Method and system for OFDM frame boundary detection in a vehicular multipath channel

1. A method for OFDM flame boundary detection in a vehicular multipath channel in which a sample including a plurality of OFDM data inputs is received by a receiver in a sampling period, the method comprising the steps of:

(a) for each sample of a plurality of samples, applying long preamble local copy correlation (LP-LCC) to the sample data inputs to yield LP-LCC results, each LP-LCC result representing energy of a single path;

(b) integrating the LP-LCC results to obtain a respective channel energy;

(c) finding a maximal channel energy among the channel energies; and

(d) using the maximal channel energy to detect a frame boundary;

further comprising the step of performing a short preamble (SP) delayed cross correlation (DCC) on the sample data inputs to validate a respective LP-LCC result.

2. The method of claim 1 , wherein the detection of the frame boundary is done within half a LP period.

3. The method of claim 1 , wherein the integration is performed by a sliding integrator.

4. The method of claim 3 , wherein the sliding integrator includes a non-flat integrating window.

5. The method of claim 1 , wherein the SP-DCC is performed substantially in parallel with the LP-LCC.

6. The method of claim 1 , further comprising the step of equalizing the multipath channel in a time domain using averaged LP replicas.

7. A method for OFDM frame boundary detection in a vehicular multipath channel comprising the steps of:

(a) acquiring a plurality of OFDM signal samples, each sample including a plurality of OFDM data inputs;

(b) processing each sample to obtain a respective channel energy;

(c) finding a maximal channel energy among the channel energies; and

(d) using the maximal channel energy to detect a frame boundary;

further comprising the step of performing a short preamble (SP) delayed cross correlation (DCC) on the sample data inputs to validate a respective LP-LCC result.

8. The method of claim 7 , wherein steps (a)-(d) are done for a period shorter than or equal to half a LP period.

9. The method of claim 7 , wherein the step of processing includes performing a long preamble local copy correlation (LP-LCC) on the data inputs of the sample to obtain a LP-LCC result and integrating all path energies as calculated by the LP-LCC, using a sliding integrator.

10. The method of claim 9 , wherein the sliding integrator includes a non-flat integrating window.

11. The method of claim 7 , further comprising the step of equalizing the multipath channel in a time domain using averaged LP replicas.

12. A method for OFDM frame boundary detection in a vehicular multipath channel comprising the steps of:

(a) obtaining a plurality of channel energies associated with respective OFDM data inputs, each channel energy including energies of all paths of the multipath; and

(b) detecting a frame boundary based on a maximal channel energy found among the plurality of channel energies; wherein the step of obtaining includes, for each channel energy, performing a long preamble local copy correlation (LP-LCC) on the respective OFDM data inputs to obtain a plurality of LP-LCC results and integrating the plurality of LP-LCC results to obtain the channel energy;

further comprising the step of performing a short preamble (SP) delayed cross correlation (DCC) on respective OFDM inputs to validate a respective LP-LCC result.

13. The method of claim 12 , wherein the steps of obtaining and detecting are performed in a time period no greater than half a long preamble (LP) period.

14. The method of claim 12 , wherein the integrating is performed by a sliding integrator.

15. The method of claim 14 , wherein the sliding integrator includes a non-flat integrating window.

16. The method of claim 12 , further comprising the step of equalizing the multipath channel in a time domain using averaged LP replicas.