JP7585876B2 - Wireless communication terminal, reception determination method and program - Google Patents

Description

The present invention relates to a wireless communication terminal, in particular a PHS wireless communication terminal.

The communication areas of PHS (Personal Handy-phone System) communication systems may overlap with other communication systems. For example, DECT (Digital Enhanced Cordless Telecommunications) and sXGP (Shared eXtended Global Platform) communication systems use frequency bands that overlap with the private standard PHS system.

When the communication areas of different communication systems overlap in this way, systems have been proposed that can detect the occurrence of radio interference and switch channels to ensure communication quality (for example, Patent Document 1).

The 7th edition of RCR-STD28, which is a proposal for a private standard PHS system, includes provisions for handling sXGP communication systems that use the same band as private standard PHS systems. These provisions require that radio wave measurements be used to check for the presence of devices using other communication methods, such as sXGP.

JP 2014-120933 A

However, some of the equipment used to measure the radio bands of PHS systems is no longer in production and is difficult to obtain. On the other hand, there are measuring devices for communication systems that use the same frequency bands as privately operated standard PHS systems, such as the sXGP and DECT systems. However, these measuring devices are not intended to investigate the presence of other systems that use the same bands, and it is difficult to use them to easily investigate the presence of devices using other communication methods that use the same radio bands as PHS.

In addition, there are spectrum analyzers that can measure frequency bands, but they only display the waveform on the screen, making it difficult to infer from the waveform whether or not there are devices using other communication methods, and there is a problem that investigations cannot be easily carried out.

The present invention was made in consideration of the above problems, and aims to provide a wireless communication terminal that can easily determine the presence or absence of devices using other communication methods.

The wireless communication terminal according to the present invention is a wireless communication terminal that communicates in one wireless communication system, and is characterized by having a receiving unit that selectively receives radio waves for each band of multiple channels of the one wireless communication system whose frequency band overlaps with one channel of another wireless communication system, a field strength determination unit that determines whether or not a radio wave having a predetermined field strength or more has been received by the receiving unit for each of the multiple channels, a radio wave determination unit that determines whether or not a radio wave determined by the field strength determination unit to have a predetermined field strength or more is a radio wave used in the one wireless communication system for each of the multiple channels, and a reception determination unit that determines whether or not the radio waves received by the receiving unit include radio waves used in the other wireless communication system based on the ratio of the number of channels determined to have radio waves having the predetermined field strength or more received among the multiple channels to the number of channels determined to have radio waves having the predetermined field strength or more used in the one wireless communication system.

A reception determination method according to the present invention is a method for determining whether or not a wireless communication terminal communicating in one wireless communication system has received radio waves used in another wireless communication system, the method comprising the steps of selectively receiving radio waves for each band of a plurality of channels of the one wireless communication system that overlap in frequency band with one channel of the other wireless communication system;
The method includes the steps of: determining whether or not radio waves having a predetermined field strength or more have been received for each of the plurality of channels; determining whether or not the radio waves determined to have the predetermined field strength or more for each of the plurality of channels are radio waves used in the one wireless communication system; and determining whether or not the received radio waves include radio waves used in the other wireless communication system based on a ratio of the number of channels among the plurality of channels for which it has been determined that radio waves having the predetermined field strength or more have been received to the number of channels for which it has been determined that the radio waves having the predetermined field strength or more are radio waves used in the one wireless communication system.

The program according to the present invention is a program for causing a wireless communication terminal that communicates in one wireless communication system to determine whether the wireless communication terminal has received radio waves used in another wireless communication system, and is characterized in that the wireless communication terminal executes the steps of selectively receiving radio waves for each band of a plurality of channels of the one wireless communication system that overlap in frequency band with one channel of the other wireless communication system, determining whether radio waves having a predetermined field strength or more have been received for each of the plurality of channels, determining whether the radio waves determined to have the predetermined field strength or more are radio waves used in the one wireless communication system for each of the plurality of channels, and determining whether the received radio waves include radio waves used in the other wireless communication system based on the ratio of the number of channels determined to have radio waves having the predetermined field strength or more received among the plurality of channels to the number of channels determined to have radio waves having the predetermined field strength or more used in the one wireless communication system.

According to the present invention, by determining whether or not radio waves of another communication method are received using a wireless communication terminal, it is possible to easily determine whether or not a device using that other communication method is present.

