JPH07143567A - Digital radio telephone system - Google Patents

Abstract

PURPOSE:To improve probability to successfully switch a speaking channel because of interference generation while the slave set of the digital radio telephone system executes direct speaking with another slave set. CONSTITUTION:This system is provided with a frequency change interval number storage part 9, a frequency interval to be changed at the time of carrier sense to be executed by a call originating side slave set in the case of generating interference during speaking and scan to be executed by a call incoming side slave set is previously decided and stored and during the inter slave set direct speaking, a control part 8 of the call originating side slave set detecting the interference of the speaking channel with an interference detection part 7 executes the carrier sense while changing a frequency at the frequency change interval stored in the frequency change interval number storage part 9, selects the speaking channel with no interference and transmits a message to the slave set. On the other hand, the call incoming side slave set executes the scan while changing the frequency at the same frequency interval as the call originating side slave set and selects the speaking channel provided with the message from the call originating side slave set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication channel (hereinafter referred to as TCH) in direct communication between handset units of a digital radio telephone device.
Referred to as) switching.

[0002]

2. Description of the Related Art In recent years, digital radio telephone devices have become capable of being connected to both a home base unit and a public base station, and further, they can be connected to other home base units or public base stations without intervention. Direct calls between handset units that are directly connected to a digital wireless telephone device are possible.

A conventional digital radio telephone device will be described below with reference to the drawings. FIG. 4 is a block diagram showing the configuration of a slave unit of a conventional digital wireless telephone device. In the figure, reference numeral 1 is a digital radio unit, which transmits and receives radio signals in a digital system to and from a non-public base station, a home base unit or another handset of a digital radio telephone device. Two
Is an antenna unit for transmitting and receiving the radio signal, 3 is a receiving unit, 4 is a transmitting unit, 5 is a voice decoding unit for decoding the digital signal demodulated by the digital radio unit 1 into a voice signal, and 6 is a transmitting unit. A voice encoding unit that encodes the voice signal input from the talk unit 4 into a digital signal, 7 an interference detection unit that detects interference of the digital signal demodulated by the digital radio unit 1, and 8 controls the operation of the entire apparatus. The control unit 10 is a slave unit of the digital wireless telephone device.

The operation of the above configuration will be described. The digital radio unit 1 demodulates the TCH radio wave input via the antenna unit 2, and the voice decoding unit 5 converts the digitally encoded signal into an analog voice signal. Is converted into voice, and the voice is transmitted to the operator. Also, the transmitter 4
Input the voice of the operator, the voice encoding unit 6 converts the analog voice signal into a digitally encoded signal, and the digital radio unit 1 modulates the carrier wave and sends it out from the antenna unit 2. Further, the control unit 8 controls the operation of the entire device. The above-mentioned configuration is the same in the slave unit of the digital wireless telephone device on either the transmitting side or the receiving side.

The call origination operation and the call reception operation in the direct call between the handset units of the digital radio telephone device are not the main purpose of the present application, and therefore detailed description thereof will be omitted. When a call is made after the call origination and call reception processing is completed, it is necessary that the TCH is not used by another digital radio telephone, and during the call, the control unit 8 of the handset of the originating digital radio telephone is currently in use. The interference state of the TCH being used is detected by the interference detection unit 7 to determine the presence or absence of interference. Hereinafter, the operation of detecting the presence or absence of the interference will be referred to as carrier sense.
After shifting to a call, another digital radio telephone device may interrupt the TCH. Interference does not always occur even if there is an interrupt, but when interference is detected by the interference detection unit 7, an operation of mutually changing to a TCH of another frequency different from the currently used frequency, that is, TCH
The operation shifts to CH switching.

Hereinafter, the TCH during a direct call between the handset units
The switching operation will be described. FIG. 5 is a flowchart showing the operation of carrier sense when the calling side handset switches the TCH during a direct call between handset units of the conventional digital wireless telephone device. Further, FIG. 6 is a flowchart showing an operation of sequentially scanning and receiving the TCHs, that is, a scanning operation, when the receiving side handset switches the TCHs. Now, it is assumed that a child carrier of a digital wireless telephone device is talking with a child carrier of another digital wireless telephone device. The radio signal received by the antenna unit 2 is demodulated by the digital radio unit 1 and input to the interference detection unit 7 via the control unit 8 to detect the interference state. The control unit 8 inputs the detection result and determines whether or not interference has occurred. When the interference is detected, the TCH switching process is started.

