JP2006311262A - Communication apparatus and its communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication apparatus which is hard to be affected by jamming even if jamming occurs and can maintain communication quality, and provide its communication method. <P>SOLUTION: In a cordless telephone instrument which performs transmission of a frame by a slot of time division multiplex, when the frame is transmitted, an error judging means 18 which judges impairment of communication environment, a frame assembly means 13 which makes communication data which is to be transmitted by one time slot to a converted frame which was compressed with predetermined compression ratio when a notification that impairment of communication environment is judged came from the error judging means 18, and a radio means 15 which transmits the converted frame by increasing transmission output according to compression ratio are installed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a communication apparatus and a communication method for wireless communication using time division multiplexing.

  A communication device that communicates by TDMA (Time Division Multiple Access) is very convenient because it can transmit information at a remote location. For example, a cordless telephone device does not need to bother to go to the place where the main unit is installed to talk to the other party, and can talk while holding the child unit, so most of the telephone devices are cordless. Yes.

  However, cordless telephone devices used at home cannot be used only within a limited range because the output of radio waves is not high, and intermittent when receiving interference from microwave ovens or computers that communicate wirelessly It is often the case that the phone call becomes a conversation.

  Patent Document 1 describes a communication device that can maintain communication quality even when such other interference is received.

The digital cordless telephone device described in Patent Document 1 discards received voice data when the received frame voice data is not normal. Then, the communication partner station is requested to retransmit the corresponding voice data. Conversely, when a request for retransmission of voice data is received from the communication partner station, the corresponding voice data is retransmitted to the communication partner station using a blank slot in a silent period during a call, and the frame transmission / reception timing is also transmitted. Is used to perform sound correction.
Japanese Patent Laid-Open No. 7-212836

  However, in the cordless telephone device described in Patent Document 1, when the voice data of the received frame is not normal, the corresponding voice data is retransmitted to the communication partner station using a blank slot in the silent period during the call. Therefore, if it is disturbed by a disturbing radio wave that is generated steadily, the retransmitted audio data may also cause a communication error, which may result in intermittent communication.

  If this is the case, if the communication device is a cordless telephone device, the call is continued in a state in which frame loss frequently occurs, so there is a possibility that it will be in a mute state, and the call quality cannot be maintained.

  Accordingly, an object of the present invention is to provide a communication device that is less susceptible to the influence of jamming radio waves and that can maintain communication quality.

  When transmitting a frame in a time division multiplex slot, the present invention determines the deterioration of the communication environment at the time of transmitting the frame, and if there is a notification from the detection means that the deterioration of the communication environment has been determined, The communication data to be transmitted in the time slot is changed to a changed frame compressed at a predetermined compression ratio, and the changed frame is transmitted by increasing the transmission output in accordance with the compression ratio.

  The present invention uses a modified frame obtained by compressing communication data transmitted in one time slot at a predetermined compression ratio, and increases the transmission output according to the compression ratio and transmits the modified frame, thereby affecting the influence of jamming radio waves. Since the apparent S / N ratio can be improved, the communication distance can be increased and the communication quality can be maintained.

  In addition, the communication device of the present invention transmits, for example, a change frame in which communication data is compressed by a predetermined compression and transmission output when the distance between the communication devices gradually increases and the communication environment deteriorates. The system operates to maintain the communication state such that communication is disabled when further away, so it can be prevented from suddenly entering the communication disabled state, and the user can gradually recognize the deterioration in communication quality. Can do.

  According to a first aspect of the present invention, in a communication apparatus that transmits a frame in a time division multiplex slot, when transmitting a frame, a detecting unit that determines deterioration of the communication environment, and a deterioration of the communication environment is determined from the detecting unit If there is a notification to that effect, a frame assembling means for changing the communication data to be transmitted in one time slot with a predetermined compression ratio, and a radio means for increasing the transmission output according to the compression ratio and transmitting the changed frame It is characterized by having.

  Based on the determination of the deterioration of the communication environment from the detection means, the communication data transmitted by the frame assembly means in one time slot is changed into a changed frame, and the wireless means transmits the output according to the compression ratio. To send this change frame. Therefore, since the communication data is compressed and the transmission time is shorter than when transmitting in a normal frame, it is possible to reduce the influence of the jamming radio wave that is generated steadily. Further, since the transmission output is increased, the noise resistance against jamming waves is further improved. Furthermore, since the transmission output is increased according to the compression ratio, if the value obtained by multiplying the transmission time and the transmission output is the same or less in the normal frame and the modified frame as the amount of power when transmitting Since the amount of power consumed does not change, it is suitable for a communication device driven by a battery such as a cordless telephone device.

