JP3288196B2 - Mobile communication terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication terminal suitable for mobile use, particularly for portable use.

[0002]

2. Description of the Related Art Conventionally, various transmission systems for transmitting digital information in predetermined slot units have been proposed. In particular, so-called intermittent reception is performed during non-communications in mobile communication terminals that perform this communication of digital information in order to reduce power consumption. This intermittent reception is performed by paging (designated call).

In order to reduce the power consumption at the time of the intermittent reception, a process of not supplying power to a block for transmitting a radio signal and a function block for receiving a radio signal during a so-called standby mode is performed. . Furthermore, a configuration is also adopted in which a timer for measuring the standby time is prepared, the system clock used for wireless communication is stopped after a certain standby time has elapsed by the timer, and a low-speed clock signal is used instead. obtain. As described above, the power consumption is further reduced by using the low-speed clock signal.

[0004] For example, one configuration example of a conventional mobile communication terminal described in Japanese Patent Application Laid-Open No. 4-170823 is shown in FIG.

In FIG. 13, an antenna 1 transmits and receives radio waves. The transmission / reception unit 2 controls the framing of the TDMA system, and performs modulation / demodulation and wireless control. The interface unit 3 is a so-called A / D, D / A
And converts the analog voice signal from the transmitter into a digital signal, and converts the digital signal into an analog signal before supplying it to the receiver 5. The system control section (my computer) 6 is a section that controls the entire apparatus. The mobile communication terminal also has a high-speed and high-accuracy first reference oscillator 8 used during communication and a low-speed second reference oscillator 9 used during so-called standby. A high-speed counter 10 and a low-speed counter 11 are provided correspondingly. The switches 12 and 13 control the power supplied to the receiving unit 2b and the first reference oscillator 8 and the power supplied to the transmitting unit 2a, respectively. Further, the switches 14 and 15 switch the input clock of the low-speed counter 11 and the reference oscillator (8 or 9) for supplying power, respectively. The mobile communication terminal includes a secondary battery 7.

First, when transmission and reception are simultaneously performed, the switches 12 and 13 are also turned on.
The switch 14 has an output connected to the high-speed counter 10. The switch 15 includes a first reference oscillator 8 and a high-speed counter 1.
0 is supplied with power.

In this way, high precision, for example, 2 ppm
The transmission / reception operation is performed using a high-speed clock signal of, for example, about 16 MHz as a reference clock.

Next, during the receiving operation, the switch 1
2 is turned on, and the switch 13 is turned off. As a result, power is not supplied to the transmission unit 2a, and the switching unit 14,
15, the same control as described above is performed. Therefore, an accurate receiving operation is performed using the high-speed clock 8 as a reference clock.

On the other hand, when waiting, the switches 12 and 13
In both cases, the off operation is performed, and as a result, the power to the transmission / reception unit 2 and the interface unit 3 is also cut off, so that the power consumption is further reduced. Further, no power is supplied to the high-speed first reference oscillator 8 and the high-speed counter 10, while the low-speed second reference oscillator 9 is, for example, 31.25 kHz.
Oscillate about a signal. During standby, power is supplied only to the oscillator, the low-speed counter 11, and the system control unit 6. That is, the operation at the time of standby includes the reference clock of the low-speed second reference oscillator 9,
Only the low-speed counter 11 operates, and performs only the operation of waiting for the timing at the time of standby.

The high-speed first reference oscillator 8 requires, for example, a current consumption of about 10 mA, while the low-speed second reference oscillator 9 consumes about 10 μA.
At the time of the standby, the system control unit 6 and the low-speed counter 11, which are usually constituted by C-MOS circuits, hardly operate, and as a result, the power consumption of the standby is very low compared to the transmission / reception operation. Will be small.

[0011]

However, in the above-described conventional apparatus, the detection of the unique word during the standby operation is a so-called open aperture, so that there is a problem that the reception performance of slot reception cannot be improved. there were. For example, when a system of a simplified mobile phone system (hereinafter, referred to as PHS) is adopted as a communication system, a slot length in which paging is performed is 625.
μs, and the cycle (superframe cycle) of the paging signal is allowed to be 1.2 seconds in the public system and up to about 15 seconds in the private system.

