JPH0734596B2 - Transceiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order.

A Industrial Field B Outline of Invention C Conventional Technology D Problems to be Solved by the Invention E Means for Solving Problems F Action G Example G ₁ First Example (FIGS. 1 to 1) Fig. 6) G ₂ Other embodiments H Effect of the invention A Industrial field of application The present invention relates to a transceiver such as a cordless telephone.

B. Outline of the Invention The present invention is, for example, in a cordless telephone of a multi-channel access system having no control channel, by performing a connection between a handset and a base unit by a predetermined procedure, a call from the handset and a telephone line are performed. Even if the incoming call and the incoming call occur simultaneously, the connection is made immediately.

C Conventional Technology In a general telephone, its telephone cord is connected to a rosette attached to a pillar or a wall. Therefore, the range in which the telephone can be moved is determined by the length of the telephone cord and is about several meters. However, if the phone cord is lengthened to increase the range of movement, the cord will become entangled or obstructed.

Therefore, in the United States and the like, a telephone system called a cordless telephone is considered.

As shown in FIG. 7, it is composed of a transceiver (1) called a handset and a transceiver (2) called a base unit, and a telephone line (3) is connected to the base unit (2). At the same time, the base unit (2) and the handset (1) are coupled by radio waves, and the telephone of the subscriber is answered by the handset (1) in the same manner as a general telephone.

Therefore, the subscriber can freely move the handset (1) when making a call, and the telephone cord is not tangled or disturbed.

The distance (service area) where the handset (1) can be separated from the base unit (2) is about 300 m. The frequency of radio waves used between the handset (1) and the base unit (2) is 49 MHz band for the up channel and 46 MHz band for the down channel, and 10 duplex channels are approved by the FCC.

Thus, according to this cordless telephone, the telephone can be conveniently used.

However, in the cordless telephone, even if 10 duplex channels are allowed for a call, a control channel for controlling which of these 10 channels is used is not prepared.

Therefore, when the cordless telephone is the MCA system (multi-channel access system), this is realized as follows.

That is, in FIG. 6, the left side is the handset (1).
The channel managed by the base unit (2) is shown on the right side. Also, [1]
The numbers from [10] to [10] indicate the channel numbers, ○ indicates an empty channel, ● indicates a channel used by oneself, and × indicates a channel used by another station.

During standby (standby mode), the handset (1) waits for a call from the base unit (2) by sequentially and repeatedly scanning all channels (reception channels), as shown in FIG. . Similarly, the base unit (2) similarly repeats scanning all channels in sequence and waits for a call from the handset (1).

When the handset (1) makes a call, when the handset (1) is set to the call mode (talk mode), the handset (1) searches for a vacant channel as shown in FIG. 3rd in the figure
Channel), the scanning is stopped on this empty channel, the identification code is repeatedly transmitted, and the return of the identification code is awaited.

Then, in the base unit (2), an identification code is obtained when the channel (third channel) is reached during scanning, and when this identification code is obtained,
Scanning is stopped on this channel, the identification code is returned, and then the call mode is entered on that channel.

Further, in the handset (1), when the identification code is returned, thereafter, the call mode is entered in that channel.

Therefore, after that, that channel (third channel)
A dialed number is sent through, and if the other party answers the call, the call is made.

On the other hand, even when an incoming call is made from the telephone line (3), only the positions of the handset (1) and the base unit (2) are switched, and as shown in FIG. ) Is used to make incoming calls and subsequent calls.

D Problem to be Solved by the Invention However, when the MCA method is realized as described above, as shown in D of the same figure, there is a call from the handset (1),
When an incoming call from the telephone line (3) occurs at the same time, both the handset (1) and the base unit (2) send an identification code on an empty channel (channel 3 and channel 9 in the figure) respectively. Since it tries to capture the other party, it takes time to connect both parties.

The present invention is intended to solve such a problem.

E Means for Solving Problems Therefore, in the present invention, for example, FIGS.
The handset (1) and the base unit (2) are connected by performing the processing shown in the figure.

F 2 When an outgoing call and an incoming call occur at the same time, the incoming call is given priority, and the connection time between the handset (1) and the base unit (2) is shortened.

G Embodiment G ₁ First Embodiment FIG. 1 shows an example of a handset (1), in which (110) is a transmitting circuit and (120) is a receiving circuit. Further, FIG. 2 shows an example of the base unit (2), in which (210) is a transmitting circuit and (220) is a receiving circuit.

