Apparatus for Receiving Satellite Broadcasting and Method Thereof

• US 20080216128A1
• Filed: 08/16/2006
• Published: 09/04/2008
• Est. Priority Date: 08/18/2005
• Status: Active Grant

• Current Assignee: LG Innotek Company Limited (LG Corporation)
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Park, Kwang Jae
• Granted Patent: US 7,865,135 B2
• Time in Patent Office: Days
• US Class Current: 725/68
• CPC Class Codes: H04B 1/30 for homodyne or synchrodyne receivers demodulator circuits H03D1/22

Abstract

A method for receiving satellite broadcasting includes: amplifying an inputted satellite broadcasting signal; converting the amplified signal to a baseband signal by mixing the amplified signal with a center frequency of a selected channel; and varying a channel bandwidth of the baseband signal.

Claims

1. An apparatus for receiving satellite broadcasting, comprising:

a radio frequency (RF) input unit for amplifying an inputted satellite broadcasting signal;

a mixer for converting an output signal of the RF input unit into a baseband signal; and

a bandwidth controller for varying a channel bandwidth for the baseband signal according to a symbol rate of a selected channel.

2. The apparatus according to claim 1, wherein the RF input unit comprises:

an input tilter for removing noise of a signal inputted from a low noise block (LNB) of an antenna unit; and

an RF amplifier for amplifying a signal filtered by the input filter.

3. The apparatus according to claim 1, wherein the bandwidth controller comprises:

a channel information detecting module for detecting a symbol rate of the selected channel;

a bandwidth determining module for determining a bandwidth according to the symbol rate of the selected channel; and

a bandwidth varying module for varying a channel bandwidth of the baseband signal to a bandwidth determined by the bandwidth determining module.

4. The apparatus according to claim 3, wherein the bandwidth determining module determines the bandwidth using the following equation:

BW=(1+α

)×

SR/log₂M,

where α

represents a roll off factor, SR represents a symbol rate, and M represents a degree of modulation.

5. An apparatus for receiving satellite broadcasting, comprising:

a radio frequency (RF) input unit for amplifying an inputted satellite broadcasting signal;

a local oscillator for outputting a center frequency of a selected channel;

a mixer for converting an output signal of the RF input unit into a baseband signal by mixing the output signal with the center frequency of the local oscillator; and

a bandwidth controller for varying a bandwidth of each channel using a symbol rate and center frequency information of the selected channel.

6. The apparatus according to claim 5, wherein the bandwidth controller comprises:

a channel information detecting module for detecting a symbol rate and a reference center frequency of the selected channel;

a bandwidth determining module for determining a bandwidth using the symbol rate and a center frequency difference of the selected channel; and

a bandwidth varying module for varying a channel bandwidth of the baseband signal to a bandwidth determined by the bandwidth determining module.

7. The apparatus according to claim 6, wherein the center frequency difference is an absolute value of a difference between the reference center frequency of the selected channel and the center frequency tuned by the local oscillator.

8. The apparatus according to claim 6, wherein the bandwidth determining module determines the bandwidth by taking a roll off factor and/or a degree of modulation into account.

9. The apparatus according to claim 8, wherein the bandwidth is obtained using the following equation:

BW=(1+α

)×

SR/log₂M+F_Receiver,

where α

represents a roll off factor, SR represents a symbol rate, M represents a degree of modulation, and F_Receiver represents a drift amount of a channel frequency.

10. The apparatus according to claim 9, wherein the drift amount of the channel frequency is a difference between the reference center frequency of the channel, and an actually-tuned center frequency.

11. The apparatus according to claim 5, wherein the inputted satellite broadcasting signal is provided by an antenna unit, wherein the antenna unit comprises:

an antenna for receiving a C band or a Ku band from a satellite; and

a low noise block (LNB) for down-converting a signal received by the antenna to an intermediate frequency, and outputting the down-converted signal to the RF input unit.

12. A method for receiving satellite broadcasting, the method comprising:

amplifying an inputted satellite broadcasting signal;

converting the amplified signal to a baseband signal by mixing the amplified signal with a center frequency of a selected channel; and

varying a channel bandwidth of the baseband signal.

13. The method according to claim 12, further comprising converting the inputted satellite broadcasting signal into an intermediate frequency by a low noise block (LNB) of an antenna unit before amplifying the inputted satellite broadcasting signal.

14. The method according to claim 12, wherein the varying of the channel bandwidth comprises varying a bandwidth of a selected channel according to a symbol rate of the selected channel.

15. The method according to claim 12, wherein the varying of the channel bandwidth comprises correcting a bandwidth of a selected channel using a shift amount of a center frequency of the selected channel.

16. The method according to claim 12, wherein the varying of the channel bandwidth comprises varying a bandwidth of a selected channel using a symbol rate of the selected channel and a center frequency difference of the selected channel.

17. The method according to claim 16, wherein the center frequency difference of the selected channel is an absolute value of a difference between a reference center frequency of the selected channel and a center frequency of a channel generated by a local oscillator.

18. The method according to claim 12, wherein the varying of the channel bandwidth uses at least one of a roll off factor, a symbol rate, a degree of modulation, and a drift amount of a channel frequency.

19. The method according to claim 12, wherein the varying of the channel bandwidth uses the following equation:

BW=(1+α

)×

SR/log₂M,

where α

represents a roll off factor, SR represents a symbol rate, and M represents a degree of modulation.

20. The method according to claim 12, wherein the varying of the channel bandwidth uses the following equation:

BW=(1+α

)×

SR/log₂M+F_Receiver,

where α

represents a symbol rate, M represents a degree of modulation, and F_Receiver represents a drift amount of the channel frequency.