Apparatus for Transmitting and Receiving Data to Provide High-Speed Data Communication and Method Thereof

• US 20120051474A1
• Filed: 11/09/2011
• Published: 03/01/2012
• Est. Priority Date: 12/23/2004
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: YU, Hee-Jung, Jeon, Taehyun, Kim, Myung-Soon, Choi, Eun-Young, Lee, Sok-Kyu, Lyu, Deuk-Su
• Granted Patent: US 8,532,231 B2
• Time in Patent Office: Days
• US Class Current: 375/346
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0618 Space-time coding
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 5/003 Arrangements for allocating sub-channels of the transmission path
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 28/065 using assembly or disassembly of packets
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

In the present invention, data generated from a source unit are distributed to at least one bandwidth; the data distributed to the respective bandwidths are encoded in order to perform an error correction; the encoded data are distributed to at least one antenna; a subcarrier is allocated to the data distributed to the respective antennas, and an inverse Fourier transform is performed; a short preamble and a first long preamble corresponding to the subcarrier are generated; a signal symbol is generated according to a data transmit mode; and a frame is generated by adding a second long preamble between the signal symbol and a data field for the purpose of estimating a channel of a subcarrier which is not used.

Claims

1-9. -9. (canceled)

10. An apparatus for wirelessly receiving and demodulating signals, the apparatus comprising:

a receiving unit configured to receive a group of time domain signals from a transmission apparatus, wherein the group of time domain signals comprises;

a synchronization signal,

first and second channel estimation signals subsequent to the synchronization signal,

a data signal subsequent to the first and second channel estimation signals, the data signal representing digital data, and

a coding information signal between the first channel estimation signal and the second channel estimation signal;

a determination unit configured to determine, based on information in the coding information signal, whether the group of time domain signals are transmitted from the transmission apparatus using space time block coding;

a synchronizer configured to perform signal synchronization using the synchronization signal; and

a channel estimator configured to perform channel estimation.

11. The apparatus of claim 10, wherein the first and second channel estimation signals are time domain representations of first and second frequency domain signals, respectively, and wherein the first and second frequency domain signals are generated based on a reference signal.

12. The apparatus of claim 11, wherein the first and second channel estimation signals are equal to inverse fast Fourier transforms of the first and second frequency domain signals, respectively.

13. The apparatus of claim 12, wherein the reference signal comprises, as its elements, A×

{0, 0, 1, 1, −

1, −

1, 1, 1, −

1, 1, −

1, 1, 1, 1, 1, 1, 1, −

1, −

1, 1, 1, −

1, 1, −

1, 1, 1, 1, 1, 0, 1, −

1, −

1, 1, 1, −

1, 1, −

1, 1, −

1, −

1, −

1, −

1, −

1, 1, 1, −

1, −

1, 1, −

1, 1, −

1, 1, 1, 1, 1, 0, 0}, where A is a non-zero real-valued coefficient, and wherein the second frequency domain signal is equal to a signal obtained by changing values of some, but not all, elements of the reference signal.

14. The apparatus of claim 13, wherein a number of the some elements of the reference signal whose values are changed is twenty-six or less.

15. The apparatus of claim 13, wherein a number of non-zero elements of the second frequency domain signal is different from a number of non-zero elements of the reference signal.

16. The apparatus of claim 15, wherein the first frequency domain signal has at least twenty-six elements whose values are equal to values of corresponding elements of the reference signal, respectively.

17. The apparatus of claim 15, further comprising a decoding unit configured to decode the data signal using space time block coding.

18. The apparatus of claim 17, wherein a length of the first channel estimation signal is equal to a length of the second channel estimation signal when the group of time domain signals are transmitted from two transmission antennas.

19. The apparatus of claim 17, wherein the second channel estimation signal is longer than the first channel estimation signal when the group of time domain signals are transmitted from more than two transmission antennas.

20. The apparatus of claim 10, wherein the channel estimator is configured to perform the channel estimation based on the first and second channel estimation signals.

