JP3278505B2 - Digital radio telephone equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital radio telephone apparatus for directly communicating between slave units.

[0002]

2. Description of the Related Art In recent years, digital radio telephones (PH)
P) has come to be able to directly communicate between child devices without going through a parent device.

[0003] When interference is received from another communication during direct communication between the slaves, the calling slave temporarily stops its own communication, newly monitors the frequency / slot to be used in the own communication, and if the frequency / slot is used. If the slot is a frequency / slot already used in another communication, monitor the next frequency / slot while avoiding using that frequency / slot in own communication, and monitor the frequency / slot not used in other communication. If you find a frequency / slot that is not yet used in other communications, search for that frequency / slot.
A synchronization signal for establishing a synchronization must be transmitted to the called slave through the slot. Also, the called slave must temporarily stop its own communication and search for the synchronization signal transmitted from the calling slave by switching the frequency and the slot one after another.

[0004] This operation is a TCH switching process for switching a traffic channel (hereinafter abbreviated as TCH) for directly communicating between slave units. Hereinafter, a conventional digital radio telephone device (P
HP) TCH switching processing at the time of direct communication between slave units will be described.

[0005] First, when the calling side handset detects interference, it stops transmission (step # 11) and determines an arbitrary frequency for measuring the interference wave level for the first time (step # 1).
2). Next, the frequency is set (step # 13), and the interference wave levels of all four reception slots of this frequency are measured (step # 14). As a result of the measurement, if there is a reception slot in which the interference wave level is equal to or less than the preset level value, it is determined that the own communication is possible in the frequency / slot (step # 15). Transmit a synchronization signal for synchronization probability (step # 1)
8) If there is no reception slot equal to or lower than the level value, it is determined that the own communication is impossible at that frequency (step # 15), and the frequency for measuring the interference wave level is next determined (step #).
16). If there is no reception slot equal to or less than the level value by the above-described determination processing, steps # 13 to # 16 are repeated, and even if the measurement of all frequencies is completed,
If there is no slot, it is determined that the own communication is not possible in all frequencies (step # 17), and TCH switching fails (step # 19).

Next, upon detecting the interference, the called-side slave unit stops transmitting (step # 21) and starts a timer for limiting the time limit for detecting the synchronization signal from the calling side (step # 21). # 24). 10 usable for direct communication between slave units
A first frequency is set among the frequencies of the waves (step # 2).
5) A search is made to see if a synchronization signal has been transmitted at that frequency from the other party's calling handset (step # 26). As a result of the search, if a synchronization signal of the other handset calling side can be detected (step # 27), the synchronization signal is transmitted (step # 27).
30). If the synchronization signal of the other handset calling side cannot be detected (step # 27), the frequency for searching the synchronization signal is determined (step # 29). If the synchronization signal is not detected by the above-described search processing, steps # 25 to # 29 are repeated until the timer started first times out. If the timer times out before the synchronization signal is detected (step # 28), It is determined that TCH switching has failed (step # 31).

[0007]

However, in the above-mentioned conventional digital radio telephone (PHP), as shown in FIG. 8, the handset communicates directly with each other causing interference (for example, communication a). Communication b) is a frequency different from the frequency causing interference (for example, frequency B) and has a high probability of switching the TCH to the same frequency (for example, frequency C). Cause interference. Also, as shown in FIG. 9, the called side handset switches to the next frequency by the partner calling side handset (for example, the carrier sense process is being performed in order from frequency D) and transmits the synchronization signal. Since it is not known whether the frequency comes, all frequencies must be searched in order from the beginning (for example, frequency A), and it takes time from the detection of interference to the synchronization probability at the frequency to which the TCH is switched. Therefore, T
There is a problem that the time of communication disconnection due to the CH switching process becomes long.

[0008] The present invention solves the above-mentioned problems, and direct communication between slave units causing interference causes switching of each TCH to a frequency that does not cause interference with each other, and direct communication between slave units causing interference. It is an object of the present invention to provide a digital radio telephone (PHP) in which the time from the detection of interference to the synchronization probability at the frequency of the switching destination of the TCH is shortened to shorten the time of communication interruption due to the TCH switching process.

[0009]

In order to achieve the above object, a digital radio telephone according to the present invention is provided with a time division multiplex communication.
In a digital radio telephone apparatus for communicating directly between handset at the slave unit, a phase by using the division multiple access communication system when
A communication unit that communicates with the handset, and communication by the communication unit;
When receiving, the reception state detection unit that detects communication interference,
A number storage unit storing a unique number to be indicated, and the communication unit
Control to establish communication with the other handset,
When the channel is changed later,
A unique number that represents the memorized self, or the person that acquired it
The next frequency to be shifted is derived based on the unique number of the
Controlling the communication unit and the reception state detection unit,
Detecting the interference state of each slot within the derived frequency of
If there is a slot without interference, the communication unit is controlled to
Control to reconnect with the other handset in the slot
A configuration including a control unit is provided .

