KR100460301B1 - Ntp server using cdma signal - Google Patents

Abstract

PURPOSE: An NTP server is provided to reduce costs for NTP server installation by extracting time information from a CDMA signal and providing NTP service over Internet. CONSTITUTION: An NTP server comprises an CDMA signal unit(10), an oscillator unit(40), a system clock synchronization unit(30), and a processor unit(20). The CDMA signal unit extracts a time information signal and a reference clock from a CDMA signal received through an antenna(1). The oscillator unit generates a system clock of a predetermined cycle by a first control signal. The system clock synchronization unit receives the reference clock and the system clock, detects a phase difference by a second control signal, generates the first control signal by the detected phase difference signal, and generates a synchronized system clock obtained by synchronizing the time information signal and the system clock. The processor unit synchronizes the time information signal and the synchronous system clock, outputs the synchronized signal, provides NTP service over Internet, and controls a system by generating the second control signal.

Description

NTP SERVER USING CDMA SIGNAL using NTM Signal

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an NTP (Network Time Protocol) server using a CDMA signal, and in particular, time information on the Internet by extracting time information required for NTP service from a code division multiple access (CDMA) signal. An NTP server uses a CDMA signal to supply accurate time information where it is needed.

The conventional NTP server obtains reference time information by receiving reference time information from a GPS satellite or receiving an IRIG-B (Inter-Range Instrumentation Group B) or a corresponding signal from the outside.

At this time, in case of receiving reference time through GPS, NTP server should install GPS antenna on the building roof and install cable from the building roof to the place where NTP server is installed. Such a conventional method has a problem of limitation of antenna installation space, installation of cables when the cable is not easy to be installed, and a large cable installation cost.

In addition, when using IRIG-B as a reference signal, there is a problem in that the user adds to the economic burden because a separate equipment for providing IRIG-B is required.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to receive NTP service on the Internet by receiving time information from CDMA signals that are not limited to time and place, thereby reducing the installation cost of the NTP server. To provide an NTP server using a CDMA signal that can expand the spread of the.

1 is a block diagram of an NTP server using a CDMA signal according to the present invention

2 is a block diagram of a CDMA receiver shown in FIG.

3 is a block diagram illustrating a processor unit shown in FIG. 1;

4 is a block diagram illustrating a system clock synchronizer illustrated in FIG. 1.

5 is a block diagram illustrating an oscillator unit illustrated in FIG. 1.

<Description of Symbols for Main Parts of Drawings>

10: CDMA receiver 12: CDMA signal receiver

14: sync channel extractor 16: time information extractor

20: processor unit 22: time information receiving unit

24: NTP service unit 26: Ethernet service unit

28: system control unit 30: system clock synchronization unit

32: phase detector 34: filter

40: oscillator

42: digital-to-analog signal conversion unit (DAC)

44: voltage control generator (VCO)

50: Ethernet network service network

NTP server using a CDMA signal according to the present invention for achieving the above object,

A CDMA receiver extracting a time information signal and a reference clock from the CDMA signal received through the antenna;

An oscillator unit generating a system clock of a predetermined period according to the first control signal;

A synchronous system clock receiving the reference clock and the system clock to detect a phase difference by a second control signal, generating the first control signal by the detected phase difference signal, and synchronizing the time information signal with the system clock A system clock synchronizer for generating a signal; And

And a processor unit for receiving the time information signal and the synchronous system clock, synchronizing and outputting the NTP service through the Internet, and generating the second control signal to control the system, wherein the CDMA receiving unit receives the CDMA signal. A signal receiving unit; A sync channel extractor for extracting a sync channel from the CDMA signal received from the CDMA signal receiver; And a time information extractor configured to extract the time information signal and the reference clock from the sync channel received from the sync channel extractor, wherein the system clock synchronizer receives the reference clock and the system clock to control the second clock. A phase detector for detecting a phase difference between the reference clock and the system clock by a signal; And a filter unit generating the system clock by using the phase difference signal received from the phase detector by the second control signal and generating the first control signal. The oscillator unit may include the first control signal. A digital-to-analog converter (DAC) for receiving a signal and converting the signal into an analog signal; And a voltage control generator for generating a system clock of a predetermined period by the signal received from the digital-analog converter.