1 is a diagram illustrating a configuration of a communication system including a communication terminal according to an embodiment of the present invention. A diagram showing the relationship between the frequency bands and channels of DECT and sXGP radio waves and the channels of PHS. 2 is a diagram showing a schematic diagram of the relationship between each DECT channel and each PHS channel. FIG. 2 is a block diagram showing a configuration of a wireless communication terminal. A diagram showing the overlap of PHS radio waves with DECT and sXGP radio waves. 6 is a flowchart showing a processing routine of another device determination process according to the present embodiment.

The following describes an embodiment of the present invention with reference to the drawings. In the following description of the embodiment and the accompanying drawings, substantially the same or equivalent parts are designated by the same reference numerals.

Figure 1 is a diagram showing the configuration of a communication system 100 including a wireless communication terminal of this embodiment. The communication system 100 is composed of a wireless communication terminal 10 that communicates by the PHS (Personal Handy-phone System) method and a PHS base station 21 that is a base station for PHS communication. In this embodiment, the following description will be given using as an example a case in which the wireless communication terminal 10 and the PHS base station 21 are a privately operated standard PHS terminal and a privately operated standard PHS base station, respectively.

The DECT base station 22 is a base station for communication using the Digital Enhanced Cordless Telecommunications (DECT) system. The sXGP base station 23 is a base station for communication using the Shared eXtended Global Platform (sXGP) system. DECT and sXGP are communication systems different from PHS, and each has channels whose frequency bands overlap with multiple PHS channels.

Figure 2 shows the relationship between the frequency bands and channels of DECT and sXGP radio waves and the channels of PHS. Figure 3 shows a schematic diagram of the relationship between each DECT channel and each PHS channel.

DECT channel F1 has a center frequency of 1895.616 MHz and overlaps with PHS channels 255 to 5. DECT channel F2 has a center frequency of 1897.344 MHz and overlaps with PHS channels 5 to 11. DECT channel F3 has a center frequency of 1899.072 MHz and overlaps with PHS channels 11 to 17. DECT channel F4 has a center frequency of 1900.800 MHz and overlaps with PHS channels 17 to 23. DECT channel F5 has a center frequency of 1902.528 MHz and overlaps with PHS channels 23 to 28. DECT channel F6 has a center frequency of 1904.256 MHz, which overlaps with PHS channels 28 to 34. sXGP channel F0 has a center frequency of 1899.100 MHz, which overlaps with PHS channels 6 to 23.

In this way, one DECT channel has a frequency band that overlaps with six PHS channels. Also, one sXGP channel has a frequency band that overlaps with 18 PHS channels.

Referring again to FIG. 1, the wireless communication terminal 10 of this embodiment has a function of executing other device determination processing, which is processing for determining whether or not a device communicating in a DECT or sXGP communication system, which is a communication system different from PHS, is present within its own communication area (i.e., within a range in which radio waves can be received). In the other device determination processing, the wireless communication terminal 10 determines whether or not it has received radio waves used in another communication system, thereby determining whether or not a communication device of another method is present. Details of this other device determination processing will be described later.

Figure 4 is a block diagram showing the configuration of the wireless communication terminal 10. The wireless communication terminal 10 has a transceiver unit 11, a modulation/demodulation unit 12, a received data analysis unit 13, a determination processing unit 16, and an output unit 17.

The transmitter/receiver 11 includes, for example, an antenna, and transmits and receives radio waves related to wireless communication. That is, the transmitter/receiver 11 transmits radio waves to other wireless communication terminals via the PHS base station 21, and receives radio waves from other wireless communication terminals via the PHS base station 21.

In this embodiment, the transmitter/receiver 11 also receives radio waves used in communication systems other than PHS, such as radio waves transmitted from a DECT communication device via a DECT base station 22 and radio waves transmitted from an sXGP communication device via an sXGP base station 23. In the other device determination process described below, the transmitter/receiver 11 selectively receives radio waves for each band of multiple channels of the PHS communication system.

The modem unit 12 performs modulation processing of the signal transmitted from the transceiver unit 11 and demodulation processing of the radio waves received by the transceiver unit 11. In the following explanation, data obtained by subjecting the radio waves received by the transceiver unit 11 to demodulation processing is referred to as received data. Note that the received data includes a preamble, a unique word UW, and CRC bits in addition to the information data that is the data body.