[0010]

According to this structure, the control unit first measures the interference wave at the calling side handset during the traffic channel switching process when interference with other communication occurs during direct communication between handset. The frequency and the frequency that is first searched for by the called-side handset with respect to the synchronization signal from the calling-side handset based on the frequency of the switching destination slot determined by this interference wave measurement, Randomize based on the understanding of the calling side and the called side so that the frequency of the switching destination slot does not match between the direct communication between the own handset and the direct communication between other handset that interfered with it. The frequency of the switching destination slot of the communication is determined.
As a result, the frequency of the slot of the traffic channel is efficiently and efficiently switched to the optimum frequency that does not cause interference, and the time required from the detection of interference to the synchronization probability at the frequency to which the traffic channel is switched is reduced.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, reference numeral 1 denotes an antenna unit having a function of transmitting / receiving a radio signal to / from a remote unit of a digital radio telephone (PHP), and 2 denotes a digital radio reception unit which receives a digital radio signal. 3 has a function, which is a receiving state detecting unit, and has a function of transmitting wireless state information such as an electric field level or an interference wave level of a current wireless signal to the control unit, and 4 is a control unit, which is for analyzing received data and receiving state. And a function of controlling the setting and changing of the frequency of the digital radio receiving unit, the changing of the reception slot timing, and the like.

The operation of the control unit 4 in the slave unit of the digital radio telephone (PHP) configured as described above will be described below. First, in the case where direct communication is performed between slave units (for example, communication a and communication b in FIG. 4), if the slave unit detects interference during communication, the traffic channel currently used by its own communication (hereinafter, referred to as “the communication channel” hereinafter) The frequency (for example, frequency B in FIG. 4) / slot of the TCH must be switched to another one avoiding the frequency / slot used by other communication. For this reason, for example, the calling handset of communication b monitors the frequency (for example, frequency D in FIG. 4) slot where the TCH is to be switched, and
If the frequency / slot is a frequency / slot already used in another communication a, avoid using the frequency / slot in the own communication and set another frequency (for example, frequency E in FIG. 4) / slot. It must decide and send a synchronization signal to the called party. In addition, the called handset must search for the frequency / slot of the TCH to which the other calling handset has switched, while switching the frequency / slot for the synchronization signal from the other calling handset.

This operation is a TCH switching process for switching the TCH for directly communicating between the slave units. Hereinafter, the TCH switching process of the control unit 4 at the time of direct communication between slave units of the digital wireless telephone (PHP) of the present embodiment will be described with reference to FIGS.

The TCH switching process of the calling handset according to the present embodiment is different from the step # 42 in FIG. 2 in that the first interference wave measurement frequency is set to the current frequency number of the current communication + 2. The point that the frequency number of the next interference wave measurement frequency is set to the frequency number of the previous frequency number + 2 at 46 is different from the conventional technique. Also, the TC of the called slave unit
In the H switching process, in step # 52 of FIG. 3, the first search frequency is the frequency number of the current frequency number +2 currently being communicated, and in step # 59, the next search frequency is the frequency number of the previous frequency number +2. This is a different point from the conventional one. Hereinafter, the entire TCH switching process will be described.

First, the calling handset is communicating (for example, FIG. 5).
When the interference is detected at the frequency B), the transmission is stopped (step # 41), and the frequency at which the interference wave level is measured for the first time is calculated by inputting the PS calling number of the called terminal in the called party,
The value is added to the current frequency number to determine the frequency of the frequency number (for example, frequency D in FIG. 5) (step #).
42). Next, the frequency is set (step # 43),
The interference wave levels of all four reception slots within that frequency are measured (step # 44). As a result of the measurement, if there is a reception slot equal to or less than the preset level value (step # 45), the transmission of the synchronization signal to the called slave unit at the frequency / slot is started (step # 4).
8). However, if there is no reception slot below the level value, it is determined that the frequency is unusable (step # 4).
5) The frequency number adjacent to the previous frequency number is skipped, and the frequency of the frequency number obtained by adding 2 to the previous frequency number (for example, frequency F in FIG. 5) is determined as the frequency for measuring the next interference wave level (step # 46). ). If there is no reception slot whose level is equal to or lower than the frequency at which the interference wave level is measured by the above-described determination processing, Steps # 43 to #
If the frequency / slot that satisfies the above condition is not found even after all frequencies (for example, every other frequency after frequency H in FIG. 5) have been measured (step # 47), TCH
It is determined that the switching has failed (step # 49).

