JPH0425245A - Base band signal switching device - Google Patents

Abstract

PURPOSE:To eliminate the need for a manual operation by detecting the phase difference of bipolar output signals from an active line and a standby line so as to adjust automatically the difference of delay in the active line or the standby line. CONSTITUTION:A delay quantity control section 3 uses the control signal of a switching controller 4 and the detection result of a phase comparator 13 to adjust the delay in a digital signal processing section of a standby line by controlling the outputs of delay quantity roughly adjusting signals 18A, 19A and delay quantity finely adjusting signals 20A, 21A. For example, when a high speed switch 12 selects the active line and a phase difference between active and standby bipolar output signals exceeds 1/4bit, the delay quantity control section 3 uses the delay quantity finely adjusting signal to control a finely adjusting analog delay circuit 9, thereby minimizing the phase difference. A digital delay circuit 7 and the finely adjusting analog delay circuit 9 are repetitively controlled to match the phase difference within 1/4bit, thereby holding the delay quantity. Thus, the adjusting time is shortened.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a baseband signal switching device, and particularly to a wireless communication receiver for working and protection lines, in which a digitally processed bipolar output signal can be used for working without missing bits. The present invention relates to a base punt signal switch that switches from the side to the standby side.

[Conventional technology]

As shown in the block diagram of FIG. 2, a conventional baseband signal switch has a working and standby digital signal processing unit
A and 2A are digital delay circuits 6A and 7A that change the delay amount of the input signal by 1/2 bit by control operation of the delay amount coarse adjustment signals 18 and 19, and a delay amount fine adjustment signal 20.
．． 21, further fine adjustment analog delay circuits 8A, 9A, which perform fine adjustment of the delay amount within 1/2 bit of the input signal, and fine adjustment analog delay circuits 8A, 9.
It has U/BCONV10.11 which is a comparator that converts the output signal of A from unipolar to bipolar.

The switching unit 5 is connected to the outputs of the working and standby digital signal processing units IA and 2A, and includes a phase comparator 13 that detects the phase difference between the working and standby bipolar signals and outputs a monitor voltage, and a phase comparator 13 that detects the phase difference between the working and standby bipolar signals and outputs a monitor voltage. If the phase difference is less than a certain threshold (for example, 1/4 bit), the M
! It has a high-speed switch 12 that performs switching between the current and standby modes without missing any bits in response to the switching signal from the 17W unit 4.

If the high-speed switch 12 is currently selecting the active side,
When the phase difference between the bipolar output signals between the working and protection lines is 1/4 bit or more, the delay amount coarse adjustment signal 19 is sent to correct the phase difference of the digital signal processing unit 2A of the standby protection side line. The delay amount fine adjustment signal 21 is adjusted so that the phase difference is 1/4 bit or less while measuring the monitor voltage of the adjustment measuring device 17 attached to the output of the phase comparator 13. After that, switch the high-speed switch 12 to the standby side to perform switching without missing bits. If the high-speed switch 12 selects the standby side, adjust the digital signal processing unit IA in the same way as described above. By doing so, it is possible to perform switching without missing bits even when switching from the backup side to the working side. When the phase difference of the bipolar signal is 1/4 bit or less, switching is possible without missing bits, but in reality, adjustment conditions are set depending on the timing conditions of data and tarok.

[Problem to be solved by the invention]

In the above-mentioned conventional baseband signal switching device, the operator measures the monitor voltage of the phase comparator with the adjusting measuring device 17 and performs a preliminary check so that the phase difference between the output signals of the digital signal processing section is below a certain value. Since it is necessary to adjust the digital signal processing section on the side or the current side, the adjustment takes time, and there are also disadvantages in that readjustment must be performed every time maintenance such as panel replacement is performed.

[Means to solve the problem]

The baseband signal switching device of the present invention includes a digital delay circuit that performs delay correction on a digital input signal bit by bit, and a digital delay circuit that receives a signal from the digital delay circuit and further converts the signal to 1/N (N is 4 or more) within 1 bit unit. (Integer) A digital signal processing unit having a fine adjustment delay circuit that performs delay correction for each bit and a U/'B converter that converts the unipolar signal output from the fine adjustment delay circuit into a bipolar signal is installed on the working and protection line sides. and a high-speed switch for switching between the digital signal processing units on the working and protection line sides under the control of a switching controller.