The received data analysis unit 13 is a functional block that performs data analysis of received radio waves, which is a prerequisite for the other device determination process. The received data analysis unit 13 includes a field strength determination unit 14 and a PHS radio wave determination unit 15.

The electric field strength determination unit 14 measures the electric field strength of the radio waves received by the transceiver unit 11 (hereinafter referred to as the received radio waves) and determines whether the measured electric field strength is 35 dBμV or more.

The PHS radio wave determination unit 15 determines whether or not a radio wave whose electric field strength is determined by the electric field strength determination unit 12 to be 35 dBμV or more is a radio wave of a private standard PHS. The PHS radio wave determination unit 15 determines whether or not a received radio wave is a radio wave for PHS communication based on a unique word UW included in the received data.

The received data analysis unit 13 performs a judgment using the electric field strength judgment unit 14 and the PHS radio wave judgment unit 15 for each frequency band corresponding to each of the multiple PHS channels that overlap with one DECT or sXGP channel, and supplies the judgment results to the judgment processing unit 16.

Based on the analysis results of the received data analysis unit 13, the determination processing unit 16 determines whether the received radio waves include radio waves used in a communication system other than PHS, and thereby determines whether a device of the other communication system is present within the communication area of the wireless communication terminal 10 (i.e., within the range in which radio waves can be received).

Specifically, the determination processing unit 16 determines whether the received radio waves include radio waves used in the other communication system based on whether the ratio of channels that have received radio waves related to the PHS communication system to channels that have received radio waves with a field strength of 35 dBμV or more among multiple PHS channels that correspond to one channel of the other communication system is less than 20%. Note that in this embodiment, since there are six PHS channels that correspond to one DECT channel, the determination criterion is set to 20%, taking into account the frequency band overlap rate.

Figure 5 is a diagram that shows the overlap of PHS radio waves with DECT and sXGP radio waves.

For example, if one channel is used for a PHS call, the signal will leak out to the surrounding one channel (as shown by the dashed line in the diagram). Because the PHS channel is spread out by one channel on both sides (i.e., ±1 channel), if many channels are used for a PHS call, the waveform may resemble that of DECT or sXGP.

In this embodiment, the wireless communication terminal 10 takes into consideration the correspondence between PHS channels and DECT and sXGP channels with overlapping frequency bands, and determines that it is only receiving PHS radio waves if the ratio of channels that are determined to have received PHS radio waves to channels that have received radio waves with a predetermined field strength or greater is greater than a predetermined ratio (20% or more in this embodiment), and determines that it is receiving radio waves used in other communication systems other than PHS (i.e., the radio waves received by the transmission/reception unit 11 include radio waves used in other communication systems) if the ratio is less than a predetermined ratio (less than 20% in this embodiment).

In addition, in the other device determination process, the frequency band corresponding to one channel of DECT and sXGP is set as the band to be determined, and the determination process is performed for the set band. Therefore, by repeatedly executing the determination process while changing the set band, it is possible to perform the determination process for each channel of other communication systems that overlaps with the PHS channel.

Referring again to FIG. 4, the output unit 17 is composed of a display unit including, for example, a speaker and a liquid crystal display panel, and outputs the judgment result of the judgment processing unit 16 by voice or image.

Next, the processing routine of the other device determination process executed by the wireless communication terminal 10 of this embodiment will be described with reference to the flowchart in FIG. 6.

First, the reception data analysis unit 13 sets the frequency band of the radio waves to be investigated (STEP 101). Here, a frequency band equivalent to one channel of another communication method is set as the frequency band to be investigated. For example, a frequency band equivalent to the F1 channel of DECT is set as the frequency band to be investigated.

Next, the reception data analysis unit 13 designates one of the multiple PHS channels corresponding to the frequency band set in STEP 101 as the target frequency band for reception data analysis (STEP 102). For example, if the frequency band corresponding to DECTF1 channel is designated as the frequency band to be investigated, the frequency band corresponding to channel 255 of the corresponding PHS channels 255 to 5 is designated as the channel (frequency band) to be analyzed. Each time the reception data analysis unit 13 repeats the processing of STEPs 103 to 108 described below, it designates the next adjacent PHS channel (frequency band) as the target for reception data analysis. For example, if the frequency band corresponding to PHS channel 255 is designated and the processing of STEPs 103 to 108 is completed, the frequency band corresponding to PHS channel 1 is designated as the channel to be analyzed.