When the called slave detects interference during communication (for example, frequency B in FIG. 5), it stops transmitting (step # 5).
1) First, the frequency for searching for a synchronization signal from the other handset is set to the same frequency as the method for determining the first interference wave level of the other handset. The frequency is determined based on the PS calling number (for example, frequency D in FIG. 5) (step # 52). Next, the time (4 frames x 5 msec =
The process is stopped (at step # 53). After the restart of the process, a timer is set as a time limit for searching for a synchronization signal from the other calling handset (step # 54), and a synchronization signal from the previously called calling handset is searched for. The frequency is set (step # 55). A search is made to see if a synchronization signal has been transmitted at the frequency from the other handset calling side handset (step # 56). As a result of the search, if a synchronization signal from the other handset side is detected (step # 57), a synchronization probability is made at that frequency and a synchronization signal is transmitted (step # 60). If the synchronization signal from the other handset side is not detected even after searching for 50 msec (= 10 frames × 5 msec) (step # 5)
7) A frequency number obtained by skipping the frequency number adjacent to the previous frequency number and adding 2 to the previous frequency number, as in the determination of the next interference wave level measurement frequency of the calling handset as the next frequency to search for the synchronization signal. (For example, frequency F in FIG. 5) is determined as the frequency for searching for the next synchronization signal (step # 59). As a result of the above-described search processing, if no synchronization signal is detected from the other handset calling side handset, steps # 55 to # 59 are repeated (for example, every other wave after frequency H in FIG. 5), and If the timer, which is the time limit for searching for a synchronization signal from the calling handset, times out (step # 58), it is determined that TCH switching has failed (step # 61).

According to the above operation, the frequency of the slot of the traffic channel is switched between the direct communication between the slave units causing the interference to the optimum frequency at which the respective TCHs do not interfere with each other. Switching can be performed efficiently in direct communication between devices, and the time from the detection of interference to the synchronization probability at the switching destination frequency of the traffic channel can be shortened.

[0018]

As described above, according to the present invention, during traffic channel switching processing when interference with other communication occurs during direct communication between slave units, the control unit controls the calling side slave unit. The frequency that is first measured by the interference wave and the frequency that is first searched by the called slave for the synchronization signal from the calling slave according to the frequency of the switching destination slot determined by the interference wave measurement Is randomized with the understanding of the calling side and called side of the slave unit for each communication, and the switching destination is switched between direct communication between the own slave unit and direct communication between other slave units that interfered with this. The frequency of the switching destination slot of its own communication is determined so that the frequency of the slot does not match. Therefore, the frequency of the slot of the traffic channel is switched between the direct communication between the slave units that caused the interference to the optimum frequency that does not cause the interference between the respective TCHs, and the efficiency of the direct communication between the slave units that caused the interference is improved. By switching well and increasing the time from the detection of interference to the synchronization probability at the frequency to which the traffic channel is switched, the time of communication interruption due to the TCH switching process can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a slave unit of a digital wireless telephone device according to an embodiment of the present invention;

FIG. 2 is a flowchart of a TCH switching process of the calling handset according to the embodiment;

FIG. 3 is a flowchart of a TCH switching process of the called slave unit according to the embodiment;

FIG. 4 is a sequence diagram of carrier sense of the calling handset according to the embodiment.

FIG. 5 is a sequence diagram of a TCH switching process according to the embodiment;

FIG. 6 is a flow chart of a conventional TCH switching process of a calling side slave unit.

FIG. 7 is a flowchart of a conventional TCH switching process of a called-side slave unit.

FIG. 8 is a sequence diagram of carrier sense of a conventional calling side handset.

FIG. 9 is a sequence diagram of a conventional TCH switching process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Antenna part 2 Digital radio reception part 3 Reception state detection part 4 Control part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04Q ^7/ 00-7/38 H04B ⁷ /24-7/26

Claims (2)

(57) [Claims] In a digital radio telephone apparatus for communicating directly between handset at 1. A time division multiplex communication, the slave unit, when
Communication using the division multiplex communication method to communicate with the remote unit
Communication interference is detected during communication between the communication unit and the communication unit
And a unique number indicating itself.
The number storage unit and the communication unit are controlled to communicate with the other handset.
Establish communication and switch channels after communication connection
Sometimes, a unique identifier that indicates the self stored in the own number storage
Or the unique number of the other party
Next, a frequency to be shifted is derived, and the communication unit and the reception
The signal state detector is controlled to control
Detects lot interference and finds slots without interference
If the communication unit is controlled,
And a control unit for controlling reconnection of the digital radio telephone. 2. The communication device according to claim 2, wherein the control unit includes a communication unit and the reception unit.
By controlling the state detector, each slot in the guided frequency
When the interference state of
Performs control that does not perform interference detection and does not use for communication.
The digital wireless telephone device according to claim 1, wherein: