JPH10294691A - Radio telephone system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of judgment result that the telephone set is outside the service area by detecting a bit error rate, comparing it with a prescribed threshold and judging that a device is out of the service area of a radio base station when the detected result exceeds the threshold. SOLUTION: A decoding part 3 decodes a speech signal SA from a reception signal obtained through an antenna 1 and a reception part 2, compares a bit string which is previously set with an actual bit string obtained from the speech signal SA, detects the bit error rate and outputs bit error rate data DB. An out-of-area judgment part 4 compares the actual bit error rate obtained from the bit error rate data DB with the threshold which is previously set. When the actual bit error rate does not exceed the threshold, the out-of-area judgment part 4 outputs no signal and an adder 6 outputs only the speech signal SA to a speaker 7. When the actual bit error rate exceeds the threshold, the out-of- area judgment part 4 outputs an out-of-area signal SK and an alarm signal generation part 5 generates an alarm signal SAL and outputs it to the adder 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio telephone device for performing radio communication via a radio line.

[0002]

2. Description of the Related Art In a mobile communication system using a radio telephone, there is a concept of a service area in which stable communication can be guaranteed. In other words, when the wireless telephone device during a call moves from the service area to the outside of the service area, a trouble such as disconnection of a call occurs. Therefore, whether the wireless telephone apparatus is within the service area depends on the user of the wireless telephone apparatus. It is also an important factor for telecommunications carriers.

[0003] Therefore, conventionally, there has been known a radio telephone apparatus that determines whether or not the radio telephone apparatus is within a service area based only on a received electric field level of a radio wave. For details of this type of wireless telephone device, refer to Japanese Patent Application Laid-Open No. 7-170571.

[0004]

In the above-described conventional radio telephone apparatus, the result of determining whether the mobile phone is out of the service area based on only the received electric field level of the radio wave, and whether the communication is not actually possible or not are determined. Did not always match, and thus the result of the determination was low in reliability. That is, even when the electric field level of the radio wave is high, it may be difficult to maintain communication when fading, multipath, etc. exist, but in the conventional wireless telephone device, it is actually out of the service area. Despite that
Since the received electric field level of the radio wave is high, it is erroneously determined that the terminal is within the service area. Conversely, even when the received electric field level of the radio wave is low, communication may be maintained without fading, multipath, etc. Regardless, the reception electric field level of the radio wave is low, so that it is erroneously determined that the radio wave is outside the service area. The present invention has been made under such a background, and an object of the present invention is to provide a wireless telephone device that can improve the reliability of a determination result as to whether or not the mobile phone is out of a service area.

[0005]

According to a first aspect of the present invention, there is provided a receiving means for receiving a radio wave including an audio signal transmitted from a radio base station, and decoding the audio signal from a reception result of the receiving means. Decoding means, a bit error rate detecting means for detecting a bit error rate of the audio signal decoded by the decoding means, and comparing a detection result of the bit error rate detecting means with a preset threshold value. A determination unit that determines that the apparatus is out of the service area of the wireless base station when the detection result exceeds the threshold value. Further, the invention according to claim 2 is the wireless telephone device according to claim 1, further comprising a notifying means for notifying that the device is out of the service area by the determining means. It is characterized by doing. The invention according to claim 3 is a receiving means for receiving a radio wave including an audio signal transmitted from a radio base station, a decoding means for decoding the audio signal from a reception result of the receiving means, A bit error rate detecting means for detecting a bit error rate of the audio signal decoded by the means, and a detection result of the bit error rate detecting means and a plurality of preset stepwise threshold values having a high threshold value. If there is a detection result that exceeds the threshold value in the order of comparison, the determination unit determines that the apparatus is out of the service area of the wireless base station in a stepwise manner. Further, the invention according to claim 4 is a receiving means for receiving a radio wave including an audio signal transmitted from a wireless base station, a decoding means for decoding the audio signal from a reception result of the receiving means, A bit error rate detecting means for detecting a bit error rate of the audio signal decoded by the means, and a low threshold value between a detection result of the bit error rate detecting means and a plurality of preset stepwise threshold values. If there is a detection result that exceeds the threshold value in the order of comparison, the determination unit determines that the apparatus is out of the service area of the wireless base station in a stepwise manner. According to a fifth aspect of the present invention, in the wireless telephone device according to the third or fourth aspect, different alarm sounds corresponding to the plurality of stepwise threshold values can be generated, and A step-by-step threshold value, comprising a notifying unit that generates the alarm sound corresponding to the threshold value used when the device is determined to be out of the service area by the determining unit. Feature