The operation of the originating side handset for carrying out carrier sense will be described below. In step 501, the controller 8 determines the number of the first frequency at which carrier sense is performed, in step 502, carrier sense is performed, and in step 503, the presence or absence of interference is determined. If it is determined in step 503 that there is no interference, the process proceeds to step 505, and the control unit 8 outputs a digital signal of a predetermined synchronization message to the digital wireless unit 1. The signal is modulated by the digital radio unit 1, and the synchronization message is transmitted from the antenna unit 2 by radio waves. If it is determined that there is interference in step 503, step 50
4, the control unit 8 adds the constant frequency change interval number to the frequency number of the TCH for which carrier sensing has just been performed to calculate the frequency number of the next carrier sense, and shifts to step 502 to carry out carrier sense. To execute. The frequency numbers are numbers assigned to a plurality of TCHs in the order of frequencies, and the numbers correspond to the TCH frequencies. In addition, the frequency change interval number is
This means the difference between the TCH frequency number specified next and the TCH number currently selected, that is, the interval between TCH numbers. Therefore, if the number of frequency change intervals is 2, the number of TCHs that are sequentially selected is, for example, 1 → 3.
→ 5 → ... The means for changing the frequency by a predetermined constant frequency difference is easily realized by the PLL synthesizer. The above operation is repeated until it is determined that there is no interference in the result of carrier sense.

The operation of the receiving side slave unit that executes the scan will be described below. In step 601, the control unit 8
The frequency at which the scan is executed is determined by the number, and the scan is executed at step 602. The radio wave received by the antenna unit 2 is converted into a digital signal by the digital radio unit 1 and output to the control unit 8. In step 603, the control unit 8 determines whether the converted digital signal is a message from the originating side handset, a synchronization message, or the like. When it is determined in step 603 that the message is from the originating side handset, the control unit 8 transmits a response digital signal as a radio wave through the digital radio units 1 and 2. When it is determined in step 603 that the message is not from the calling side child device, the process proceeds to step 604, and the control unit 1 adds a constant frequency change interval number to the TCH frequency number that has just been scanned. Thus, the frequency number of the TCH for which the scan is to be executed next is calculated, and the process proceeds to step 602 to execute the scan. This operation is repeated until it is determined in step 603 that the message is from the calling side child device. When the transmission / reception of the wireless signal before the call state is successful, the call is restarted similarly to the calling side child device.

As described above, in the conventional digital radio telephone apparatus, when the TCH is switched, the first frequency for carrying out carrier sensing or scanning is determined by the number,
If the result of the carrier sense or scan is unsuccessful, T
By adding a constant frequency change interval number to the CH frequency number, the frequency number at which the carrier sense or scan is executed next is determined.

[0010]

In such a conventional digital radiotelephone device, there are two sets of handset units in direct communication between handset units, and each handset side handset detects interference and When the group performs the TCH switching operation, the number of the next frequency is set using a constant frequency change interval number when performing carrier sensing or scanning, so that the frequency number to be set first is the same in both groups. In that case, since TCHs of the same frequency are sequentially set and carrier sensing and scanning are executed, the carrier sensing result always fails in either group. Therefore, there has been a problem that TCH switching will not succeed forever. No frequency is initially set when executing carrier sense and scan, and no slave unit is set to number 1. Therefore, TCH switching does not always fail, but the number of frequency change intervals is constant. As long as it is, the probability of successful switching is low.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a digital radio telephone device capable of increasing the probability of successful TCH switching in a direct call between handset units in the digital radio telephone device.

[0012]

In order to achieve the above object, the present invention provides a digital radio having a slave unit for converting voice into a digital signal and transmitting and receiving the digital signal through a radio communication channel for communication. In the telephone device,
The slave unit includes a digital radio unit that transmits and receives the digital signal, an interference detection unit that detects an interference state of the communication channel, and a communication channel in a direct communication between the slave units in which the slave unit directly communicates with another slave unit. A frequency change interval number storage unit that stores a predetermined reference for selecting the unit, and a control unit that controls the operation of the entire device, and when the slave unit is performing a direct call between the slave units. When the calling handset detects interference in the call channel during the call, the control unit of the calling handset sequentially changes the frequencies of the call channels at the frequency intervals stored in the frequency change interval number storage section. Then, a call channel with no interference is detected, and a predetermined message signal is transmitted to the other handset by the call channel, and the receiving side handset stores the same reference as the calling side handset in the frequency change interval storage unit. Remember , By changing the frequency of the call channel sequentially at that frequency interval and selecting the call channel that received the predetermined message sent by the calling side, It is a digital wireless telephone device for switching and establishing.

[0013]

According to the present invention, in the above-mentioned configuration, the frequency change interval number storage unit promises and stores the frequency change intervals of carrier sense and scan executed when the TCH is switched between the slave units in advance. The control unit of the cordless handset changes the frequency of the TCH at that frequency interval and performs carrier sense to select a TCH without interference. At TC
Change H and perform scan.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A slave unit of an embodiment of a digital radio telephone apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of this embodiment. The same components as those in the conventional example shown in FIG. 4 are assigned the same reference numerals and detailed explanations thereof are omitted. The present embodiment is different from the conventional example in that a frequency change interval number storage unit 9 is provided.

In the above structure, the TCH switching operation at the time of direct communication between the handset of the calling side handset and the handset of the receiving side handset of the digital radio telephone apparatus of the present invention will be described. FIG. 2 is a flow chart showing the operation of carrier sense executed when the TCH is switched between the calling side handset and the receiving side handset during a direct call between handset units of the digital wireless telephone device of the embodiment. Number intervals of TCH frequencies that are sequentially selected when the calling side slave unit executes carrier sense,
That is, the frequency change interval number is determined in advance, and the frequency change interval number is stored in the frequency change interval number storage unit 9. Note that the frequency number to be set first is determined in advance, as is conventional. Now, there are 10 frequencies assigned for direct communication between handset units in the digital wireless telephone device, and the number of frequency change intervals determined is 1, 3,
Either 7 or 9. With this setting, for example,
If the current frequency number is 1, and the frequency change interval number is 1, then 1 → 2 → 3 → 4 → 5 → 6 → 7 → 8 → 9 → 10, and if the frequency change interval number is 3 , 1 → 4 → 7 → 10 → 3 → 6 → 9 → 2 → 5 → 8, and when the frequency change interval number is 7, 1 → 8 → 5 → 2 → 9 → 6 → 3 → 10 → 7 → 4, and when the frequency change interval number is 9, 1 → 10 → 9 → 8 → 7 → 6 → 5 → 4 → 3 → 2. Thus, in any case, carrier sensing or scanning of all 10 waves can be performed by changing the frequency 10 times. First, in step 201, the control unit 8 sets the frequency change interval number to the frequency change interval number storage unit 9
Then, the process shifts to step 202 to determine the number of the first frequency at which the carrier sense is executed, the carrier sense is executed in step 203, and the result of the carrier sense is judged in step 204. Step 204
If the result of the determination in step 1 is yes, the control section 8 outputs a digital signal to the digital radio section 1. This digital signal is modulated by the digital radio unit 1 and a predetermined synchronization message is transmitted from the antenna unit 2 by radio waves. If the determination result in step 204 is unacceptable, the process proceeds to step 206, and the control unit 8 sets the number of frequency change intervals stored in the frequency change interval number storage unit 9 to the number of the frequency at which the carrier sense is executed. Is added to calculate the frequency number of the next carrier sense, and the process returns to step 203 to execute the carrier sense. This operation is repeated until the carrier sense determination result is acceptable.
When the transmission and reception of the wireless signal before the call state is successful in this way, the call is resumed.

In addition, the receiving side slave unit stores the frequency changing interval number at the time of executing the scan in advance in the frequency changing interval number storage unit 9 in accordance with the transmitting side slave unit. When executing the scan, the control unit 8 determines the frequency change interval number based on the frequency change interval number initially stored in the frequency change interval number storage unit 9 in step 301, and then executes the scan in step 302. The frequency number is determined, and the process proceeds to step 303 to execute the scan. In this case, the radio wave received by the antenna unit 2 is demodulated by the digital radio unit 1 and output to the control unit 8. In step 304, the control unit 8 determines whether or not the received signal is a message from the calling side handset that was talking, a synchronization message, or the like. If the determination result is acceptable, the control unit 8 outputs the digital signal to the digital radio unit 1, modulates the digital radio unit 1,
Radio waves are transmitted from the antenna unit 2. If the determination result is unsuccessful, the process proceeds to step 305, and the control unit 8 adds the frequency change interval number stored in the frequency change interval number storage unit 9 to the frequency number of the scan. Next, the number of the frequency for scanning is calculated, and the process returns to step 303 to execute scanning. This operation is repeated until the determination result in step 303 becomes acceptable. When the transmission / reception of the wireless signal before the call state is successful, the call is resumed.

When carrier sensing and scanning are performed by setting the frequency in this way, the number of frequency change intervals preset for a pair between certain slave units and the number of frequency change intervals preset for another slave unit are completely eliminated. Since the probability of being the same is low, the probability of setting frequencies at the same frequency intervals is low, and therefore the probability of successful TCH switching setting is high.