  The second invention of the present application is characterized in that the detecting means has a function of determining deterioration of the communication environment when a communication error becomes a predetermined value or more.

  Communication is difficult, for example, when the detection means determines that the communication environment has deteriorated and the communication error has exceeded the specified value, so that synchronization cannot be established or the validity of the communication data using the check code cannot be confirmed. The state can be detected.

  The third invention of the present application is characterized in that the detection means has a function of judging the deterioration of the communication environment when the received signal strength becomes a predetermined value or less.

  The detection means determines that the communication environment has deteriorated when the received signal strength is less than or equal to a predetermined value, so that even if no communication error has occurred and the communication data is normal, the communication partner device gradually leaves. If a frame to be transmitted is a change frame based on the received signal strength that becomes weaker as a result of communication, it is possible to prevent a communication error from occurring.

  A fourth invention of the present application is characterized in that the frame assembling means has a function of notifying another apparatus as a notification information of a communication command included in the change frame when transmitting the change frame. is there.

  When the frame assembling means transmits the change frame, the communication command contained in the change frame is notified to other devices as notification information, so that the communication partner device can easily determine that the frame is the change frame. Can be recognized.

  The fifth invention of the present application is characterized in that the frame assembling means has a function of notifying another apparatus as notification information of a synchronization establishment bit string included in the change frame when the change frame is transmitted. It is.

  When the frame assembling means transmits the change frame, it notifies the synchronization establishment bit string included in the change frame to other devices as notification information, so that the communication partner device can easily change the frame. I can recognize that.

  The sixth invention of the present application is characterized in that the frame assembling means has a function of changing the communication command to a changed frame compressed at a predetermined compression ratio when notifying other apparatus as a synchronization establishment bit string as notification information. It is what.

  Further, the frame assembling means can compress the communication command at a predetermined compression ratio when notifying other apparatus as the synchronization establishment bit string as notification information. It is possible to ensure high strength against noise.

  According to a seventh aspect of the present application, the detection means includes a first threshold value that triggers the frame assembly means to generate a modified frame, and a second threshold value that triggers the frame assembly means to return to the original one slot. The deterioration of the communication environment is determined with the first threshold value being larger than the second threshold value.

  As a result of the determination by the detection means in this way, it is possible to prevent frequent state transitions from the normal frame to the change frame and from the change frame to the normal frame.

  According to an eighth aspect of the present invention, in a communication method for a communication apparatus that transmits a frame in a time-division multiplexed slot, when transmission of a frame is detected, the communication data to be transmitted in one time slot is detected. The modified frame is compressed at a predetermined compression ratio, and the modified frame is transmitted by increasing the transmission output according to the compression ratio.

  When the deterioration of the communication environment is detected, the communication frame transmitted in one time slot is changed to a modified frame that is compressed at a predetermined compression ratio, and the transmission output is increased according to the compression ratio and the modified frame is transmitted. Accordingly, since the communication data is compressed and the transmission time is shorter than when transmitting in a normal frame, it is possible to reduce the influence of the disturbing radio waves that are generated steadily. Further, since the transmission output is increased, the noise resistance against jamming waves is further improved. Furthermore, since the transmission output is increased according to the compression ratio, if the value obtained by multiplying the transmission time and the transmission output is the same or less in the normal frame and the modified frame as the amount of power when transmitting Since the amount of power consumed does not change, it is suitable for a communication device driven by a battery such as a cordless telephone device.

  The ninth invention of the present application is characterized in that the deterioration of the communication environment is determined when the communication error becomes a predetermined value or more.

  Determining that the communication environment has deteriorated beyond the specified value for the deterioration of the communication environment to detect difficult communication conditions such as frames that cannot be synchronized and the validity of communication data with check codes cannot be confirmed. be able to.

  The tenth invention of the present application is characterized in that the deterioration of the communication environment is determined when the received signal strength becomes a predetermined value or less.

  By determining the deterioration of the communication environment when the received signal strength is less than or equal to the predetermined value, even if no communication error has occurred and the communication data is normal, the communication partner device gradually moves away. With the received signal strength that becomes weaker as a reference, if a frame to be transmitted is a changed frame, it is possible to prevent a communication error from occurring.

  The eleventh invention of the present application is characterized in that when a change frame is transmitted, a communication command included in the change frame is notified to other devices as notification information.

  When a change frame is transmitted, the communication command included in the change frame is notified to other devices as notification information, so that the communication partner device can easily recognize that the frame is a change frame. it can.

  The twelfth invention of the present application is characterized in that when a change frame is transmitted, a synchronization establishment bit string included in the change frame is notified to other devices as notification information.

  When transmitting a change frame, the synchronization establishment bit string included in the change frame is notified to other devices as notification information, so that the communication partner device can easily recognize that the frame is a change frame. Can do.

  The thirteenth invention of the present application is characterized in that when a synchronization establishment bit string is notified to other devices as notification information, the communication command is also a changed frame compressed at a predetermined compression ratio.

  Furthermore, when the synchronization establishment bit string is notified to other devices as notification information, the communication command can be compressed at a predetermined compression ratio. And high strength can be secured.

  In the fourteenth aspect of the present application, the deterioration of the communication environment is determined based on the first threshold value that triggers the generation of the changed frame and the second threshold value that triggers the return to the original one slot. The threshold value is a value larger than the second threshold value.

  By determining the deterioration of the communication environment in this way, it is possible to prevent frequent state transitions from a normal frame to a changed frame and from a changed frame to a normal frame.

(Embodiment)
A communication apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7, taking a cordless telephone apparatus as an example. FIG. 1 is a diagram illustrating a cordless telephone device that is an example of a communication device according to an embodiment of the present invention. FIG. 2 is a diagram for explaining a configuration of a parent device that is an example of a communication device according to an embodiment of the present invention. FIG. 3 is a diagram for explaining an example of wireless means of the communication apparatus according to the embodiment of the present invention. FIG. 4 is a diagram for explaining the configuration of a frame used when the cordless telephone apparatus according to the embodiment of the present invention communicates. FIG. 5 is a diagram showing an example of a communication command used when the cordless telephone apparatus according to the embodiment of the present invention transmits a change frame. FIGS. 6A to 6C are diagrams illustrating frames transmitted by the cordless telephone apparatus according to the embodiment of the present invention. FIG. 7 is a flowchart for explaining the operation of the cordless telephone apparatus according to the embodiment of the present invention.

  First, the configuration of a cordless telephone device, which is an example of a communication device according to an embodiment of the present invention, will be described with reference to FIG.

  As shown in FIG. 1, a cordless telephone device 1 that is an example of a communication device according to an embodiment of the present invention includes a parent device 2 and three child devices 3. Base unit 2 and handset 3 communicate with each other by TDMA. The base unit 2 is connected to the telephone line 4, and the handset 3 communicates with the base unit 2 to make a call via the telephone line 4. In FIG. 1, three slave units 3 are shown, but one or four or more slave units 3 may be used. Further, the functions of the communication device according to the embodiment of the present invention are mounted on the parent device 2 and the child device 3, but in this embodiment, the configuration and operation of the parent device 2 will be described.

  Next, the structure of the main | base station 2 which concerns on this Embodiment is demonstrated based on FIG. 2 and FIG. Base unit 2 includes microphone 10, voice encoding means 11, transmission voice data buffer 12, frame assembling means 13, digital modulation means 14, wireless means 15, digital demodulation means 16, and synchronization bit comparison means. 17, error determination means 18, error slot determination means 19, frame decomposition means 20, control data buffer 21, received voice data buffer 22, registration information storage means 23, voice decoding means 24, speaker 25.

  The microphone 10 converts the sound into an analog electric signal and outputs it to the sound encoding means 11.

  The voice encoding means 11 converts the voice electrical signal into a digital signal and compresses it, and outputs it as compressed voice data to the transmission voice data buffer 12. When there is a notification from the error slot judging means 19 that the high compression mode is set, it is output to the transmission audio data buffer 12 as high compression audio data.

  The transmission audio data buffer 12 temporarily stores the compressed audio data or the highly compressed audio data compressed by the audio encoding unit 11.

  The frame assembling unit 13 generates transmission data based on the determination by the error slot determination unit 19 and outputs the transmission data to the digital modulation unit 14. The frame assembling unit 13 generates a modified frame as high-compression audio data with a high compression ratio when the error is greater than or equal to the first threshold value as determined by the error slot determining unit 19. If the error is determined to be less than or equal to the second threshold by the determination from the error slot determination means 19, the frame is restored to the audio compression data with the normal compression ratio.

