KR19990020659U - Output Signal Synchronizer of Redundancy Time / Frequency Generation Card of Mobile Communication System Base Station - Google Patents

Abstract

The present invention relates to an apparatus for synchronizing an output signal of a duplication time / frequency generation card of a mobile communication system base station. In particular, a phase synchronization loop for synchronizing a reference time and a system clock is implemented by redundancy, and the generated system clock is received from GPS. Synchronize with the reference time, regenerate the system clock, and output the generated system clock by resynchronizing with the system clock output from the active time / frequency generation card, thereby outputting from the active time / frequency generation card. Duplicated time / frequency generator card to generate synchronized system clock without clock break when phase shift between system clock and system clock output from standby time / frequency generator card It relates to an output signal synchronization device of.

Description

Output Signal Synchronizer of Redundancy Time / Frequency Generation Card of Mobile Communication System Base Station

The present invention relates to a duplication time / frequency generation card of the mobile communication system base station, in particular to synchronize the phase of the signal output when the duplication of the time / frequency generation card.

In general, a time / frequency generation card in a mobile communication system continuously compares a reference time (PPS) received from a GPS (Global Positioning System) satellite with a reference clock (10 MHz) and time data (abbreviated as TOD). By calibrating the internally generated time and length of time, all base stations are synchronized to standard time. The time / frequency generation card serving as a network synchronizer of the mobile communication system is implemented with redundancy to improve the accuracy and reliability of the system.

1 is a block diagram of a conventional redundant time / frequency generation card.

As shown, a first time / frequency generation card 1 which operates in an active state such that all base stations of the mobile communication system are synchronized to generate a reference time and a reference clock; A second time / frequency generation card 5 which is switched in the event of a failure of the first time / frequency generation card 1 and operates in a standby state to provide the reference time and reference clock to the channel card 8 without interruption; It consists of a channel card (8) which receives a reference time and a reference clock from the redundant time / frequency generation card (1) (5) and processes call related operations.

In the above, the first and second time / frequency generation cards 1 and 5 generate a system clock (19.6608 MHz), respectively, and generate a system clock (19.6608 MHz) generated at a reference clock (10 MHz) received from the GPS. And a phase locked loop for outputting in synchronization.

Referring to the operation of the conventional redundant time / frequency generation card configured as described above are as follows.

First, the first time / frequency generating card 1 generates a base station reference time, PP2S (Pulse Per 2 Seconds) based on a reference time of 1 PPS (Pulse Per Second), and a system clock based on a reference clock of 10 MHz. 19.6608 MHz is generated and output to the channel card 8.

At this time, the phase-locked loop 2 receives a 10 MHz reference clock from the GPS, and outputs in synchronization with the reference clock 19.6608 MHz, which is a system clock required for the service operation of the base station. That is, the phase locked loop 2 generates 19.6608 MHz, which is a system clock, and in order to synchronize this 19.6608 MHz with a 10 MHz reference clock, it is necessary to generate a comparison frequency of the same frequency that can be compared with phase synchronization. Divide to produce a phase comparison frequency of 4.8 KHz. In addition, by dividing the 10MHz to be the phase reference to generate 4.8MHz, the phase of the two phase comparison frequency is controlled to match, and eventually outputs by synchronizing 19.6608MHz to 10MHz.

Then, when a failure occurs in the first time / frequency generation card 1 that is active, the transfer operation of the second time / frequency generation card 5 that is in standby is performed. Thus, the second time / frequency generation card 5 generates the base station reference time PP2S and the system clock 19.6608 MHz to provide the channel card 8 without interruption.

However, the first time / frequency generating card 1 includes one phase locked loop 2, and the second time / frequency generating card 5 also includes one phase locked loop 6. The phase-locked loops (2) (6) generate 19.6608 MHz of the system clock, respectively, and synchronize them to 10 MHz of the reference clock, so that when the frequency of the reference clock and the system clock are not integer multiples, the two time / frequency generation cards The phases of the system clocks between (1) and (5) do not coincide. As a result, it is impossible to match the phases of the system clocks between different time / frequency generating cards, resulting in clock distortion during redundant switching. Thus, the channel card 8, which is provided with the system clock of 19.6608 MHz and performs the call related processing operation, cannot process the call related operation until it is resynchronized and the system becomes unstable.