Then, at the time of transmission, in the handset (1), the audio signal St from the transmitter (111) is changed to the low frequency amplifier (112).
Is supplied to the VCO (not shown) of the PLL (113) through and is converted to the FM signal Su of the upstream channel, and this FM signal Su is
It is supplied to the antenna (100) through a high frequency power amplifier (114) and a band pass filter (115) whose pass band is all upstream channels, and is supplied to the base unit (2).
Sent to.

Then, in the base unit (2), the signal (radio wave) Su from the handset (1) is received by the antenna (200), and the received signal Su is a bandpass filter (221) having all upstream channels as pass bands. ) And the high frequency amplifier (222) to the mixer circuit (223), and the local oscillation signal of a predetermined frequency from the PLL (224) is supplied to the mixer circuit (223) to convert the signal Su into an intermediate frequency signal. This intermediate frequency signal is supplied to the FM demodulation circuit (226) through the intermediate frequency amplifier (225) to demodulate the audio signal St, and this signal St is converted into the low frequency amplifier (22
7) → 2 wire to 4 wire conversion circuit (231) → relay circuit (232)
Is sent out to the telephone line (3) through the signal line.

In this case, the relay circuit (232) is a line relay for turning on / off the connection between the base unit (2) and the telephone line (3), and a call is made after the base unit (2) and the line (3) are connected. When suspending, the line (3)
It has a hold relay and so on for holding.

In addition, when receiving a voice signal Sr from the telephone line (3)
Is supplied to the handset (128) of the handset (1) by the same processing as when transmitting. That is, the voice signal Sr from the line (3) is converted into the relay line (232) → the conversion circuit (231).
→ The PLL (21
It is supplied to the VCO (not shown) in 3) and is converted into the FM signal Sd of the downlink channel which forms a pair with the FM signal Su, and this signal Sd is
It is supplied to the antenna (200) through the high frequency power amplifier (214) and the band bus filter (215) having the pass band in all the downstream channels, and is transmitted to the handset (1).

Then, in the handset (1), the signal Sd from the base unit (2) is received by the antenna (100), and the received signal Sd has a bandpass filter (121) having a pass band in all downlink channels and a high frequency wave. The local oscillation signal of a predetermined frequency is supplied from the PLL (124) to the mixer circuit (123) while being supplied to the mixer circuit (123) through the amplifier (122), and the signal Sd is an intermediate frequency signal. The signal is supplied to the FM demodulation circuit (126) through the intermediate frequency amplifier (125) to demodulate the audio signal Sr, and the signal Sr is supplied to the receiver (128) through the low frequency amplifier (127).

Further, in the handset (1), reference numeral (140) represents a control circuit for controlling a communication channel and the like. The control circuit (140) is composed of a one-chip type microcomputer. For example, (141) is a CPU for 4-bit parallel processing, (142) is a ROM in which a program is written, and (143) is RAM for work area, (144) is an input / output port. The ROM (142) is also provided with a routine (300) shown in FIG. 3, for example.

Furthermore, the microcomputer (140) has a dial key (151),
The talk switch (152) and the ROM (153) are connected.
In this case, the dial key (151) is a non-lock type push switch for inputting the other party's telephone number,
The talk switch (152) is a three-position selector switch for selecting the operation mode of the handset (1), and when the switch (152) is at the contact O, the power of the circuits other than the microcomputer (140) is turned off. When the contact S is turned off (off mode), the signal Sd from the base unit (2) is in a standby state (standby mode),
At the contact point T, the handset (1) and the base unit (2) are in a call state (talk mode), and are normally connected to the standby contact point S.

The ROM (153) is for giving an identification code ID, and these keys and the outputs of the ROMs (151) to (153) are supplied to the microcomputer (140).

Further, (161) indicates an MSK modulation circuit, which receives a code signal such as an identification code ID and a dial signal DS from the microcomputer (140) and converts this code signal from a binary signal to FIG. 5A. Audio band MSK signal Sm as shown
Alternatively, as shown in FIG. 9B, the signal St is converted into the MSK signal Sm outside the audio band on the low frequency side of the signal St, and the signal Sm is supplied to the amplifier (112). In this case, the signal Sm of FIG. A is used when opening a communication channel between the handset (1) and the base unit (2), and therefore the code signal modulating the signal Sm. The transmission speed of is set to a high speed of 1.2 kbps, for example. Also,
The signal Sm in FIG. 9B is used when the call channel between the handset (1) and the base unit (2) is open and a call is made.
The transmission speed of the code signal that modulates Sm is 110 bps, for example.
It is said to be slow.

Further, (162) indicates a reception detection circuit, which is connected to the demodulation circuit (126), and which receives the signal S from the base unit (2).
The presence or absence of the signal Sd is detected by utilizing the difference in the frequency component of the output of the demodulation circuit (126) depending on the presence or absence of d, and the detection signal NSQL is supplied to the microcomputer (140).