The processor unit receives the time information signal and the synchronization system clock and outputs a time information signal synchronized with the synchronization system clock; An NTP service unit for standardizing the time information signal received from the time information receiver by a third control signal and supplying it to a network; A system controller for generating the second control signal, receiving a synchronous system clock from the system clock synchronizer and transmitting the synchronized system clock to the time information receiver, and controlling an overall operation of the NTP server using the CDMA signal; And an Ethernet service unit which services the time information signal received from the NTP service unit to the network by Ethernet communication standard.

The system controller may be configured to supply stable time information by using a system clock generated by the oscillator unit for a predetermined time when normal information cannot be received due to a bad base station or a bad receiver.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a block diagram of an NTP server using a CDMA signal according to the present invention.

As shown in FIG. 1, the NTP server using the CDMA signal includes a CDMA receiver 10, a processor 20, a system clock synchronizer 30, an oscillator 40, and an Ethernet network service network 50. It is configured to include.

The CDMA receiver 10 receives a CDMA signal through the antenna 1 and extracts a time information signal TOD and a reference clock 1PPS from the CDMA signal.

Currently, mobile phones are divided into a scheme using frequency division multiple access (FDMA) and a scheme using code division multiple access (CDMA).

The service using the dual CDMA is the service using the 016, 018, 019 area code. In addition, CDMA base stations are distributed throughout the country due to the popularization of mobile phones, and CDMA base station signals can be received anywhere in the country.

The CDMA signal transmitted from the mobile phone base station is composed of a pilot channel, a sync channel, a paging channel, and a traffic channel. Among these, the pilot channel and the synchronization channel are channels transmitted from an unspecified number, and include the time information signal in this channel, and extract the time information signal TOD from this channel.

There are several CDMA base station signals that can be received at one point. Of these signals, the base station having the best reception rate is selected using the pilot channel described above, the synchronization channel of the selected base station is received, and the information and time information of the base station are extracted by multiplying a predefined PN code to obtain an approximate time information. Generates a time information signal TOD. Then, from the frame of 1200bps, a reference clock (1PPS) with no timing information signal but accurate timing information is generated.

The processor unit 20 receives the time information signal TOD extracted from the CDMA signal from the CDMA receiver 10, and receives the synchronized system clock SCLK from the system clock synchronizer 30. The information signal TOD is output in synchronization with the synchronization system clock SCLK. As a result, the processor unit 20 provides NTP service through the network and controls the system of the NTP server using the CDMA signal.

The system clock synchronizer 30 receives the reference clock 1PPS from the CDMA receiver 10, receives a synchronized system clock OSC from the oscillator 40, and receives the same from the processor 20. The phase difference between the reference clock 1PPS and the system clock OSC is detected by the second control signal CONTLL. The second control signal CONTLL received from the processor 20 generates the first control signal OC to the oscillator 40 using the phase difference signal and filters the phase difference signal. To generate a system clock (1PPS) (10MHz) externally. The system clock synchronizer 30 synchronizes the system clock OSC received from the oscillator 40 with the reference clock 1PPS received from the CDMA receiver 10. To the processor unit 20.

The oscillator 40 receives the first control signal OC from the system clock synchronizer 30 to generate a system clock OSC of a predetermined period to the system clock synchronizer 30. In this case, the system clock OSC generated by the oscillator 40 is the reference clock 1PPS and the oscillator by the first control signal OC received from the system clock synchronizer 30. This clock corrects the phase difference with the previous system clock OSC generated at 40.

The Ethernet network service network 50 is a network communication network for NTP service according to the Ethernet Institute of Electrical and Electronic Engineers (IEEE) 802.3 standard.