21. The apparatus of claim 20, wherein the synchronization signal comprises a first sequence of time-domain signals, wherein each of the time-domain signals of the first sequence has a first duration, wherein the first channel estimation signal comprises a second sequence of time-domain signals, wherein each of the time-domain signals of the second sequence has a second duration, wherein the second channel estimation signal comprises a third sequence of time-domain signals, wherein each of the time-domain signals of the third sequence has a third duration, and wherein the first duration is shorter than the second duration and the third duration.

22. The apparatus of claim 10, wherein the synchronization signal comprises a first sequence of time-domain signals, wherein each of the time-domain signals of the first sequence has a first duration, wherein the first channel estimation signal comprises a second sequence of time-domain signals, wherein each of the time-domain signals of the second sequence has a second duration, wherein the second channel estimation signal comprises a third sequence of time-domain signals, wherein each of the time-domain signals of the third sequence has a third duration, and wherein the first duration is shorter than the second duration and the third duration.

23. The apparatus of claim 12, wherein the synchronization signal comprises a first sequence of time-domain signals, wherein each of the time-domain signals of the first sequence has a first duration, wherein the first channel estimation signal comprises a second sequence of time-domain signals, wherein each of the time-domain signals of the second sequence has a second duration, wherein the second channel estimation signal comprises a third sequence of time-domain signals, wherein each of the time-domain signals of the third sequence has a third duration, and wherein the first duration is shorter than the second duration and the third duration.

24. The apparatus of claim 17, wherein the synchronization signal comprises a first sequence of time-domain signals, wherein each of the time-domain signals of the first sequence has a first duration, wherein the first channel estimation signal comprises a second sequence of time-domain signals, wherein each of the time-domain signals of the second sequence has a second duration, wherein the second channel estimation signal comprises a third sequence of time-domain signals, wherein each of the time-domain signals of the third sequence has a third duration, and wherein the first duration is shorter than the second duration and the third duration.

25. A receiving apparatus in a wireless communication system, the apparatus comprising:

a receiving unit configured to receive a frame comprising sequentially a short preamble, a first long preamble, a signal symbol, a second long preamble, and a data symbol, wherein the short preamble comprises a symbol for synchronization; and

a determination unit configured to determine, based on information in the signal symbol, whether the frame is transmitted using space time block coding.

26. The apparatus of claim 25, wherein the first and second long preambles are inverse fast Fourier transforms of first and second frequency domain signals, respectively, wherein the first and second frequency domain signals are originated from a basic frequency domain signal, wherein the first, the second, and the basic frequency domain signals are orthogonal frequency division multiplexing (OFDM) signals, and wherein the basic frequency domain signal occupies a predetermined bandwidth with 64 subcarriers.

27. The apparatus of claim 26, wherein the basic frequency domain signal comprises, sequentially at the 64 subcarriers, A×

{0, 0, 0, 0, 0, 0, 1, 1, −

1, −

1, 1, 1, −

1, 1, −

1, 1, 1, 1, 1, 1, 1, −

1, −

1, 1, 1, −

1, 1, −

1, 1, 1, 1, 1, 0, 1, −

1, −

1, 1, 1, −

1, 1, −

1, 1, −

1, −

1, −

1, −

1, −

1, 1, 1, −

1, −

1, 1, −

1, 1, −

1, 1, 1, 1, 1, 0, 0, 0, 0, 0}, where A is a non-zero real-valued coefficient, and the second frequency domain signal is equal to a frequency domain signal generated by changing values of some, but not all, elements of the basic frequency domain signal.

28. The apparatus of claim 27, wherein a number of the some elements of the basic frequency domain signal whose values are changed is twenty-six or less.

29. The apparatus of claim 27, wherein a number of non-zero elements of the second long sequence is different from a number of non-zero elements of the basic frequency domain signal.

30. The apparatus of claim 29, wherein the signal symbol further comprises data length information, a bit for parity error, and tail bits.

31. The apparatus of claim 25, further comprising a channel estimator configured to perform channel estimation based on the first and second long preambles.