Further, (163) indicates an MSK demodulation circuit, which is connected to the demodulation circuit (126) and demodulates a code signal from the MSK signal Sm sent from the base unit (2). Supplied to the microcomputer (140).

Further, (164) represents a ring tone signal forming circuit, which is controlled by the microcomputer (140) and forms a bell sound signal (ring tone signal) when a call is received. Supplied to the Ringer (165).

Further, a signal CH designating a channel is supplied from the microcomputer (140) to the PLLs (113) and (124), and a signal TXEN for controlling whether or not the FM signal Su is sent is PL.
Supplied to L (113). The muting signal MUTE is supplied from the microcomputer (140) to the amplifier (127).

Further, in the base unit (2), (240) indicates a control circuit. The control circuit (240) is configured similarly to the control circuit (140) of the handset (1) and has the same function, and the circuit (141) of the control circuit (140).
For the circuits corresponding to (144), replace the numbers in the 100s
Numbers in the 200s are attached and explanations are omitted. However, ROM
For example, the routine (400) shown in FIG. 4 is provided in (242).

The ROM (253) and the circuits (261) to (264) are also the same as the ROM (153) and the circuits (161) to (164) of the handset (1), and the same applies to each signal. The description is also omitted. However, the forming circuit (264) forms the tone encode signal (DTMF signal) TE corresponding to the telephone number when making a call to the other party.

Furthermore, (265) shows a ring tone signal detection circuit,
This is for detecting a bell sound signal (ring tone signal) when a call is received by being connected to the telephone line (3), and the detection signal BL is supplied to the microcomputer (240).

And the handset (1) and the base unit (2)
In accordance with routines (300) and (400), CP
The following processes are performed by U (141) and (241).

That is, in the handset (1), in the standby (standby mode), in the step (301), the signal CH
Controls the PLLs (113) and (124) to set the upstream and downstream channels corresponding to the value of the signal CH, and then checks the switching position of the talk switch (152) in step (302). Since it is connected to the contact S in standby mode,
Proceed from step 2) to step (303). Then, in this step (303), it is checked by the signal NSQL whether or not the FM signal Sd is received by the downlink channel set in the step (301), and when the signal Sd is not received, the process proceeds to the step (303). To step (304), the signal CH is set to the value of the next channel (adjacent channel) in this step (304), and then the process returns to step (301).

When the signal Sd is received in step (303), the process proceeds from step (303) to step (305), in which the identification code ID from the demodulation circuit (163) and the ROM (153). If it does not match (from the base unit (2) of another subscriber), the process proceeds from step (305) to step (304).

Therefore, in the handset (1), when waiting,
Steps (301) to (305) are repeated, and as shown in FIG. 6A, all downlink channels are sequentially and repeatedly scanned.

In the base unit (2), steps (401) to (405) and (441) of the routine (400) are executed during standby. In this case, steps (401) to (405) perform the same processing as steps (301) to (305), and a description thereof will be omitted, but in step (402),
The presence or absence of an incoming call from the outside line (3) is detected by the detection signal BL, and when there is no incoming call, the process proceeds from step (402) to step (403). In step (403), the presence / absence of the FM signal Su is checked instead of the presence / absence of the FM signal Sd in step (303). Further, a step (441) is provided between the step (401) and the step (402), which is a flag IFLG described later.
Is checked and IFLG = “0” is reset during standby, the process proceeds from step (441) to step (402).

Therefore, in the base unit (2), steps (401) to (405) and (441) are repeated during standby, and all the upstream channels are sequentially and repeatedly scanned as shown in FIG. Become.

When the handset (1) makes a call, the talk switch (152) is switched to the talk mode contact T. Then, this is determined in step (302), the process proceeds from step (302) to step (311), and in this step (311), the uplink and downlink channels set by step (301) are used by another station. If it is not used, the process proceeds from step (311) to step (312). Then, in this step (312), the sending of the FM signal Su is permitted by the signal TXEN, and then in the step (313), the identification code ID of the ROM (153) is converted into the MSK signal Sm by the modulation circuit (161) and the amplifier ( 112)
6 and thus the identification code ID is transmitted to the base unit (2) by the FM signal Su of the upstream channel set in step (301).

In this case, if the identification code ID is not returned from the base unit (2), the transmission of the identification code ID in the step (313) is performed for at least one round of scanning the channel in the base unit (2). It is repeated.

