CN2506027Y - Line cable data receiver for computer - Google Patents

Abstract

A cable data receiver for computers, which is a downstream data receiver, consists of a channel processing module, a data processing module, a power supply module and an input signal joint, wherein, the channel processing module is integrated with a high radio-frequency head, a demodulating and channel decoding unit and the output is connected with the data processing module, output of which is connected with the computer. The output of the data processing module is connected with the computer through a PCI bus and. the data processing module is programmable gate array module. The receiver of the utility model is a monodirectional receiving device and only responsible for receiving cable downstream data broadcast that complies with a DVB-C standard and has simple structure, low cost and high reliability. The number of one-way users is not limited for rich cable downstream frequency resources and working under broadcast mode.

Description

The cable data sink that is used for computer

Technical field

The utility model relates to a kind of data sink, and especially a kind of cable (Cable) data sink that is used for computer belongs to communication technical field.

Background technology

Present most of cable television network (CATV) all is by optical fiber, coaxial hybrid network, and promptly arterial grid adopts optical fiber, and cheap coaxial cable (being called for short cable or Cable) is partly adopted in user's access.Transmission direction from user terminal to the coaxial cable head end is called up, and the direction from the coaxial cable head end to user terminal is called descending.Every cable can provide 700MHz bandwidth resources to 1000MHz for the user, supports simulated television and digital data transmission simultaneously.In China, the coverage rate of cable TV is very high, far above the popularity rate of phone, is a fine wideband transmission system, and cable television network itself is exactly a radio network.Utilize cable television network to carry out data broadcasting, have advantageous advantage.Cable data broadcasting towards family is more cheap than satellite broadcasting, convenient.

Now, mainly contain two classes at the online terminal equipment that uses of cable TV, a class is the simulated television product, mainly receives descending analog television broadcast, can not support data service well.Another kind of is cable modem, aims at data service design, but also have some problems in using and promoting:

1. cable modem all is based on 802.14 and the DOCSIS design of protocol, is a kind of bi-directional device, and luminous energy receiving cable downlink data can also not send upstream data on cable.But at present, the technology of cable uplink is not very ripe, and frequency resource is limited, has greatly limited the actual serviceability of cable modem.

2. the cable modem uplink that meets above-mentioned agreement adopts modulation to add the time-division multiplex technique, realizes that difficulty is bigger, and cost is higher.And because the funnel The noise, the supported number of users of single line cable (cable modem number) is less.

3. need private communication facility (as cable burst demodulation device) in cable head-end and be used, the networking difficulty is bigger.

Summary of the invention

The purpose of this utility model is to provide a kind of cable data sink that is used for computer at the deficiency of prior art, this receiver is a unidirectional receiving equipment, only is responsible for receiving the cable downlink data broadcasting that meets the DVB-C standard, and is simple in structure, cost is low, the reliability height.Because cable downstream frequency aboundresources works in broadcast mode again, therefore, single receipts number of users is unrestricted.

By adopting outer mutual technology (network interface card or dialing MODEM are installed on computers,, constitute two-way channel) also can provide two-way services as cable modem with the cable downstream signal by telephone wire or Internet transmit ascending data.

The purpose of this utility model is achieved in that

A kind of cable data sink that is used for computer, this receiver is the downlink data receiver, form by channel processing module, data processing module and power module, wherein channel processing module by tuner, separate that to be in harmonious proportion the channel-decoding unit integrated, output connects data processing module, and the output of data processing module connects computer.

The output of described data processing module connects computer by pci bus.

The joint of described input signal is a F type joint.

Described data processing module is the programmable gate array module.

Described data processing module is connected to buffer.

Described buffer is the dual-port buffer.

Described power module is more than one, is the incorporate power transfer module of the high stable of separate setting.

The earth terminal of described power module is provided with isolates simulation ground and digitally electric capacity, inductance.

The utility model mechanism is simple, flexible, the reliability height.Wherein channel processing module is U1, by tuner, separate and be in harmonious proportion channel bank and form, can be in the 100-1000MHz frequency range downstream signal on the receiving cable, by filtering, demodulation, channel decoding, deinterleave and descrambling, the TS that obtains DVB-C wraps.Data processing module is to be made up of frame synchronization, address detected, metadata cache, several parts of pci bus interface, is responsible for giving computer with the TS bag of channel processing module output and handles.Power module is respectively 30V, 9V and 5V power supply, channel bank and data processing unit power supply respectively.

The utlity model has following advantage:

1. unidirectional receiving equipment, cost is low, and the reliability height is convenient to popularize.It makes full use of the broadcast capability of cable television network, and number of users is unrestricted.By outer mutual technology, adopt low speed telephone wire or Internet, also can realize various asymmetrics (upstream traffic is little, and downlink traffic is big) two way traffic easily, as the VOD program request, WWW browses.

16,32,64,128QAM 2. can receive the MPG-2 transport stream that meets the DVB-C standard, input signal: 65-860MHZ, minimum data symbol rate: 1Msymbols/s, the maximum data symbol rate: 7M symbols/s, modulation system:.10. therefore, can watch MPG-2 TV and data broadcasting on computers simultaneously.

3. on wired receiving computer, plug network interface card, just can expand to wired bridge, the Data Bridge of wired network broadcasting is online to computer local area.

4.PCI data-interface, plug and play under WindowsNT, 98 and 2000 environment is not conflicted with the main plug-in card parts of PC.

5. high all integrated, the high stability design, easy for installation.

Description of drawings

Fig. 1 is a functional block diagram of the present utility model.

Fig. 2 is the utility model channel processing module functional block diagram.

Fig. 3 is the utility model data processing module functional block diagram

Fig. 4 is the utility model channel processing module circuit theory diagrams.

