10 only in the single communication mode.

In the second embodiment, the case where a reception-only antenna is used as the sub-antenna 24 has been described as an example, but a transmission / reception antenna may be used. In this case, control for switching the sub antenna to the main antenna in preparation for the transmission slot period can be dispensed with, and the control load on the control circuit can be reduced.

In the second embodiment, the case has been described as an example where the antenna switching control is executed in one frame cycle, but the antenna switching control may be executed in one slot cycle or a plurality of frame cycles.

Further, when the mobile communication terminal is provided with a function of detecting the moving speed of the terminal, the execution cycle of the antenna switching control may be variably set according to the detected moving speed. . For example, when the moving speed of the terminal is higher than a predetermined speed, the change in the reception level due to fading or the like becomes fast. Therefore, the execution period of the antenna switching control is set to, for example, one frame length or one slot length. On the other hand, when the moving speed of the terminal is lower than the predetermined speed, the change in the reception level becomes relatively slow, and therefore the execution cycle of the antenna switching control is set to, for example, a plurality of frame lengths.

The execution cycle of the antenna switching control may be variably set according to the position of the mobile communication terminal. For example, the position of the own terminal is detected using the GPS function. Then, when the detected position is a position where the radio propagation environment is likely to be deteriorated, such as a city center part or a mountain part, the execution cycle of the antenna switching control is set to, for example, one frame length or one slot length. On the other hand, when the position of the terminal is a position where the radio propagation environment is relatively good, such as in the suburbs or the countryside, the execution cycle of the antenna switching control is set to, for example, a plurality of frame lengths.

As described above, it becomes possible to execute the optimum receiving antenna diversity control according to the moving speed and the position of the terminal.

Other types of mobile communication terminals and their configurations,
The transmission power on / off control and antenna switching control procedures and contents can be modified in various ways without departing from the scope of the present invention.

[0065]

As described in detail above, according to the first invention, when packet data is received by using a plurality of receiving slots and the packet data are simultaneously transmitted in the same frame, the received packet data Since the transmission power is turned on and off in the redundant bit, the transmission power is turned on and off in the redundant bit period that does not necessarily need to be received in the received packet data. Of the received packet data can be prevented from affecting the necessary data portion of the received packet data. As a result, it is possible to prevent the quality of received data from deteriorating even if the transmission battery saving function is used during packet communication.

According to the second invention, when packet data is received using a plurality of reception slots, the reception quality is measured within the redundant bits of the reception packet data,
By switching the antennas based on the measurement results, the antenna switching control is performed during the redundant bit period in the received packet data that does not necessarily need to be received. It is possible to avoid affecting the necessary data part in the packet data. By this means, it is possible to prevent the quality of received data from deteriorating even if antenna switching is performed during packet communication.

[Brief description of drawings]

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

2 is a flowchart showing a control procedure and its contents when receiving data in the mobile communication terminal shown in FIG.

3 is a flowchart showing a supply timing control procedure of the transmission power supply voltage Vtx and its contents when transmitting / receiving packet data in the mobile communication terminal shown in FIG.

4 is a timing chart showing a supply timing of a transmission power supply voltage Vtx when transmitting / receiving packet data in the mobile communication terminal shown in FIG. 1.

FIG. 5 is a diagram showing a slot configuration of a physical channel for packet communication.

FIG. 6 is a block diagram showing a circuit configuration of a mobile communication terminal according to a second embodiment of the present invention.

FIG. 7 is a flowchart showing a control procedure of reception antenna diversity and its contents in the mobile communication terminal shown in FIG.

8 is a timing chart showing a control operation of antenna switching operation timing in the mobile communication terminal shown in FIG.

FIG. 9: 3 slot reception and 1 in packet communication
6 is a timing chart showing a transmission power on / off control operation in the case of slot transmission.

FIG. 10 is a timing chart showing a reception antenna diversity control operation when one slot is used for transmission and reception.

[Explanation of symbols]

1 ... Antenna (main antenna) 2 ... Antenna duplexer (DUP) 3 ... Receiving circuit (RX) 4 ... Frequency synthesizer (SYN) 5 ... Transmission circuit (TX) 6, 14 ... A / D converter 7. Digital demodulation circuit (DEM) 8 ... Time division multiple access circuit (TDMA) 9 ... Error correction code decoding circuit (CH-COD) 10 ... Speech code decoding circuit (SP-COD) 11, 16 ... D / A converter 12 ... Speaker 13 ... Microphone 15 ... Digital modulation circuit (MOD) 17A, 17B ... Control circuit 17a ... PE bit detection function 17b ... Transmission power timing control function 17c ... Antenna switching timing control function 18 ... Battery 19 ... Power supply circuit (POW) 20 ... Memory (MEM) 21 ... Key input section 22 ... Display 23 ... Transmission power supply circuit 24 ... Antenna (sub antenna) 25 ... Antenna switch 26 ... Received field strength detector (RSSI)

Continued front page    F term (reference) 5J021 AA02 CA06 DB04 EA04 FA31                       HA05 HA10                 5K059 CC03 DD05 DD27                 5K067 AA26 AA43 BB04 CC08 CC21                       CC24 EE02 KK03                 5K101 KK20 LL12 NN11 NN45 VV01

Claims (2)

[Claims] 1. In a mobile communication terminal that performs wireless transmission / reception by a transmission circuit and a reception circuit according to a time division multiple access system, power is supplied to the transmission circuit during a period including a transmission slot allocated to the own terminal, and other periods A transmission power supply circuit for stopping the supply of power to the transmission circuit, a detection means for detecting a predetermined redundant bit period from the packet data received by the reception circuit, and a redundant bit detected by the detection means. A mobile communication terminal, comprising: a control unit that controls the transmission power supply circuit so as to turn on / off the power supply to the transmission circuit within a period. 2. In a mobile communication terminal that performs wireless transmission / reception by a transmission circuit and a reception circuit according to a time division multiple access system, first and second antennas that are spatially separated from each other, and the first and second antennas. An antenna switching circuit that selectively switches two antennas to connect to the transmission circuit and the reception circuit, a detection unit that detects a predetermined redundant bit period from the packet data received by the reception circuit, and the detection unit. Within the detected redundant bit period, the first and second antennas are alternately switched to measure the reception quality of each, and one of the first and second antennas is selected based on the measurement result. A mobile communication terminal comprising: control means for controlling the antenna switching circuit so as to connect to the transmitting circuit and the receiving circuit.