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a wireless telephone device according to one embodiment of the present invention. In this figure, 1 receives a radio wave R transmitted from a wireless base station (not shown). This radio wave R includes a sound signal SA as a digital signal. Reference numeral 2 denotes a receiving unit that receives the radio wave R via the antenna 1, and outputs a reception result as a reception signal SR.

Reference numeral 3 denotes a decoding unit for decoding the audio signal SA from the received signal SR. The decoding unit 3 detects a bit error rate by comparing a preset bit string with an actual bit string obtained from the audio signal SA, and outputs the detection result as bit error rate data DB. .

Reference numeral 4 denotes an out-of-service judging unit for judging whether or not the radio telephone device is out of the service area. The out-of-service judging unit 4 determines an actual bit error rate obtained from the bit error rate data DB and a preset threshold value. Are compared to make the above determination. That is, when the actual bit error rate exceeds the threshold, the out-of-service determining unit 4 determines that the wireless telephone device is out of the service range, and outputs the out-of-service signal Sk indicating the determination. On the other hand, if the actual bit error rate does not exceed the threshold, the out-of-service determining unit 4 determines that the wireless telephone device is not out of the service range, and does not output any signal.

An alarm signal generator 5 generates an alarm signal SAL corresponding to an alarm sound when the out-of-service signal Sk is input. Here, the alarm sound is for notifying the user that the wireless telephone device is out of the service area.

Reference numeral 6 denotes an adder for adding the audio signal SA and the alarm signal SAL. Reference numeral 7 denotes a speaker which generates a sound corresponding to the audio signal SA and an alarm sound corresponding to the alarm signal SAL.

Next, the operation of the wireless telephone device according to the above-described embodiment will be described. In FIG. 1, when a radio wave R is transmitted from a radio base station (not shown), the radio wave R
The signal is received by the receiving unit 2 via the antenna 1. Thereby, the receiving unit 2 outputs the reception result to the decoding unit 3 as a reception signal SR.

The decoding unit 3 converts the received signal SR into an audio signal SA.
And outputs it to the adder 6, while comparing the bit sequence set in advance with the bit sequence obtained from the audio signal SA to detect the bit error rate. Then, decoding section 3 outputs bit error rate data DB corresponding to the detected bit error rate to out-of-service determining section 4.

As a result, the out-of-service determining unit 4 compares the actual bit error rate obtained from the bit error rate data DB with a preset threshold value. Now, assuming that the actual bit error rate does not exceed the threshold value, the out-of-service determining unit 4 determines that the wireless telephone device is not out of service, and does not output any signal.

As a result, the adder 6 outputs the audio signal SA
Only the sound is output to the speaker 7, and the sound is output from the speaker 7. As a result, the user can make a call in a good reception state.

If the bit error rate of the voice signal SA exceeds a threshold value preset in the out-of-service area determination unit 4 due to fading during the call, the out-of-service area determination unit 4 It is determined that it is out of the service area, and outputs the out-of-service signal Sk to the alarm signal generation unit 5. Thereby, the alarm signal generation unit 5
An alarm signal SAL is generated and output to the adder 6.

As a result, the adder 6 outputs the audio signal SA
In addition, the alarm signal SAL is output to the speaker 7, and the speaker 7 outputs an alarm sound in addition to the sound. As a result, the user recognizes that the wireless telephone device is out of the service area, that is, that the communication is being disabled.

As described above, according to the radio telephone apparatus according to the embodiment of the present invention, whether the radio telephone apparatus is out of the service area is determined based on the bit error rate. The effect that the reliability of the determination can be improved as compared with the above-described determination based on the reception electric field level of a radio wave as in a telephone device is obtained.