  The digital modulation means 14 performs digital modulation according to the output of the frame assembly means 13 and outputs the result to the wireless means 15.

  The radio unit 15 converts the output of the digital modulation unit 14 into an RF (Radio Frequency) signal and sends it into the air. Further, it receives the RF signal of the communication partner, converts the frequency into a baseband signal, and outputs it to the digital demodulation means 16. In addition, the wireless unit 15 includes a transmission output variable unit 15a that increases the transmission output of the frame when the error slot determination unit 19 notifies the high compression mode. Here, an example of the wireless unit 15 including the transmission output variable unit 15a will be described with reference to FIG.

  As shown in FIG. 3, the wireless unit 15 transmits an transmitted radio wave or receives a received radio wave, an antenna 30 that switches a path during transmission or reception, and amplifies the received radio wave. A receiving side amplifying unit (LAN) 32, a transmitting side amplifying unit (PA) 33 for amplifying the transmitted radio wave, an attenuator (ATT) 34 for adjusting the output of the transmitted radio wave, and the output of the digital modulation means 14 as an RF signal And an RF-IC (Integrated Circuit) 35 that receives the RF signal of the communication partner and converts the frequency into a baseband signal.

  The transmission output variable means 15 a can be an attenuator (ATT) 34 that adjusts the attenuation amount according to the notification from the error slot determination means 19. The attenuation amount of the attenuator (ATT) 34 is such that when the output of the attenuator (ATT) 34 when transmitting compressed audio data in a normal frame is “1”, highly compressed audio data with a compression ratio doubled is transmitted. In the changed frame, the output of the attenuator (ATT) 34 is set to be “2” or less. That is, when transmitting a modified frame with a high compression ratio and a short transmission time, the amount of power at the time of transmission is set to be twice or less than normal.

  Returning to FIG. 2, the digital demodulation means 16 receives the output signal of the wireless means 15, performs digital demodulation, and outputs it to the synchronization bit comparison means 17 and the frame decomposition means 20.

  The synchronization bit comparison unit 17 detects a synchronization bit from the output of the digital demodulation unit 16. When a synchronization bit is detected, a synchronization signal is generated from this synchronization bit and output to the error determination means 18.

  The error determination means 18 performs error determination when the next synchronization signal cannot be obtained within a fixed period of the TDMA communication cycle from the synchronization signal, and notifies the error slot determination means 19 of error determination when an error is detected.

  The error slot determination unit 19 notifies the reception audio data buffer 22 when there is an error determination of the error determination unit 18. The error slot determination unit 19 refers to the communication destination information registered in the registration information storage unit 23 when the error determination unit 18 has made an error determination and the reception level is a predetermined level or less. If the other party is a communication apparatus that can handle the changed frame, the frame assembling means 13 is notified of this.

  The frame decomposing means 20 decomposes the output of the digital demodulating means 16 into frames, outputs communication commands to the control data buffer 21, and outputs received audio data to the received audio data buffer 22.

  The control data buffer 21 buffers communication commands in the frame.

  The reception audio data buffer 22 buffers the reception audio data decomposed by the frame decomposition means 20.

  The registration information storage means 23 takes out information of the communication partner from the control data buffer 21 and stores it at the time of wireless registration.

  The voice decoding unit 24 decodes the voice from the communication data of the received voice data buffer 22 based on the communication command (notification information) of the changed frame stored in the control data buffer 21 and outputs an analog signal.

  The speaker 25 outputs the analog signal from the voice decoding unit 24 as sound.

  The configuration of the frame transmitted and received by the cordless telephone device 1 according to the embodiment of the present invention configured as described above will be described in detail based on FIG. 4 and FIG.

  As shown in FIG. 4, the frame configuration includes four transmission slots and four reception slots following the four transmission slots.

  In one slot, a 16-bit ramp bit, a 16-bit preamble, a 16-bit SYNC, a 64-bit A field, a 320-bit B field, a 4-bit X field, and a 4-bit Z field And is used for transmission and reception.

  The ramp bit is used for determining the sample bit, and is fixed data of “1010 1010 1010 1010”. The preamble is fixed data “1010 1010 1010 1010” in a frame transmitted from the parent device 2 to the child device 3, and “0101 0101 0101 0101” in a frame transmitted from the child device 3 to the parent device 2. Fixed data.

