JPH0457529A - Time division direction control transmission system - Google Patents

Abstract

PURPOSE:To eliminate near end crosstalk noise from an adjacent digital service unit(DSU) and to output a stable reception data by providing a correlation detector detecting a training signal sent from an office channel unit(OCU) to a DSU. CONSTITUTION:A transmission data 41 from the OCU is sent while the phase is matched with the phase of a 1st pattern from a 1st training pattern transmission circuit 31 and the transmission data 41 is received as a reception data 41A in the reception section 13 of the DSU. Moreover, the transmission data 42 of the DSU is sent while the phase is matched with the phase of a 2nd pattern from a 2nd training pattern transmission circuit 11 and the transmission data 42 is received as a reception data 42A in the reception section 33 of the OCU. A correlation detector 14 applies correlation detection to the 1st training signal from an OCU 3 to specify the phase of the training signal. Thus, no data is outputted because of different timing with respect to a near end crosstalk from the adjacent DSU and stable reception data is outputted.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a time-division direction control transmission system, and in particular, to a digital service unit (DSU) installed in a residential area and an office channel unit installed in an office side. (O
The present invention relates to a time-division direction control transmission method that eliminates the influence of near-end crosstalk on the DSU side in a method in which training patterns of digital signals are mutually sent between the DSU and the DSU.

[Conventional technology]

Conventionally, in this type of time-division direction control transmission system, the OCU is
The first training pattern is being sent to the SU, while the DSTJ is sending out the second training pattern to the OCU. Here, DSU and OC
Each receiving unit in U performed a bit-by-bit receiving operation without recognizing the training pattern.

[Problem to be solved by the invention]

Among the conventional time-division direction control transmission methods mentioned above, D
Since the SU side performs a receiving operation on all received signals without recognizing the training pattern from a specific OCU, it also performs a receiving operation on near-end crosstalk signals from an adjacent DSU, for example. This has the disadvantage that the operation of the DSU becomes unstable.

[Means to solve the problem]

The time-division direction control transmission system of the present invention is a time-division direction control transmission system in which training patterns are mutually transmitted between an office channel unit installed at a station and a digital service unit installed in a home. The digital service unit includes a correlation detector that detects a training pattern sent from the office channel unit, and a receiving section that performs a receiving operation only at the timing when the correlation detector is driven by a control signal.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a time chart for explaining this embodiment. In FIG. 1, 1 is a DSU, 2 is a subscriber line, 3 is an OCU, 11 is a second training pattern sending circuit, 12 is a hybrid circuit, 13 is a receiver, 14 is a transmission rate detector, and 31 is a first 32 is a hybrid circuit, and 33 is an OCU receiving section.

The operation of transmitting and receiving signals between DSUI and 0CU3 will be explained using the time chart of FIG. 2.

The transmission data 41 of the OCU is transmitted with the first pattern signal from the first training pattern transmission circuit 31 and the data signal aligned in phase. This transmission data 41 is D
The receiving unit 13 of the SU receives it as received data 41A. Furthermore, the transmission data 42 of the DSU is transmitted with the second pattern signal from the second training pattern transmission circuit 11 and the data signal being in phase. This transmission data 42 is received by the reception unit 33 of the OCU as reception data 42A. Here, the correlation detector 14 performs correlation detection on the first training signal from the 0CLI 3 and specifies the phase of the training signal. The output of this correlation detector 14 is the timing signal 43 shown in FIG. 2, and the receiving section 13 operates only when this timing signal 43 is controlled at a high level. Therefore, since the received data 41A is output only at the specified timing from 0CU3, for example, near-end crosstalk from an adjacent DSU is not output at different timings.

〔Effect of the invention〕

As explained above, the present invention includes a correlation detector on the DSU side that detects the training signal transmitted from the OCU, thereby identifying the phase of the received signal of the DSU, and operating the receiving section of the DSU only in that phase period. be able to.

Therefore, it is possible to remove near-end crosstalk noise from adjacent DSUs, and it is possible to provide a DSU that can output stable received data.

1... Second training pattern sending circuit, 12° 32... Hybrid circuit, 13.33... Correlation detector, 31... First training pattern sending circuit, 41.42... Transmission Data, 41A, 42A...
Received data, 43...timing signal.

Claims (1)

[Claims] In a time-division direction control transmission system in which training patterns are mutually transmitted between an office channel unit installed at a station and a digital service unit installed in a home, the digital service unit transmits training patterns from the office channel unit. 1. A time-division direction control transmission system comprising: a correlation detector that detects a training pattern, and a receiver that performs a reception operation only at the timing when the correlation detector is driven by a control signal.