JP2513324B2 - Dual polarization transmission device - Google Patents

Description

The present invention relates to wireless digital transmission, and more particularly to a wireless digital transmission device using both polarizations.

[Conventional technology]

FIG. 2 is a block diagram of a conventional dual polarization transmission device.
In the figure, (a) shows the transmitting side and (b) shows the receiving side.
The sending end signal processing circuit 11 is a baseband interface signal.
101 is input to perform signal processing (multiplexing, etc.) for wireless digital transmission. The modulation circuit 12 modulates the signal after the signal processing and outputs a modulated signal 103. This modulated signal 1
03 is converted to the RF frequency band and transmitted with the required polarization.

On the other hand, on the receiving side in FIG. 3B, the cross polarization interference canceling circuit 21 cancels the interference from the different polarization included in the reception modulation signal 201. The demodulation circuit 22 demodulates the modulated signal and outputs the baseband signal 203. The receiving end signal processing circuit 24 separates the multiplexed signals on the transmitting side and outputs the baseband interface signal 205. The hitless switching circuit 25 has a working signal 205 and a backup signal (a signal obtained by branching the working signal at the sending end and transmitted through a backup line) 20.
When 6 and 6 are input, when the transmission quality of the working line is deteriorated, switching is performed without bit error and the received signal 207 is output.

[Problems to be Solved by the Invention]

In the above-mentioned conventional dual polarization transmission device, dual polarization transmission may not be performed at the initial stage of line operation, and only single polarization transmission may be performed, and transition to dual polarization transmission may occur as line demand increases.
Or, in a 1 + N system (N ≧ 2), M (<N)
In some cases, only the system may shift to dual polarization transmission. In such a case, a receiver that does not include the cross polarization interference cancel circuit 21 used in the single polarization transmission system also includes the cross polarization interference cancel circuit 21 to support both polarization transmission. Required to do so. However, when the cross polarization interference canceling circuit 21 is newly added, the transmission delay generated in this circuit may affect the transmission, and the transmission may be momentarily interrupted.
Therefore, there is a problem that it is difficult to realize the above-mentioned addition of lines without interruption.

An object of the present invention is to provide a transmission device capable of realizing line extension and the like without interruption.

[Means for solving the problem]

The transmission device of the present invention includes, on the transmission side, a circuit that performs a transmission end signal process of a baseband interface signal and a circuit that modulates the processed signal. Also, on the receiving side, when a polarization interference elimination circuit that is selectively inserted to prevent interference due to different polarization, a demodulation circuit that demodulates the signal, and a polarization interference elimination circuit are inserted. In addition, a delay adjustment circuit that can be set to the same delay amount as the signal delay amount that occurs in the polarization interference cancellation circuit, a circuit that performs processing to reproduce the baseband interface signal, and a hitless circuit that rescues the line quality. I have it. Here, the delay adjustment circuit is set to a state in which there is no delay when the polarization interference removal circuit is inserted, and when the polarization interference removal circuit is not inserted, the same delay as that generated in the interference removal circuit occurs. It is configured to be adjustable so as to be in a state.

[Action]

With this configuration, when a new interference canceling circuit is attached to the receiving side, the delay amount of the delay adjusting circuit is adjusted at the same time, thereby eliminating the influence of the delay in the interference canceling circuit and preventing instantaneous interruption of transmission.

〔Example〕

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

FIG. 1 is a block diagram of an embodiment of the present invention, in which FIG. 1A shows the transmitting side and FIG. 1B shows the receiving side.

In the figure (a), 11 is a transmission end signal processing circuit, 12 is a modulation circuit, and the baseband interface signal 101 is converted into a modulation signal 103 via a processing signal 102, and further converted into an RF frequency band, It transmits with the polarized wave of.

