Abstract: Provided is a satellite broadcasting terminals. The satellite broadcasting terminal includes: a first antenna receiving a radio signal of a first band or a second band; a second antenna receiving a radio signal of a third band; a first stream demodulating unit demodulating a first stream signal received through the first band; a second stream demodulating unit demodulating a second stream signal received through the second band; a playing unit playing the demodulated first or second stream signal; and a gap filler receiving unit selectively providing the first stream signal to the first stream demodulating unit in response to a radio signal intensity of the third band, the first stream signal being received through the third band.

Abstract: A receiver circuit of a satellite digital video broadcast system includes: a multiplication unit outputting a synchronized reception symbol by multiplying a reception symbol by frequency error information as a feedback; a common autocorrelation unit acquiring autocorrelation values for each symbol by multiplying the synchronized reception symbol by an autocorrelation coefficient; a frame synchronization unit detecting a SOF (Start Of Frame), which is a synchronization word indicating start of a frame, from the autocorrelation values for each symbol; a frequency synchronization unit estimating the frequency error information based on the autocorrelation values for each reception symbol and the SOF; and an SNR estimation unit estimating an SNR (Signal to Noise Ratio) based on the autocorrelation values for each symbol and the SOF.

Abstract: Provided are an apparatus and method for robust Binary Phase Shift Keying/Quadrature Phase Shift Keying (BPSK/QPSK) blind modulation classification. The apparatus includes first and second likelihood value calculators for calculating a likelihood value of a received baseband signal each for of BPSK and QPSK modulation modes. A maximum setting unit derives a maximum value of the likelihood values or ith likelihood ratios calculated by the first and second likelihood value calculators. A flag is set for the maximum value to “1” and a flag for the remaining value is set to “0”. First and second flag combining units combine the flags for the modulation modes. A modulation mode flag setting unit selects a maximum value from the flags combined by the first and second flag combining units.

Abstract: Provided are a 3-port orthogonal mode transducer, and a receiver and receiving method using the same. The 3-port orthogonal mode transducer includes: a transmission port having a rectangular shape elongated in a horizontal direction and configured to transmit a Ka-band (30 GHz) vertical polarization signal; a first reception port having a rectangular shape inclined at about +45 degrees at a location being at about +45 degrees with respect to the transmission port and configured to receive a K-band (20 GHz) vertical or horizontal polarization signal phased-delayed about +45 degrees; and a second reception port having a rectangular shape inclined at about ?45 degrees at a location being at about ?45 degrees with respect to the transmission port and configured to receive a K-band (20 GHz) vertical or horizontal polarization signal phase-delayed about ?45 degrees.

Abstract: Provided are an apparatus and method for robust Binary Phase Shift Keying/Quadrature Phase Shift Keying (BPSK/QPSK) blind modulation classification against errors in a satellite communication system. The apparatus includes first and second likelihood value calculators for calculating a likelihood value of a received baseband signal each for of BPSK and QPSK modulation modes, respectively, a maximum setting unit for deriving a maximum value of the likelihood values or ith likelihood ratios calculated by the first and second likelihood value calculators and setting a flag for the maximum value to “1” and a flag for the remaining value to “0”, first and second flag combining units for combining the flags for the modulation modes, respectively, a modulation mode flag setting unit for selecting a maximum value from the flags combined by the first and second flag combining units, and a modulation classification mode deciding unit.

Abstract: Disclosed is a frequency hopping system for converting frequencies of signals into RF (radio frequency) signals, which comprises: a frequency hopper for outputting signals with temporarily varied frequencies according to a predetermined pattern; a fixed PLL (phase locked loop) unit for outputting frequency-fixed signals; a mixer for mixing the output signals of the frequency hopper and the fixed PLL unit, and outputting frequency-hopped local signals; and a modulator for receiving I and Q (in-phase and quadrature-phase) signals from a baseband device, synthesizing the I and Q signals with the frequency-hopped local signals, combining the two synthesized signals, and outputting RF signals.