JP2002368671A - Wireless communication terminal and wireless communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the frequency of measurement of reception strength radio waves sent from a base station to a required minimum value accompanying the moving state of a terminal user, so as to reduce the power consumption. SOLUTION: When deciding that its own station has not been switched for a prescribed period and reception strength of its own station channel is a prescribed value or higher, a deciding section 23 outputs it to a measurement stop instruction section 24. Thus, the measurement stop instruction section 24 outputs a signal aiming the stop of reception strength measurement of a peripheral channel to a reception strength measurement section 12. When deciding that the reception strength of its own station channel is less than a prescribed value for a period that no reception strength measurement of the peripheral channels is made, the deciding section 23 outputs it to a measurement restart instruction section 25. Thus, the measurement restart instruction section 25 outputs a signal to the effect of making restart of the reception strength measurement of the peripheral channels, to the reception strength measurement section 12.

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 and a radio communication method for judging whether to switch the frequency of a carrier wave used for communication based on the reception strength of radio waves having a plurality of frequencies transmitted from a base station. About.

[0002]

2. Description of the Related Art For example, PDC (Personal Digital Cel)
In a lular) system, as shown in FIG. 5, base stations are installed at a certain interval, and each base station transmits a radio wave having a different frequency with an antenna having directivity. An area covered by radio waves of the same frequency transmitted by one base station is generally called a zone. Since the frequency of the radio wave that can be received differs for each zone, when moving from the zone to which the current zone belongs to another zone, the frequency of the radio wave for communication must be switched. For example, with reference to FIG. 5, when the user 30 holding the mobile phone belongs to the zone 201, the frequency of the radio wave used when performing communication is the frequency assigned to the zone 201. However, when the user 30 moves to the zone 202, the frequency of the radio wave for performing communication with the movement must be switched to the frequency of 202. For this reason, the mobile terminal also measures the reception intensity of radio waves in zones other than the zone to which the mobile terminal belongs, and determines whether to switch the frequency of radio waves used when performing communication based on the measurement results. .
Such a determination is made every predetermined period even in a standby state in order to reliably perform outgoing and incoming calls.

[0003]

By the way, the frequency switching of the carrier wave described above is performed, for example, when the user of the terminal moves in a wide area such that the terminal user moves over a plurality of zones, the reception radio wave is sequentially adjusted in accordance with the movement. This is effective because it is necessary to switch the frequency of the terminal user. On the other hand, when the moving range of the terminal user is narrow, for example, when moving within one zone,
When the user stays in a certain place without moving, the frequency of the radio wave is not required to be changed, so that it is not necessary to measure the reception intensity of the radio wave transmitted from the base station. However, in the conventional wireless communication terminal, even when the frequency switching as described above is not necessary, the reception intensity of the radio wave is always measured every predetermined period, so that the power consumption is large and the power is efficiently used. There was a problem that can not be.

[0004] The present invention has been made in view of such circumstances, and the power consumption can be reduced by minimizing the frequency of measuring the reception intensity of the radio wave transmitted from the base station in accordance with the moving situation of the terminal user. It is an object of the present invention to provide a wireless communication terminal and a wireless communication method that reduce the cost.

[0005]

In order to achieve the above object, the present invention measures reception intensities of radio waves of a plurality of different frequencies transmitted from a base station, and uses the measured intensity upon communication based on the measurement results. A wireless communication terminal that determines whether to switch the frequency of a radio wave, a first determination unit that determines whether a frequency of a first radio wave used in the communication has been switched during a predetermined period set in advance, and A second determining means for determining whether or not the reception intensity of the radio wave is equal to or greater than a first predetermined value set in advance; and the frequency of the first radio wave is not switched during the predetermined period, and A measurement stop instructing unit for stopping the measurement of the reception intensity of the radio wave of another frequency when the reception intensity of the first radio wave is determined to be equal to or higher than the first predetermined value; Stop And a measurement restart instruction means for restarting the reception intensity measurement of the radio wave of the other frequency when the reception intensity of the first radio wave becomes less than a first predetermined value in a state where the first radio wave is received. To provide a wireless communication terminal.

