JPH0746226A - Error monitor circuit - Google Patents

Abstract

PURPOSE:To monitor the real error number of reproduced data to be sent to a carrier equipment by detecting an unmatched number of active and standby reception data inputted from a transmission section to a reception section and detecting a parity error after reception of transmission data with a parity added thereto. CONSTITUTION:A transmission means 1 adds a radio block frame synchronizing signal and a parity bit respectively to active distribution data and standby distribution data generated by dividing received data into two and sends the data by two frequencies f1, f2 as active transmission data and standby transmission data. A deciding means 4 at a receiver side checks the presence of a parity error in the active reception data and the standby reception data and sends line information generating the parity error as result of a decision. On the other hand, an uninterruptible changeover means 3 eliminates the synchronizing signal and the parity bit from the active reception data and the standby reception data and sends the result to the carrier equipment and the active data and the standby distribution data are compared one by one bit each at a comparison counter section 5 to detect unmatch. A data error sent from the means 4 and the section 5 is displayed on an error number display section 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an error monitor circuit used in a digital multiplex radio system.

A carrier line and a wireless line are connected,
When data is transmitted from one carrier device to the other carrier device via a wireless line, the wireless line transmits a frame synchronization signal used only in the wireless line, a parity bit, etc., to the data to be transmitted. On the receiving side, the status of the wireless line is monitored using the parity bit, and the added bit is removed and sent as reproduction data to the other carrier device.

However, since the actual number of errors contained in the data (hereinafter referred to as the actual number of errors) cannot be known in the parity check, when the error is detected from the reproduced data on the side of the carrier, the location of the failure is determined. May take some time. Therefore, it is necessary for the receiving side to be able to monitor the number of actual errors in the reproduced data sent to the carrier side.

[0004]

2. Description of the Related Art FIG. 4 is an explanatory view when a conventional example is applied to a twin path system, and FIG. 5 is an operation explanatory view of FIG.

The operation of FIG. 4 will be described below with reference to FIG. First, on the transmission side of FIG. 4, the distributor 11 divides the data from the carrier device into two and sends them to the code processing parts 12 and 14. Therefore, these code processing parts increase the speed of the working / preliminary distribution data. A gap is created, a frame synchronization signal used only in the wireless section, a parity bit, etc. are added to this gap and sent to the transmitters 13 and 15 as working / preliminary transmission data in a predetermined format. The transmitting unit generates a modulated wave using the input working / preliminary transmission data and sends it to the receiving side at transmission frequencies f ₁ and f ₂ .

On the receiving side, the receiving units 21 and 23 extract the above-mentioned working / spare transmission data from the received signal and perform a code processing section.
Send to 22, 24. After detecting the frame synchronization signal, the code processing part compares the counting result of the parity counting with the parity bit sent from the transmitting side, and when the comparison result does not match, sends the H level to the judging part 4. At the same time, the portion added on the transmitting side is removed to take out the working / preliminary distribution data, and this data is sent to the hitless switching unit 3.

Therefore, the phase comparison / control section 33 of the hitless switching section adjusts the amount of phase shift of the phase matching sections 31 and 32 so that the phases of the data passed through the phase matching section coincide with each other.
Since the switch control signal for selecting the working side is sent to the switch 34, the working distribution data that has passed through the phase matching portion 32 is sent to the carrier device as reproduction data.

Next, the operation of the judging section will be described. Generally, in the case of odd parity, the parity bit P becomes "0" when the number of "1" is odd, and the number of "1" is even, Or when it is 0, parity bit P becomes "1". For example, Figure 5-
In case of, since the number of "1" between PP is 9 and odd, the parity bit becomes "0".

The number of parity bits for the information bits is determined by how many errors are detected,
If the parity bit is 1 bit for 1000 information bits, an error rate up to 10 ⁻³ can be detected, and if the valid bit is 1 bit for the information bit, the actual error rate can be detected.