32. The apparatus of claim 25, wherein the short preamble comprises a first sequence of time-domain signals, wherein each of the time-domain signals of the first sequence has a first duration, wherein the first long preamble comprises a second sequence of time-domain signals, wherein each of the time-domain signals of the second sequence has a second duration, wherein the second long preamble comprises a third sequence of time-domain signals, wherein each of the time-domain signals of the third sequence has a third duration, and wherein the first duration is shorter than the second duration and the third duration.

33. The apparatus of claim 26, wherein the short preamble comprises a first sequence of time-domain signals, wherein each of the time-domain signals of the first sequence has a first duration, wherein the first long preamble comprises a second sequence of time-domain signals, wherein each of the time-domain signals of the second sequence has a second duration, wherein the second long preamble comprises a third sequence of time-domain signals, wherein each of the time-domain signals of the third sequence has a third duration, and wherein the first duration is shorter than the second duration and the third duration.

34. A method for wirelessly receiving and demodulating signals, the method comprising:

receiving a synchronization signal;

receiving a first channel estimation signal after reception of the synchronization signal;

receiving a coding information signal after reception of the first channel estimation signal;

receiving a second channel estimation signal after reception of the coding information signal;

receiving a data signal representative of digital data after reception of the second channel estimation signal;

performing timing synchronization using the synchronization signal;

performing channel estimation for demodulation of the data signal; and

determining, based on first information in the coding information signal, whether the data signal is transmitted using space time block coding.

35. The method of claim 34, wherein the first and second channel estimation signals are inverse fast Fourier transforms of first and second frequency domain signals, respectively, wherein the first and second frequency domain signals are originated from a reference frequency domain signal, and wherein the reference frequency domain signal occupies a predetermined bandwidth with 64 subcarriers.

36. The method of claim 35, wherein the reference frequency domain signal comprises, sequentially at the 64 subcarriers, A×

{0, 0, 0, 0, 0, 0, 1, 1, −

1, −

1, 1, 1, −

1, 1, −

1, 1, 1, 1, 1, 1, 1, −

1, −

1, 1, 1,−

1, 1, −

1, 1, 1, 1, 1, 0, 1, −

1, −

1, 1, 1, −

1, 1, −

1, 1, −

1, −

1, −

1, −

1,−

1, 1, 1, −

1, −

1, 1, −

1, 1, −

1, 1, 1, 1, 1, 0, 0, 0, 0, 0}, where A is a non-zero real-valued coefficient, and the second frequency domain signal is equal to a frequency domain signal generated by changing values of some, but not all, elements of the basic frequency domain signal.

37. The method of claim 36, wherein a number of the some elements of the basic frequency domain signal whose values are changed is twenty-six or less.

38. The method of claim 36, wherein a number of non-zero elements of the second frequency domain signal is different from a number of non-zero elements of the basic frequency domain signal.

39. The method of claim 38, wherein the coding information signal includes second information indicative of coding rate and modulation.

40. The method of claim 34, wherein the channel estimation is performed based on the first and second channel estimation signals.

41. The method of claim 34, wherein the synchronization signal comprises a first sequence of time-domain signals, wherein each of the time-domain signals of the first sequence has a first duration, wherein the first channel estimation signal comprises a second sequence of time-domain signals, wherein each of the time-domain signals of the second sequence has a second duration, wherein the second channel estimation signal comprises a third sequence of time-domain signals, wherein each of the time-domain signals of the third sequence has a third duration, and wherein the first duration is shorter than the second duration and the third duration.

42. The method of claim 35, wherein the synchronization signal comprises a first sequence of time-domain signals, wherein each of the time-domain signals of the first sequence has a first duration, wherein the first channel estimation signal comprises a second sequence of time-domain signals, wherein each of the time-domain signals of the second sequence has a second duration, wherein the second channel estimation signal comprises a third sequence of time-domain signals, wherein each of the time-domain signals of the third sequence has a third duration, and wherein the first duration is shorter than the second duration and the third duration.