According to the above configuration, according to the wireless communication terminal of the present invention, the mobile station does not make a transition beyond the zone during the predetermined period, and receives the radio wave (hereinafter, own channel) of the zone to which the terminal belongs. If the intensity is equal to or greater than a first predetermined value, it is determined that there is a low possibility that the zone to which the current zone belongs will shift to another zone, and the radio waves of other zones existing in the vicinity (hereinafter, referred to as “the zone”). The measurement of the reception intensity of the peripheral channel is stopped. On the other hand, the measurement of the reception intensity of the own station channel is always performed, and when the reception intensity decreases, it is determined that there is a high possibility of shifting to another zone, and the measurement of the reception intensity of the peripheral channel is restarted.
In this way, only when there is a high possibility of moving beyond the zone, by measuring the reception strength of the peripheral channel,
Minimize the reception intensity measurement of peripheral channels. As a result, power consumption can be significantly reduced, and power can be used efficiently.

The present invention also provides a method realized by the wireless communication terminal, a computer-readable recording medium storing a program for realizing a process performed by the wireless communication terminal using a computer, and a program. I do.

The wireless communication terminal according to the present invention includes a so-called CDMA (Code Division Multiple Access) system and a PDC (Pe
A portable terminal called a PDA (Personal Digital Assistants) is also included in addition to a mobile phone of the rsonal Digital Cellular System (Personal Digital Assistants) type and a PHS (Personal Handyphone System) (registered trademark). Here, in the case of a PDA, a calling (incoming call, communication) process which will be described later, which is a feature of the present invention, is performed by a PDA, even if the communication means is externally connected in addition to a built-in communication means.
What is performed by the main body is included in the present invention.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, a mobile phone will be described as an example of the wireless communication terminal of the present invention.

FIG. 1 is a diagram showing a configuration of a mobile phone according to an embodiment of the present invention. In FIG.
Is an antenna for wireless communication. Numeral 11 denotes transmission data carried on a carrier wave and transmitted from the antenna 14, and
A wireless processing unit that demodulates and decodes an incoming signal received via the antenna 14 and outputs the received data to the control unit 13 or the reception intensity measuring unit 12 based on the attribute of the received data. Reference numeral 13 denotes a control unit for controlling an internal circuit of the terminal, which will be described later in detail. Reference numeral 14 denotes a timer in which a predetermined time is set in advance as a count value, which operates based on a start / stop / reset instruction input from the control unit 13, and that when the count value becomes "0". Is output to the control unit 13. Reference numeral 15 denotes a display unit including a liquid crystal display panel or the like, and displays display data supplied from the control unit 13. Reference numeral 16 denotes an operation unit provided with a numeric keypad for inputting a telephone number, various function keys, and the like. Reference numeral 17 denotes a speaker, and reference numeral 18 denotes a microphone (microphone).

The control unit 13 has a CPU (Central Proc).
essing Unit), ROM (Read Only Memory) storing various programs executed by the CPU, and CP
A RAM (Random A) that stores data generated in the process performed by U and data necessary for the process.
ccess Memory). The CPU performs various processes, but here, only the processes related to the gist of the present invention are extracted, and each component in the control unit in FIG. 1 is represented as a functional configuration block. The processing performed by these units will be described later.

Next, the operation of the portable telephone according to the present embodiment having the above configuration will be described with reference to FIGS. Hereinafter, in a zone configuration as shown in FIG. 5, it is assumed that the user 30 holding the mobile phone belongs to the zone 201. In addition, as shown in FIG.
The communication area is composed of a number of zones 200, 201, 202,. These zones are regions where radio waves having different directivities and transmitted by base stations that manage the zones reach different areas.

Now, it is assumed that the user 30 holding the mobile phone turns on the power of the mobile phone in the zone 201 of FIG. By this operation, the radio wave of the zone to which the mobile phone belongs (the radio wave of the own station channel) and the radio wave of the surrounding zone (peripheral area) transmitted from the base station 101 which manages the zone 201 to which the mobile phone belongs. Channel radio waves). Specifically, the radio wave of the frequency assigned to the zone to which the terminal belongs (the radio wave of the own station channel), the zones 200 and 202 existing around the radio wave.
Radio wave of frequency assigned to (radio wave of surrounding channel)
Via the antenna 10 and the wireless processing unit 11
3 and the received signal strength measurement unit 12.