  SYNC is a synchronization establishment bit string used for frame synchronization establishment. The frame transmitted from the parent device 2 to the child device 3 has fixed data “1110 1001 1000 1010”, and the frame transmitted from the child device 3 to the parent device 2 has fixed data “0001 0110 0111 0101”. .

  The A field is composed of an 8-bit header part, a 40-bit tail part, and a 16-bit CRC, and a communication command is stored in the header part and the tail part. For example, when the parent device 2 notifies the child device 3 of an incoming call or notifies the parent device 2 of a call request from the child device 3, a communication command corresponding to the state is stored. In the change frame, a communication command indicating that this frame is a change frame is stored in the header part and the tail part. As shown in FIG. 5, in the present embodiment, when a change frame is transmitted, if a request is made from the child device 3 to the parent device 2, “0000 0001” is stored in the header portion, and the upper eight bits of the tail portion are stored. “0000 0010” is stored in the bit. Also, “1000 0000” is stored in the header part as a response of the base unit 2 to the request, and “0000 0010” is stored in the upper 8 bits of the tail part.

  Returning to FIG. 4, the B field stores 320-bit compressed audio data, which is compressed audio data from the parent device 2 to the child device 3 or from the child device 3 to the parent device 2, for example. Further, in the B field, if a communication command indicating that the frame is changed in the A field, 160-bit highly compressed audio data obtained by further compressing the compressed audio data twice is stored. That is, by making the compressed audio data into highly compressed audio data, the data length of the B field is halved.

  In the X field, CRC which is a check code of the B field is stored in 4 bits, and in the Z field, CRC from the A field to the X field is stored in 4 bits.

  The operation of the cordless telephone apparatus 1 according to the embodiment of the present invention that performs communication using the frame configured as described above will be further described with reference to FIGS.

  As shown in FIG. 7, first, the base unit 2 of the cordless telephone device 1 communicates with the handset 3 in a normal operation (S10). The base unit 2 uses the error determination unit 18 to determine a frame that is transmitted in the transmission slot of the handset 3 and has a communication error in which synchronization cannot be established because a ramp bit or preamble cannot be received. Then, it is counted for a certain period, and it is determined whether or not the number of communication errors is greater than or equal to a threshold A (first threshold) (S20).

  If the number of communication errors is less than the threshold value A in S20, the base unit 2 proceeds to S10 and continues communication with the handset 3 in the normal state.

  When the number of communication errors is greater than or equal to threshold A in S20, base unit 2 has a received signal strength (RSSI: Received Signal Strength Indicator) of the received frame equal to or less than threshold B (second threshold). Whether or not the error slot determination means 19 determines whether or not, from the wireless means 15 (S30).

  If the RSSI is larger than the threshold value B in S30, the parent device 2 moves to S10 and continues communication with the child device 3 in the normal state.

  If the RSSI is equal to or less than the threshold value B in S30, the error slot determination means 19 refers to the communication destination information registered in the registration information storage means 23, and the communication apparatus that can correspond to the changed frame by the other party of the communication destination It is determined whether or not. In this case, since the slave unit 3 is compatible, the error slot determination unit 19 notifies the frame assembly unit 13 of the fact. The frame assembling means 13 generates a modified frame that is highly compressed audio data obtained by further compressing the compressed audio data. Then, the digital modulation means 14 performs digital modulation in accordance with the output of the frame assembly means 13 and outputs the result to the slave unit 3 via the wireless means 15. At that time, the transmission output variable means 15 a of the wireless means 15 raises the transmission output according to the compression ratio of the frame assembling means 13 by the notification from the error slot determination means 19. That is, when the compression ratio is doubled, the transmission output is approximately doubled (S40).

  When communication is performed with a change frame from the parent device 2 to the child device 3 or from the child device 3 to the parent device 2, the error determination means 18 counts a frame of a communication error that cannot be established synchronously for a certain period. It is then determined whether or not it is equal to or less than a threshold value C (second threshold value) (S50).

  If there are more communication error frames than the threshold C in S50, the process proceeds to S40 and communication with the changed frame is continued.

  When the communication error frame is equal to or smaller than the threshold C in S50, the base unit 2 determines whether or not the RSSI of the received frame is equal to or larger than the threshold D (S60).