For this reason, the second reference oscillator 9 for measuring the timing between slots for standby as described above is used.
When the oscillation of this oscillator is ± 100 ppm, the error in the standby interval is as follows when a low-speed reference oscillation clock is used immediately after completion of reception of all slots in a public system. Is calculated.

(1.2s−625 μs) * 100 ppm + (1 / 31.25 kHz) = 153 μs 153 μs * 384 kbit / S〓59 (bit) Thus, the unique word detection period is ± 59 bits.
Must be set with a width of As a result, there has been a problem that the detection accuracy of the unique word is reduced. That is, when the reception quality is poor, there is a high possibility that the unique word is erroneously detected.

[0014] Further, if the unique word detection period is extended, the period during which the terminal operates in the receiving state becomes longer, and the power consumption is unnecessarily increased. That is, in the standby mode, the main power consumption is the power during the receiving operation, and in the case of the above example, it is originally 625 μsec.
625 μsec + 15 on average,
This means that the receiving operation needs to be performed for 3 μsec.

Here, the second term on the left side of the above equation is
Since the second reference oscillator 9 for measurement is self-running without synchronizing with the received signal, the second reference oscillator 9 represents a value obtained by incorporating the phase error at the maximum value.

Further, in the self-employed system, if the paging cycle is set to, for example, 6.1 seconds in order to reduce the current consumption during standby, the following calculation is performed.

(6.1 s−625 μs) * 100 ppm + (1 / 31.25 kHz) = 625 μs As described above, in the worst case, a reception operation is performed as a paging signal addressed to the own terminal by mistake in an adjacent slot.
There is a high possibility that the original paging signal addressed to the terminal itself will not be received.

Further, in this case, the average receiving operation period is 1250 μsec, which is twice the normal period.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a mobile communication terminal capable of improving paging signal reception performance while reducing power consumption during standby. It is to be.

[0020]

In the mobile communication terminal according to the present invention, the detection period of the unique word is set narrow by accurately setting the detection value of the unique word. For this reason, it becomes possible to improve the reception performance of the paging signal at the time of standby and to reduce the power consumption.

Specifically, in the first aspect of the present invention, the first
Based on the output signal of the standby position counter, the first
The power of the oscillation means is turned on.

Further, in the second invention, the time base counter counts predetermined bit positions and symbol positions in the slot.

In the third aspect of the present invention, the unique word detecting means detects a unique word in the received signal.

In the fourth aspect of the present invention, the second waiting position counter inputs a received symbol clock signal or a received bit clock signal.

In the fifth aspect of the present invention, a microprocessor is further provided, and the microprocessor sets a count value in the first and second waiting position counters.

In the sixth aspect of the present invention, the aperture setting means sets a period for detecting a unique word based on an output signal of the time base counter.
Further, the resynchronization means resynchronizes the time base counter when the aperture control means detects a unique word.

In the seventh aspect of the present invention, a deviation between the timing of detecting the unique word and the timing of detecting the actually received unique word is detected by the deviation detecting means.

In the eighth invention, the value of the output signal of the time base counter at the time when the unique word is detected is stored in the unique word detection position register.

In the ninth aspect of the present invention, a value smaller than the amount of deviation at the timing when a unique word is detected is added to the set value at the time of the immediately preceding slot reception. Then, the added value is set in the first and second standby position counters.

In the tenth aspect of the present invention, the shift amount is stored in the storage means over a plurality of slots. Then, a set value is set in the first and second standby position counters based on the plurality of average values of the plurality of shift amounts.

According to the eleventh aspect of the present invention, the length of the unique word detection period in the next slot is set based on the amount of shift of the unique word.

[0032]

[Embodiment 1 ] As shown in FIG. 1, the antenna 1 has an R for sharing the antenna 1 for transmission and reception.
The F switch 21 is connected. This RF switch 2
1 is connected to a transmission RF amplifier 20 and a reception RF amplifier 22. In the transmission RF amplifier 20,
An up-converter 18 for converting the carrier frequency to a predetermined RF frequency is connected, while a receiving RF amplifier 22 is connected to a down-converter 23 for lowering the RF signal to a frequency capable of demodulating the RF signal.

