JPH11136768A - Digital cordless telephone set and digital signal communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital cordless telephone set that correctly sends a MODEM signal as a radio signal. SOLUTION: The digital cordless telephone set that conducts transmission/ reception for the 4-channel multiplex TDMA-TDD system is provided with a digital coding means 3 that samples a transmission analog signal at an 8 kHz period and codes the signal into pulse code modulation PCM data of 8-bit unit and with a channel data transmission means 8 that transmits every 160-bit PCM data coded by the digital coding means 3 through two different channels. Since uncompressed PCM data are transmitted, the receiver side decodes the data correctly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital cordless telephone apparatus used for a PHS (Personal Handy Phone System) and the like, and a digital signal communication method therefor. It was made.

[0002]

2. Description of the Related Art Digital cordless telephones include a PHS used outdoors and a cordless telephone used in homes and offices. In these digital cordless telephone systems, four slots for transmission and four slots for reception are used as an access method between a fixed base station (hereinafter, referred to as a base unit) connected to a telephone network and a mobile station (hereinafter, referred to as a slave unit). 4-channel multiplexing TDM using 4 slots
The A-TDD method is adopted. 4 Tx / Rx slots, 1 TDM including a total of 8 slots
The A-TDD frame is set to a time length of 5 ms and 1
The time length of the slot is set to 625 μs.

In this system, an analog signal is compression-encoded by an ADPCM (Adaptive Differential PCM) system and transmitted and received. The ADPCM is a method of predicting a current input signal from a past input signal and quantizing a prediction difference, and a quantization step is determined based on a past quantization value. The transmitting side transmits only the quantized data of the prediction difference to the receiving side.

[0004] A master or slave on the transmitting side samples an analog signal at a period of 8 kHz, compresses the digital signal into 4-bit digital data by ADPCM, and transmits the digital data. The information transfer rate is 8 kHz × 4 bits, 32 kbps, and 160-bit audio data is transmitted using one slot for communication.

[0005] The master or slave on the side that has received the ADPCM data decodes and expands this into an analog signal.

In a digital cordless telephone, a modem signal such as facsimile or personal computer communication can be wirelessly communicated, and 64 kbps using up to two slots can be used.
Data communication up to s is possible.

[0007]

However, in a conventional digital cordless telephone, an analog signal is compression-encoded by ADPCM. Therefore, when an analog signal to be transmitted is a modem signal exceeding 9600 bps, a decoding process is not performed. There is a problem that the modem signal is not correctly decoded and the data is partially fragmented.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and provides a digital cordless telephone device capable of correctly performing wireless communication of a modem signal.
It is an object of the present invention to provide a digital signal transmission method therefor.

[0009]

Therefore, in the present invention, 4
In a digital cordless telephone device performing transmission / reception of a channel multiplexing TDMA-TDD system, digital encoding means for sampling an analog signal to be transmitted at a period of 8 kHz and encoding it into 8-bit PCM (pulse code modulation) data; Channel data transmitting means for transmitting 160-bit PCM data encoded by the converting means using two different channels.

In the digital signal communication method according to the present invention, the transmitting side samples an analog signal to be transmitted at a period of 8 kHz, encodes the data into 8-bit PCM data, and divides the data into 160-bit data. Transmission is performed using two different channels, and the receiving side receives the two channels and incorporates the 16 channels embedded in each channel.
PCM data is reproduced in units of 8 bits from data of 0 bits each and converted to an analog signal at a period of 8 kHz.

As described above, since the analog signal is uncompressed by the PCM code processing, even when transmitting a modem signal exceeding 9600 bps, correct decoding can be performed on the receiving side. Further, since PCM data is transmitted using two channels (slots), it is possible to transmit and receive 8-bit PCM data under the 4-channel multiplexing TDMA-TDD system adopted in PCM. is there.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a digital cordless telephone apparatus for performing transmission / reception of a 4-channel multiplexed TDMA-TDD system, in which an analog signal to be transmitted is sampled at a period of 8 kHz and is transmitted in 8-bit units. Digital encoding means for encoding the PCM data of the present invention, and channel data transmitting means for transmitting the 160-bit PCM data encoded by the digital encoding means using two different channels. Yes, since uncompressed PCM data is transmitted, correct decoding on the receiving side is possible.