The transmitter/receiver unit 11 receives radio waves on the specified channel (frequency band) (STEP 103).

The electric field strength determination unit 14 measures the electric field strength of the radio waves received by the transmission/reception unit 11 and determines whether the measured electric field strength is 35 dbμV or more (STEP 104).

If it is determined that the electric field strength is not 35 dbμV or more (i.e., less than 35 dbμV) (STEP 104: NO), proceed to STEP 108.

On the other hand, if it is determined that the electric field strength is 35 dBμV or more (STEP 104: YES), the reception data analysis unit 13 counts the radio wave as a valid radio wave (i.e., increments the count by 1) (STEP 105).

Next, for the radio waves counted as valid radio waves in STEP 105, the PHS radio wave determination unit 15 determines whether or not the radio waves are PHS radio waves (STEP 106). Note that the determination of whether or not the radio waves are PHS radio waves is performed using the unique word included in the received data as described above.

If it is determined that the signal is not a PHS signal (STEP 106: NO), the process proceeds to STEP 108.

On the other hand, if it is determined that the signal is a PHS signal (STEP 106: YES), the received data analysis unit 13 counts the signal as a PHS signal (i.e., increments the count by 1) (STEP 107).

The reception data analysis unit 13 determines whether or not the investigation has been completed for the frequency band set as the investigation target in STEP 101 (STEP 108). That is, the reception data analysis unit 13 determines whether or not the investigation has been completed for each of the multiple frequency bands to be analyzed (e.g., PHS channels 255 to 5) included in the frequency band set as the investigation target (e.g., DECT channel F1).

If it is determined that the investigation of the set band has not been completed (STEP 108: NO), the process returns to STEP 102 and the next channel (frequency band) of the PHS is specified as the frequency band to be analyzed.

On the other hand, if it is determined that the investigation of the set band is complete (STEP 108: YES), the determination processing unit 16 determines whether the ratio of channels that have received PHS radio waves to channels that have received valid radio waves (i.e., radio waves with a field strength of 35 dbμV or more) is less than 20% (STEP 109).

If it is determined that the percentage of channels that receive PHS radio waves is less than 20% (STEP 109: YES), the determination processing unit 16 determines that the received radio waves include radio waves used for a communication method other than PHS, i.e., that there is a target device using a communication method other than PHS within the communication area of the wireless communication terminal 10 (STEP 110).

On the other hand, if it is determined that the percentage of channels that receive PHS radio waves is not less than 20% (i.e., 20% or more) (STEP 109: NO), the determination processing unit 16 determines that the received radio waves do not include radio waves used for communication methods other than PHS, that is, that there are no target devices of communication methods other than PHS within the communication area of the wireless communication terminal 10 (STEP 111).

The output unit 17 receives the judgment of STEP 110 or STEP 111 and outputs the judgment result (STEP 112).

Through the above series of processing steps, it is determined whether devices of communication systems other than PHS are present within the communication area.

Measuring electric field strength and judging PHS radio waves using a unique word are functions that are provided in existing PHS communication terminals, and by using this function to incorporate software (programs) that perform operations such as the received data analysis unit 13 and the judgment processing unit 16 into the wireless communication terminal 10, it is possible to execute the above-mentioned other device judgment process.

Therefore, according to the wireless communication terminal 10 of this embodiment, since the determination can be made using the functions as a PHS communication terminal without using a dedicated device, it becomes possible to easily determine whether or not there are devices of other communication methods in the radio wave environment to which the communication terminal belongs.

In addition, by investigating whether there are other communication systems using the same frequency band as PHS, it is possible to determine the possibility of interference with calls due to radio interference, which is expected to improve communication quality.

The embodiments of the present invention are not limited to those described in the above examples. For example, the above examples have been described with reference to an example in which a private standard PHS terminal is used to investigate the radio band of a private standard PHS. However, the present invention is not limited to this, and the configuration of the wireless communication device in this example can also be applied to cases in which a wireless communication device other than a private standard PHS (e.g., a DECT communication device, an sXGP communication device) conducts a similar investigation.