Now, assuming that the data on the receiving side is as shown in FIG. 5-, an error pulse is output because there is a 1-bit error between PP, but this pulse is the parity bit P.
From the next to the parity bit P, the duty is 50% (see Fig. 5- ,,).

Here, the error pulse generation as described above is performed by the error pulse generation portion as shown in the judgment unit 4 of FIG.
41 is producing the above 50% duty error pulse. On the other hand, the sign processing part 22 sends H level from the parity bit P to the next parity bit when there is a mismatch, so that the AND gate 42 is turned on and an error pulse is added to the counter 43. To count the number of.

On the other hand, the code processing section 24 sends the L level because the parity check coincides with the parity check performed on the transmitting side, so that the corresponding counter (not shown) does not count and the count value Remains the initial value.
Therefore, the determination part 45 sends information of the working line whose count value is larger than the initial value to the outside as the determination result.

[0013]

As described above, when the line status is detected by the parity bit, it is determined that there is no error in the parity frame and that there is no error, or there is an error of 3 or more odd numbers. However, since it is judged as one error, there is a problem that the actual error number of the data transmitted from the wireless device to the carrier device cannot be monitored.

It is an object of the present invention to be able to monitor the number of actual errors in reproduced data sent to a carrying device.

[0015]

FIG. 1 is a block diagram showing the principle of the present invention. In the figure, 1 is a working line data and a spare line data generated by dividing the input data into two, and a radio section frame synchronization signal and a parity bit are respectively added to the working line data as the working line data and the spare line data. The transmitting means 3 for transmitting to the protection line removes the frame synchronization signal for wireless section and the parity bit from the working reception data and the protection reception data to obtain the working distribution data and the protection distribution data. It is a non-instantaneous-interruption switching means for transmitting the distribution data selected by the switch (SW) in response to the switch control signal to be applied, as reproduction data, after performing phase matching between the preliminary distribution data.

Reference numeral 4 is a judging means for checking the presence / absence of a parity error in the input working reception data and spare reception data, and sending out the line information in which the parity error has occurred as a judgment result. Reference numeral 5 is working distribution data and protection distribution data. Comparing / counting part for counting the number of disagreements by comparing each one bit by bit,
Reference numeral 6 is an error number display portion for displaying the actual number of errors of the distribution data that has passed through the line corresponding to the determination result, using the input determination result and the output of the comparison / counting portion.

The actual number of errors in the reproduced data sent from the hitless switching means can be monitored.

[0018]

[Operation] When the wireless line status is monitored and the line is switched as described above, the transmitting side adds a plurality of bits including the parity bit to the data, and the receiving side counts the number of error pulses. Although the error is being monitored, if it is monitored for a long time, it will be averaged, so the value will be the same as the actual number of errors, and there will be no problem.

However, it is different to see how many errors are present in the data sent from the wireless device to the carrier device (the data added in the wireless section is removed and returned to the original data rate). there is a possibility.

This system is a digital multiplex radio system having a standby system 1 for the active system 1, and as shown in FIG. 1, the data on the active side and the standby side are compared to detect an error bit, and the switch SW is operated. The number of errors of data sent to the transport device is monitored at the input side, that is, at the interface with the transport device.

That is, in the case of a twin path system in which the transmitting side distributes the same signal to the active system and the standby system and transmits at two radio frequencies (f ₁ , f ₂ ) and the receiving side selects one, The standby system and the current system compare the data sent to the transport device with each other and output "0" when they match and "1" when they do not match.

Therefore, when it is determined that one line is in a normal state (for example, the number of parity errors is less than or equal to a predetermined value per unit time), if "1" of the other line is counted, it becomes Although the number of error bits in the interface section can be detected, this number is the actual number of errors that occurred in the other wireless line.

[0023]

FIG. 2 is an explanatory view when the present invention is applied to a twin path system, and FIG. 3 is a configuration diagram of an embodiment of the present invention.