Further, in FIG. 2B, 21 is a cross polarization interference canceling circuit configured to be selectively inserted in the path of the received signal, 22 is a demodulation circuit, 24 is a receiving end signal processing circuit, and 25 is a hit. It is a response switching circuit, which uses the received modulated signal 201 as a processed signal 202, obtains a baseband signal 203 from this, outputs a baseband interface signal 205, and further outputs a received signal 207. Here, the demodulation circuit 22 and the receiving end signal processing circuit
A delay adjustment circuit 23 is inserted between the delay adjustment circuit 23 and the delay circuit 24.

The delay adjustment circuit 23 has the same delay amount as the delay amount generated in the cross polarization interference removal circuit 21, and by selectively short-circuiting this, the substantial delay amount in the delay adjustment circuit 23 is eliminated. Is configured as follows. This delay adjustment circuit
The adjustment of the presence or absence of delay in 23, the cross-polarization interference cancellation circuit 21 is a state of no delay when inserted in the reception path, when the cross-polarization interference removal circuit 21 is not inserted, there is a state of delay. To do.

Therefore, when the receiver is in a state in which the cross polarization interference canceller 21 is not inserted in correspondence with the single polarization transmission at the initial stage of the line operation, and then shifts to the dual polarization transmission as the line demand increases, etc. At the same time, when the cross polarization interference canceling circuit 21 is inserted, the delay adjusting circuit 23 is adjusted to a state where there is no delay at the same time. This allows the delay adjustment circuit 23
The delay that has occurred in (1) is switched to the delay of the cross polarization interference cancellation circuit 21, and as a result, the output of the receiving apparatus is held in a state where the delay is not changed. Therefore, it is possible to prevent instantaneous interruption of transmission at the time of adding a line and to add a line without interruption.

In this system, the transmission delay between end stations is within the hitless switching range regardless of the presence or absence of transmission of both polarized waves.

〔The invention's effect〕

As described above, according to the present invention, by providing the delay adjustment circuit for equalizing the transmission delay difference depending on the presence or absence of the cross polarization interference cancellation circuit, the influence of the delay of the interference cancellation circuit when the interference cancellation circuit is attached. There is an effect that it is possible to increase the number without any interruption to the line in operation.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, in which FIG. 1A shows a transmitting side and FIG. 1B shows a receiving side. FIG. 2 is a block diagram of a conventional dual polarization transmission device. And (a) in the figure.
Shows the transmitting side, and FIG. 7B shows the receiving side. 11 …… Transmission end signal processing circuit, 12 …… Modulation circuit, 21 …… Cross polarization interference elimination circuit, 22 …… Demodulation circuit, 23 …… Delay adjustment circuit, 24 …… Reception end signal processing circuit, 25 …… Hitless switching circuit.

Claims (2)

(57) [Claims] 1. In digital transmission using both polarizations, a transmitting side is provided with a circuit for processing a transmitting end signal of a baseband interface signal and a circuit for modulating the processed signal, and the receiving side is provided with the circuit. Is a cross polarization interference cancellation circuit that is selectively inserted in each of the working line and the protection line to prevent interference due to different polarization, and a demodulation that demodulates the output signal of the cross polarization interference cancellation circuit. A circuit, and a delay adjustment circuit connected to the output of the demodulation circuit and set to the same delay amount as the signal delay amount generated in the cross polarization interference cancellation circuit when the cross polarization interference cancellation circuit is inserted, A reception signal processing circuit for reproducing a baseband interface signal from the output of the delay adjustment circuit, and selectively switching the outputs of the reception signal processing circuits of the working line and the protection line without interruption. A dual-polarization transmission device comprising a hitless circuit that operates. 2. The delay adjustment circuit is set in a state in which there is no delay when the cross polarization interference cancellation circuit is inserted, and the cross polarization when the cross polarization interference cancellation circuit is not inserted. The dual-polarized wave transmission device according to claim 1, wherein the dual-polarized wave transmission device is configured to be adjustable so that a delay that is the same as the delay that occurs in the interference cancellation circuit is generated.