That is, it is sufficient if the device has the following functions: (1) receiving radio waves in the radio band of its own communication system and measuring the field strength, and (2) determining whether the received radio waves are radio waves used in its own communication system and distinguishing between radio waves used in its own communication system and radio waves used in other communication systems. In this case, in the above embodiment, the criterion used was whether the ratio of channels that received PHS radio waves among channels that received valid radio waves was less than 20%, but by appropriately changing the criterion according to the strength of the radio waves and a situation in which radio waves used in its own communication system and radio waves used in other communication systems are mixed, it is possible to realize processing similar to that of the above embodiment in communication terminals other than PHS.

100 Communication system 10 Wireless communication terminal 11 Transmitter/receiver 12 Modem unit 13 Received data analyzer 14 Field strength determination unit 15 PHS radio wave determination unit 16 Determination processing unit 17 Output unit

Claims (6)

A wireless communication terminal that communicates in one wireless communication system,
a receiving unit that selectively receives radio waves for each band of a plurality of channels of the one wireless communication system whose frequency band overlaps with a channel of another wireless communication system;
a field strength determination unit that determines whether or not a radio wave having a field strength equal to or greater than a predetermined value is received by the receiving unit for each of the plurality of channels;
a radio wave determination unit that determines whether or not a radio wave determined by the field strength determination unit to have a field strength equal to or greater than a predetermined value is a radio wave used in the one wireless communication system, for each of the plurality of channels;
a reception determination unit that determines whether or not the radio waves received by the receiving unit include radio waves used in the other radio communication system based on a ratio of the number of channels among the plurality of channels in which it is determined that radio waves having a field strength equal to or greater than the predetermined level are received to the number of channels in which it is determined that the radio waves having the field strength equal to or greater than the predetermined level are used in the radio waves of the one radio communication system;
A wireless communication terminal comprising: The wireless communication terminal according to claim 1, characterized in that the reception determination unit determines that the radio waves received by the reception unit include radio waves used in the other wireless communication system when the ratio of the number of channels in which it is determined that radio waves having a field strength equal to or greater than the predetermined level are received to the number of channels in which it is determined that the received radio waves are radio waves used in the one wireless communication system is less than a predetermined value. The first wireless communication system is a PHS (Personal Handy-phone System) communication system,
The wireless communication terminal according to claim 1 or 2, characterized in that the radio wave determination unit determines whether or not the radio waves are radio waves used for PHS communication based on a unique word contained in the signal data of the radio waves received by the receiving unit. The wireless communication terminal according to claim 3, characterized in that the other wireless communication system is a DECT (Digital Enhanced Cordless Telecommunications) or sXGP (Shared eXtended Global Platform) communication system. A reception determination method for determining whether or not a wireless communication terminal communicating in one wireless communication system has received a radio wave used in another wireless communication system, comprising:
selectively receiving radio waves for each band of a plurality of channels of the one wireless communication system whose frequency band overlaps with a channel of another wireless communication system;
determining whether or not a radio wave having a field strength equal to or greater than a predetermined value is received for each of the plurality of channels;
determining whether or not a radio wave determined to have a field intensity equal to or greater than the predetermined value is a radio wave used in the one wireless communication system for each of the plurality of channels;
determining whether the received radio waves include radio waves used in the other wireless communication system based on a ratio of the number of channels among the plurality of channels in which it is determined that radio waves having a field strength equal to or greater than the predetermined level are received to the number of channels in which it is determined that the radio waves having the field strength equal to or greater than the predetermined level are used in the one wireless communication system;
A reception determination method comprising: A program for causing a wireless communication terminal that communicates in one wireless communication system to determine whether or not the wireless communication terminal has received a radio wave used in another wireless communication system, comprising:
The wireless communication terminal,
selectively receiving radio waves for each band of a plurality of channels of the one wireless communication system whose frequency band overlaps with a channel of another wireless communication system;
determining whether or not a radio wave having a field strength equal to or greater than a predetermined value is received for each of the plurality of channels;
determining whether or not a radio wave determined to have a field intensity equal to or greater than the predetermined value is a radio wave used in the one wireless communication system for each of the plurality of channels;
determining whether the received radio waves include radio waves used in the other wireless communication system based on a ratio of the number of channels among the plurality of channels in which it is determined that radio waves having a field strength equal to or greater than the predetermined level are received to the number of channels in which it is determined that the radio waves having the field strength equal to or greater than the predetermined level are used in the one wireless communication system;
A program characterized by executing the above.

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