JP2000124879A - Data transmission/reception equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide, with a simple configuration security of transmission data which can be adopted to CATV. SOLUTION: Transmission data and error pattern data corresponding to these transmission data are added and output by an adder circuit 6 and transmitted, while being combined (9) with an error pattern signal corresponding to the error pattern data. On the side of reception, since a signal corresponding to the error pattern data is generated by the separated error pattern signal and subtracted from the received added output by a subtraction circuit 13, only a specified reception subscriber capable of generating the error pattern data based on the error pattern signal can read the relevant transmission data, and the confidentiality of communication can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmitting apparatus and a data transmitting / receiving apparatus suitable for CATV.

[0002]

2. Description of the Related Art Recently, in CATV, data transmission using a television channel has been performed, and various data have been transmitted from a head end side of a center to each subscriber side.

A network such as a CATV has a tree structure. Even if it is desired to individually transmit data from the center side to the receiving side according to each subscriber, each data uses a common network. Each data is commonly transmitted on the same channel.

[0004] Therefore, on each subscriber side receiving,
Data of other destinations which are received in common and are different from each other are also once received and read, and data destined for itself is selected and extracted from the data.

That is, a data transmitting / receiving apparatus employed in a conventional CATV or the like is configured as shown in FIG. 2. First, data transmitted from the center side is sequentially supplied to an error coding and synchronization signal adding circuit 1. Here, a synchronization signal and an error detection / correction code adopting the Hamming check method or the like are added to form transmission data having an array as shown in FIG. 3, that is, a format data structure.

The transmission data from the error coding and synchronization signal adding circuit 1 modulates a carrier corresponding to a transmission channel such as a CATV in a modulation and amplification circuit 2, and transmits each subscriber terminal through a tree-shaped transmission path 3. Sent to.

On each subscriber terminal side, the data transmission signal transmitted via the transmission line 3 is received by the demodulation circuit 4,
Demodulation corresponding to each channel is performed and supplied to an error decoding and synchronization signal removing circuit 5.

The error decoding and synchronization signal removal circuit 5 detects and corrects data errors, removes synchronization signal components, and derives original data.

As described above, in the conventional data transmission / reception apparatus for CATV or the like, each subscriber receives and demodulates data transmitted in common, detects and corrects errors, removes a synchronization signal, and then removes the data content. Was decrypted, and the contents were sorted and taken in to the data addressed to itself.

[0010]

As described above, conventionally,
In CATV and the like, data addressed to each subscriber transmitted from the center side is commonly transmitted to each subscriber via a network.

[0011] Therefore, on the receiving side, data destined for another subscriber is received and demodulated at the same time, regardless of whether or not the data is preferred, and the data destined for the other party can be easily read out. It was low and some kind of response was requested.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a first invention is a transmission error pattern data generating method which generates error pattern data corresponding to different transmission data in a data transmission device. A generation circuit, an error pattern data from the transmission error pattern data generation circuit, an addition circuit for adding the transmission data, an addition output signal from the addition circuit, and an error pattern signal corresponding to the error pattern data. And a transmitting unit for combining and transmitting the signals.

As described above, according to the first aspect of the present invention, the adder circuit adds the transmission data and the error pattern data corresponding to the transmission data, and adds the error signal corresponding to the error pattern data to the added output signal. Since the pattern signal is added and transmitted, only the subscriber who can generate an error data pattern corresponding to the received error pattern signal deletes the added error pattern data from the transmission addition output signal, and Can be received separately from others.

According to a second aspect of the present invention, in a data transmitting / receiving apparatus, a transmission error pattern data generating circuit for generating error pattern data corresponding to different transmission data,
An error pattern data from the transmission error pattern data generation circuit, and an addition circuit for adding the transmission data;
A transmitting unit that combines and outputs an addition output signal from the addition circuit and an error pattern signal corresponding to the error pattern data; and receives a combined signal from the transmission unit, and outputs the addition output signal and the error pattern. A reception unit that separates and derives a signal, a reception error pattern data generation circuit that generates error pattern data corresponding to the transmission error pattern data based on the error pattern signal from the reception unit, And a subtraction circuit to which the error pattern data is supplied from the data generation circuit and which deletes the transmission error pattern data from the addition output signal derived from the receiving unit.