〔Example〕

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

FIG. 1 is a block diagram of one embodiment of the present invention. The working and backup digital signal processing units 1-2 convert the input signals of the input terminals 14 and 15 of the working line and the protection line into the digital delay circuit 6 using delay amount rough adjustment signals 18A and 19A from the delay amount control unit 3, which will be described later. Alternatively, the delay amount of 7 is changed in 172-bit steps, and the delay amount is further adjusted within 1/2 bit by the fine adjustment analog delay circuit 8 or 9 using the delay amount fine adjustment signals 2OA and 21A from the delay amount control section 3. Make fine adjustments. U/BCONV10.11 converts unipolar signals into bipolar signals as in the conventional example. The phase comparator 13 of the switching section 5 is an analog multiplier that detects the phase difference between the bipolar output signals of the active and standby digital signal processing sections 1 and 2, and outputs the detected signal to the delay amount control section 3. Furthermore, the high-speed switch 12 is a semiconductor switch, and can switch the output without missing bits when the phase difference between the active and standby bipolar output signals is less than a certain threshold (for example, 1/4 bit). It's a switch.

Here, the delay amount control section 3 adjusts the delay amount of the digital signal processing section on the line side in standby based on the control signal of the switching controller 4 and the detection result of the phase comparator 13 using a delay amount rough adjustment signal 18.
A, 19A and delay amount fine adjustment, outputs of Nos. 2OA and 21A are controlled.

For example, if the high-speed switch 12 selects the active side,
When the phase difference between the current and standby bipolar output signals exceeds 1/4 bit, the delay amount control section 3 controls the fine adjustment analog delay circuit 9 using the delay amount fine adjustment signal to adjust the phase. The phase difference should be minimized. If the phase difference at this time was within 1/4 bit, the delay amount was held; otherwise, the digital delay circuit 7 was controlled by the delay amount rough adjustment signal, and the delay amount was shifted by 1/2 bit. after,
Furthermore, the analog delay circuit 9 for fine adjustment is controlled by the delay amount fine adjustment signal to minimize the phase difference, and if the phase difference at this time is within 1/4 bit, the delay amount is maintained, If not, as described above, after repeating the control of the digital delay circuit 7 and the fine adjustment analog delay circuit 9 to adjust the phase difference to within 1/4 bit, and performing 6 phase adjustments to maintain the delay amount. In this state, no bits are lost even if the high-speed switch 12 is switched from the working side to the standby side. Similarly, even if the high-speed switch 12 selects the protection side, by performing phase adjustment in the same procedure, it is clear that no bits will be lost even when switching from the protection side to the working side.

〔Effect of the invention〕

As explained above, the present invention detects the phase difference between the bipolar output signals of the working line and the protection line, and automatically adjusts the difference in the amount of delay between the working line and the protection line. This has the effect that no operation is required, and there is no need for an adjustment measuring device for the operator to confirm. Therefore, there is an effect that the maintenance time for the operating panel can also be shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional baseband signal switch. 1.2. LA, 2A...Digital signal processing section, 3.
...Delay amount control unit, 4...Switching controller, 5...Switching unit, 6, 7.6A, 7A...Digital delay circuit, 8
．． 9.8A, 9A...Analog delay circuit for fine adjustment, 1
0.11... U/BCONV, 12... High speed switch, 13... Phase comparator, 14... Working side input terminal, 15... Standby side input terminal, 16... Output terminal.

Claims (1)

[Claims] 1. A digital delay circuit that performs delay correction on a digital input signal in units of bits, and 1/N (N is an integer of 4 or more) within 1 bit unit after receiving the signal of the digital delay circuit. A digital signal processing unit having a fine adjustment delay circuit that performs delay correction for each bit and a U/B converter that converts a unipolar signal output from the fine adjustment delay circuit into a bipolar signal is provided on the working and protection line sides respectively. , a baseband signal switching device having a high-speed switch that switches between the digital signal processing units on the working and protection line sides under the control of a switching controller, wherein mutual output signals of the digital signal processing units on the working and protection line sides are switched. A phase comparator detects the delay phase difference of A baseband signal switching device comprising: a delay amount control section that sends out control signals of a coarse adjustment signal and a delay amount fine adjustment signal. 2. The digital delay circuit receives the delay coarse adjustment signal and automatically performs delay correction in 1-bit units, and then the fine adjustment delay circuit receives the delay amount fine adjustment signal and the high-speed switch corrects the bit. 2. The baseband signal switching device according to claim 1, wherein delay correction is automatically performed for every 1/N bit, which is a threshold value for switching without loss.