According to the above configuration, the NTP server using the CDMA signal of the present invention can solve the installation constraint problem of the NTP server by extracting time information from the CDMA signal to the NTP service to the Internet.

Next, the operation of each component of FIG. 1 will be described in more detail with reference to FIGS. 2 to 5.

2 is a block diagram of the CDMA receiver 10 shown in FIG.

As illustrated in FIG. 2, the CDMA receiver 10 includes a CDMA signal receiver 12, a synchronization channel extractor 14, and a time information extractor 16.

The CDMA signal receiving unit 12 serves to receive the CDMA signal through the antenna 1.

The sync channel extractor 14 receives the CDMA signal from the CDMA signal receiver 12 and extracts a sync channel from the CDMA signal.

The time information extractor 16 receives the sync channel from the sync channel extractor 14 and extracts a time information signal TOP and a reference clock 1PPS from the sync channel.

3 is a block diagram of the processor unit 20 shown in FIG. 1.

As illustrated in FIG. 3, the processor unit 20 includes a time information receiver 22, an NTP service unit 24, an Ethernet service unit 26, and a system controller 28.

The time information receiver 22 receives the time information signal TOP from the CDMA receiver 10, receives the synchronous system clock SCLK from the system controller 28, and transmits the time information signal TOP to the time information signal TOP. The synchronous system clock (SCLK) is synchronized and output. At this time, the synchronous system clock SCLK is a system clock corrected for a phase difference between the reference clock 1PPS extracted from the CDMA signal and the system clock OSC generated by the oscillator unit 40. Accordingly, the time information signal TOP 'output from the time information receiver 22 is a signal output by synchronizing the time information signal TOP received from the CDMA receiver 10 with the synchronization system clock SCLK. Because of this, it has accurate time information in which no phase difference occurs.

The NTP service part 24 receives the time information signal TOP 'from the time information receiver 22 and receives a third control signal SC from the system control part 28, thereby receiving the third control signal. (SC) serves to supply the time information signal TOP 'to the network in accordance with the Request For Comments (RFC) 1305 standard and other timing standards.

The system controller 28 generates a second control signal CONTLL for controlling the system clock synchronizer 30, receives the synchronous system clock SCLK from the system clock synchronizer 30, and receives the time information. It transmits to the receiver 22 and controls the overall operation of the NTP server using the CDMA signal. In addition, the system controller 28 is generated by the system clock (OSC) generated in the oscillator unit for a predetermined time (Holdover time) when the time information can not be received due to a base station failure or a receiver failure during normal operation It supplies a stable time using the synchronized synchronous system clock (SCLK).

The Ethernet service unit 26 services the time information signal TOP " received from the NTP service unit 24 to the network according to the Ethernet IEEE802.3 standard. The Ethernet service unit 26 is the NTP service unit. Responsible for various Ethernet services, including information provided by (24) and telnet.

4 is a block diagram of the system clock synchronizer 30 shown in FIG. 1.

As shown in FIG. 4, the system clock synchronizer 30 includes a phase detector 32 and a filter 34.

The phase detector 32 receives the reference clock 1PPS from the CDMA receiver 10, receives the system clock OSC from the oscillator 40, and receives the first clock received from the processor 20. The phase difference signal is detected by detecting the phase difference between the reference clock 1PPS and the system clock OSC by the two control signals CONTLL.

The filter 34 controls the first oscillator 40 using the phase difference signal received from the phase detector 32 by the second control signal CONTLL received from the processor 20. Generate signal OC. In this case, the value of the first control signal OC changes according to the phase difference between the reference clock 1PPS and the system clock OSC. The filter unit 34 filters the phase difference signal received from the phase detector 32 to generate a system clock (1PPS) (10 MHz) to the outside.

The phase detector 32 of the system clock synchronizer 30 inputs a new system clock OSC whose phase difference is corrected by the first control signal OC from the oscillator 40. The above operation is repeated until the phase difference between the reference clock 1PPS and the system clock OSC coincides.

Here, the system clock synchronizer 30 may adjust the time to a unit of μs by synchronizing the reference clock 1PPS with the system clock OSC.

FIG. 5 is a block diagram of the oscillator unit 40 shown in FIG. 1.

As shown in FIG. 5, the oscillator 40 includes a digital-to-analog signal converter (DAC) 42 and a voltage control generator (VCO) 44.

The digital-analog signal converter (DAC) 42 receives the first control signal OC from the system clock synchronizer 30, converts it into an analog signal, and outputs the analog signal.

The voltage control generator 44 generates a system clock (OSC) of a predetermined period by the analog signal received from the digital-to-analog converter 42.

Accordingly, the oscillator unit 40 may control the reference clock 1PPS and the system clock OSC by the first control signal OC changed according to a phase difference between the reference clock 1PPS and the system clock OSC. The system clock OSC is corrected by the phase difference of.

As shown in FIG. 1, the processor unit 20 receives a time information signal TOD from the CDMA receiver 10 and synchronizes a phase difference from the system clock synchronizer 30. ), And synchronizes the time information signal TOD with the synchronization system clock SCLK.

As a result, the NTP server using the CDMA signal of the present invention receives time information from the CDMA signal and provides NTP service to the Internet, thereby reducing the installation cost of the NTP server and increasing the spread of the NTP server.

The present invention is not limited to the above-described embodiments, but can be variously modified and changed by those skilled in the art, which should be regarded as included in the spirit and scope of the present invention as defined in the appended claims. something to do.

As described above, the NTP server using the CDMA signal according to the present invention uses the NTP server that receives the time information from the GPS receiver to extract the time information from the CDMA signal, thereby facilitating the installation by the user and installing the NTP server. Cost can be implemented at low cost. In addition, since the NTP server can be expanded and the NTP server can be expanded, the Internet content market can be expanded.

Claims (6)

delete delete delete A CDMA receiver extracting a time information signal and a reference clock from the CDMA signal received through the antenna; An oscillator unit generating a system clock of a predetermined period according to the first control signal; A synchronous system clock receiving the reference clock and the system clock to detect a phase difference by a second control signal, generating the first control signal by the detected phase difference signal, and synchronizing the time information signal with the system clock A system clock synchronizer for generating a signal; And And a processor unit for receiving the time information signal and the synchronous system clock, synchronizing and outputting the NTP service through the Internet, and generating the second control signal to control the system. The system clock synchronizer is: A phase detector configured to receive the reference clock and the system clock and detect a phase difference between the reference clock and the system clock by the second control signal; And And a filter unit generating the system clock by using the phase difference signal received from the phase detection unit by the second control signal and generating the first control signal. The oscillator unit: A digital-analog converter (DAC) for receiving the first control signal and converting the analog signal into an analog signal; And A voltage control generator for generating a system clock of a predetermined period by a signal received from the digital-analog converter, The CDMA receiving unit: A CDMA signal receiving unit which receives the CDMA signal; A sync channel extractor for extracting a sync channel from the CDMA signal received from the CDMA signal receiver; And A time information extractor configured to extract the time information signal and the reference clock from the sync channel received from the sync channel extractor; The processor unit: A time information receiver for receiving the time information signal and the synchronous system clock and outputting a time information signal synchronized with the synchronous system clock; An NTP service unit for standardizing the time information signal received from the time information receiver by a third control signal and supplying it to a network; A system controller for generating the second control signal, receiving a synchronous system clock from the system clock synchronizer and transmitting the synchronized system clock to the time information receiver, and controlling an overall operation of the NTP server using the CDMA signal; And It includes an Ethernet service unit for servicing the time information signal received from the NTP service unit to the network by the Ethernet communication standard, When the system control unit does not receive time information due to a base station failure or a receiver failure during normal operation, the system controller supplies stable time information using a system clock generated by the oscillator unit for a predetermined time. Entity server used. delete delete