According to a second aspect of the present invention, 8-bit PCM data encoded by the digital encoding means is
A data dividing unit for dividing the data into upper 4 bits and lower 4 bits is provided.
The lower 4 bits of data for the bits are transmitted using different channels, and the PCM data is transmitted in units of 8 bits under the 4-channel multiplexing TDMA-TDD system adopted in the PHS. can do.

According to a third aspect of the present invention, the channel data transmitting means transmits 20 pieces of 8-bit PCM data encoded by the digital encoding means using different channels. This makes it possible to transmit 8-bit PCM data under the 4-channel multiplexing TDMA-TDD system.

According to a fourth aspect of the present invention, there is provided a digital cordless telephone apparatus for performing transmission / reception of a 4-channel multiplexed TDMA-TDD system, wherein a channel for receiving 160 bits of PCM data incorporated in each of two different channels. Data receiving means, 8-bit data storing means for storing 8-bit PCM data based on the received data, and converting 8-bit PCM data stored in the 8-bit data storing means into analog signals at a period of 8 kHz Analog signal converting means for receiving the data transmitted from the telephone device of claim 1 and decoding the analog signal.

According to a fifth aspect of the present invention, the 8-bit data storage means receives four bits received from each of the two channels.
The PCM data is constructed and stored in units of 8 bits by combining bit data. The data transmitted from the telephone device according to the second aspect can be received and an analog signal can be decoded.

According to a sixth aspect of the present invention, in the digital signal communication method of the 4-channel multiplexing TDMA-TDD system, the transmitting side samples an analog signal to be transmitted at a period of 8 kHz and encodes it into 8-bit PCM data. , Is divided into 160-bit data, and transmitted using two different channels.
Receiving one channel and one embedded in each channel
The PCM data in the unit of 8 bits is reproduced from the data of 60 bits, and is converted into an analog signal at a period of 8 kHz. Since the uncompressed PCM data is transmitted, a modem exceeding 9600 bps is transmitted. Even when transmitting a signal, the signal can be correctly decoded on the receiving side.

According to a seventh aspect of the present invention, the transmitting side divides the coded 8-bit PCM data into upper 4-bit data and lower 4-bit data, and transmits the upper 4 bits of 160 bits. The data and the lower 4 bits of data for 160 bits are transmitted using two different channels, respectively, and the receiving side transmits the upper 4 bits of data and the lower 4 bits of data received from each of the two channels. To reproduce PCM data in 8-bit units. PCM data in 8-bit units can be transmitted under the 4-channel multiplexing TDMA-TDD system adopted in PHS.

According to an eighth aspect of the present invention, the transmitting side transmits 20 pieces of coded 8-bit PCM data using two different channels, and the receiving side transmits each of the two channels. 20 received from
The PCM data in 8-bit units is reproduced from the data for each data.
Under the 4-channel multiplexing TDMA-TDD system, transmission of PCM data in units of 8 bits is possible.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) As shown in FIG. 1, a digital cordless telephone apparatus according to a first embodiment comprises a master unit (FIG. 1A) and a slave unit (FIG. 1B). Become. A master unit (FIG. 1A) is connected to a telephone line 1 for separating and transmitting analog signals to be transmitted and received, and a two-wire / four-wire conversion circuit 2 for separating or combining an analog transmission signal and an analog reception signal. , The analog reception signal input from the telephone line 1
digital encoding means 3 for encoding into 8-bit PCM code at a sampling cycle of kHz;
A data dividing means 4 for dividing the data in bit units into four bits, and a data storing means 4 for storing the data divided into four bits
A 160-bit data buffer 6 for temporarily storing 160-bit data;
A channel frame assembling section 7 for constructing a channel frame using 4-bit data of 160 bits taken into the bit data buffer 6, and channel data transmitting means for transmitting the assembled channel frame using two channels (slots) 8 and a wireless transmission unit 9 for performing transmission, and a wireless reception unit 10 for performing reception.
Channel data receiving means 11 for receiving data of two channels, and a channel frame decomposing unit for separating and generating 160-bit code data from each channel frame
12, a 160-bit data buffer 13 for temporarily storing 160-bit data, and a 160-bit data buffer
The apparatus includes an 8-bit data storage unit for storing data temporarily stored in the storage unit 13 and storing data in units of 8 bits, and an analog signal conversion unit 15 for decoding digital data in units of 8 bits into analog signals.

On the other hand, the slave unit (FIG. 1 (b)) has a facsimile transmission / reception function, and a facsimile modem 16 for transmitting / receiving a facsimile modem signal and a facsimile machine input from the facsimile modem 16.
Digital encoding means 17 for encoding an X modem signal into an 8-bit PCM code at a sampling period of 8 kHz.
Data dividing means 18 for dividing the encoded 8-bit data into 4-bit data, 4-bit data storing means 19 for storing the 4-bit data, 160
A 160-bit data buffer 20 for temporarily storing bits of data, a channel frame assembling unit 21 for forming a channel frame using 4-bit data of 160 bits taken into the 160-bit data buffer 20, and an assembled channel frame Channel data transmitting means 22 for transmitting data using two channels, a radio transmitting section 23 for performing transmission, a radio receiving section 24 for performing reception, and channel data for receiving data from the two channels. A receiving means 25; and a channel frame decomposing unit 26 for separating / generating 160-bit code data from each channel.
And a 160-bit data buffer 27 for temporarily storing 160-bit data, and a 160-bit data buffer 27
An 8-bit data storage means 28 for fetching data temporarily stored in the memory and storing 8-bit data, and an analog signal converting means 29 for decoding 8-bit digital data into analog signals.

In this digital cordless telephone device,
An analog signal input from the telephone line 1 to the master unit is input to the digital encoding means 3 through the two-wire / four-wire conversion circuit 2, and the digital encoding means 3 encodes the analog signal by the PCM method. FIG. 2 shows this encoding method. The digital encoding means 3 converts the input analog signal (FIG. 2-1) into 8 signals.
Sampling is performed at a sampling period of kHz (FIG. 2-2), and the magnitude (amplitude) of the signal at that time is converted into 8-bit digital data.

FIG. 2-3 shows a converted 8-bit PCM.
Numerals enclosed by circles indicate digital data at corresponding positions of the analog signal (FIG. 2-1).

As shown in FIG. 2-3, the data dividing means 4 converts the 8-bit PCM data encoded by the digital encoding means 3 into upper 4 bits (a) and lower 4 bits (b), respectively. And the divided data is stored in the 4-bit data storage means 5 (FIG. 2-4).

From the data stored in the 4-bit data storage means 5, the upper 4
The bit data is sequentially taken into the 160-bit data buffer 6, and when the 160-bit data is accumulated, the frame is used to compose a frame of channel 1 (FIG. 2-5). 5 is sequentially fetched into the 160-bit data buffer 6 and the 160-bit data is accumulated. Then, the data is used to store the frame of the channel 2 (FIG. 2-6). ). 4 for each channel frame
This includes zero 4-bit data (a1 to a40, b1 to b40).

The channel data transmitting means 8 transmits these frame data using the first and third TDMA slots of the four TDMA transmission / reception slots (FIG. 2-7). The transmission is performed by the wireless transmission unit 9.

When data similarly encoded by the slave unit is transmitted through the wireless transmission unit 23 of the slave unit, the channel data receiving means 11 of the master unit transmits the wireless data (FIG. 3-8). ), The data of channel 1 (FIG. 3-9) and data of channel 2 (FIG. 3-10) are received through the wireless reception unit 10.

When the channel 1 is received, the channel frame decomposing unit 12 decomposes the channel frame, stores the 160-bit data contained therein in the 160-bit data buffer 13, and stores the data in the 8-bit data storage unit. 14
Is 4 stored in the 160-bit data buffer 13.
The bit data is stored as upper 4 bits of the 8-bit data. When the channel 2 is received, the channel frame decomposing unit 12 decomposes the channel frame,
The 160-bit data contained therein is stored in a 160-bit data buffer 13 and stored in an 8-bit data storage unit 14.
Is 4 stored in the 160-bit data buffer 13.
The bit data is stored as the lower 4 bits of the 8-bit data (FIG. 3-11).

The analog signal converting means 29 stores the PCM data in 8-bit units from the 8-bit data storing means 14 (FIG. 3).
12) is read out and converted into an analog signal at a period of 8 kHz (FIG. 3-13). The decoded analog signal (FIG. 3
-14) is transmitted to the telephone line 1 through the two-wire / four-wire conversion circuit 2.

The transmission / reception operation of the slave unit is substantially the same as that of the master unit except for the transmission / reception to the telephone line 1.
At the time of transmission, for example, an analog modem signal output from the FAX device of the slave unit is converted into 8-bit PCM data, divided into upper 4 bits and lower 4 bits, respectively. 160 collected
Bit data is the slot of channel 1 and lower 4
160-bit data, which is a collection of bit data, is transmitted in the channel 2 slot.

When a modem signal is received, the data of channel 1 and channel 2 are received, and the data contained therein are combined to generate 8-bit PCM data, based on which the analog signal is decoded. Is done. Then, the decoded analog modem signal is sent to the FAX modem 16.

In this digital cordless telephone device,
Since the transmission data is encoded into uncompressed 8-bit PCM data and transmitted using two slots, correct decoding on the receiving side is possible even when transmitting a modem signal exceeding 9600 bps. is there.

(Second Embodiment) The digital cordless telephone apparatus of the second embodiment transmits coded 8-bit PCM data using two slots without division.

As shown in FIG. 4, the digital cordless telephone device includes data storage means 41 and 42 for storing the 8-bit PCM data encoded by the digital encoding means 3 and 17 as they are. Embodiment (FIG. 1)
Does not have the data dividing means 4 and 18 which are present in the apparatus.
The configuration is different from the first embodiment only in that point.

In this digital cordless telephone device,
The digital encoding means 3 encodes the analog signal input from the telephone line 1 to the master unit into 8-bit PCM data in the same manner as in the first embodiment (FIG. 5C). The encoded PCM data is stored in the data storage unit 41 as it is.

The channel frame assembling unit 7 sequentially stores the 8-bit PCM data stored in the data storage unit 41 into one.
When the data is taken into the 60-bit data buffer 6 and 160-bit data is accumulated, the data is used for channel 1
(FIG. 5-4). And then,
The PCM data is continuously taken in from the data storage means 41 to the 160-bit data buffer 6, and when the 160-bit data is again stored in the 160-bit data buffer 6, the frame of the channel 2 is used (FIG. 5). 5)
Is configured. Each channel frame includes 20 8-bit data as 160-bit data.

The channel data transmission means 8 transmits these frame data using the first and third TDMA slots of the four TDMA transmission / reception slots (FIG. 5-6).

On the other hand, when receiving similarly encoded data, the channel data receiving means 11 of the master unit converts the radio data (FIG. 6-8) into the channel 1 (FIG. 6-9) and the channel 2 (FIG. 6-9). 6-10) is received.

When the channel 1 is received, the channel frame decomposing unit 12 decomposes the channel frame, stores 160-bit data contained therein in the 160-bit data buffer 13, and stores the data in the 8-bit data storage unit. 14
Is 8 stored in the 160-bit data buffer 13.
The bit data is stored as first to twentieth 8-bit data. Also, when channel 2 is received,
The channel frame decomposing unit 12 decomposes the channel frame and converts the 160-bit data contained therein into one bit.
The 8-bit data storage means 14 stores the 8-bit data stored in the 60-bit data buffer 13 into the 21st to 40th 8-bit data following the previously stored data. (FIG. 6-11).

The analog signal conversion means 15 reads the PCM data in 8-bit units from the 8-bit data storage means 14 and converts the PCM data into analog signals at a period of 8 kHz (FIG. 6-12). The decoded analog signal (FIG. 6-13)
The signal is transmitted to the telephone line 1 through the line 4 line conversion circuit 2.

The transmission / reception operation of the slave unit is substantially the same as that of the master unit except for transmission / reception to / from the telephone line 1.

Also in the second embodiment, the transmission data is encoded into uncompressed 8-bit PCM data,
Since this is transmitted using two slots, 96
Even when transmitting a modem signal exceeding 00 bps, correct decoding can be performed on the receiving side.

Note that in these embodiments, the first and third
Although the second TDMA slot was used, any two slots could be used to achieve this communication.

[0045]

As is apparent from the above description, since the digital cordless telephone of the present invention is configured to transmit and receive uncompressed PCM data, even if it is a modem signal exceeding 9600 bps, it can be used on the receiving side. Correct decoding is possible.

Further, the digital signal communication method of the present invention uses the 4-channel multiplexing TDMA-
Under the TDD scheme, uncompressed 8-bit PCM data can be transmitted.

Further, even in voice transmission, since transmission is performed without code compression, high-quality voice communication with less distortion can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a digital cordless telephone device according to a first embodiment of the present invention;

FIG. 2 is an explanatory diagram showing a transmission operation of the digital cordless telephone device according to the first embodiment;

FIG. 3 is an explanatory diagram showing a receiving operation of the digital cordless telephone device according to the first embodiment;

FIG. 4 is a block diagram showing a configuration of a digital cordless telephone device according to a second embodiment of the present invention;

FIG. 5 is an explanatory diagram showing a transmission operation of the digital cordless telephone device according to the second embodiment;

FIG. 6 is an explanatory diagram showing a receiving operation of the digital cordless telephone device according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Telephone line 2 2-wire 4-wire conversion circuit 3, 17 Digital encoding means 4, 18 Data division means 5, 194 4-bit data storage means 6, 20 160-bit data buffer 7, 21 Channel frame assembling section 8, 22 channel data transmission Means 9, 23 Radio transmitting unit 10, 24 Radio receiving unit 11, 25 Channel data receiving unit 12, 26 Channel frame decomposing unit 13, 27 160-bit data buffer 14, 288 8-bit data storing unit 15, 29 Analog signal converting unit 16 FAX modem 41, 42 Data storage means

Claims (8)

[Claims] 1. A digital cordless telephone device for performing transmission / reception of a four-channel multiplex TDMA-TDD system, wherein digital encoding means for sampling an analog signal to be transmitted at a period of 8 kHz and encoding the PCM data in 8-bit units; A digital cordless telephone device comprising: channel data transmitting means for transmitting PCM data of 160 bits each encoded by the digital encoding means using two different channels. 2. A channel data transmitting means comprising: data dividing means for dividing PCM data in 8-bit units encoded by the digital encoding means into upper 4-bit data and lower 4-bit data; 2. The digital cordless telephone device according to claim 1, wherein the transmitting unit transmits the upper 4 bits of data for 160 bits and the lower 4 bits of data for 160 bits using different channels. 3. The method according to claim 1, wherein the channel data transmitting means is a PC in 8-bit units encoded by the digital encoding means.
2. The digital cordless telephone device according to claim 1, wherein 20 M data items are transmitted using different channels. 4. A digital cordless telephone apparatus for performing transmission / reception of a four-channel multiplex TDMA-TDD system, wherein 160 digital signals are incorporated in each of two different channels.
Channel data receiving means for receiving bit by bit PCM data; 8-bit data storage means for storing 8-bit PCM data based on the received data; 8-bit data stored in the 8-bit data storage means And an analog signal converting means for converting the PCM data into an analog signal at a cycle of 8 kHz. 5. The method according to claim 1, wherein the 8-bit data storage means stores
The digital cordless telephone device according to claim 4, wherein the 8-bit unit PCM data is formed by combining 4-bit data received from each of the three channels and stored. 6. A digital signal communication method using a 4-channel multiplexing TDMA-TDD method, wherein a transmitting side samples an analog signal to be transmitted at a period of 8 kHz, encodes the signal into PCM data in 8-bit units,
This is divided into data of 160 bits each, and different 2
Transmission is performed using two channels. The receiving side receives the two channels, reproduces PCM data in units of 8 bits from the data of 160 bits incorporated in each channel, and reproduces the PCM data in an 8-kHz cycle. A digital signal communication method, comprising: 7. The transmitting side divides the encoded 8-bit PCM data into upper 4-bit data and lower 4-bit data, and transmits the upper 4-bit data for 160 bits and the upper 4-bit data. And the lower 4 bits of data are transmitted using two different channels, and the receiving side combines the upper 4 bits of data and the lower 4 bits of data received from each of the two channels. 7. The digital signal communication method according to claim 6, wherein the PCM data is reproduced in units of 8 bits. 8. The transmitting side transmits 20 pieces of the encoded PCM data in units of 8 bits using two different channels, and the receiving side transmits 20 pieces of data received from each of the two channels. 7. The digital signal communication method according to claim 6, wherein PCM data in 8-bit units is reproduced from said data.