Fig. 5 is the utility model data processing and cache module circuit theory diagrams.

Fig. 6 is the utility model pci interface and bus processing module circuit theory diagrams.

Fig. 7 is the utility model pci interface modular circuit schematic diagram.

Fig. 8 is the utility model power module circuitry schematic diagram.

Embodiment

Below in conjunction with accompanying drawing, introduce the content of this utility model in detail.

As shown in Figure 1, the utility model is a kind of cable data sink that is used for computer, and this receiver is made up of channel processing module, data processing module and power module.Wherein channel processing module by tuner, separate that to be in harmonious proportion the channel-decoding unit integrated, output connects data processing module, the output of data processing module connects computer.This receiver is a unidirectional receiving equipment, is responsible for the cable downlink data and receives, and simple in structure, cost is low, the reliability height, and number of users is unrestricted.

The channel processing module U1 of the utility model cable data receiver by tuner, separate and be in harmonious proportion the channel-decoding unit and form, be integrated in the incorporate tuner, as shown in Figure 2.The Headend signal is transferred to data receiver card through cable of cable TV.To base band, at first carry out matched filtering and equilibrium through frequency translation, reduce the influence of channel distortions.Demodulator circuit is by carrier clock and recover digital signal synchronously.The differential decoding circuit is used to overcome phase ambiguity, recovers the correct planisphere of QAM (quadrature amplitude modulated (QAM) signal), carries out symbol then to the byte mapping.For reducing the influence of error burst, make friends with to knit the decoding with RS, last descrambling obtains correct data.

Physical circuit is seen Fig. 4, more than is operated in the integral high frequency head to be finished by U1, and the U1 input meets TUNERINT, and U1 through port line IF D0-D7 output meets the TS stream of DVB-S standard.

Shown in Fig. 3,5, U1 output is to meet the TS of DVB-C standard stream.Ensuing frame synchronization, address detected are finished by the field programmable logic array (FPGA) of data processing module U3.Access hole line RAM-R, the RAM-W of two-port RAM U2 all receive on the U3.Data processing module U3 controls the control mouth line of all chips as the central processing unit of device, is responsible for the management of calling of data.Data processing module U3 through port line DQ0-15 meets S5933, and the mouth line AD0-31 by S5933 connects and can directly be connected with the pci interface (shown in Fig. 6,7) of computer plug and play, gives computer by pci interface and handles.

In order to realize that computer and satellite receiver can asynchronous workings, be computer can be the free time reading of data from the satellite receiver, therefore need the data that satellite receiver receives be cushioned, here adopt dual port RAM U2, promptly have two sets of data and address bus to be respectively applied for the read-write of computer and satellite receiver, and this two covers read-write can be operated simultaneously.Circle queue is adopted in the management of buffer U2, and it has two pointers, and one is read pointer, and one is write pointer, indicates the address of the buffer of current read and write respectively.Like this when satellite receiver receives the data that oneself need, it the data write buffer, and sends an interruption to computer according to write pointer.The computer interruption that needn't make an immediate response, it can come reading of data in idle itself, can reduce the stand-by period like this, raises the efficiency.Dual port RAM adopts IDT7026.

Pci bus interface is between satellite receiver and pci bus interface " bridge ", complete accord with PCI 2.1 standards.Satellite receiver is inserted in plug and play in the computer, can obtain system resource automatically, peak data transfer rate 133Mbyte/s.The utility model adopts the S5933 chip, and physical circuit is seen Fig. 6,7, and the data of pci bus interface PCI 5V32 obtain from being connected with S5933 U5 mouth line AD0-31 shown in Figure 6, and are subjected to the control of data processing module U2.

The utility model satellite data receiver operation is under the microcomputer environment.Various computers are compatible especially, and power level is uneven, and power supply ripple that has and clutter are very big, and this just makes just can not work to other computer at the satellite receiver that can work on some computers.So need all take meticulous design to every group of power supply, as shown in Figure 8.Because the 5V power supply ripple of computer is bigger, can not directly use, so the 12V power supply of computer is changed to 8V, change to 5V again by U7, U8, through twice voltage stabilizing, guarantee that the 5V power supply is clean.The 9V power supply obtains back output is handled in the 12V power supply voltage stabilizing of computer by U9.The 30V power supply adopts high stable, incorporate 5V-30V power transfer module (U10), and ripple control has greatly improved the adaptive capacity of satellite receiver in the various computing machine below 20 millivolts.In addition,, added electric capacity EC3, EC1 and inductance L 1 is isolated, also carried out effective isolation on simulation ground with digitally in place to the input voltage sensitivity.

Claims (8)

1, a kind of cable data sink that is used for computer, it is characterized in that: this receiver is the downlink data receiver, form by channel processing module, data processing module and power module, wherein channel processing module by tuner, separate that to be in harmonious proportion the channel-decoding unit integrated, output connects data processing module, and the output of data processing module connects computer.

2, the cable data sink that is used for computer according to claim 1, it is characterized in that: the output of described data processing module connects computer by pci bus.

3, the cable data sink that is used for computer according to claim 1 is characterized in that: the joint of described input signal is a F type joint.

4, the cable data sink that is used for computer according to claim 1 and 2, it is characterized in that: described data processing module is the programmable gate array module.

5, the cable data sink that is used for computer according to claim 1, it is characterized in that: described data processing module is connected to buffer.

6, the cable data sink that is used for computer according to claim 5, it is characterized in that: described buffer is the dual-port buffer.

7, the cable data sink that is used for computer according to claim 1, it is characterized in that: described power module is more than one, is the incorporate power transfer module of the high stable of separate setting.

8, the cable data sink that is used for computer according to claim 7 is characterized in that: the earth terminal of described power module is provided with isolates simulation ground and digitally electric capacity, inductance.

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