As described above, according to the second aspect of the present invention, on the transmitting side, as in the first aspect, the addition output signal of the transmission data and the corresponding error pattern data is converted into the error pattern corresponding to the error pattern data. The signal is transmitted with the signal added, and the receiving side generates an error data pattern corresponding to the received unique error pattern signal and deletes the added error pattern data. Only the specific receiving subscriber that can generate the data pattern can read its corresponding data.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a data transmitting / receiving apparatus according to the present invention will be described below in detail with reference to FIG. The same components as those of the conventional data transmitting / receiving apparatus shown in FIGS. 2 and 3 are denoted by the same reference numerals, and detailed description will be omitted.

That is, in FIG. 1, on the center side of a CATV or the like, data to be transmitted to a specific receiver or subscriber is transmitted to an error encoding and synchronization signal adding circuit 1.
, Where a data structure to be transmitted to the subscriber is formed in the same manner as in the prior art, and is supplied to an addition circuit 6 composed of a half-addition circuit (mod2 adder).

A transmission error pattern data generation circuit 7 is connected to the addition circuit 6, and the transmission error pattern data generation circuit 7 includes a CPU 71 and an error pattern generator (E).
PG) 72.

The CPU 71 generates an error pattern signal unique to the data to be transmitted to the specific receiver or subscriber, and supplies the generated error pattern signal to the error pattern generator 72 and the transmission RF modem 8, respectively. Is done.

The error pattern generator 72 newly generates corresponding error pattern data based on the error pattern signal from the CPU 71, and the generated error pattern data is supplied to the adding circuit 6.

Accordingly, the addition circuit 6 adds the data from the error coding and synchronization signal adding circuit 1 and the error pattern data unique to a specific transmission destination, and adds the output signal to the modulation and amplification circuit 2. To supply.

The modulation amplification circuit 2 converts the added output signal into a CAT signal.
After modulating and amplifying the carrier corresponding to the V transmission channel to form a modulated wave, the modulated wave is supplied to the combining circuit 9. here,
The modulation amplification circuit 2 is a four-phase (differential) phase modulation (QPSK)
Circuit or a quadrature amplitude modulation (QAM) circuit.

On the other hand, in the transmitting RF modem 8, a carrier having a frequency different from that of the carrier of the modulation and amplification circuit 2 is modulated by the error pattern signal and supplied to the synthesizing circuit 9. The multiplexed composite signal of the sum and the output signal is transmitted to each subscriber on the receiving side via the tree-shaped transmission path 3.

On each subscriber side receiving via the transmission line 3, first, the separation circuit 10 separates the added output signal and the error pattern signal from the received combined signal, and the added output signal is supplied to the demodulation circuit 4 and demodulated. After that, the half adder circuit (mod
The error pattern signal is supplied to the reception RF modem 11 and the subtraction circuit 13 composed of two adders).

The error pattern signal supplied to the reception RF modem 11 is demodulated and output, and supplied to the CPU 121 of the reception error pattern data generation circuit 12. Like the transmission error pattern data generation circuit 7, the reception error pattern data generation circuit 12 includes a CPU 121 and an error pattern generator 122. The CPU 121 processes an error pattern signal from the reception RF modem 11 under program control. The error pattern generation circuit 122 generates error pattern data corresponding to the error pattern signal.
Control.

Therefore, the error pattern generating circuit 122
Under the control of the CPU 121, error pattern data corresponding to the error pattern signal, that is, transmission error pattern data is generated and supplied to the subtraction circuit 13.

Since the subtraction circuit 13 subtracts the error pattern data from the received demodulated addition output signal by subtraction, the subtraction circuit 13 outputs data of an array in which a synchronization signal and error code data are added to the original data. The received data having the structure is output and supplied to the error decoding and synchronization signal removing circuit 5.