The up-converter 18 has π /
A modulator 17 based on the 4-shift QPSK system is connected, while the down converter 23 has a π / 4 shift Q
A demodulator 24 based on the PKS system is connected. The modulator 17 is connected to a channel encoder 16 based on the TDMA / TDD system.
4 is connected to a channel decoder 25 based on the TDMA / TDD system. Further, a timing control section 26 for reproducing a slot timing signal based on the received signal is provided. The other parts have the same configuration as the conventional mobile communication terminal shown in FIG.

FIG. 2 is a diagram showing a detailed internal configuration of the channel decoder 25 and the timing control unit 26 shown in FIG. In FIG. 2, a unique word detector 25a detects a unique word for detecting a slot position based on demodulated received data (D) output from the demodulator 24. Descramble 25b
Returns the scrambled data. Further, the cyclic remainder code (CRC) calculator 25c detects a bit error. Further, the reception buffer 25d sends out the received signal to the interface unit 3 or the system control unit 6.

The time base counter 26a includes the demodulator 2
4, the bit position in the slot is counted based on the received clock (c). The slot counter 26b has a TD
The slot positions multiplexed by MA / TDD are counted.
Further, the frame counter 26c counts the number of frames, and the phase detector 26d detects the phase of the clock (b) of the second reference oscillator 9 at the end of the slot reception.
The first waiting position counter 26e counts a position for receiving the next paging signal. The second standby position counter 26f has basically the same operation as the first standby position counter 26e, but the clock signal for performing the counting is different.
The aperture control unit 26g controls a section in which a unique word is detected. The timing oscillator 26h generates various timing signals in the apparatus based on signals from the time base counter 26a, the slot counter 26b, the frame counter 26c, and the like.

FIG. 3 is a diagram showing the internal configuration of the unique word detector 25a. In FIG. 3, the shift register 25a1 stores the received data (d) in 32 bits. The 32-bit comparator 25a2
The unique word pattern is detected based on the output signal of the shift register 25a1. Adder 25a3
Is an adder for counting the number of mismatched bits in the output signal of the 32-bit comparator 25a2. While N
The OR gate 25a4 detects whether the output of the adder 25a3 is 1 or less. Further, an AND gate 25
a5 is a unique word detection signal (h) indicating that a unique word has been detected within the detection period based on the output signal of the NOR gate 25a4 and the unique word detection aperture signal (g) output from the aperture control unit 26g. ).

FIG. 4 shows an internal configuration diagram of the phase detector 26d. In FIG. 4, the rising detector 26d1
Detects the rising edge of the low-speed clock (b), the phase detection counter 26d2 is reset by the output signal of the rising edge detector 26d1, and counts the received clock (c). Further, the phase detection register 26d3 stores the output signal of the phase detection counter 26d2 at the timing indicated by the carry output (output at the slot reception completion position) k of the time base counter 26a. Supply output signal.

FIG. 5 shows an aperture control unit 26g.
Is shown in FIG. In FIG. 5, an aperture width register 26g1 stores an aperture width set by the system control unit 6. Also, a subtractor 26g2
Subtracts the value set in the aperture width register 26g1 from the unique word detection timing of 100 (bit). The adder 26g2 also outputs 10
The value set in the aperture width register 26g1 is added to 0 (bit). Further, the first comparator 26g4 detects coincidence between the output signal (j) of the time base counter 26a and the output signal of the subtracter 26g2. The second comparator 26g5 is similarly provided with an adder 26g5.
3 and the output (j) of the time base counter 26a. The flip-flop 26g7 outputs the output signal of the first comparator 26g4 to s.
The signal is input to the et terminal, the output signal of the second comparator 26g5 is input to the reset terminal, and a unique word detection aperture signal indicating a unique word detection period is output.

Hereinafter, the operation of this embodiment will be described.
First, the PHS frame configuration and power supply control will be described.

