4 results about "FCCH" patented technology

The invention discloses a time-frequency offset tracking method in a Tiantong satellite monitoring low-orbit satellite system, which belongs to the field of satellite communication, and comprises the following steps: acquiring satellite orbit information, satellite ephemeris information and positioning information of a low-orbit satellite, and resolving current Doppler frequency offset information; performing frequency pre-compensation according to the Doppler frequency offset information, and performing compensation by using the frequency offset captured by the FCCH; the satellite-borne terminal receiver carries out carrier frequency estimation by using a downlink channel, so that the carrier residual frequency difference of a received signal is estimated, and frequency correction is carried out; starting downlink timing tracking; uplink frequency offset compensation is started, so that the frequency of a signal from the low-orbit satellite to the Tiantong satellite is the expected carrier frequency of the Tiantong satellite; and carrying out transmission timing correction by adopting the spaceborne terminal timing drift rate, and carrying out uplink timing adjustment. According to the method, normal access and stable data transmission of the satellite-borne terminal can be realized.

The invention relates to the technical field of satellite communication, in particular to a satellite communication frequency offset estimation and synchronization method, a storage medium and a satellite communication terminal.The satellite communication frequency offset estimation and synchronization method comprises the steps that a satellite wireless signal containing a frequency correction channel burst and a broadcast control channel burst is received; detecting frequency correction channel burst to obtain coarse carrier frequency offset; positioning baseband data corresponding to a broadcast control channel burst in the satellite wireless signal; pre-compensating baseband data corresponding to the broadcast control channel burst by using coarse carrier frequency offset, and calculating residual frequency offset of a residual frequency offset signal; obtaining a total carrier frequency offset according to the coarse carrier frequency offset and the residual frequency offset; and performing complete compensation, demodulation and channel decoding on the baseband data corresponding to the broadcast control channel burst by using the total carrier frequency offset to obtain decoded data. According to the method, the coarse estimation of the FCCH and the fine estimation and verification mechanism of the BCCH are combined, and the synchronization reliability can still be ensured under the complex channel condition.

The application discloses a GSM-R multi-path interference detection method and device, wherein the method comprises the following steps: performing channelization processing on wideband in-phase / quadrature I / Q data collected along a railway to obtain a plurality of GSM-R channel I / Q data; through resampling processing, a plurality of GSM-R channel I / Q data with a sampling rate matched with a GSM-R symbol rate is obtained; a frequency correction channel FCCH burst signal is extracted from the plurality of GSM-R channel I / Q data after resampling; a phase sequence of the FCCH burst signal is extracted, and the phase sequence is subjected to differential processing to obtain a phase difference sequence; the phase difference sequence is subjected to frequency domain transformation to obtain a phase difference spectrum; frequency domain peak value distribution characteristics of the phase difference spectrum are compared and analyzed with preset multi-path interference frequency domain characteristics to obtain a GSM-R multi-path interference detection result. The application can realize accurate detection of GSM-R multi-path interference.

This application relates to the field of satellite communication technology, specifically to a satellite communication frequency offset estimation and synchronization method, a storage medium, and a satellite communication terminal. The satellite communication frequency offset estimation and synchronization method includes: receiving a satellite radio signal containing a frequency correction channel burst and a broadcast control channel burst; detecting the frequency correction channel burst to obtain a coarse carrier frequency offset; locating the baseband data corresponding to the broadcast control channel burst in the satellite radio signal; pre-compensating the baseband data corresponding to the broadcast control channel burst using the coarse carrier frequency offset, and calculating the residual frequency offset for the residual frequency offset signal; obtaining the total carrier frequency offset based on the coarse carrier frequency offset and the residual frequency offset; and performing full compensation, demodulation, and channel decoding on the baseband data corresponding to the broadcast control channel burst using the total carrier frequency offset to obtain decoded data. This invention combines coarse estimation of the FCCH with fine estimation and verification mechanisms of the BCCH, ensuring the reliability of synchronization even under complex channel conditions.