Daewoo Electronics Co., Ltd.

Young-Rok Park

Olivier Dejonghe

The present invention provides an improved receiver capable of receiving either a satellite broadcast signal or a cable TV signal associated with a TV. The inventive receiver comprises a first BPF for filtering received broadcast signals, a first local oscillator for generating a first oscillation signal, a first mixer for generating a first IF signal, a SAW filter producing a waveformed band signal, a second local oscillator, for generating a second and a third oscillation signal, a second mixer for generating a second and a third IF signal, a switching block for switching the second and the third IF signal, a second BPF for producing a baseband channel signal selected from the cable TV signal, a first LPF for producing a baseband I signal of satellite broadcast channel, a shifter for shifting a phase of the third IF signal, a third mixer for generating a phase-shifted third oscillation signal, and a second LPF for producing a baseband Q signal of satellite broadcast channel.

Method and apparatus for selectively receiving a satellite broadcast signal or a cable television signal

The disclosure describes an apparatus for correcting a frequency offset in a OFDM receiving system. The apparatus comprises a loop filter for receiving a predetermined phase value, multiplying the phase value by a gain value, accumulating the multiplied values, and outputting the accumulated value; a voltage control oscillator for multiplying the accumulated value outputted from the loop filter by the gain value, feeding back the result, and adding the feedback values; a derotator for obtaining sine and cosine waves from the result outputted from the voltage control oscillator, multiplying the obtained value by an output signal from an A/D converter, and outputting the multiplied value to an OFDM demodulator; a correlation calculation unit for calculating a correlation value from a value outputted from the OFDM demodulator; and a frequency offset estimator for generating a phase signal according to a frequency offset outputted sequentially within a predetermined frequency offset range, outputting the phase signal to the loop filter, determining an approximate value of the frequency offset within 1/4 range of a carrier frequency interval by using a value outputted from the correlation calculating unit for a corrected symbol, and correcting the frequency offset according to a final determined frequency offset estimation value.

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Seoul, South Korea

Young-Rok Park