When the control unit 13 acquires these radio waves, it resets the count value of the timer 14 (step SP11 in FIG. 2) and then starts (step S11).
P12) Perform processing. By such processing, the timer 14 starts counting. On the other hand, the reception intensity measurement unit 12 measures the reception intensity of the acquired radio wave and outputs the measurement result to the control unit 13. The reception intensity of each radio wave measured by the reception intensity measurement unit 12 is calculated by the reception intensity calculation processing unit 2 in the control unit 13.
1 is input. The reception intensity calculation processing unit 21 stores the reception intensity of these input radio waves until the reception intensity data acquired from the reception intensity measurement unit 12 reaches a predetermined sampling number. Hereinafter, the reception intensity of the radio wave of the frequency currently assigned to the zone to which the user belongs is defined as the reception intensity of the own channel, the reception of the radio wave of a frequency different from the frequency of the own channel allocated to the peripheral zones 200, 202,. The strength is called the reception strength of the surrounding channel.

When the received power data measured by the received power measuring section 12 reaches a predetermined number, the received power calculation processing section 21 averages the stored received power data based on a predetermined calculation formula. This calculation formula may use a method defined in a communication method adopted by the mobile phone, or may use another calculation formula.

When calculating the average value of the accumulated reception intensity data based on a predetermined formula, the reception intensity calculation processing unit 21 outputs the calculation results to the local station switching determination processing unit 22. The own-station switching determination processing unit 22 determines whether switching of the frequency of a radio wave used at the time of communication is necessary based on the input average reception intensity. Hereinafter, the self-station switching determination processing will be described with reference to FIG.

First, it is determined whether or not the average reception intensity L0 of the own station channel is lower than a preset standby deterioration level Lth (step SP31). As a result, when the average reception strength L0 of the own station channel is not lower than the standby deterioration level Lth (“N” in step SP31).
O "), followed by the maximum value MAX of the average received power of the surrounding channels
It is determined whether (Li) is greater than a value obtained by adding the average reception intensity L0 of the own station channel and the zone shift level difference ΔL (step SP32). Here, the zone shift level difference ΔL is calculated from the standby permission level Ltn to the standby deterioration level.
A value equal to or greater than the value obtained by subtracting Lth, ΔL ≧ Ltn−Lth.

If the maximum value MAX (Li) of the average reception intensity of the peripheral channel is larger than the value obtained by adding the average reception intensity L0 of the local station channel and the zone shift level difference ΔL (in step SP32, “ YES ”), determines that the user of the mobile phone has moved across the zone, and sets the maximum average reception strength to the frequency of the radio wave used for communication.
The frequency is switched to the frequency of the radio wave indicating MAX (Li) (step SP33). That is, when the frequency of the radio wave indicating the maximum average reception intensity in the zones shown in FIG. 5 is the frequency corresponding to the zone 200, the user 30 holding the mobile phone moves from the zone 201 to the zone 201. It is determined that the radio wave has moved to 200 and the frequency of the radio wave for communication is changed to the zone 201
From the frequency assigned to the zone 200 to the frequency assigned to the zone 200.

On the other hand, if it is determined in step SP32 that the maximum value MAX (Li) of the average reception intensity of the peripheral channel is equal to or less than the value obtained by adding the reception intensity L0 of the local station channel and the zone shift level difference ΔL (step SP32). "NO" in SP32), it is determined that there is no switching of the own station (step SP32).
34) The process ends.

If it is determined in step SP31 that the average reception intensity L0 of the own channel is lower than the standby deterioration level Lth ("YE" in step SP31).
S "), it is determined whether or not the maximum value MAX (Li) of the average reception strength of the peripheral channels is higher than the standby permission level Ltn (step SP35). As a result, when the maximum value MAX (Li) of the average reception strength of the peripheral channels is higher than the standby permission level Ltn (“YE in step SP35”).
S "), that is, when there is an average reception intensity of a peripheral channel indicating a value higher than the average reception intensity of the own station channel, it is determined that the user of the mobile phone has moved across the zone, The frequency of the radio wave for communication is switched from the local station to the peripheral channel indicating the maximum average reception intensity MAX (Li) (step SP33), and then the process is terminated.

If the maximum value MAX (Li) of the average reception intensities of the peripheral channels is less than the standby permission level Ltn in step SP35 ("NO" in step SP35), the reception state of the own station channel is also changed. Although it has decreased, it is determined that the level has not yet reached the level for switching to the peripheral channel, and the process ends without switching the own station channel. When the base station switching processing is completed in this way, the own station switching determination processing section 22 outputs a processing result to the determination section 23.