FIG. 6 is an explanatory diagram for explaining the control of the air signal and the power supply during the simultaneous transmission and reception operation. PH
S is 4-multiplex TDMA / TDD, and in normal communication (for transmitting and receiving a voice signal), communication is performed using one slot for each of uplink and downlink within a 5 ms frame as shown in FIG. Therefore, in FIG. 1, the channel encoder 16, the modulator 17, the up-converter 1
8, the transmission RF amplifier 20 is a part corresponding to the transmission slot, and the reception RF amplifier 22, the down converter 2
3, a demodulator 24 and a channel decoder 25 are parts corresponding to reception slots. And the RF switch 21
The PLL 19 is a portion corresponding to both slots for transmission and reception, and is supplied with power. However, PLL19
For, it takes a certain time from when the power is supplied to when the reference signal for channel selection is stably output, so that the power is applied at a time sufficiently earlier than the start of the transmission and reception slots. . Also, power is always supplied continuously to the timing recovery unit (reproducing the 384 kHz reception clock) in the demodulation unit.

In addition, the interface unit 3 continuously processes the audio signal, and the first reference oscillator 8 supplies the basic clock, so that the power is continuously supplied.

Next, the operation in the so-called standby mode will be described.

FIG. 7 is an explanatory diagram showing a slot configuration of a control signal in the PHS. In FIG. 7, the numeral at the bottom of the symbol indicates the number of bits.
The bit length is 1/384 kbit (s). As shown here, the length of the unique word for retiming the slot is 32 bits.

FIG. 8 is an explanatory diagram showing details of the operation of each unit at the time of standby.

At the time of receiving a paging slot for its own terminal, the RF switch 2 is turned on in the same manner as shown in FIG.
1. Power is applied to the reception RF amplifier 22, down converter 23, demodulator 24, channel decoder 25, PLL 19, and first reference oscillator 8. As described above, power is constantly applied to the system control unit 6, the second reference oscillator 9, and the timing control unit 26.

In the phase detector 26d shown in FIG. 4, the phase detection counter 26d2 resets each time the low-speed clock (b) from the second reference oscillator 9 rises.
Then, since the reception clock (c) is counted again, when the slot reception is completed, the count value of the phase detection counter 26d2 is stored in the phase detection register 26d3 by the carrier output (k) of the time base counter 26a.

The carrier output (h) is an interrupt signal of the system control unit (microcomputer) 6,
The system control unit 6 performs processing of the reception slot by decoding the broadcast information. If a call for this terminal is instructed in the broadcast information, this terminal shifts to the communication mode with the base station.

In the broadcast information, when there is no call to the terminal (and there is no operation request of the operator such as key operation), the standby operation is started again.

For this reason, as shown in FIG. 9, the system control section 6 reads out the data of the phase detection register 26d3, sets this as noff, and obtains the following M and N.

M = ｛(1.2 s−625 μs−31 μs * Mde
(lay-2.6 μs * noff) / 31 μs} truncation N = [{1.2 s-625 μs-2.6 μs * noff-31 μs
* (M + Mdelay)｝ / 31 μs] Here, Mdeley applies the power supply of the first reference oscillator 8 to determine the time until the clock (a) is stabilized and the time until the PLL 19 is stabilized. This is indicated by the number of clocks of the second reference oscillator 9 and is a fixed numerical value that can be set in advance by the device.

The system controller 6 sets the MN in the first and second standby counters 26e and 26f, respectively, and shuts off the power to the first reference oscillator 8.

The first standby position counter 26e of the timing control unit 26 counts the measurement clock (b) from the time when the slot reception is completed, and when the count value reaches the above M, the system control unit 6 Make an interrupt. In response to this interrupt, the system controller 6 turns on the power of the first reference oscillator 8 again. As a result, the oscillation clock (a) gradually rises, and a normal oscillation clock (a) is output after a predetermined period has elapsed. Thereafter, when the count value of the first standby position counter 26e becomes (M + Mdeley), the second standby position counter 26f starts the counting operation. During this time, the system controller 6 turns on the power to the RF switch 21, the receiving RF amplifier 22, the down converter 23, the demodulator 24, and the channel decoder 25 in accordance with a predetermined sequence.

Then, the second waiting position counter 26
When the count value of f becomes N, the second standby position counter 26f outputs the activation instruction signal m to the time base counter 26a, and starts counting bits in the slot.