As described above, according to the digital radiotelephone device of this embodiment, when the TCH is switched in the direct call between the handset units, the number of frequency intervals for carrying out the carrier sense and the scan are individually set in advance and mutually set. By storing, and changing the frequency number according to the number of frequency change intervals for carrier sensing and scanning, switching of TCHs between slave units can be performed by TCHs between other slave units.
The probability of being the same as that of switching TCH is decreased, and the probability of successful switching of TCH is increased.

In this embodiment, the case where the frequency change interval number storage unit stores the number of intervals of frequency numbers has been described, but it goes without saying that the frequency difference itself, that is, the frequency interval may be stored.

[0020]

As is apparent from the above description, the present invention provides a digital radiotelephone device having a slave unit for converting voice into a digital signal and transmitting / receiving the digital signal through a radio communication channel for communication. The slave unit has a digital radio unit that transmits and receives the digital signal, an interference detection unit that detects an interference state of the call channel, and a direct call between the slave units in which the slave unit directly talks with another slave unit. A frequency change interval number storage unit that stores a predetermined reference for selecting a channel, and a control unit that controls the operation of the entire device, and when the slave unit is performing a direct call between slave units When the slave device on the calling side detects interference in the call channel during the call, the control unit of the slave device on the calling side sequentially performs the call channel at the frequency intervals stored in the frequency change interval number storage unit. Change the frequency to detect a call channel with no interference, send a predetermined message signal to the other handset on the call channel, and the callee handset will use the same criteria as the caller handset to change the frequency. Stored in the number storage unit, the frequency of the call channel is sequentially changed at the frequency intervals to be received, and the call channel on which the predetermined message transmitted by the caller has been received is selected, and By switching the call channel to the callee side slave unit and establishing it, the frequency when switching the call channel between the slave units does not always become the same as the switching frequency between other slave units, therefore, The probability that interference will occur in the switched communication channel will decrease, and the probability that communication channel switching will succeed will increase.
According to the digital radiotelephone device of the present invention, it has been confirmed by an experiment that the probability of succeeding in switching the communication channel is three times higher than the conventional one.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a slave unit of an embodiment of a digital wireless telephone device of the present invention.

FIG. 2 is a flow chart showing an operation of carrier sense executed by a calling side child device in TCH switching of an embodiment of a digital radio telephone apparatus of the present invention.

FIG. 3 is a flowchart showing an operation of scanning executed by the receiving side child device in the TCH switching of the embodiment of the digital wireless telephone apparatus of the present invention.

FIG. 4 is a block diagram showing a configuration of a slave unit of a conventional digital wireless telephone device.

FIG. 5 is a flow chart showing an operation of carrier sense executed by a calling handset of a conventional digital wireless telephone device in switching TCH.

FIG. 6 is a flowchart showing an operation of a scan executed by a receiving side child device of a conventional digital wireless telephone device in switching TCH.

[Explanation of symbols]

 1 Digital Radio Section 7 Interference Detection Section 8 Control Section 9 Frequency Change Interval Number Storage Section 10 Digital Wireless Telephone Device Handset

Claims (2)

[Claims] 1. A digital radiotelephone device comprising a slave unit for converting voice into a digital signal and transmitting and receiving the digital signal through a radio communication channel to make a call.
The slave unit includes a digital radio unit that transmits and receives the digital signal, an interference detection unit that detects an interference state of the communication channel, and a communication channel in a direct communication between the slave units in which the slave unit directly communicates with another slave unit. A frequency change interval number storage unit that stores a predetermined reference for selecting the unit, and a control unit that controls the operation of the entire device, and when the slave unit is performing a direct call between the slave units. When the calling handset detects interference in the call channel during the call, the control unit of the calling handset sequentially changes the frequencies of the call channels at the frequency intervals stored in the frequency change interval number storage section. Then, a call channel with no interference is detected, and a predetermined message signal is transmitted to the other handset by the call channel, and the receiving side handset stores the same reference as the calling side handset in the frequency change interval storage unit. Remember , By sequentially changing the frequency of the call channel at the frequency intervals and receiving, and selecting the call channel that received the predetermined message transmitted by the calling side handset, the calling side handset and the receiving side handset A digital radiotelephone device adapted to switch and establish a call channel. 2. The frequency change interval storage unit stores the frequency interval by the number difference value of the numbers given to the call channels, and when the slave unit executes carrier sense and scan, the frequency of the call channel currently selected. No. of the frequency change interval is added to the number of intervals stored in the frequency change interval storage unit to determine the frequency number of the next communication channel to be selected, thereby sequentially determining the frequencies of the communication channels. Item 1. A digital wireless telephone device according to item 1.