Thus, the conventional redundant time / frequency generation card uses a single phase locked loop to independently synchronize the system clock of the base station to the reference clock. Therefore, if the frequency of the reference clock and the frequency of the system clock do not become integer multiples, the redundant time / frequency generation card The system clock could not be synchronized with each other, causing a clock distortion phenomenon during redundant switching.

In addition, due to the clock broken due to redundant switching, the channel-related operations cannot be handled in the channel card, resulting in an unstable system.

The purpose of the present invention is to solve the above-mentioned conventional problems, and in particular, by implementing a phase-locked loop that synchronizes the system clock to the reference clock in a redundant manner, based on the system clock of the time / frequency generation card in operation. Resynchronize the clock to generate a synchronized system clock when the time / frequency generation card is redundantly switched to improve the stability and reliability of system operation. To provide.

The present invention (apparatus) to achieve the above object,

A first system clock synchronized with a reference clock from a GPS indicating a standard time and a first system clock generated from a counterpart time / frequency generation card to output a second system clock for the synchronizer to a channel card; A time / frequency generating card; And a second time / frequency generation card for synchronizing the first system clock generated from the first time / frequency generation card with the first system clock synchronized with the reference clock from the GPS and outputting the second system clock. The technical configuration features.

1 is a block diagram of a redundant time / frequency generation card of a conventional mobile communication system base station;

2 is a block diagram of an output signal synchronization device of a redundant time / frequency generation card of a mobile communication system base station according to the present invention;

<Explanation of symbols for main parts of the drawings>

10: First time / frequency generation card 11: First phase locked loop

12: 2nd phase locked loop 20: 2nd time / frequency generating card

21: 1st phase synchronization loop 22: 2nd phase synchronization loop

30: channel card

Hereinafter, the configuration and operation of an embodiment according to the technical spirit of the present invention "the device for synchronizing the output signal of the redundant time / frequency generation card of the mobile communication system base station" will be described in detail with reference to the accompanying drawings.

<Example>

First, an embodiment configuration of an output signal synchronizing apparatus of a redundant time / frequency generating card of a mobile communication system base station is shown in FIG. 2. The first system clock and the counterpart time / frequency generating card synchronized with the reference clock from the GPS are shown in FIG. 2. A first time / frequency generating card 10 for synchronizing the first 'system clock generated at 20 to output a second system clock to the channel card 30; A second time / frequency generation card for synchronizing the first system clock generated from the first time / frequency generation card 10 with the first system clock synchronized with the reference clock from the GPS and outputting the second system clock; It consists of 20.

The first time / frequency generating card 10 includes a first phase locked loop 11 and a first phase locked loop 11 for generating a first system clock and synchronizing with a reference clock received from GPS. The first system clock and the first system clock output from the second time / frequency generation card 20 are received, and the second system clock is generated to generate the first system clock and the first system clock. And a second phase locked loop 12 outputting in synchronization with the system clock output from the active time / frequency generation card.

In addition, the second time / frequency generation card 20 generates a first 'system clock and outputs the first' phase synchronization loop 21 in synchronization with a reference clock received from GPS, and the first 'phase synchronization loop ( The first system clock and the first system clock output from the first time / frequency generation card 10 are input, and the second system clock and the first system clock are generated. And a second 'phase synchronization loop 22 which outputs in synchronization with the system clock output from the active time / frequency generation card among the system clocks.

Referring to the embodiment of the output signal synchronization device of the redundant time / frequency generation card of the mobile communication system base station according to the present invention configured as described above are as follows.

First, when the first time / frequency generation card 10 is operated in an active state, the second time / frequency generation card 20 is operated in a standby state.

Thus, the first time / frequency generation card 10 receives 10 MHz, which is a reference clock, 1 PPS, which is a reference time, and time data TOD from the GPS to generate a base station system clock and a base station reference time therein. At this time, the first phase locked loop 11 generates 19.6608 MHz, which is the first system clock, and synchronizes the generated first system clock to 10 MHz received from the GPS, thereby allowing the second phase locked loop 12 and the second time / frequency. Output to the second'phase sync loop 22 in generation card 20. In addition, the first 'phase synchronization loop 21 in the second time / frequency generation card 20 generates 19.6608 MHz, which is the first' system clock, and synchronizes the generated first 'system clock to 10 MHz from the GPS. The second phase locked loop 12 and the second phase locked loop 12 in the first time / frequency generating card 10 are outputted.

