JPH065828B2 - Scramble processing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a scramble processing method, and more particularly to a scramble processing method used in a orthogonal polarization digital wireless communication line provided with a cross polarization interference canceling circuit.

[Conventional technology]

In the microwave and quasi-millimeter wave band digital wireless communication lines, the bipolar type digital multiplexed signal sent from the multiplexing terminal equipment is converted to a unipolar signal in the transmission code processing board provided on the transmission terminal side. Then, the speed is converted and additional bits such as parity check bits for wireless section monitoring and frame synchronization signals are inserted, and further scrambling processing to smooth the transmission spectrum and reproduce the bit synchronization on the receiving side. After receiving it, it is sent to the modulator of the transmitter. This scrambling process is generally performed by obtaining a modulo 2 sum of a pseudo random code obtained from an m-sequence (longest linear code sequence) code sequence generator using a shift register and a receiving end. On the station side, the same pseudo-random code as on the transmitting terminal side is used for descrambling to restore the original signal. In the conventional digital wireless communication system, the interleaved frequency arrangement is used in which the carrier frequencies of two orthogonal polarizations are arranged such that the carrier frequencies of the respective polarizations are in the middle of the carrier frequencies of the opposite polarizations. Cage,
In order to simplify the device configuration and improve mass productivity, the same transmission code processing board is used for each digital multiplexed signal, and thus the same pseudo random code is used for scrambling processing.

In recent years, in order to make the use of frequency bands even more effective,
Attention has been paid to a co-channel frequency arrangement that uses the same carrier frequency for both orthogonal V and H polarizations. The cross polarization method has a problem of removing cross polarization interference generated between cross polarizations due to rainfall or the like, and various methods have been proposed to solve this problem, but JP-A-55-133156. The method proposed in (1) is noted as a method suitable for a digital wireless communication line with co-channel frequency allocation. This method does not use a pilot signal, but detects cross-polarization interference by calculating the correlation from the demodulated baseband signals of two polarizations. It is based on the assumption that the data signals to be captured are independent and uncorrelated. This precondition is satisfied when a data signal is normally input from the multiplexing terminal device for two polarized waves, and therefore the interference canceling circuit also operates normally. However, when both V and H polarized waves are scrambled by the same pseudo-random code as in the conventional system, both digital signals from the V and H polarized wave multiplexing terminal devices become "0". In this case (such a condition also occurs during line operation, but it becomes a particular problem at the time of line testing at the time of construction), the same code is applied to both V and H polarized waves from the transmission code processing board that performs scramble processing. There is a problem in that the code sequence is transmitted and the receiving system including the interference canceling circuit malfunctions. As a method for solving this problem, Japanese Patent Application No. 59-257826 discloses that the pseudo-random code for performing the scrambling process is not one type and is selected so that the V-polarized wave and the H-polarized wave have no correlation with each other. The method of doing is proposed.

[Problems to be Solved by the Invention] In an actual orthogonal polarization digital radio communication line, a standby radio system is provided outside the active radio system, and simultaneous switching of a bit-free error is required for switching from the active line to the standby line. The switching method is adopted. Normally, this synchronization switching is performed after the transmission code processing board that performs scramble processing at the transmission end station side and before the reception code processing board that performs descramble processing at the reception end station side, and reception synchronization at the reception end station side. In many cases, it is configured to detect the supervisory control signal together with the extraction of the frame synchronization signal before the switching circuit. In addition, as for the standby radio system, only one system is set for one polarization with respect to the n active radio systems provided for both polarizations.
It is not uncommon for an n: 1 working spare configuration to be employed.
In the case of such a configuration, there is a problem that the line configuration is difficult as will be described later in detail by simply changing the pseudo-random code of the transmission and reception code processing board that performs scramble processing. An object of the present invention is to provide a scramble processing system that can configure a line with two types of pseudo-random codes without changing the above-mentioned conventional configuration conditions.

[Means for solving problems]

The scramble processing method of the present invention is used for an orthogonal polarization digital wireless communication line for transmitting different information by first and second polarized waves having the same carrier frequency and orthogonal to each other, and
In the second polarization, the data signal is scrambled by the first pseudo random code and transmitted, and in the second polarization, the data signal is scrambled by the second pseudo random code uncorrelated with the first pseudo random code. In the scramble processing method of processing and transmitting, the standby radio system provided in the first polarization includes a transmission synchronization switching circuit that performs synchronization switching of the scrambled data signal on the transmission terminal side.
Each wireless system of the second polarization scrambles the input signal to the transmitting terminal side with the first pseudo-random code and supplies the first scramble circuit and the input signal to the transmission synchronization switching circuit. A second scramble circuit that scrambles with a second pseudo random code and supplies the scrambled signal to the transmission device, and descrambles the demodulated signal with the second pseudo random code before the reception synchronization switching circuit on the receiving terminal side. It comprises scramble conversion means for performing scrambling with the first pseudo-random code after processing, and a descramble circuit for performing descrambling with the first pseudo-random code after the reception synchronization switching circuit.