Here, the same symbols are the same symmetrical objects throughout the drawings. Further, the EX-OR gate 51 and the counter 52 are constituent parts of the comparison / counting part 5, and the error indicator 61 is a constituent part of the error number output part 6. The operation of FIGS. 2 and 3 will be described below on the assumption that the standby system is in a normal state. The parts described in detail above will be briefly described, and the part of the present invention will be described in detail.

First, in FIG. 2, the data from the carrier device is divided into two by the hybrid 11 and added to the active radio device 71 and the standby radio device 72. Therefore, the transmitters of the active / spare radio devices 71, 72 add bits to be used only in the radio section to the input data as described above, and add the bits used in the active / spare line to the active / spare radio devices 73, 74. Send to.

On the other hand, the receivers of the active / spare radio units 73 and 74 compare the active / spare distribution data obtained by removing the additional bits from the active / spare transmission data extracted from the received signal with the comparing / counting part 5 and the switch 75. Send to. Since the comparing / counting unit compares the current / preliminary data with each other to count the number of mismatches, the number of actual errors in the reproduced data at the input side of the switch 34 can be detected.

Next, since the hitless (non-instantaneous interruption) switching method is used for switching between the working / standby radio equipment, as shown in FIG. 3, the receiving side has a working / standby phasing circuit, The phases of the working / preliminary distribution data that have passed through the phase matching portions 31 and 32 match.

Since the EX-OR gate 51 compares the working / preliminary distribution data whose phases are completely matched with each other and sends an error bit to the counter 52 at the portion where they do not match, this counter counts the number of error bits and outputs an error. It is sent to the display 61.
Since the judgment result indicating that the working line has a parity error is also input from the judging means 4 to the error indicator,
The actual error number of the currently reproduced data sent from the non-instantaneous-interruption switching means to the carrier device side can be known.

Further, in the case of the active system N and the standby system 1, the standby line is periodically switched (or the transmitting side TSW is transmitting) when the standby line is normal, and each active system is temporarily made the same configuration as the twin path system. Error monitor. Further, when switching to the protection line due to a line failure, the actual error number of the active system appears in the counter 52, so that the actual error rate of the failed active system can be monitored while operating.

[0030]

As described in detail above, according to the present invention, it is possible to monitor the number of actual errors in the reproduced data sent to the carrier.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram of the present invention.

FIG. 2 is an explanatory diagram when the present invention is applied to a twin path system.

FIG. 3 is a configuration diagram of an embodiment of the present invention.

FIG. 4 is an explanatory diagram when a conventional example is applied to a twin path system.

5 is an operation explanatory diagram of FIG. 4;

[Explanation of symbols]

1 Transmission function means 3 Non-interruption switching means 4 Judgment means 5 Comparison / counting part 6 Error number output part

Claims (1)

[Claims] 1. A transmitting side, which is obtained by dividing input data into two parts, and adds a frame synchronization signal for wireless section and a parity bit to the working distribution data and the preliminary distribution data, respectively, and the working transmission data and the preliminary transmission data are added. As a result, the transmission means (1) for sending to the working line and the protection line is checked on the receiving side for the parity error of the input working reception data and the protection reception data, and the line information that generated the parity error is judged. Means to send as
(4) And, the frame synchronization signal for wireless section and the parity bit are removed from the currently received data and the previously received data to obtain the currently distributed data and the previously distributed data. After matching the phases, switch (SW) corresponding to the applied switch control signal.
In a digital multiplex wireless system having a hitless switching means (3) for transmitting the distribution data selected by the device as reproduction data, the current distribution data and the preliminary distribution data are compared with each other bit by bit, and the number of mismatches is counted. An error number display part that displays the actual number of errors in the distribution data that has passed through the line corresponding to the judgment result using the counting part (5) and the input judgment result and the output of the comparison / counting part ( 6) is provided, and the error monitor circuit is configured to monitor the actual number of errors in the reproduction data sent from the hitless switching means.