1. A digital television receiver, comprising:
a demodulator adapted to demodulate an input signal containing first service data multiplexed with second service data;
a first Reed-Solomon (RS) decoder adapted to decode the demodulated signal for first forward error correction (FEC) in order to correct errors in the first and second service data that occurred during reception of the input signal;
a demultiplexer adapted to demultiplex the first service data and the second service data from the FEC-decoded signal; and
a second Reed-Solomon (RS) decoder adapted to decode the demultiplexed first service data for second forward error correction (FEC) in order to additionally correct errors in the first service data that occurred during the reception of the input signal.
2. The digital television receiver of claim 1, wherein the first RS decoder is further adapted to remove first parity data from the first and second service data in the demodulated signal.
3. The digital television receiver of claim 2, wherein the second RS decoder is further adapted to remove second parity data from the demultiplexed first service data.
4. The digital television receiver of claim 3, wherein a length of the first parity data is different from a length of the second parity data.
5. The digital television receiver of claim 4, wherein the length of the first parity data is less than the length of the second parity data.
6. The digital television receiver of claim 1, wherein the second RS decoder is further adapted to reorder the demultiplexed first service data.
7. The digital television receiver of claim 1, further comprising an MPEG header remover adapted to remove MPEG headers from the demultiplexed first service data.
8. The digital television receiver of claim 1, further comprising a data deinterleaver adapted to deinterleave the first and second service data in the demodulated signal.
9. The digital television receiver of claim 1, further comprising a channel equalizer adapted to channel-equalize the demodulated signal.
10. The digital television receiver of claim 1, further comprising a trellis decoder adapted to decode the demodulated signal using a Viterbi decoding algorithm.
11. The digital television receiver of claim 1, wherein the demodulator is further adapted to detect sync information in the input signal.
12. A method of decoding a digital broadcast signal, the method comprising:
demodulating an input signal containing first service data multiplexed with second service data;
Reed-Solomon (RS) decoding the demodulated signal for first forward error correction (FEC) in order to correct errors in the first and second service data that occurred during reception of the input signal;
demultiplexing the first service data and the second service data from the RS-decoded signal; and
Reed-Solomon (RS) decoding the demultiplexed first service data for second forward error correction (FEC) in order to additionally correct errors in the first service data that occurred during the reception of the input signal.
13. The method of claim 12, wherein RS decoding the demodulated signal comprises removing first parity data from the first and second service data in the demodulated signal.
14. The method of claim 13, wherein RS decoding the demultiplexed first service data comprises removing second parity data from the demultiplexed first service data.
15. The method of claim 14, wherein a length of the first parity data is different from a length of the second parity data.
16. The method of claim 15, wherein the length of the first parity data is less than the length of the second parity data.
17. The method of claim 12, further comprising reordering the demultiplexed first service data.
18. The method of claim 12, further comprising removing MPEG headers from the demultiplexed first service data.
19. The method of claim 12, further comprising deinterleaving the first and second service data in the demodulated signal.
20. The method of claim 12, further comprising channel-equalizing the demodulated signal.
21. The method of claim 12, further comprising decoding the demodulated signal using a Viterbi decoding algorithm.
22. The method of claim 12, further comprising detecting sync information in the input signal.
23. A broadcast transmitter, comprising:
a first Reed-Solomon (RS) coder adapted to code first service data for first forward error correction (FEC) in order to reduce errors in the first service data that occur during data transmission;
a multiplexer adapted to multiplex the FEC-coded first service data with second service data;
a second Reed-Solomon (RS) coder adapted to code the multiplexed first and second service data for second forward error correction (FEC) to reduce errors in the first and second service data that occur during data transmission; and
a modulator adapted to modulate the FEC-coded first and second service data for data transmission.
24. The broadcast transmitter of claim 23, wherein the first RS coder is further adapted to add first parity data to the first service data.
25. The broadcast transmitter of claim 24, wherein the second RS coder is further adapted to add second parity data to the multiplexed first and second service data.
26. The broadcast transmitter of claim 25, wherein a length of the first parity data is different from a length of the second parity data.
27. The broadcast transmitter of claim 26, wherein the length of the first parity data is greater than the length of the second parity data.
28. The broadcast transmitter of claim 23, wherein the first RS coder is further adapted to reorder the first service data.
29. The broadcast transmitter of claim 23, further comprising an MPEG header inserter adapted to insert MPEG headers in the FEC-coded first service data.
30. The broadcast transmitter of claim 23, further comprising a data interleaver adapted to interleave the FEC-coded first and second service data.
31. The broadcast transmitter of claim 23, further comprising a trellis coder adapted to trellis-code the FEC-coded first and second service data.
32. The broadcast transmitter of claim 23, further comprising a mapper adapted to map the FEC-coded first and second service data into corresponding symbols.
33. The broadcast transmitter of claim 23, further comprising a frame formatter adapted to add sync information to the FEC-coded first and second service data.
34. A method of encoding a digital broadcast signal, the method comprising:
Reed-Solomon (RS) coding first service data for first forward error correction (FEC) in order to reduce errors in the first service data that occur during data transmission;
multiplexing the RS-coded first service data with second service data;
Reed-Solomon (RS) coding the multiplexed first and second service data for second forward error correction (FEC) in order to reduce errors in the first and second service data that occur during data transmission; and
modulating the RS-coded first and second service data for data transmission.
35. The method of claim 34, wherein RS-coding first service data comprises adding first parity data to the first service data.
36. The method of claim 35, wherein RS-coding the multiplexed first and second service data comprises adding second parity data to the multiplexed first and second service data.
37. The method of claim 36, wherein a length of the first parity data is different from a length of the second parity data.