Then, the first time / frequency generation card 10 operating in the active state performs a second phase on the first system clock generated in the first phase synchronization loop 11 of the time / frequency generation card 10 operating in the active state. Control the sync loop 12 to use. Thus, the second phase locked loop 12 generates a new system clock of 19.6608 MHz, which is a new base station system clock, and is then added to the first system clock outputted in synchronization with 10 MHz in the first phase locked loop 11. 2 is synchronized to the system clock and output to the channel card (30).

Meanwhile, the second time / frequency generation card 20 operating in the standby state is the first time / frequency operating in the active state among the first system clock and the first system clock inputted to the second phase synchronization loop 22. The first system clock output from the generation card 11 is controlled to be used in the second'phase synchronization loop 22. Thus, the second 'phase locked loop 22 generates a second' system clock and generates a second clock based on the first system clock output from the first phase locked loop 11 in the first time / frequency generating card 10. 2 'System clock is outputted in phase synchronization. However, since the second time / frequency generation card 20 operates in a standby state, the second time / frequency generation card 20 is in a high impedance state with the channel card 30, and thus the second system clock is not output to the channel card 30. .

Thus, the 19.6608 MHz system clocks, which are output in synchronization with the 10 MHz reference clock in the redundant time / frequency generation card, are synchronized in phase and output the synchronized signals.

Then, when a failure occurs in the first time / frequency generation card 10, the transfer to the second time / frequency generation card 20 in the standby state is made, and is output from the first time / frequency generation card 10 in operation. Since the system clock of 19.6608 MHz was generated in synchronization with the system clock of 19.6608 MHz, the clock is not broken even when the switching is performed, and the synchronized system clock is generated.

In this way, the channel card receiving the system clock and performing the call-related processing operation can operate normally even when the time / frequency generation card is redundantly switched, thereby improving the stability and reliability of the system operation.

As described above, the present invention " output signal synchronization device of the duplication time / frequency generation card of the mobile communication system base station " is particularly implemented by operating a phase synchronization loop that synchronizes the system clock to the reference clock with redundancy. By resynchronizing the system clock based on the system clock of the frequency generation card, the system clock is generated when the time / frequency generation card is redundantly switched to improve the stability and reliability of the system operation.

Claims (3)

A redundant time / frequency generating apparatus for generating a base station system clock and a base station reference time for a network of a mobile communication system, A second system for synchronizing to the channel card 30 by synchronizing the first system clock synchronized with the reference clock from the GPS indicating the standard time with the first 'system clock generated from the counterpart time / frequency generation card 20 A first time / frequency generating card 10 for outputting a clock; A second time / frequency generation card for synchronizing the first system clock generated from the first time / frequency generation card 10 with the first system clock synchronized with the reference clock from the GPS and outputting the second system clock; And an output signal synchronization device of a redundant time / frequency generation card of a base station of a mobile communication system. The method of claim 1, wherein the first time / frequency generating card 10 comprises: A first phase locked loop 11 generating a first system clock and synchronizing with a reference clock received from the GPS; and a first system clock and a second time / frequency outputted from the first phase locked loop 11; Receives a first system clock output from the generation card 20, generates a second system clock, and synchronizes the system clock output from the active time / frequency generation card between the first system clock and the first system clock. And a second phase locked loop (12) for outputting a second system clock. The method of claim 1, wherein the second time / frequency generation card 20, A first 'phase synchronization loop 21 for generating a first' system clock and synchronizing with a reference clock received from GPS; and a first 'system clock and a first outputted from the first' phase synchronization loop 21; The first system clock output from the first time / frequency generation card 10 is input, and the second system clock is generated to generate the second system clock and the first system clock is output from the active time / frequency generation card. And a second 'phase synchronization loop (22) for outputting a second' system clock in synchronization with the system clock.