Granted Patent B2

US 8,064,553 · App. 12/107,998 · Granted Nov 22, 2011

Abstract

Claims (43)

1. A method of estimating a coarse frequency offset in a receiver, said method comprising:

providing at least one candidate frequency offset in Orthogonal Frequency-Division Multiplexing (OFDM) symbols having transmission and multiplexing configuration control (TMCC) bins and auxiliary channel (AC) bins;

modulating said TMCC bins and AC bins using differential binary phase shift keying (DBPSK) modulation;

estimating a phase difference between a first symbol and a second symbol for said candidate frequency offset of said TMCC and AC bins to obtain a resulting phase difference;

correcting said resulting phase difference based on a difference between said candidate frequency offset and a Fast Fourier Transform (FFT) center bin to obtain a corrected phase difference;

mapping said corrected phase difference to numeric numbers, wherein said numeric numbers correspond to at least one of +1 or −1; and

adding said numeric numbers for said candidate frequency offset to obtain a summation result.

2. The method of claim 1 , wherein said +1 correspond to a phase difference between −45° and +45° and between 135° and 225°, and wherein said −1 correspond to a phase difference other than between said −45° and +45° and said 135° and 225°.

3. The method of claim 1 , further comprising repeating the estimating process to accumulate said summation result to obtain accumulation results for all candidate frequency offsets.

4. The method of claim 3 , further comprising comparing said accumulation results for all candidate frequency offsets to obtain a maximum accumulation result.

5. The method of claim 1 , wherein said receiver comprises any of an Integrated Services Digital Broadcasting—Terrestrial (ISDB-T) and an Integrated Services Digital Broadcasting—Terrestrial digital Sound Broadcasting (ISDB-TSB) receiver of transmission mode 2 .

6. A method of estimating a coarse frequency offset in a receiver, said method comprising:

providing at least one candidate frequency offset in Orthogonal Frequency-Division Multiplexing (OFDM) symbols having transmission and multiplexing configuration control (TMCC) bins and auxiliary channel (AC) bins;

modulating said TMCC bins and AC bins using differential binary phase shift keying (DBPSK) modulation;

estimating a phase difference between a first symbol and a second symbol for said candidate frequency offset of said TMCC bins to obtain a resulting phase difference;

correcting said resulting phase difference based on a difference between said candidate frequency offset and a Fast Fourier Transform (FFT) center bin to obtain a corrected phase difference;

determining a most likely common phase difference transmitted on said TMCC bins based on said phase difference, wherein said TMCC bins carrying the same information and phase differences for all said TMCC bins are the same;

subtracting said corrected phase difference by said common phase difference to obtain a new phase difference, wherein said new phase difference is zero;

mapping said corrected phase difference to numeric numbers, wherein said numeric numbers correspond to at least one of +1 or −1; and

adding said numeric numbers for said candidate frequency offset for all said TMCC bins and said AC bins to obtain a summation result.

7. The method of claim 6 , wherein said +1 correspond to a phase difference between −90° and +90°, and wherein said −1 correspond to a phase difference other than between said −90° and +90°.

8. The method of claim 6 , further comprising repeating the estimating process to accumulate said summation result to obtain accumulation results for all candidate frequency offsets.

9. The method of claim 8 , further comprising comparing said accumulation results for all said candidate frequency offset to obtain a maximum accumulation result.

10. The method of claim 6 , wherein said receiver comprises any of an Integrated Services Digital Broadcasting—Terrestrial (ISDB-T) and an Integrated Services Digital Broadcasting—Terrestrial digital Sound Broadcasting (ISDB-TSB) receiver of transmission mode 3 with high Doppler and noisy channels.

11. An Integrated Services Digital Broadcasting (ISDB) receiver that estimates a coarse frequency offset comprising:

means for capturing at least one candidate frequency offset in Orthogonal Frequency-Division Multiplexing (OFDM) symbols having transmission and multiplexing configuration control (TMCC) bins and auxiliary channel (AC) bins;

means for modulating said TMCC bins and AC bins using differential binary phase shift keying (DBPSK) modulation;

a memory unit comprising a computer program set of instructions;

a display unit operatively connected to said memory unit; and

a processor adapted to execute said computer program set of instructions, wherein said processor:

estimates a phase difference between a first symbol and a second symbol for said candidate frequency offset of said TMCC and AC bins to obtain a resulting phase difference;

corrects said resulting phase difference based on a difference between said candidate frequency offset and a Fast Fourier Transform (FFT) center bin to obtain a corrected phase difference;

maps said corrected phase difference to numeric numbers, wherein said numeric numbers correspond to at least one of +1 or −1; and

adds said numeric numbers for said candidate frequency offset to obtain a summation result.

12. The receiver of claim 11 , wherein said +1 correspond to a phase difference between −45° and +45° and between 135° and 225°, and wherein said −1 correspond to a phase difference other than between said −45° and +45° and said 135° and 225°.

13. The receiver of claim 11 , wherein said processor repeats the estimating process to accumulate said summation result to obtain accumulation results for all candidate frequency offsets.

14. The receiver of claim 13 , wherein said processor compares said accumulation results for all candidate frequency offsets to obtain a maximum accumulation result.

15. The receiver of claim 11 , wherein said receiver comprises any of an Integrated Services Digital Broadcasting—Terrestrial (ISDB-T) and an Integrated Services Digital Broadcasting—Terrestrial digital Sound Broadcasting (ISDB-TSB) receiver of transmission mode 2 .

16. The receiver of claim 11 , wherein said processor determines a most likely common phase difference transmitted on said TMCC bins based on said phase difference, wherein said TMCC bins carrying the same information and phase differences for all said TMCC bins are the same.

17. The receiver of claim 16 , wherein said processor subtracts said corrected phase difference by said common phase difference to obtain a new phase difference, wherein said new phase difference is zero.

18. The receiver of claim 17 , wherein said processor adds said numeric numbers for said candidate frequency offset for all said TMCC bins and said AC bins to obtain a summation result.

19. The receiver of claim 18 , wherein said +1 correspond to a phase difference between −90° and +90°, and wherein said −1 correspond to a phase difference other than between said −90° and +90°.

20. The receiver of claim 11 , wherein said receiver comprises any of an Integrated Services Digital Broadcasting—Terrestrial (ISDB-T) and an Integrated Services Digital Broadcasting—Terrestrial digital Sound Broadcasting (ISDB-TSB) receiver of transmission mode 3 with high Doppler and noisy channels.

Assignments (23)