Method for achieving time service through FM (frequency modulation) broadcast

A technology of frequency modulation broadcasting and time code, applied in the field of communication, can solve the problems of high cost of building stations, susceptible to interference of satellite timing, and complicated receiving equipment

Active Publication Date: 2017-06-30
NAT TIME SERVICE CENT CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in recent years, with the rapid development of TV broadcasting and the Internet, the use of FM-SCA FM broadcasting to assist communication services has been greatly reduced, and with the popularization of smart phones and 3G and 4G networks, people rely less and less on SCA broadcasting to obtain financial information , weather and other informati...

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  • Method for achieving time service through FM (frequency modulation) broadcast
  • Method for achieving time service through FM (frequency modulation) broadcast
  • Method for achieving time service through FM (frequency modulation) broadcast

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Embodiment Construction

[0024] The present invention specifically comprises the following steps:

[0025] 1) The insertion of time information, including the following steps

[0026] 1.1) Use the atomic clock to keep the time at the FM broadcasting station, and at the same time trace the time back to the time kept by the National Time Service Center of the Chinese Academy of Sciences;

[0027] 1.2) Encode the time information and time code information per second, and encode by one frame per second, and the timing information of each frame is composed of frame header, time code information, CRC check bit and reserved bits; the frame header is the time Information; the frame header of each frame is the same, all adopt pseudo-random sequence PRN code, its period length is 127 chips, and the original polynomial X 7 +X 3 +1, recorded as PN0 code;

[0028] Described time code information is made up of altogether 45 bits by start symbol, year, month, day, hour, minute, second, adopts binary code, and spe...

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Abstract

The invention provides a method for achieving the time service through FM (frequency modulation) broadcast, and the method comprises the steps: inserting standard time information into an FM broadcast signal in an SCA channel of the FM broadcast through employing the pseudo-random code spread spectrum modulation technology, and carrying out the broadcasting; enabling a receiving end to receive the FM broadcast signal, demodulating the moment information and time information from the FM broadcast signal, and achieving the high-precision time service. According to the invention, through the coding of the time information and the spread spectrum gain of a PN code, the method is provided under the condition that the normal operation of a conventional FM broadcast is not affected. The time precision corresponding to the bandwidth of 5KHz is 0.2 millisecond, and the precision of time service is at the level of sub-millisecond after the impact from a transmission distance is removed.

Description

technical field [0001] The invention relates to a technique for realizing time service by using FM broadcasting, in particular to realizing spread spectrum modulation by using an FM additional channel SCA channel, so as to realize high-precision transmission of time code and time information, and belongs to the field of communication technology. Background technique [0002] FM FM Additional Channel (FM-SCA) broadcasting is an auxiliary communication service carried out through FM broadcasting, that is, using additional channels to transmit various service information in the existing FM FM broadcasting, referred to as SCA for short. SCA broadcasting is widely used in the transmission of traffic information, financial information, weather information, background music, and radio paging services, and has achieved certain social and economic benefits. However, in recent years, with the rapid development of TV broadcasting and the Internet, the use of FM-SCA FM broadcasting to a...

Claims

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Application Information

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IPC IPC(8): H04J3/06H04H20/86H04B1/69H04L27/12H04L27/20
CPCH04B1/69H04H20/86H04J3/0611H04J3/0638H04L27/12H04L27/20
Inventor 向渝王善和华宇黄长江胡召鹏
Owner NAT TIME SERVICE CENT CHINESE ACAD OF SCI
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