Receiver and a receiving method

1. An apparatus, comprising:

a first estimator configured to estimate non-reference information to provide estimated information, said non-reference information comprising n symbols at least one of immediately preceding and immediately succeeding reference information that is known to said apparatus and is comprised in a signal received at the apparatus;

an error estimator configured to use the estimated information to determine an error in said signal received;

a frequency error corrector configured to compensate for said error; and

a second estimator configured to estimate m symbols of said non-reference information to provide estimated information, wherein said second estimator is operatively connected to receive the error in said received signals from said error estimator;

wherein m is greater than n.

2. The apparatus as claimed in claim 1 , wherein said reference information comprises a training sequence.

3. The apparatus as claimed in claim 1 , wherein said reference information is provided in a middle region of the signal.

4. The apparatus as claimed in claim 1 , wherein said first estimator comprises an equaliser.

5. The apparatus as claimed in claim 1 , wherein said first estimator is configured to carry out one of a reduced state sequence estimation method and a decision feedback estimation method.

6. The apparatus as claimed in claim 1 , wherein said error comprises a frequency error.

7. The apparatus as claimed in claim 1 , wherein the error estimator comprises a frequency estimator.

8. The apparatus as claimed in claim 7 , wherein said frequency estimator uses a linear minimum means square error method to estimate a frequency.

9. The apparatus as claimed in claim 1 , wherein said error estimator is configured to provide a frequency offset correction to at least some of the received signal.

10. The apparatus as claimed in claim 1 , further comprising:

a second error estimator configured to use said estimated m symbols from said second estimator.

11. The apparatus as claimed in claim 10 , wherein said second error estimator is configured to estimate a frequency offset using said received signal.

12. The apparatus as claimed in claim 10 , wherein said second error estimator comprises a frequency offset corrector configured to correct a frequency of the received signal.

13. An apparatus as claimed in claim 1 , wherein the error estimator is configured to use the reference information to determine the error in said signal received.

14. An apparatus, comprising:

estimating means for estimating non-reference information to provide estimated information, said non-reference information comprising n symbols at least one of immediately preceding and immediately succeeding reference information that is known to said apparatus and is comprised in a signal received at the apparatus;

error estimating means for using the estimated information to determine a frequency error in said signal received;

frequency error correcting means for compensating for said error; and

second estimating means configured to estimate m symbols of said non-reference information to provide estimated information, wherein said second estimating means is operatively connected to receive the error in said received signals from said error estimating means;

wherein m is greater than n.

15. A method, comprising:

estimating by an estimator non-reference information to provide estimated information, said non-reference information comprising n symbols at least one of immediately preceding and immediately succeeding reference information that is known to an apparatus and is comprised in a signal received at the apparatus;

using the estimated information by an error estimator to determine an error in said signal received;

compensating by a frequency error corrector for said error; and

estimating by a second estimator m symbols of said non-reference information to provide estimated information, wherein said second estimator is operatively connected to receive the error in said received signals from said error estimator;

wherein m is greater than n.

16. The method as claimed in claim 15 , further comprising:

estimating a frequency offset using said received signal.

17. The method as claimed in claim 15 , further comprising:

correcting a frequency of the received signal.

18. The method as claimed in claim 15 , comprising using the reference information by the error estimator to determine the error in said signal received.

19. An apparatus, comprising:

a first stage comprising a first estimator configured to estimate a first number of symbols of a received signal, a first error estimator configured to estimate a frequency error based on the estimated first number of symbols, and a first frequency error corrector configured to carry out a first frequency offset correction on a second number of symbols of the received signal to provide a modified signal; and

a second stage comprising a second estimator configured to estimate at least the second number of symbols of the modified signal, a second error estimator configured to estimate a frequency error based on the estimated second number of symbols estimated by said second estimator, and a second frequency error corrector configured to carry out a second frequency offset correction on the received signal using the frequency error estimated by said second error estimator;

wherein said first number is less than said second number.

20. An apparatus as claimed in claim 19 , wherein one or both of said first estimator and said second estimator comprises an equaliser.

21. An apparatus as claimed in claim 19 , wherein one or both of said first error estimator and said second error estimator is configured to use a linear minimum means square error method.

22. A method, comprising:

a first stage comprising:

estimating, by a first estimator a first number of symbols of a received signal,

estimating, by the first error estimator, a frequency error based on the estimated first number of symbols, and

carrying out, by the first frequency error corrector, a first frequency offset correction on a second number of symbols of the received signal to provide a modified signal; and

a second stage comprising:

estimating, by a second estimator, at least the second number of symbols of the modified signal,

estimating, by the second error estimator, a frequency error based on the estimated second number of symbols, and

carrying out, by the second frequency error corrector, a second frequency offset correction on the received signal using the frequency error that is based on the estimated second number of symbols;

wherein said first number is less than said second number.