Therefore, the error decoding and synchronization signal removing circuit 5 removes the error code data and the synchronization signal from the received data structure in the same manner as in the prior art. Can be extracted and read.

As a result, on the reception side, the reception RF
Not only subscribers who do not have the modem 11 and the reception error pattern data generation circuit 12 but also the reception RF modem 1
1 and the reception error pattern data generation circuit 12, if the reception side does not have a means for decoding the error pattern signal output from the reception RF modem 11, the reception side generates the error pattern data corresponding to the transmission side. Cannot be generated. That is, only the specific receiving subscriber can remove the error pattern data from the received added output signal, and the security of data addressed to the specific subscriber is ensured.

In this way, the center side is transmitted to the specific subscriber by adding the error pattern data exceeding the normal error correction capability, and only the specific subscriber receives the data. Therefore, confidentiality of communication can be maintained even in one-way data transmission as in CATV.

In the above embodiment, it has been described that the data structure, that is, the data format indicating the arrangement of data and codes is different for each specific receiving subscriber, and the error pattern data formed corresponding thereto is also different. However, the same effect can be obtained even if the data in the data structure is formed differently for each specific subscriber instead of the data structure.

As described above, in the data transmission apparatus and the data transmission / reception apparatus according to the present invention, the transmission side preliminarily adds error pattern data specific to transmission data to a specific subscriber and transmits the data. Is
It can be secured by a simple circuit configuration, and a remarkable effect can be obtained when applied to CATV or the like.

[0033]

According to the present invention, the transmitting side adds error pattern data corresponding to a specific receiver,
Since the corresponding information is added and transmitted separately, the receiving side can secure security with a simple configuration of generating the preset error pattern data from the added information and deleting it from the received data, The effect is practically large.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a data transmission / reception device according to the present invention.

FIG. 2 is a configuration diagram of a conventional data transmission / reception device adopted for CATV.

FIG. 3 is a data array diagram of transmission data formed by the apparatus in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Error encoding and synchronization signal addition circuit 2 Modulation amplification circuit 3 Transmission line 4 Demodulation circuit 5 Error decoding and synchronization signal removal circuit 6 Addition circuit 7 Transmission error pattern generation circuit 71 CPU 72 Error pattern generator 8 Transmission RF modem 9 Synthesis Circuit 10 Separation circuit 11 Reception RF circuit 12 Reception error pattern generation circuit

Claims (6)

[Claims] A transmission error pattern data generation circuit for generating error pattern data corresponding to different transmission data; an addition circuit for adding the error pattern data from the transmission error pattern data generation circuit to the transmission data; A data transmission device comprising: a transmission unit that combines and transmits an addition output signal from the addition circuit and an error pattern signal corresponding to the error pattern data. 2. The data transmitting apparatus according to claim 1, wherein the transmission error pattern data generation circuit generates the different error pattern data according to a data structure of the transmission data. 3. The data transmitting apparatus according to claim 1, wherein the adding circuit includes a half adder. 4. A transmission error pattern data generation circuit for generating error pattern data corresponding to different transmission data, an addition circuit for adding the error pattern data from the transmission error pattern data generation circuit and the transmission data. A transmitting unit for combining and outputting the added output signal from the adding circuit and an error pattern signal corresponding to the error pattern data; and receiving a combined signal from the transmitting unit, and A receiving unit that separates and derives a pattern signal, a receiving error pattern data generating circuit that generates error pattern data corresponding to the transmission error pattern data based on the error pattern signal from the receiving unit, Before the error pattern data is supplied from the pattern data generation circuit and is derived from the receiving unit. Data transmitting and receiving apparatus according to claim from the addition output signal that comprises a subtraction circuit for deleting the transmission error pattern data. 5. The transmission error pattern data generating circuit generates different error pattern data according to a data structure of the transmission data.
A data transmitting / receiving device according to any one of the preceding claims. 6. The data transmitting / receiving apparatus according to claim 4, wherein each of the adding circuit and the subtracting circuit is configured by a half adder.