On the other hand, in the unique word detector 25a, the received data is sequentially input, and the unique word pattern: 0101 0000 11 in the data sequence.
101111 0010 1001 1001 001
Check if 1 is present.

If the unique word is detected within a predetermined unique word detection period due to an error within one bit, a unique word detection signal (h) is output through the AND gate 25a5. The unique word detection signal (h) is reset to 100 (the last bit position of the unique word) by the time base counter 26a as the time base counter setting signal (i) via the aperture control unit 26g. Timing and synchronization will be achieved. By such an operation, it is possible to accurately reproduce the standby timing of the paging signal, and it is possible to reduce the aperture width. Therefore, improvement in reception performance is expected.

When a unique word cannot be detected within a preset detection period, resynchronization of the time base counter 26a is not performed. However, at the slot reception completion timing, the first and second standby position counters 26e and 26f are set as in the case where the slot is normally received.

Embodiment 2 FIG . In the first embodiment, the first
Although the power supply of the reference oscillation circuit 8 is controlled by the system control unit 6, it is also preferable that the timing control unit 26 directly controls the power supply without passing through the system control unit 6.

Embodiment 3 FIG . In the first and second embodiments, the first and second waiting position counters 26e, 26e
Although the processing is performed by 6f, it is also preferable that the timing control section 26 sets the processing.

Embodiment 4 FIG . Further, by providing the channel decoder 25 with the function of detecting the broadcast information for the terminal itself in the paging signal, it is possible to prevent the system control unit 6 from operating because the terminal is not called during standby. . By performing such an operation, it is possible to further reduce power consumption during standby.

Embodiment 5 FIG . In the aperture control unit 26g shown in FIG. 5, the unique word detection register 26g stores the output signal of the time base counter 26a at the time of the unique word detection as shown by the broken line.
In the case where the oscillation frequency of the second reference oscillator 9 is deviated, the first and second standby position counters 26e and 26f are set to correct the deviation, thereby providing a unique word detection period. Can be narrowed.

FIG. 10 is a flowchart showing the operation of the system control unit 6 when such a configuration is employed.

A flow chart shown in FIG.
The difference from the flowchart shown in FIG. 9 is that the unique word detection position register 26g8 is read (nde
tect), the difference from the original value 100 is expressed as an error nerror, and a value obtained by multiplying the error nerror by α (<1) is corrected to the standby time. Where 1
The reason why the smaller α is multiplied by the error is to prevent excessive response even when the received signal fluctuates due to paging or the like.

In the fifth embodiment, M and N are obtained as follows.

M = [｛1.2 s−625 μs−31 μs * Mde
lay + 2.6 μs * (nerror−noff)｝ / 31 μs] N = [｛1.2 s−625 μs−2.6 μs * (nerror−n
off) -31μs * (M + Mdelay )} / 31μs] truncated Example 6. In the first to fifth embodiments, the unique word detection error is performed for each paging signal reception slot for the terminal. However, in order to avoid excessive response, it is also preferable to use the average value of the shift amount for a plurality of times. It is. FIG.
1 shows a memory map of the system control unit 6 in the sixth embodiment. As shown in FIG.
The configuration is such that the unique word detection positions for four times can be stored, and at the time when the four detection positions are read, the system control unit 6 calculates 100 times from the average value of the four times.
The value obtained by subtracting is used as the correction value.

As described above, in the sixth embodiment, the correction is performed once every four times.

Embodiment 7 FIG . FIG. 12 shows an example of performing the sequential correction process. When the error value for four times has been calculated, the correction value nadj is calculated, and at the same time, the correction value nadj is calculated from the error value stored in the system control unit 6. The value obtained by subtracting the value nadj is stored again.

Embodiment 8 FIG . In the above embodiment, the numerical value set in the aperture width register 26g1 of the aperture control unit 26g does not change, but it is also preferable to control the aperture width in accordance with the shift amount of the unique word detection position. It is. For example, when the shift amount of the unique word is less than 1, the aperture width is gradually narrowed (the minimum value is, for example, about 4), and when the unique word is not detected or the shift amount exceeds 4, the aperture width is gradually widened. (The maximum value is open.)