〔Example〕

 The present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a line according to an embodiment of the present invention. In the case where each of V and H polarized waves is composed of three radio systems, the transmitting and receiving terminal stations except the intermediate relay station are shown. Only the configuration is shown. In FIG. 1, the configuration of the V polarization (first polarization) including the standby radio system SP and the active radio systems SYS1 and SYS2 is the same as that of the conventional line configuration. The converted signal is subjected to speed conversion and additional bits are inserted, and then scrambled by a pseudo random code A (first pseudo random code) generated by an m-sequence code generator composed of N stages of shift registers. , Transmitter (T) 2
Sent to. The standby radio system SP is provided with a transmission synchronization switching circuit 3 for performing synchronization switching between the transmission code processing board 1 and the transmission device (T) 2. On the receiving terminal side,
The synchronization is detected by the frame synchronization board 5 from the demodulated output of each receiving device (R) 4 and sent to the reception code processing board 7 via the reception synchronization switching circuits 6 and 6a, where the same pseudo-random code A as on the transmission side is sent. It is configured to be descrambled by. On the other hand, in the transmission code processing board 8 of each of the wireless systems SYS3, SYS4 and SYS5 of the H polarization (second polarization), after the signal processing of the input signal 100, the same pseudo random code A as the V polarization is generated. No correlation between the first scramble circuit (A) 9 which scrambles the data and supplies the output to the transmission synchronization switching circuit 3 and the pseudo-random code A generated by the m-sequence code generator including the M-stage shift register. A second scramble circuit (B) 10 that scrambles with a pseudo random code B (second pseudo random code) and supplies the output to the transmitter 2 of each wireless system is provided. Also, on the receiving terminal side, the received demodulated signal 101 scrambled by the pseudo random code B in the frame synchronization board 11 is descrambled once by the pseudo random code B, and the pseudo random code A again.
A scramble conversion circuit 12 for performing scrambling is provided, and a reception code processing board 7 for V polarization is provided after the reception synchronization switching circuit.

FIG. 2 is a frequency layout diagram showing the frequency layout of the orthogonal deviation digital wireless communication line of FIG. 1 described above. For each V deviation wireless system SP, SYS1, SYS2, the H polarization orthogonal to this is shown. SYS3, SYS4, SYS5 are arranged in a co-channel frequency arrangement, and each V-polarized radio system is scrambled with a pseudo-random code A, and each H-polarized radio system is scrambled with a pseudo-random code B. There is. As is clear from the configuration of FIG.
According to the configuration of the present embodiment, even in the conventional configuration in which the synchronous switching is performed after the scramble processing is performed, when the active radio system SYS4 of H polarization is switched to the standby radio system SP, the SP is always pseudo-random. The signal scrambled by the code A is transmitted, and SY of the reverse polarization of the same frequency is transmitted.
Since there is no correlation with S3, there is no possibility that the cross polarization interference canceling circuit (not shown in the drawing) on the receiving side will malfunction.

On the other hand, if the scramble circuit of the transmission code processing board for H polarization is simply changed to scramble with the pseudo-random code B, the following problems occur. That is, since SP and SYS3 are uncorrelated when the SYS4 or the SYS5 is switched to the SP, the pseudo random code for scrambling the SYS3 is different from A and B.
In addition, when the SYS3 is repaired by the SP, a signal is sent in parallel to the SP and the SYS3, and the SP and the SYS3 cannot be kept uncorrelated. Further, in the case of the method of transmitting the monitoring control signal in the wireless section by a digital method and detecting it in front of the reception synchronization switching circuit, it becomes difficult to detect the monitoring control signal if the scrambling process of the transmitted signal changes.

In the above description, an orthogonal polarization digital wireless communication line having an n: 1 working spare configuration has been described.
The technical idea of the present invention can also be applied to the case of an n: 2 working spare configuration having a spare radio system for both V and H polarizations.

〔The invention's effect〕

As described above in detail, according to the scramble processing method of the present invention, signals between orthogonal polarizations are always mutually independent in the conventional line configuration in which synchronous switching is performed after scramble processing in the n: 1 working backup configuration. There is an effect that a correlated orthogonal polarization digital wireless communication line can be constructed by using two kinds of pseudo-random codes. This method is particularly effective in the case where an H-polarized wave is added to an existing line including only the V-polarized wave including the standby radio system.

[Brief description of drawings]

FIG. 1 is a block diagram showing a line configuration of an embodiment of the present invention, and FIG. 2 is a frequency allocation diagram for explaining the effect of FIG. 1, 8 ... Transmission code processing board, 2 ... Transmission device (T), 3
...... Transmission synchronization switching circuit, 4 ...... Reception device (R), 5, 1
1 ... Frame synchronization board, 6, 6a ... Reception synchronization switching circuit, 7 ... Reception code processing board, 9, 10 ... Scramble circuit (A, B), 12 ... Scramble conversion circuit (A /
B).

Claims (1)

[Claims] 1. An orthogonal polarization digital radio communication line for transmitting separate information in first and second polarizations of the same carrier frequency, which are orthogonal to each other, and a data signal is first transmitted in the first polarization. In a second polarization, the data signal is scrambled with a second pseudo-random code that is uncorrelated with the first pseudo-random code, and then transmitted. A backup radio system provided in the first polarization includes a transmission synchronization switching circuit that performs synchronization switching of the scrambled data signal on the transmission terminal side, and each radio system of the second polarization transmits A first scramble circuit that scrambles the input signal to the terminal side with the first pseudo random code and supplies the scrambled signal to the transmission synchronization switching circuit and the second pseudo random code. And a second scrambling circuit supplies the scrambled to the transmitting apparatus dam code,
The reception synchronization switching circuit is provided with scramble conversion means for descramble-processing the demodulated signal with the second pseudo random code and then scrambling with the first pseudo random code before the reception synchronization switching circuit on the reception terminal side. And a descramble circuit for performing a descramble process with the first pseudo-random code.