Then, in the base unit (2), while waiting, all the upstream channels are sequentially scanned by repeating steps (401) to (405) and (441).
When the scan reaches the upstream channel where the handset (1) is transmitting the identification code ID, the process proceeds from step (403) to step (405), the scan is stopped, and the identification code ID is sent. Is determined.

Then, the process proceeds from step (405) to step (421), and in this step (421), the signal TXEN causes FM.
Transmission of the signal Sd is permitted, and then in step (422), the identification code ID of the ROM (253) is set to M by the modulation circuit (261).
The SK signal Sm is supplied to the amplifier (212). Therefore, as shown in FIG. 9B, the identification code ID is determined by the FM signal Sd of the downlink channel paired with the uplink channel set in step (301). Returned to handset (1).

Then, the process proceeds from step (422) to step (490), in which the base unit (2) and the telephone line (3) are connected, that is, the signal
Muting of the amplifier (227) is released by MUTE, and the conversion circuit (23
1) and the line (3) are connected.

In the handset (1), step (31
At the same time as transmitting the identification code ID in 3), it is checked by the output signal of the demodulation circuit (163) whether or not the identification code ID is returned in step (314) (actually, in step (313) (314) alternately in a time-division manner and over the shorter of the period in which the channel scan in the base unit (2) makes one round and the period until the return of the identification code ID is confirmed. ing).

Then, in this case, since the base unit (2) has returned the identification code ID, the process proceeds from step (314) to step (390), and in this step (390), the handset (1) and the base unit (2). ) Is connected, that is, in the handset (1), the muting of the amplifier (127) is released by the signal MUTE.

Therefore, the handset (1) is connected to the telephone line (3) through the base unit (2).

Therefore, in the handset (1), dial key (15
When 1) is operated according to the telephone number of the other party, the corresponding dial signal DS is formed by the microcomputer (140) and is converted into the MSK signal Sm by the modulation circuit (161).
Similarly, it is transmitted to the base unit (2).

Then, in the base unit (2), the dial signal DS is taken out from the demodulation circuit (263), and this signal DS
Based on, the formation circuit (264) is controlled by the microcomputer (240) to form a tone encode signal TE corresponding to the telephone number of the other party, and this signal TE is passed through the amplifier (227),
Further, it is sent to the telephone line (3) through the conversion circuit (231) and the relay circuit (232). Therefore, this signal
When the other party is called by the TE and the other party answers the call, the call becomes possible as described above.

In step (311), if the channel set in step (301) is already used by another station, the process proceeds from step (311) to step (304), and the signal is transmitted by this step (304). CH is set to the value of the next channel, and the process returns to step (301).
Therefore, steps (312) to (314), (421), (4
The processing of 22) will be performed on an empty channel, and subsequent calls will be made on that empty channel.

If the correct identification code ID is not returned from the base unit (2) in step (314), the process proceeds from step (314) to step (315).
Then, in this step (315), the transmission of the signal Su is stopped by the signal TXEN, and then the process proceeds to the step (30
Go to 4). Therefore, when the identification code ID is not returned from the base unit (2), the base unit (2) is similarly called in the next vacant channel.

Thus, when the handset (1) makes a call, when the talk switch (152) is set to the talk contact T, an empty channel is searched for, the base unit (2) is called by the empty channel, and a response is sent from the base unit (2). If there is, a channel is opened between the handset (1) and the base unit (2), and it becomes possible to call and talk with the other party.

When an incoming call is received from the telephone line (3), steps (411) to (414) of the routine (400) and steps (321) and (322) of the routine (300) are executed.
In this case, these steps (411) to (414) and (32
1) and (322) are steps (311) to (314) and (42).
1) and (422), the signal BL is discriminated in step (402) when there is an incoming call, so the process proceeds from step (402) to step (411), and thereafter. As shown in FIG. 6C, the telephone line (3) is connected to the handset (1) through the base unit (2) in the same manner as when making a call.

On the other hand, if the handset (1) is called and the telephone line (3) is called at the same time, the following processing is performed.

That is, in this case, the identification code ID is transmitted from the handset (1) in step (313), and
At step (413), the identification code ID is transmitted from the base unit (2). And in this case, in general,
As shown in FIG. 6D, since the transmission channel of the handset (1) and the transmission channel of the base unit (2) are different, the FM signals Sd, Su of the other party cannot be received, and therefore the identification code ID is transmitted to the other party. Will not be returned.

Then, in the handset (1), step (31
Since the identification code ID is not returned in 4), the process proceeds from step (314) to step (315) to step (304). Therefore, as shown in FIG. 8E, the next empty channel is searched for in the same manner as at the time of normal call origination, and the identification code ID is transmitted again on this empty channel.

In addition, in the base unit (2), the step (41
Since the identification code ID is not returned in 4), the process proceeds from step (414) to step (415), in which the transmission of the FM signal Sd is stopped by the signal TXEN, and then step (416). ), The flag IFLG indicating whether or not the identification code ID is returned is set to "1", the loop counter CNTR is reset to "0", and the process proceeds to step (404).

When the step (404) and the subsequent step (401) are reached, the identification code ID is set to the channel next to the channel that previously transmitted, and then the step (441).
At IFLG = “1”, the process proceeds from step (441) to step (442). And this step (44
In 2), the counter CNTR is incremented by "1", and then in step (443), it is checked whether the value of the counter CNTR becomes "10" or more.
If it is less than, the process proceeds to step (403).

Therefore, thereafter, steps (401) to (404) are repeated with steps (441) to (443) in between, and as shown in FIG. 8E, each channel is sequentially searched in the same manner as during standby.

Then, during this search, the handset (1) is transmitting the identification code ID on the next empty channel at the time of calling, so when the search of the base unit (2) reaches that channel, the process is step ( 403) to step (4
Go to step (421) through 05), then step (422)
Returns the identification code ID.

Therefore, thereafter, as shown in FIG. 7F, the telephone line (3) is connected to the handset (1) through the base unit (2) in the same manner as at the time of a normal incoming call.

When steps (401) to (404) are repeated and each channel is searched by repeating steps (441) to (443), CNTR = 10 after one round of this search. The process proceeds from step (443) to step (444), IFLG = "0" is reset in this step (444), and then the process proceeds to step (403). Therefore, when the search does not receive the identification code ID even after making a round of all the channels, the standby mode is subsequently entered.

Thus, according to the present invention, in an MCA type cordless telephone without a control channel, when a call is made from the handset (1) and an incoming call is made from the telephone line (3) at the same time, the handset (1) is Since the base unit (2) is called on an empty channel and the base unit (2) is searching each channel, the handset (1) should call the base unit (2) by the time the search completes one cycle. Can
Therefore, even if an outgoing call and an incoming call occur at the same time, the incoming call can be received by opening a channel between the handset (1) and the base unit (2).

Moreover, for that purpose, it is only necessary to add steps (441) to (444) and (416) to the processing routine (400) of the base unit (2), which is simple.

G ₂ Other Embodiments In the above description, the circuits (161) to (164), (261)
The operation of (264) can be realized by software. Further, the telephone number of the other party can be sent out by a dial pulse.

The identification code ID in steps (313) and (413)
And the presence or absence of the FM signal Sd, Su from the other party is checked, and if this signal Sd, Su is obtained, step (31
The identification code ID may be checked in 4) and (414). Furthermore, not only cordless telephones, transceivers,
The present invention can also be applied to a carrier-type intercom that uses a commercial AC power line.

H Effect of the Invention According to the present invention, an MCA without a control channel
In the cordless telephone of the method, when a call is made from the handset (1) and an incoming call is made from the telephone line (3) at the same time, the handset (1) calls the base unit (2) on another free channel. ,
Since the base unit (2) is searching each channel, the handset (1) is searched by the time the search completes one cycle.
Can call the base unit (2), thus opening a channel between the handset (1) and the base unit (2) to receive an incoming call even if an outgoing call and an incoming call occur simultaneously. it can.

Moreover, for that purpose, it is only necessary to add steps (441) to (445) to the processing routine (400) of the base unit (2), which is simple.

[Brief description of drawings]

1 and 2 are system diagrams of an example of the present invention, and FIGS. 3 to 7 are diagrams for explaining the same. (1) is the handset, (2) is the base unit, (11
0) and (210) are transmission circuits, (120) and (220) are reception circuits, and (140) and (240) are control circuits.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location 7304-5K H04B 7/26 111 7304-5K 109 S

Claims (1)

[Claims] 1. A transmitter / receiver in which a first and a second transmitter / receiver are combined, and a call is made between the first and the second transmitter / receiver by using one passage channel of a plurality of call channels. In the device, when calling one of the first and second transceivers from the other, the one passage channel is used to send a code signal from the one to the other, and in the other, the code signal is transmitted. When received,
When the code signal indicating the reception is returned through the one call channel, and the transmission and the return of the code signal are normally performed,
The one side and the other side are connected through the one call channel, and thereafter the call between the one side and the other side is permitted, and in the first transceiver, the reception from the second transceiver is received. Is not received, the first transmitter / receiver checks the return of the reception / reception code signal from the second transmitter / receiver while sequentially scanning the plurality of communication channels, and this return is detected. A transmitting / receiving device configured to connect the first and second transmitters / receivers through the returned call channel to permit the call.