Next, a modification of the wireless telephone device according to the above-described embodiment will be described. In this modification, the out-of-service determination unit 4 shown in FIG.
3) are set. That is, the out-of-service determining unit 4 determines the bit error rate obtained from the bit error rate data DB and the highest threshold value among a plurality of threshold values,
Next, the second highest threshold value and the third highest threshold value are sequentially compared.

The out-of-service determining unit 4 determines that the bit error rate is 1
If the threshold exceeds the second highest threshold, the out-of-service signal Sk1 corresponding to the first highest threshold is output, and the bit error rate does not exceed the first highest threshold. And if it exceeds the second highest threshold,
The out-of-service signal Sk2 corresponding to the second highest threshold is output.

The out-of-service determining unit 4 determines that the bit error rate is 1
If the second threshold is not exceeded and the third highest threshold is exceeded, the out-of-service signal Sk3 corresponding to the third highest threshold is output. That is, the out-of-service determining unit 4 determines whether the wireless telephone device is out of the service range based on the three-step criterion.

When each of the out-of-service signals Sk1 to Sk3 is input, the alarm signal generator 5 generates alarm signals SAL1 to SAL3 respectively corresponding to three types of alarm sounds. Here, among the above three types of alarm sounds, the one corresponding to the alarm signal SAL1 has a high volume, the one corresponding to the alarm signal SAL2 has a medium volume, and the one corresponding to the alarm signal SAL3. What is done is a small volume.

In the above configuration, when the bit error rate data DB is input to the out-of-service judging section 4, the out-of-service judging section 4 firstly determines the bit error rate obtained from the bit error rate data DB and the highest threshold value. Compare with Now, assuming that the bit error rate does not exceed the first highest threshold,
Next, the out-of-service determining unit 4 compares the bit error rate with the second highest threshold. Now, assuming that the bit error rate does not exceed the second highest threshold, the out-of-service determining unit 4 compares the bit error rate with the third highest threshold.

Assuming that the bit error rate does not exceed the third highest threshold, the out-of-service determining unit 4 determines that the wireless telephone device is not out of service and does not output any signal. Hereinafter, the out-of-service determination unit 4 repeats the above-described three-stage comparison.

If it is assumed that the bit error rate does not exceed the first highest threshold value and does not exceed the second highest threshold value during a call, the out-of-service determining unit 4 determines that the radio telephone device It is determined that it is out of the service area, and the out-of-service signal Sk2 corresponding to the second highest threshold is output to the alarm signal generation unit 5.

As a result, the alarm signal generator 5 outputs the alarm signal S corresponding to the out-of-service signal Sk2.
AL2 is output to the adder 6, and a medium volume alarm sound is output from the speaker 7. As a result, the user recognizes that the wireless telephone device is located outside the service area.

Assuming now that the bit error rate has deteriorated, that is, the bit error rate has exceeded the first highest threshold value, the out-of-service determining unit 4 determines that the wireless telephone device is out of the service range. The out-of-service signal Sk1 corresponding to the high threshold is output to the alarm signal generator 5. That is,
In this case, the output signal of the out-of-service determining unit 4 has changed from the out-of-service signal Sk2 to the out-of-service signal Sk1.

Thus, the alarm signal generation unit 5 outputs an alarm signal S corresponding to the out-of-service signal Sk1.
AL1 is output to the adder 6, and a loud alarm sound is output from the speaker 7. That is, in this case,
That is, the alarm sound output from the speaker 7 changed from the medium volume to the large volume. As a result, the user recognizes that the wireless telephone device is located outside the service area more than before.

In the above-described modified example, an example has been described in which the out-of-service determination unit 4 sequentially compares the three thresholds with the bit error rate from the highest threshold, but the present invention is not limited to this. Instead, the bit error rates may be compared sequentially from the lowest threshold. In this case, if the bit error rate does not exceed the first lowest threshold, the out-of-service determining unit 4 determines that the wireless telephone device is not out of the service range and does not output any signal.