  If the RSSI of the received frame is smaller than the threshold value D in S60, the base unit 2 proceeds to S40 and continues communication with the changed frame.

  If it is equal to or greater than the threshold value D in S60, the process proceeds to S10 and returns to a normal state in which communication is performed using a frame having a normal bit length.

  The threshold value A and the threshold value C, which are the number of determinations of the frequency of occurrence of communication errors, are set to a larger value. In other words, the transition from the frame in the case of normal compression of the audio data to the changed frame in the high compression mode is performed by detecting the occurrence of the number of communication errors greater than or equal to the threshold A, but the return is less than or equal to the threshold C This is done by detecting the occurrence. This is because if the state transition is based only on the threshold A, the state transition frequently occurs due to a change in the communication environment. Accordingly, the return is set to be equal to or less than the threshold value C, and the threshold value A is set to a value larger than the threshold value C, thereby providing a hysteresis characteristic.

  When receiving the changed frame, the slave unit 3 analyzes the communication command of the A field, and if it recognizes that it is the changed frame, it analyzes the expansion of the communication data of the B field for the high compression mode.

  For example, as shown in FIG. 6 (A) to FIG. 6 (C), when the transmission slot and the reception slot are 4 slots and the master unit 2 communicates with four slave units 3, FIG. ) Assume that the communication environment of the slave unit 3 receiving voice data of each slot transmitted in one frame shown in FIG. 6C in the slot 3 is deteriorated as shown in FIG.

  Base unit 2 changes the audio data to be transmitted in one time slot to slave unit 3 into a high-compression audio data compressed by a double compression ratio, and outputs a transmission according to the compression ratio. Is doubled and this modified frame is transmitted. That is, as shown in FIG. 6 (B), since the audio data is compressed, the transmission time is shortened and the jamming radio wave is generated steadily than when transmitting in a normal frame used when the communication environment is good. The influence of can be reduced. Therefore, if the communication distance between the parent device 2 and the child device 3 is constant, the communication quality can be maintained and the communication distance can be increased.

  Further, since the transmission output is increased, the noise resistance against jamming waves is further improved. Furthermore, since the transmission output is increased according to the compression ratio, if the value obtained by multiplying the transmission time and the transmission output is the same or less in the normal frame and the modified frame as the amount of power when transmitting Since the amount of power consumed does not change, it is suitable for a battery-powered communication device such as the handset 3 of the cordless telephone device 1.

  Next, a cordless telephone apparatus according to another embodiment of the present invention will be described with reference to FIG. FIG. 8 is a diagram showing an example of a synchronization establishment bit string used when a cordless telephone apparatus according to another embodiment of the present invention transmits a change frame. A cordless telephone apparatus according to another embodiment of the present invention is characterized in that a changed frame is notified to another communication apparatus using a synchronization establishment bit string (notification information).

  As shown in FIG. 8, when transmitting a normal frame, SYNC, which is a synchronization establishment bit string used for establishing frame synchronization, is “1110 1001 1000 1010” in a frame transmitted from the parent device 2 to the child device 3. Yes, the frame transmitted from the child device 3 to the parent device 2 is “0001 0110 0111 0101”.

  However, when the communication environment deteriorates, it is transmitted in a changed frame as highly compressed audio data with a high compression ratio. In that case, this SYNC is used to notify the communication destination that it is a changed frame.

  For example, “1000 1010 1110 1001” is used for a frame transmitted from the parent device 2 to the child device 3, and “0111 0101 0001 0110” is used for a frame transmitted from the child device 3 to the parent device 2.

  By changing SYNC in this way, this changed frame compresses not only audio data, which is communication data stored in the B field, but also the fields below the SYNC, the A field, the B field, the X field, and the Z field. Therefore, it is possible to improve the strength against noise such as jamming radio waves.

  The synchronization establishment bit string of SYNC can be appropriately set as long as it is negotiated between the parent device and the child device.

  The embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment. For example, if the compression ratio is tripled, the transmission output is three times or less, and the compression ratio is If the power is four times, the transmission output can be changed as appropriate if the amount of power is the same or less, such as four times or less.

  The present invention is suitable for a communication apparatus that performs wireless communication by time division multiplexing because it is less susceptible to the influence of jamming waves and can maintain communication quality.

