Method for error compensation in an OFDM system with diversity

1. A method comprising:

capturing a plurality of symbols from tones of a multi-tone wireless signal,

identifying pilot symbols from among the captured symbols,

forming a first error estimation of channel effects based on the pilot symbols,

correcting information symbols in other non-pilot tones of the signal based on the first error estimation;

identifying a plurality of corrected information symbols within the captured symbols that are likely to have been accurately detected; and

forming a second error estimation of the channel effects from the identified plurality of corrected information symbols.

2. The method of claim 1 , further comprising correcting remaining captured symbols according to the second error estimation.

3. The method of claim 1 , further comprising capturing via a plurality of diverse antennas the tones of the multi-tone wireless signal.

4. An apparatus comprising:

a first stage including, for each of a plurality of captured tones of a wireless signal, wherein one of the plurality of tones is a pilot tone:

a pilot symbol detection portion to detect a pilot symbol of the pilot tone;

a first error estimation portion coupled to the pilot symbol detection portion to form a first error estimate of a channel effect based on the pilot symbol;

a first error correction portion coupled to the first error estimation portion to perform an error correction process on the non-pilot tones of the signal based on the first error estimate of the channel effect;

a second stage coupled to the first stage and including:

a pseudo pilot selector portion to process a plurality of respective outputs of the first error correction portion of the first stage and a corresponding plurality of the corrected non-pilot tones of the signal to select based on the probability that information symbols of the non-pilot tones have been correctly identified a subset of the corrected non-pilot tones; and

for each of the plurality of captured non-pilot tones, a second error estimation portion coupled to the pseudo pilot selector portion to form a second error estimate of the channel effect based on the subset of corrected non-pilot tones.

5. The apparatus of claim 4 , further comprising, for each of the plurality of captured tones, a second error correction portion coupled to the second error estimation portion to perform an error correction process based on the second error estimate and the captured signal.

6. The apparatus of claim 5 , further comprising a diversity combiner coupled to respective outputs of the second error correction portions.

7. The apparatus of claim 4 , further comprising a delay portion coupled between the captured signal and the first error correction portion.

8. The apparatus of claim 4 , further comprising a delay portion coupled between the captured signal and the pseudo pilot selector portion.

9. The apparatus of claim 4 , further comprising a delay portion coupled between the pseudo pilot selector portion and the second error correction portion.

10. The apparatus of claim 4 , further comprising a plurality of antennas to capture the wireless signals.

11. A method, comprising:

capturing a multi-tone wireless signal on each of a plurality of diversity branches of a receiver,

for each diversity branch:

capturing a plurality of symbols from tones of the respectively captured wireless signal,

identifying pilot symbols from among the captured symbols,

forming a first error estimation of channel effects based on the pilot symbols,

correcting information symbols in other non-pilot symbols of the signal based on the first error estimation;

merging corrected information symbol and captured symbols from the plural diversity branches,

identifying a plurality of corrected information symbols that are likely to have been accurately detected; and

forming a second error estimation of the channel effects from the identified plurality of corrected information symbols.

12. The method of claim 11 , further comprising correcting remaining captured symbols according to the second error estimation.

13. The method of claim 11 , wherein a given corrected information symbol is estimated to be accurately detected when all copies of the given symbol from among all diversity branches are within a correct decision boundary.

14. The method of claim 11 wherein a given corrected information symbol is estimated to be correctly detected according to:

calculating a probability that the given corrected information symbol is in a correct decision boundary; and

comparing the calculated probability to a threshold.