On the other hand, if the bit error rate exceeds the first lowest threshold, the out-of-service determining unit 4 compares the second lowest threshold with the bit error rate. Here, when the bit error rate does not exceed the second lowest threshold, the out-of-service determining unit 4 outputs the out-of-service signal Sk3 corresponding to the first lowest threshold.

When the bit error rate exceeds the second lowest threshold, the out-of-service determining unit 4 compares the third lowest threshold with the bit error rate. Here, when the bit error rate does not exceed the third lowest threshold, the out-of-service determining unit 4 outputs the out-of-service signal Sk2 corresponding to the second lowest threshold. When the bit error rate exceeds the third lowest threshold, the out-of-service determining unit 4
The out-of-service signal S corresponding to the third lowest threshold value
Output k1.

Further, in the above-described modified example, an example has been described in which three types of alarm sounds are distinguished according to the volume, such as high volume, medium volume, and low volume. However, the present invention is not limited to this. By changing the ringing pattern, three types of alarm sounds may be distinguished.

As described above, according to the radio telephone apparatus according to the above-described modified example, whether the radio telephone apparatus is out of the service area is determined based on the comparison result between the threshold value and the bit error rate in a plurality of steps. Since a plurality of types of alarm sounds corresponding to the stepwise judgment result are used, the user can be notified stepwise.

[0033]

As described above, according to the first and second aspects of the present invention, whether or not a device is out of service is determined by the determination means based on the bit error rate. As compared with the above-described radio telephone apparatus, the reliability of the judgment can be improved as compared with the above-described judgment based on the electric field level of the radio wave. Claims 3 and 4
According to the invention described in (1), since a plurality of stepwise threshold values are compared with the bit error rate, it is possible to determine stepwise whether or not the device is out of service. Can be Further, according to the fifth aspect of the present invention, since a plurality of alarm sounds corresponding to a plurality of determination results are notified by the notifying means, the user is notified stepwise about how much the device is outside the service area. The effect that it can be obtained is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a wireless telephone device according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Antenna 2 Receiving part 3 Decoding part 4 Out of service judging part 5 Alarm signal generating part 6 Adder 7 Speaker

Claims (5)

[Claims] A receiving unit that receives a radio wave including an audio signal transmitted from a wireless base station; a decoding unit that decodes the audio signal based on a reception result of the receiving unit; and a decoding unit that decodes the audio signal. A bit error rate detecting means for detecting a bit error rate of the audio signal, and comparing a detection result of the bit error rate detecting means with a preset threshold value, the detection result exceeds the threshold value. In a case, the apparatus further comprises a determination unit for determining that the apparatus is out of the service area of the wireless base station. 2. The wireless telephone device according to claim 1, further comprising: notifying means for notifying, when the judging means judges that the device is out of the service area, a notification to that effect. 3. A receiving unit for receiving a radio wave including an audio signal transmitted from a radio base station; a decoding unit for decoding the audio signal based on a reception result of the receiving unit; Bit error rate detection means for detecting the bit error rate of the audio signal, By comparing the detection result of the bit error rate detection means and a plurality of preset stepwise thresholds in descending order of the threshold, A radio telephone device comprising: a determination unit that, when there is the detection result exceeding the threshold, determines that the device is out of the service area of the radio base station in a stepwise manner. 4. A receiving unit for receiving a radio wave including an audio signal transmitted from a wireless base station; a decoding unit for decoding the audio signal based on a reception result of the receiving unit; Bit error rate detection means for detecting the bit error rate of the audio signal, By comparing the detection result of the bit error rate detection means and a plurality of preset stepwise thresholds in ascending order of the threshold value, A radio telephone device comprising: a determination unit that, when there is the detection result exceeding the threshold, determines that the device is out of the service area of the radio base station in a stepwise manner. 5. An alarm sound corresponding to each of the plurality of stepwise thresholds may be generated, and the determination means may cause the apparatus to move out of the service area among the plurality of stepwise thresholds. The wireless telephone device according to claim 3, further comprising: a notifying unit that generates the alarm sound corresponding to the threshold value used when it is determined that there is a wireless telephone device.