The figure explaining the cordless telephone apparatus which is an example of the communication apparatus which concerns on embodiment of this invention The figure explaining the structure of the main | base station which is an example of the communication apparatus which concerns on embodiment of this invention The figure explaining an example of the radio | wireless means of the communication apparatus which concerns on embodiment of this invention The figure explaining the structure of the flame | frame used when the cordless telephone apparatus which concerns on embodiment of this invention communicates The figure which shows an example of the communication command used when the cordless telephone apparatus which concerns on embodiment of this invention transmits a change frame. The figure explaining the flame | frame which the cordless telephone apparatus which concerns on embodiment of this invention transmits The flowchart explaining operation | movement of the cordless telephone apparatus which concerns on embodiment of this invention. The figure which shows an example of the synchronization establishment bit sequence used when the cordless telephone apparatus which concerns on other embodiment of this invention transmits a change frame.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cordless telephone apparatus 2 Parent | base station 3 Sub_unit 4 Telephone line 10 Microphone 11 Voice encoding means 12 Transmission voice data buffer 13 Frame assembly means 14 Digital modulation means 15 Radio means 15a Transmission output variable means 16 Digital demodulation means 17 Synchronous bit comparison means DESCRIPTION OF SYMBOLS 18 Error determination means 19 Error slot determination means 20 Frame decomposition means 21 Control data buffer 22 Reception voice data buffer 23 Registration information storage means 24 Voice decoding means 25 Speaker 30 Antenna 31 Switch part 32 Reception side amplification part (LAN)
33 Transmitting side amplifier (PA)
34 Attenuator (ATT)
35 RF-IC

Claims (14)

In a communication device that transmits frames in a time division multiplexed slot,
Detecting means for determining deterioration of the communication environment when transmitting the frame;
When there is a notification from the detecting means that the communication environment has been deteriorated, a frame assembling means for converting the communication data to be transmitted in one time slot into a change frame compressed at a predetermined compression ratio;
And a wireless unit configured to increase the transmission output according to the compression ratio and transmit the modified frame. The communication device according to claim 1, wherein the detection unit has a function of determining deterioration of the communication environment when a communication error becomes a predetermined value or more. The communication device according to claim 1, wherein the detection unit has a function of determining deterioration of the communication environment based on a received signal strength being a predetermined value or less. 4. The frame assembly means according to claim 1, further comprising a function of notifying another device of a communication command included in the change frame as notification information when the change frame is transmitted. The communication device according to the section. 4. The frame assembly means according to claim 1, further comprising a function of notifying another apparatus as notification information of a synchronization establishment bit string included in the change frame when the change frame is transmitted. A communication device according to any of the above sections. 6. The function of claim 5, wherein the frame assembling means has a function of converting the communication command into a changed frame compressed at a predetermined compression ratio when the synchronization establishment bit string is notified to another apparatus as notification information. The communication device described. The detection means includes a first threshold value that triggers the frame assembly means to generate the changed frame and a second threshold value that triggers the frame assembly means to return to the original one slot. Judge deterioration of
The communication apparatus according to claim 1, wherein the first threshold value is larger than the second threshold value. In a communication method of a communication device that transmits a frame in a time division multiplexed slot,
When transmitting the frame and detecting the deterioration of the communication environment,
A change frame in which communication data transmitted in one time slot is compressed at a predetermined compression ratio,
A communication method for a communication apparatus, wherein the change frame is transmitted by increasing a transmission output in accordance with the compression ratio. 9. The communication method of a communication apparatus according to claim 8, wherein the deterioration of the communication environment is determined when a communication error becomes a predetermined value or more. 10. The communication method of a communication apparatus according to claim 8, wherein the deterioration of the communication environment is determined when a received signal strength becomes a predetermined value or less. 11. The communication method of a communication apparatus according to claim 8, wherein when the change frame is transmitted, a communication command included in the change frame is notified to other apparatuses as notification information. . 11. The communication of a communication device according to claim 8, wherein when transmitting the change frame, the synchronization establishment bit string included in the change frame is notified to other devices as notification information. Method. 13. The communication method of a communication device according to claim 12, wherein when the synchronization establishment bit string is notified to other devices as notification information, the communication command is also a changed frame compressed at a predetermined compression ratio. Deterioration of the communication environment is determined based on a first threshold that triggers the generation of the changed frame and a second threshold that triggers the return to the original one slot.
The communication method of the communication apparatus according to claim 8, wherein the first threshold value is larger than the second threshold value.

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