The determination unit 23 first determines whether or not a zone transfer has been performed, that is, whether or not the own station channel has been switched, based on the processing result obtained from the own station switching determination processing unit 22. (Step SP16 in FIG. 2). As a result,
If the channel of the own station has been switched (“Yes” in step SP16), it is determined that the movement width of the terminal is large, and the process returns to step SP11 in FIG. 2 and performs the processing from step SP11 described above. Repeat. on the other hand,
If it is determined that the zone transfer has not been performed (“No” in step SP16), then it is determined whether or not the timer 14 has expired (step SP17). As a result, if the timer 14 has not expired ("No" in step SP17), that is, if the predetermined period has not elapsed, the process returns to step SP13 to measure the reception intensities of the own station channel and the peripheral channels. Is performed continuously.

On the other hand, if the timer 14 has expired in step SP17, it is determined whether or not the average reception strength of the channel of the own station is larger than a predetermined value Lz (dB) (step S17). Step SP18). As a result,
If the average reception strength of the own station channel is equal to or less than the predetermined value Lz (“No” in step SP18), the process returns to step SP11 and repeats the above processing. on the other hand,
In step SP18, when the average reception strength of the own station channel is larger than Lz, it is determined that the condition for stopping the measurement of the reception strength of the peripheral channel is satisfied, and this is output to the measurement stop instruction unit 24. . As a result, the measurement stop instructing unit 24 determines that the user is unlikely to move beyond the zone, and instructs the measurement stop instructing unit 24 to stop measuring the reception intensity of the peripheral channel.

As a result, the reception intensity measurement unit 12 stops measuring the reception intensity of the peripheral channel (step SP1).
9). As a result, the reception intensity measurement unit 12 performs only the reception intensity measurement of the own station channel (step SP20).

Subsequently, the reception strength of the own station channel measured by the reception strength measuring unit 12 is output to the reception strength calculation processing unit 21 as needed. Then, when the number of data of the reception strength reaches the predetermined number, the reception strength calculation processing unit 21
An averaging process is performed on these reception intensity data (step SP21), and the calculation result, that is, the average reception intensity of the own station channel is output to the determination unit 23. Here, during the period in which the measurement of the reception intensity of the peripheral channel is stopped, the local station switching determination processing cannot be performed. The average reception strength of the channel is output.

Subsequently, the determination section 23 determines whether or not the average reception intensity of the channel of the own station is larger than a predetermined value Lz (step SP22). If it is determined that the average reception intensity of the own channel is larger than the predetermined value Lz (“Yes” in step SP22), the radio wave condition of the own channel is still good, and there is a possibility that the zone may be shifted. Therefore, it is determined that there is no need to restart the reception intensity measurement of the peripheral channel, and the process returns to step SP20, and the reception intensity measurement processing of only the own station channel is continuously performed. On the other hand, in step SP23, when the average reception intensity of the own station channel is equal to or less than the predetermined value Lz, the radio wave condition of the own station channel is not good and there is a possibility that the mobile station may shift to another zone. Judge, measurement restart instructing unit 25
To the local station that the average reception strength of the channel is equal to or less than a predetermined value Lz.

The measurement restart instructing unit 25 sends the
When a signal indicating that the reception intensity of the own channel has become equal to or less than the predetermined value is obtained, a signal indicating that the reception intensity measurement of the peripheral channel is to be restarted is output to the reception intensity measurement unit 12. As a result, the reception intensity measurement unit 12 restarts the reception intensity measurement of the peripheral channel.

Then, the reception strength measurement section 12 again measures the reception strength of the local station channel and the peripheral channels, and
By outputting the data of these reception intensities to the reception intensity calculation processing section 21, the processing from step SP11 described above is repeatedly performed.

As described above, according to the present invention, the channel of the own station is not switched during the predetermined period set in advance. The average reception strength of the channel of the own station is higher than the predetermined value set in advance. When the two conditions are satisfied, there is a low possibility that the user holding the terminal moves from the zone to which the user currently belongs, that is, it is necessary to perform a zone transfer process (switching from the own station channel to a peripheral channel). Therefore, the measurement of the reception strength of the peripheral channel is stopped. Thus, power consumption can be reduced by minimizing the measurement of the reception strength of the peripheral channel. Also,
When the above condition is not satisfied, that is, when there is a high possibility that the zone will be shifted, the zone shift processing can be performed promptly by restarting the measurement of the reception intensity of the peripheral channel.

