APPARATUS AND METHOD FOR TRANSMITTING DATA USING A PLURALITY OF CARRIERS

• US 20090220019A1
• Filed: 12/06/2006
• Published: 09/03/2009
• Est. Priority Date: 12/06/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kwon, Yeon Hyeon, Yun, Young Woo, Noh, Min Seok, Han, Seung Hee
• Granted Patent: US 8,059,738 B2
• Time in Patent Office: Days
• US Class Current: 375/261
• CPC Class Codes: H04L 27/2604 Multiresolution systems by means of multiresolution subcarriers H04L27/183, H04L27/3488
• CPC Class Codes: H04L 27/262 Reduction thereof by selection of pilot symbols
• CPC Class Codes: H04L 27/2621 Reduction thereof using phase offsets between subcarriers
• CPC Class Codes: H04L 27/3483 using a modulation of the constellation points
• CPC Class Codes: H04L 27/3488 Multiresolution systems
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames

Abstract

A data transmitting and receiving method of transmitting supplementary data in an OFDM communication system is disclosed. The method of transmitting and receiving the OFDM signal includes: mapping an input bit stream into at least one transfer symbol; changing at least one of amplitudes and phases of the transfer symbols that are transmitted by a specific sub-carrier group having a plurality of sub-carriers using constellation modification information to indicate specific additional data; and transmitting the transfer symbols, to which the changing is carried out, to a receiving end by an orthogonal frequency division multiplexing data processing, the constellation modification information being identical to each other with respect to the transfer symbols that are transmitted by the specific sub-carrier group.

Claims

1. A method of transmitting an orthogonal frequency division multiplexing signal comprising:

mapping an input bit stream into at least one transfer symbol;

changing at least one of amplitudes and phases of the transfer symbols that are transmitted by a sub-carrier group having a plurality of sub-carriers according to constellation modification information to indicate specific additional data; and

transmitting the transfer symbols to a receiving end by an orthogonal frequency division multiplexing data processing, wherein the constellation modification information are identical to each other with respect to the transfer symbols that are transmitted by the sub-carrier group.

2. The method of claim 1, wherein the changing comprises modulating the transfer symbols transmitted by the sub-carrier group according to the constellation modification information.

3. The method of claim 1, wherein the constellation modification information has different amplitude or phase according to the additional data.

4. The method of claim 1, wherein, when the mapping is carried out by an M-ary quadrature amplitude modulation, the constellation modification information has a phase of 0 degrees to 90 degrees.

5. The method of claim 1, wherein, when the mapping is carried out by an M-ary phase shift keying, the constellation modification information has a phase of 0 degrees to 360/M degrees.

6. The method of claim 1, wherein the sub-carrier group comprises a plurality of sub-carriers to transmit pilot signals.

7. The method of claim 1, wherein the sub-carrier group comprises a plurality of sub-carriers to transmit user data signals.

8. An orthogonal frequency division multiplexing signal transmitting apparatus to transmit a data symbol to a receiving end using a plurality of sub-carriers, the transmitting apparatus comprising:

a first mapping module to map an input bit stream into at least one transfer symbol; and

a second mapping module to change at least one of amplitudes and phases of the transfer symbols that are transmitted by a specific sub-carrier group having a plurality of sub-carriers, using constellation modification information to indicate specific additional data by changing the at least one of the amplitudes and the phases of the transfer symbols that are transmitted by the specific sub-carrier group using constellation modification information identical to each other.

9. A method of receiving an orthogonal frequency division multiplexing signal transmitted by a plurality of sub-carriers, comprising:

estimating at least one of amplitudes and phases of receiving symbols received by the plurality of sub-carriers by estimating at least one of modified amplitudes and phases from previously determined amplitudes and phases;

acquiring additional data to indicate at least one of the estimated amplitudes and phases;

recovering the amplitudes and phases of the receiving symbols using at least one of the estimated amplitudes and phases; and

acquiring data contained in the recovered receiving symbols.

10. A receiving end to receive an orthogonal frequency division multiplexing signal transmitted by a plurality of sub-carriers, comprising:

a first demodulating module to estimate at least one of amplitudes and phases of receiving symbols received by the plurality of sub-carriers by estimating at least one of modified amplitudes and phases from previously determined amplitudes and phases, and to acquire additional data to indicate at least one of the estimated amplitudes and phases; and

a second demodulating module to recover the amplitudes and phases of the receiving symbols using at least one of the estimated amplitudes and phases, and to acquire data contained in the recovered receiving symbols.

11. A method of transmitting an orthogonal frequency division multiplexing signal comprising:

converting an input bit stream corresponding to data to be transmitted to a receiving end into at least one transfer symbol and of transmitting the input bit stream using a plurality of sub-carriers; and

carrying out a micro constellation conversion of converting at least one of amplitudes and phases of the transfer symbols that are transmitted by a specific sub- carrier group using constellation modification information to indicate specific additional data, wherein the constellation modification information is identical to each other with respect to the transfer symbols that are transmitted by the specific sub-carrier group.

12. The method of claim 11, wherein the carrying out the micro constellation conversion comprises modulating the transfer symbols transmitted by the sub-carrier group according to the constellation modification information.

13. The method of claim 11, wherein the constellation modification information has amplitudes and phases different from each other according to the additional data.

14. The method of claim 11, wherein, when the transfer symbols are generated by an M-ary quadrature amplitude modulation, the constellation modification information has a phase of 0 degrees to 90 degrees.

15. The method of claim 11, wherein, when the transfer symbols are generated by an M-ary phase shift keying, the constellation modification information has a phase of 0 degrees to 360/M degrees.

16. The method of claim 11, wherein the sub-carrier group comprises a plurality of sub-carriers to transmit pilot signals.

17. The method of claim 11, wherein the sub-carrier group comprises a plurality of sub-carriers to transmit user data signals.

18. A method of transmitting an orthogonal frequency division multiplexing signal using a plurality of sub-carriers to reduce a peak-to-average power ratio of an orthogonal frequency division multiplexing signal using first modulated data to control phases of the plurality of sub-carriers by a specific group unit, the method comprising:

changing phases of transfer signals that are transmitted by the specific sub-carrier group using the first modulated data such that constellation coordinates of a constellation map corresponding to the transfer signals can be maintained; and

re-changing the phases of the transfer signals using second modulated data to indicate the first modulated data.

19. The method of claim 18, wherein the first modulated data comprise a phase value commonly applied to the sub-carrier group.

20. The method of claim 18, wherein the second modulated data comprises a phase value commonly applied to the sub-carrier group.

21. The method of claim 18, wherein the second modulated data have phases different from each other according to the first modulated data.

22. The method of claim 18, wherein, when the transfer signals are generated by an M-ary quadrature amplitude modulation, the first modulated data comprise at least one from 0 (zero), n/2, and 3n/2.

23. The method of claim 18, wherein, when the transfer signals are generated by a binary phase shift keying, the second modulated data comprise one of 0 (zero) and π

(pi).

24. A method of receiving an orthogonal frequency division multiplexing signal transmitted by a plurality of sub-carriers, comprising:

estimating phases of receiving signals received by a plurality of sub-carriers in a way of estimating a first phase modified from a predetermined phase;

acquiring a second phase indicated by the estimated first phase; and

removing the first phase and the second phase with respect to the receiving signals.