[0068]

The mobile communication terminal according to the present invention uses the second oscillating means having a frequency lower than the symbol rate of the received signal and the output signal of the second oscillating means at a predetermined timing of the received signal. Phase detection means for detecting the phase of a certain clock, a first standby position counter which receives a clock output from the second oscillation means as a clock input, and a second reception clock which receives a received symbol clock or a received bit clock as a clock input. With the standby position of the standby position, it is possible to accurately set the reception timing during standby while keeping the current consumption during standby low.
This has the effect of improving the reception performance.

That is, according to the first aspect of the present invention, since the power of the first oscillating means is turned on based on the output signal of the first standby position counter, the reception performance of the unique word can be reduced while the current consumption is kept low. Can be improved.

Further, according to the second aspect of the present invention, since a time base counter for counting a predetermined bit position in a slot is provided, a mobile communication terminal with improved reception performance can be obtained.

According to the third aspect of the present invention, since a unique word detecting means for detecting a predetermined unique word in the received signal is included, a mobile communication terminal with improved reception performance can be obtained.

According to the fourth aspect of the present invention, a mobile communication terminal having improved reception performance can be obtained because the second standby position counter for inputting the received symbol clock or the received bit clock is included.

According to the fifth aspect of the present invention, since a microprocessor and an interrupt means for the microprocessor are provided, an appropriate count value is set in the first and second standby position counters. Thus, a mobile communication terminal with improved performance can be obtained.

According to the sixth aspect of the present invention, the period in which the unique word is detected is set based on the output signal of the time base counter, so that a mobile communication terminal with improved performance can be provided. .

According to the seventh aspect of the present invention, the difference between the unique word detection timing calculated based on the values set in the first and second standby counters and the actually received unique word detection timing is calculated. Since the detection is performed, a mobile communication terminal with improved performance can be provided.

According to the eighth aspect of the present invention, the deviation of the unique word detection timing can be detected with higher accuracy.
A mobile communication terminal with improved performance can be provided.

According to the ninth aspect of the present invention, since a value smaller than the deviation amount of the unique word detection timing is set in the standby position counter, the deviation of the unique word detection timing is effectively corrected, and the performance is further improved. A mobile communication terminal is obtained.

According to the tenth aspect of the present invention, the value of the waiting position counter is updated based on the average value of the deviation of the detection timing of the unique word, so that a mobile communication terminal with little fluctuation in performance can be obtained.

According to the eleventh aspect of the present invention, the length of the unique word detection period is changed based on the amount of shift of the unique word detection timing. It is possible to obtain a mobile communication terminal with improved performance.

[Brief description of the drawings]

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

FIG. 2 is an internal block configuration diagram of a channel decoder and a timing control unit.

FIG. 3 is an internal block diagram of a unique word detector.

FIG. 4 is an internal block diagram of a phase detector.

FIG. 5 is an internal block configuration diagram of an aperture control unit.

FIG. 6 is a time chart for explaining a power supply control method during a transmission / reception operation.

FIG. 7 is an explanatory diagram of a slot configuration of a control signal in the PHS.

FIG. 8 is a time chart illustrating the operation of each unit when the mobile communication terminal according to the present embodiment is on standby.

FIG. 9 is a flowchart illustrating a method of setting a standby position counter in the present embodiment.

FIG. 10 is a flowchart illustrating a method of setting a standby position counter according to the fifth embodiment.

FIG. 11 is an explanatory diagram illustrating a part of a memory map of a system control unit according to a sixth embodiment.

FIG. 12 is an explanatory diagram illustrating a part of a memory map of a system control unit according to a seventh embodiment.

FIG. 13 is a block diagram of a conventional mobile communication terminal.

[Explanation of symbols]

3 Interface unit, 4 transmitter, 5 receiver, 6
System controller, 7 secondary battery, 8 first reference oscillator, 9 second reference oscillator, 10 high-speed counter, 11
Low-speed counter, 12, 13 switch, 14, 15
Switch, 16 channel encoder, 17 modulator, 18
Up converter, 19 PLL, 20 transmit RF
Amplifier, 21 RF switch, 22 reception RF amplifier,
23 down converter, 24 demodulator, 25 channel decoder, 26 timing controller, 25a unique word detection positioner, 26a time base counter,
26d phase detector, 26e first standby position counter, 26f second standby position counter, 26g
Aperture control unit, 26g8 unique word detection position register.