43. A receiver for receiving a two-stream multi-input/multi-output (MIMO) signal transmitted from a single source conveying data in a frame format transmitted over a wireless channel, said receiver having a plurality of antennas connected to receiver circuits, said receiver circuits comprising:

a frame synchronizer for performing an initial frame synchronization based on symbols representing one or more short preamble sequences and one or more first long preamble sequences contained in a preamble of a received frame, said preamble also containing signal information indicating whether said two-stream MIMO signal is coded using space time block coding (STBC), said short preamble and first long preamble symbols being located in said preamble before said signal information; and

a MIMO channel estimator for performing a MIMO channel estimation based on symbols representing one or more second long preamble sequences located in said preamble following said signal information.

44. An apparatus for receiving and decoding a frame from a transmitter in a wireless communication system, the apparatus comprising:

a receiving unit configured to receive a frame, the frame comprising;

a short preamble comprising a symbol for timing synchronization,

first and second long preambles subsequent to the short preamble, wherein the first and second long preamble provide references for channel estimation,

a data field subsequent to the first and second long preambles, and

a signal symbol between the first long preamble and the second long preamble, wherein the signal symbol comprises information about coding rate, modulation, and space time block coding;

a determination unit configured to determine, based on the information in the signal symbol, whether the received frame is transmitted using space time block coding; and

a demodulator configured to perform demodulation of the data field.

45. The apparatus of claim 44, wherein the first and second long preambles are time domain representations of first and second long sequences, respectively, and the first and second long sequences are originated from a basic long sequence.

46. The apparatus of claim 45, wherein the first and second long preambles are equal to inverse fast Fourier transforms of the first and second long sequences, respectively.

47. The apparatus of claim 46, wherein the basic long sequence comprises, as its elements, A×

{0, 0, 1, 1, −

1, −

1, 1, 1, −

1, 1, −

1, 1, 1, 1, 1, 1, 1,−

1, −

1, 1, 1, −

1, 1, −

1, 1, 1, 1, 1,0, 1, −

1, −

1, 1, 1, −

1, 1, −

1, 1, −

1, −

1, −

1, −

1, −

1, 1, 1, −

1, −

1, 1, −

1, 1, −

1, 1, 1, 1, 1, 0, 0}, where A is a non-zero real-valued coefficient, and wherein the second long sequence is equal to a sequence obtained by changing values of some, but not all, elements of the basic long sequence.

48. The apparatus of claim 47, wherein a number of the some elements of the basic long sequence whose values are changed is twenty-six or less.

49. The apparatus of claim 47, wherein a number of non-zero elements of the second long sequence is different from a number of non-zero elements of the basic long sequence.

50. The apparatus of claim 49, wherein values of at least twenty-six elements of the first long sequence are equal to values of corresponding elements of the basic long sequence, respectively.

51. The apparatus of claim 44, wherein the symbol for timing synchronization and the signal symbol are orthogonal frequency divisional multiplexing (OFDM) symbols.

52. The apparatus of claim 44, wherein the signal symbol comprises data length information, a bit for parity error, and tail bits, and the tail bits consist of six bits.

53. The apparatus of claim 44, wherein the short preamble comprises a first sequence of time-domain signals, wherein each of the time-domain signals of the first sequence has a first duration, wherein the first long preamble comprises a second sequence of time-domain signals, wherein each of the time-domain signals of the second sequence has a second duration, wherein the second long preamble comprises a third sequence of time-domain signals, wherein each of the time-domain signals of the third sequence has a third duration, and wherein the first duration is shorter than the second duration and the third duration.

54. The apparatus of claim 46, wherein the short preamble comprises a first sequence of time-domain signals, wherein each of the time-domain signals of the first sequence has a first duration, wherein the first long preamble comprises a second sequence of time-domain signals, wherein each of the time-domain signals of the second sequence has a second duration, wherein the second long preamble comprises a third sequence of time-domain signals, wherein each of the time-domain signals of the third sequence has a third duration, and wherein the first duration is shorter than the second duration and the third duration.