| 摘要 |
PURPOSE: A gap filler for a satellite broadcasting system is provided to generate a system clock having high frequency stability and retransmit a signal using the system clock. CONSTITUTION: An RF receiving unit(100) has an LNA(Low Noise Amplifier)(104) and a tuner(106). The LNA(104) amplifies a signal received through an antenna(102), and converts a band of the amplified signal into an IF(Intermediate Frequency) band. The tuner(106) receives an IF signal from the LNA(104), divides the IF signal into an I signal and a Q signal of a baseband, performs a frequency tuning function, and controls a gain of the LNA(104). A baseband signal processing unit(110) has a TDM(Time Division Multiplexing) receiving unit(112), a buffering and synchronous signal generating unit(114) and a CDM(Code Division Multiplexing) modulating unit(116). The TDM receiving unit(112) demodulates and decodes a TDM signal outputted from the tuner(106), and outputs the decoded TDM signal. The buffering and synchronous signal generating unit(114) generates a system clock, stores demodulated broadcasting data in a memory, and provides the broadcasting data to the CDM modulating unit(116) according to the system clock. The CDM modulating unit(116) performs the CDM of the broadcasting data, synthesizes CDM signals of several channels, and provides the synthesized CDM signal to an RF(Radio Frequency) transmitting unit(120). The RF transmitting unit(120) has a D/A converting unit(122), a high power amplifier(124) and a transmission antenna(126). The D/A converting unit(122) converts the synthesized CDM signal into an analog signal. The high power amplifier(124) amplifies the signal and transmits the amplified signal through the transmission antenna(126).
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