Continuation of the front page (58) Fields investigated (Int.Cl. ⁷ , DB name) H04B 1/40 H04B 7/26 H04Q 7/38 H04L 7/08

Claims (11)

(57) [Claims] 1. A mobile communication terminal used in a wireless communication system adopting a time division multiplexing method, comprising: a first oscillating means; and a power supply for said first oscillating means, which temporarily waits for a signal from a base station. Power cutoff means for cutting off, second oscillating means for oscillating a signal having a frequency lower than the symbol rate of the received signal, phase of the clock signal of the output signal of the second oscillating means at a predetermined timing in the received signal A first standby position counter for inputting a clock signal of an output signal of the second oscillation unit as a clock signal; and an output signal of the phase detection unit and an output signal of the first standby position counter. And a power-on means for turning on the power of the first oscillating means. 2. The mobile communication terminal according to claim 1, further comprising a time base counter for counting a predetermined bit position or a symbol position in a slot, wherein said phase detecting means is based on an output signal of said time base counter. Detecting a phase of a clock signal of an output signal of the second oscillating means at a predetermined timing in the received signal. 3. The mobile communication terminal according to claim 2, further comprising a unique word detecting means for detecting a predetermined unique word in the received signal, wherein the time base counter outputs the unique signal to the output signal of the unique word detecting means. A mobile communication terminal which counts a predetermined bit position or symbol position in a slot based on the mobile communication terminal. 4. The mobile communication terminal according to claim 2, further comprising a second waiting position counter for inputting a received symbol clock signal or a received bit clock signal as a clock signal, wherein the time base counter is configured to receive the second waiting position. A mobile communication terminal for counting a predetermined bit position or symbol position in a slot based on an output signal of a counter. 5. The mobile communication terminal according to claim 1, wherein a period during which a unique word is detected when a received signal is received is set based on an output signal of the time base counter. Aperture control means;
When a unique word is detected by the unique word detection means, the aperture control means re-synchronizes the time base counter,
A mobile communication terminal comprising: 6. The mobile communication terminal according to claim 1, wherein a timing of detecting a unique word calculated based on a value set in the first and second standby position counters, A deviation detecting means for detecting a deviation in the timing of detection of the actually received unique word, and correcting values set in the first and second standby position counters based on an output signal of the deviation detecting means. A mobile communication terminal characterized by the above-mentioned. 7. The mobile communication terminal according to claim 1, wherein a microprocessor for controlling exchange of a predetermined signal based on a predetermined communication control protocol and receiving data of a predetermined slot are provided. After completion, interrupt means for interrupting the microprocessor, wherein the microprocessor receives the output signal of the phase detection means, and receives the next standby slot based on the value of the input signal. A mobile communication terminal, wherein a count value is set in the first and second standby position counters. 8. The mobile communication terminal according to claim 7, further comprising: a unique word detection position register for storing a value of an output signal of a time base counter at the time of detection of the unique word, wherein said microprocessor stores said unique word. A mobile communication terminal for reading a value of a stored number signal of a detection position register and detecting a shift in unique word detection timing. 9. The mobile communication terminal according to claim 1, wherein a value smaller than a shift amount of the unique word detection timing is added to a set value at the time of receiving the immediately preceding slot, and the added value is added. And a setting value updating means for setting the first and second standby position counters, and the added value is used in the next slot. 10. The mobile communication terminal according to claim 1, further comprising: storage means for storing a unique word detection position or the shift amount over a plurality of slots, wherein the storage means stores the unique word detection position or the shift amount. A mobile communication terminal comprising: a setting unit configured to set a set value in the first and second standby position counters based on the detected unique word detection position or a value obtained by averaging the deviation amount. 11. The mobile communication terminal according to claim 1, further comprising: a period length setting unit that sets a length of a detection period of a next unique word based on a shift amount of the unique word. A mobile communication terminal comprising: