JP2815009B2 - Wireless communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system for wireless local access.

[0002]

2. Description of the Related Art In the telecommunications field, an existing high-speed wired network (CATV) is used for personal use of each dwelling unit.
And optical cables) as the backbone, and within multiple local areas connected to it, wireless local access (Wireless Local Access,
Hereinafter, it is described as WLA. ). In particular, it is a method suitable for the early practical use of a wide area information network in an area where infrastructure facilities are scarce.

[0003] In this WLA, wireless transmission with a low error rate between a base station in a local area and each dwelling unit is required, but there is no concrete example of this technology so far.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a radio communication system which is economical and has excellent communication quality.

[0005]

In order to solve the above-mentioned problems, a wireless communication system according to the present invention comprises: an operation terminal receiving a user's input; a data processing device which is an interface with the operation terminal and performs program processing; A wireless device installed outdoors to perform data communication with a wireless device outside the system; an outdoor distributor installed near a TV receiving antenna of a TV cable to relay an intermediate signal;
An indoor distributor that is installed near the TV receiver of the TV cable and relays the intermediate signal; the wireless device is connected to the outdoor distributor; and the data processing device is the operation terminal and the indoor distributor. Connected to the TV receiver, the data processor and the wireless device transmit and receive data via the intermediate signal, and communicate with the external wireless device through the wireless device according to a user's instruction; The result is displayed on the TV receiver.

[0006]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a configuration diagram of a wireless communication system according to the present invention. In FIG. 1, 1 is a dwelling unit and 2 is a TV.
3 is a coaxial cable, 4 is a TV receiver, 5 is a wireless device, 6 is an outdoor distributor, 7 is an indoor distributor, 8 is a data processor, 9 is a keyboard,
0 indicates an outdoor branch cable, and 11 indicates an indoor branch cable.

It is assumed that a TV receiving antenna 2, a coaxial cable 3, and a TV receiving device 4 are already attached to the dwelling unit 1. For the existing coaxial cable 3, a TV
An outdoor distributor 6 is mounted at an appropriate location near the receiving antenna 2, and an indoor distributor 7 is mounted at an appropriate location near the TV receiver 4. The wireless device 5 is connected to the outdoor distributor 6 by an outdoor branch cable 10, and the data processing device 8 is connected to the indoor distributor 7 by an indoor branch cable 11. Accordingly, bidirectional data communication is performed between the wireless device 5 and the data processing device 8 via the outdoor distributor 6 and the indoor distributor 7. The data processing device 8 has a built-in processor, and performs a routine process in response to a user request from the keyboard 9 or a request from an external wireless device connected to the backbone. Then, the processing result is displayed on the TV receiver 4 as necessary.

FIG. 2 shows the internal configuration of the outdoor distributor and the indoor distributor. In FIG. 2, 6 is an outdoor distributor,
7 is an indoor distributor, 61 is a high-pass filter, 62 is a low-pass filter, 71 is a high-pass filter, 72 is a low-pass filter, 3 is a coaxial cable, 10 is an outdoor branch cable, and 11 is an indoor branch cable. I have.

Both the outdoor distributor 6 and the indoor distributor 7 are composed of a high-pass filter and a low-pass filter. High pass filters 61, 71 inside both distributors 6, 7
The reason is that a signal in a low frequency band that is frequency-division multiplexed (FDMA) with respect to a TV signal does not affect an existing device. The low-pass filters 62 and 72 have a characteristic of allowing the outdoor branch cable 10 and the indoor branch cable 7 to pass only a DC signal for power supply and a signal in a low frequency band subjected to FDMA. Each filter 6
1, 62, 71 and 72 are constituted by passive elements,
The element parameters are determined so as to match the characteristic impedance of the coaxial cable 3.

FIG. 3 shows a frequency allocation diagram of FDMA. 3, reference numeral 12 denotes the high-pass filter 6 shown in FIG.
1 and 71, and 13 represents the characteristics of the low-pass filters 62 and 72 in FIG.

FIG. 4 shows an internal configuration diagram of the data processing device. In FIG. 4, 11 is an indoor branch cable,
Reference numeral 14 denotes a mixer / demultiplexer, 15 denotes a power supply unit, 16 denotes a low-pass filter, 17 denotes a wired modem, 18 denotes a central processing unit, 19 memory, and 20 denotes an interface with an operation terminal.

In the data processing device, the power supply unit 1
A DC signal is supplied to the indoor branch cable 11 from a low pass filter 16 through the low pass filter 16. Further, a signal in a low frequency band for the wired modem 17 is superimposed / extracted on the indoor branch cable 11 via the mixing / demultiplexing device 14. Here, the signal in the low frequency band may be either baseband transmission or carrier wave transmission. Central processing unit 18
Is connected to the wired modem 17, and is connected to the user request via the interface 20 or the wired modem 1.
In response to a request from outside the system via
The routine processing is performed in accordance with the program held in step S9. As a result, display processing on the TV receiver, or
Access to a wireless terminal outside the system is performed.

FIG. 5 shows the same frequency allocation diagram as FIG. 3, and the line 21 represents the characteristics of the low-pass filter of FIG. When the signal of the low frequency band is transmitted in the base band, it is desirable to set the cut-off frequency of the characteristic 21 of the low-pass filter to be small in order to remove the influence of the low frequency band near DC as much as possible.

FIG. 6 shows an internal configuration diagram of the wireless device. In FIG. 6, reference numeral 10 denotes an outdoor branch cable, 22 denotes a mixer / demultiplexer, 23 denotes a low-pass filter, 24 denotes a power supply unit, 25 denotes a wired modem, 26 denotes a channel codec unit, 27 denotes a memory, and 28 denotes a memory. Is a wireless modem, 2
Reference numeral 9 denotes an antenna.

Inside the wireless device, the outdoor branch cable 10
A DC signal applied from the data processing device via the low-pass filter 23 is extracted in the power supply unit 24 as operating power. A signal in a low frequency band for the wired modem 28 is superimposed / extracted on the outdoor branch cable 10 via the mixing / demultiplexing device 22. In the channel codec unit 26, based on the contents of the memory 27 in which the protocol conversion information is stored, the wired modem 25
And the communication protocol of the wireless modem 28 are converted. Wireless communication is performed outside the system through the antenna 29.

With the above configuration, it is possible to construct an economical and highly reliable wireless communication system using the existing TV equipment and having little radio wave propagation obstruction due to the penetration of the wall of the building.
Suitable as wireless local access technology.

FIG. 7 shows a configuration diagram of a TV door phone system to which the wireless communication system of the present invention is applied.

In FIG. 7, reference numeral 30 denotes a TV door phone,
1 is a door phone side wireless device, 5 is a system side wireless device, 8 is a data processing device, 4 is a TV receiver, 32
Represents a telephone. Other parts are the same as those in FIG.

Here, communication from the TV intercom 30 to the data processing device 8 is defined as an uplink, and communication from the data processing device 8 to the TV intercom 30 is defined as a downlink.

The video information and the audio information input to the TV door phone 30 are each subjected to analog / digital conversion, then data compression and transmission by uplink.
In the data processing device 8, after the data decompression and the digital / analog conversion, the video information is sent to the TV receiving device 4,
Voice information is transmitted to the telephone 32.

Next, the voice information input to the telephone set 32 is subjected to analog / digital conversion in the data processing device 8, and then data is compressed and transmitted via the downlink. In the TV door phone 30, audio data is obtained after data expansion and digital / analog conversion.

FIG. 8 is a timing chart of the time division multiplexed (TDMA) uplink and downlink in the wired section between the system side wireless device and the data processing device.

In FIG. 8, one frame 125us is composed of an uplink video slot 62.5ms, an audio slot 31.25ms, and a downlink audio slot 3
Two-way communication is performed by dividing into three times 1.25 ms.

With the above configuration, the TV can be easily installed on the existing TV equipment only by installing the unit and branching.
A door phone system can be constructed.

The wireless communication between the wireless devices 31 and 5 in FIG. 7 is optimized as to the information speed, communication distance, and the like by using the wideband code division multiplexing (WCDMA) technology, thereby developing as a telemetry system or a telecontrol system. It is also possible to make it.

[0027]

By using an existing cable for TV reception for transmitting intermediate signals, a wireless device can be installed outdoors without unnecessary wiring work, and a stable wireless propagation path with relatively small diffraction loss. , And economical and highly reliable wireless communication becomes possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a wireless communication system of the present invention.

FIG. 2 is an internal configuration diagram of an outdoor distributor and an indoor distributor.

FIG. 3 is a frequency allocation diagram of FDMA.

FIG. 4 is an internal configuration diagram of a data processing device.

FIG. 5 is a frequency allocation diagram of FIG. 3;

FIG. 6 is an internal configuration diagram of a wireless device.

FIG. 7 is a configuration diagram of a TV door phone system.

FIG. 8 is a timing chart of uplink and downlink in TDMA.

[Explanation of symbols]

 Reference Signs List 1 dwelling unit 2 TV receiving antenna 3 coaxial cable 4 TV receiving device 5 wireless device 6 outdoor distributor 7 indoor distributor 8 data processing device 9 keyboard 10 outdoor branch cable 11 indoor branch cable

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Satoshi Hako, 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-3-214995 (JP, A) 3-165637 (JP, A) Fully open 1988-26146 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04J 1/08 H04N 7/08

Claims (3)

(57) [Claims] 1. A data processing apparatus , comprising: a data processing apparatus;
A wireless device for transmitting and receiving data to be processed, and connecting a television broadcast receiving antenna to the television broadcast receiving device.
A first distributor and a second distributor on an antenna line
Wherein the first distributor is provided from the wireless device to the data processing device.
Data to the receiver and reception from the TV broadcast receiving antenna
Input data to the antenna line on the data processor
And, said second distributor data and Te to the data processing device
Separate the data to the Levi broadcast receiver from the antenna line
Or from the data processing device to the wireless device
Is transmitted to the antenna line, and the radio signal is transmitted between the data processing device and the wireless device.
A wireless communication system for transmitting and receiving data using an intermediate signal that is frequency-division multiplexed by arranging it on the lower frequency side of a signal . Wherein operating power to the wireless device, the first
Distributor and low-pass filter of the second distributor
The wireless communication system according to claim 1, wherein the data is supplied from the data processing device through a data processor . Wherein the intermediate signal, claim time division multiplexing the video information and audio information, for said video information one-way communication, for the audio information and performing full duplex communication 1 or claim 2 wireless communication system according.