38. The method of claim 37, wherein the length of the first parity data is greater than the length of the second parity data.
39. The method of claim 34, further comprising reordering the first service data.
40. The method of claim 34, further comprising inserting MPEG headers in the RS-coded first service data.
41. The method of claim 34, further comprising interleaving the RS-coded first and second service data.
42. The method of claim 34, further comprising trellis-coding the RS-coded first and second service data.
43. The method of claim 34, further comprising mapping the RS-coded first and second service data into corresponding symbols.
44. The method of claim 34, further comprising adding sync information to the RS-coded first and second service data.
45. A digital television (DTV) receiver, comprising:
a demodulator configured to demodulate a digital television (DTV) signal containing first service data multiplexed with second service data;
a first decoder configured to decode the demodulated DTV signal for first error correction in order to correct errors in the first and second service data that occurred during reception of the DTV signal;
a data separator configured to separate the first service data and the second service data from the decoded DTV signal; and
a second decoder configured to further decode the separated first service data for second error correction in order to additionally correct errors in the first service data that occurred during the reception of the DTV signal, wherein the first and second decoders perform different error correction functions.
46. The DTV receiver of claim 45, wherein the first decoder is a trellis decoder and the second decoder is a Reed-Solomon (RS) decoder.
47. A method of processing digital broadcast data, the method comprising:
demodulating a digital television (DTV) signal containing first service data multiplexed with second service data;
decoding the demodulated DTV signal for first error correction by performing a first error correction function in order to correct errors in the first and second service data that occurred during reception of the DTV signal;
separating the first service data and the second service data from the decoded DTV signal; and
decoding the separated first service data for second error correction by performing second error correction function in order to additionally correct errors in the first service data that occurred during the reception of the DTV signal, wherein the first and second error correction functions are different from each other.
48. The method of claim 47, wherein the first error correction function is trellis decoding and the second error correction function is Reed-Solomon (RS) decoding.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A magnetic joystick, comprising:
a control stick, having a handle;
a spring, ensheathing the control stick;
a spring seat, arranged underneath the spring while supporting the same;
a base, arranged underneath the spring seat while supporting the same by a supporting part thereof;
a pivotal joint, arranged on the base while having an opening enabling the control stick to be fitted therein and extend therefrom;
a carrier disk, arranged under the pivotal joint while connecting to the bottom of the control stick to be driven thereby; and
a plurality of magnetic sensors;
wherein, a plurality of magnets are positioned on the carrier disk while enabling the polarities of the plural magnets to be interlaced aligned; and each of the plural magnetic sensors is disposed at a position corresponding to the plural magnets so as to use the detection of the intensity change of magnetic field, caused by the translation of the carrier disk, for evaluating the position of the carrier disk.
2. The magnetic joystick of claim 1, wherein the control stick is a hollow tube.
3. The magnetic joystick of claim 2, wherein the handle further comprises a switch for enabling an electrical signal to be issued and transmitted to a controller so as to direct the same to carry out a command corresponding to the electrical signal as the switch is activated.
4. The magnetic joystick of claim 3, wherein the electrical signal is transmitted by a signal line guided out by the use of the hollow tube and electrically connected to the controller.
5. The magnetic joystick of claim 4, wherein the switch is substantially a pressure switch capable of being activated while it is subjected to a pressure larger than a resisting force provided by the spring.
6. The magnetic joystick of claim 5, wherein the pressure switch is a device selected form the group consisting of a piezo-electric crystal and a strainer.
7. The magnetic joystick of claim 1, wherein the control stick is rigidly connected to the carrier disk for enabling the carrier disk to be driven to move by the control disk.
8. The magnetic joystick of claim 1, wherein the control stick is loosely connected to the carrier disk for enabling the carrier disk to be movable relative to the control stick.
9. The magnetic joystick of claim 8, wherein a force feedback spring is arranged surrounding the control stick at the portion thereof sandwiched between the carrier disk and the pivotal joint for balancing the carrier disk at a level status.
10. The magnetic joystick of claim 1, wherein the carrier disk is a planar plate.
11. The magnetic joystick of claim 1, wherein the carrier disk is a convex plate.
12. The magnetic joystick of claim 1, wherein a first positioning pin is arranged at the joint of the control stick and the pivotal joint for limiting the movable directions of the control stick.
13. The magnetic joystick of claim 1, wherein a second positioning pin is arranged at the base for limiting the movable directions of the pivotal joint.
14. The magnetic joystick of claim 1, wherein the axis of polarization of each magnet of the plural magnets, characterized by its north and south magnetic poles, is aligned parallel to the longitudinal axis of the control stick.
15. The magnetic joystick of claim 1, wherein the axis of polarization of each magnet of the plural magnets, characterized by its north and south magnetic poles, is aligned perpendicular to the longitudinal axis of the control stick.
16. The magnetic joystick of claim 1, wherein the axis of polarization of each magnet of the plural magnets, characterized by its north and south magnetic poles, is aligned to incline to the longitudinal axis of the control stick by a less than 90 degrees inclination angle.
17. The magnetic joystick of claim 14, wherein the sensitive axis of each magnetic sensor of the plural magnetic sensors is aligned parallel to the longitudinal axis of the control stick.
18. The magnetic joystick of claim 15, wherein the sensitive axis of each magnetic sensor of the plural magnetic sensors is aligned perpendicular to the longitudinal axis of the control stick.
19. The magnetic joystick of claim 16, wherein the sensitive axis of each magnetic sensor of the plural magnetic sensors is aligned parallel to the axes of polarization of the magnets corresponding thereto.
20. The magnetic joystick of claim 1, wherein the magnetic sensor is a Hull-effect sensor.
21. The magnetic joystick of claim 1, wherein the control stick is a detachable stick.