In this embodiment, zones 201 to 200 managed by the same base station are used.
Although the description has been given of the movement to the zone, when the managed base station moves to a different zone, for example, when the base station moves from the zone 200 to the zone 301 in FIG.

The processing performed by the above-described reception intensity measurement unit 12, reception intensity calculation processing unit 21, self-station switching determination processing unit 22, determination unit 23, measurement stop instruction unit 24, and measurement restart instruction unit 25 is as follows. A program for realizing the processing is recorded on a computer-readable recording medium, and the program recorded on the recording medium is stored in a CPU in the control unit 13.
May be read and executed to execute various processes.

The "computer-readable recording medium" includes a portable medium such as a magneto-optical disk, a ROM, a flash memory, a ROM and a RAM built in the terminal.
And the like. Also, the above program
It may be for realizing a part of the functions described above. Furthermore, a program that can realize the above-described functions in combination with a program that has already been recorded, that is, a so-called difference file (difference program) may be used.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes a design and the like without departing from the gist of the present invention. It is.

[0034]

As described above, according to the radio communication terminal of the present invention, the radio wave covering the zone to which the terminal belongs, ie, the radio wave covering the zone to which the terminal belongs is not performed during the predetermined period, and the radio wave is not transmitted. If the reception intensity of the station channel is equal to or higher than the first predetermined value, it is determined that there is a low possibility that the zone to which the station belongs to another zone is shifted, and the reception intensity measurement of the peripheral channels is stopped. I do. On the other hand, the measurement of the reception intensity of the own station channel is always performed, and when the reception intensity decreases, it is determined that there is a high possibility of shifting to another zone, and the measurement of the reception intensity of the peripheral channel is restarted. As described above, only when there is a high possibility of moving beyond the zone, the reception intensity measurement of the peripheral channel is performed to minimize the reception intensity measurement of the peripheral channel. As a result, power consumption can be significantly reduced, and power can be used efficiently.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing an operation of the wireless communication terminal according to one embodiment of the present invention.

FIG. 3 is a flowchart showing an operation of the wireless communication terminal according to one embodiment of the present invention.

FIG. 4 is a flowchart illustrating the content of a local station channel switching determination process performed by a local station switching determination processing unit.

FIG. 5 is a diagram for explaining a zone configuration.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Antenna, 11 ... Wireless processing part, 12 ... Reception strength measuring part, 13 ... Control part, 14 ... Timer, 15 ... Display part, 1
Reference numeral 6: operation unit, 17: speaker, 18: microphone, 21: reception intensity calculation processing unit, 22: own station switching determination processing unit, 23:
Judgment unit, 24: Measurement stop instruction unit, 25: Measurement restart instruction unit

Claims (2)

[Claims] 1. A wireless communication terminal which measures reception intensity of radio waves of a plurality of different frequencies transmitted from a base station and determines switching of a frequency of a radio wave used in communication based on a result of the measurement. First determining means for determining whether or not the frequency of the first radio wave to be used has been switched during a predetermined period set in advance, and a first predetermined value in which the reception intensity of the first radio wave is set in advance A second determination unit for determining whether or not the frequency of the first radio wave is not changed during the predetermined period, and the reception intensity of the first radio wave is equal to or more than the first predetermined value. When it is determined that there is, the measurement stop instructing means for stopping the reception intensity measurement of the radio wave of another frequency, and the reception intensity of the first radio wave in a state where the measurement of the reception intensity of the other frequency is stopped. Is the first If it becomes less than the predetermined value, the radio communication terminal, characterized by comprising a measuring resumption instruction means for resuming the radio wave reception intensity measurement of the other frequency. 2. A wireless communication method for measuring the reception intensity of radio waves of a plurality of different frequencies transmitted from a base station and determining the switching of the frequency of the radio wave used for communication based on the measurement result. Determining whether the frequency of the first radio wave to be used has been switched during a predetermined period set in advance; and determining whether the reception intensity of the first radio wave is equal to or higher than a predetermined first predetermined value. Determining the frequency of the first radio wave is not switched during the predetermined period, and when it is determined that the reception intensity of the first radio wave is equal to or more than the first predetermined value, Stopping the reception intensity measurement of the radio wave of another frequency; and in the state where the reception intensity measurement of the other frequency is stopped, the reception intensity of the first radio wave is less than a first predetermined value. Radio communication method characterized by the case, comprising a step of resuming the radio wave reception intensity measurement of the other frequency.