Removing bias in a pilot symbol error rate for receivers

1. A method for measuring a reception quality on a wireless communication link to a receiver, the method comprising:

receiving at said receiver a plurality of pilot symbols in a data stream to obtain a channel estimate for a channel;

removing a substantial portion of a bias from at least a portion of said plurality of received pilot symbols, removing said bias before detecting said plurality of pilot symbols; and

deriving the reception quality for said wireless communication link using said plurality of pilot symbols with said bias substantially removed therefrom.

2. A method for measuring a reception quality on a wireless communication link to a receiver, the method comprising:

receiving at said receiver a plurality of pilot symbols in a data stream to obtain a channel estimate for a channel;

removing a substantial portion of a bias from at least a portion of said plurality of received pilot symbols;

deriving the reception quality for said wireless communication link using said plurality of pilot symbols with said bias substantially removed therefrom

demodulating said received plurality of pilot symbols while neglecting other channel estimation errors; and

correlating the channel estimate to said received plurality of pilot symbols to derive an indication of correlation between the channel estimate and said corresponding demodulated received plurality of pilot symbols.

3. A method, as set forth in claim 1 , further comprising:

providing channel estimation for said channel based on said plurality of pilot symbols.

4. A method, as set forth in claim 3 , further comprising:

detecting said plurality of pilot symbols to estimate an error rate of said plurality of pilot symbols after substantially removing said bias; and

omitting a particular received pilot symbol of said received plurality of pilot symbols when computing the channel estimate for the particular received pilot symbol to obtain an unbiased pilot symbol error rate.

5. A method, as set forth in claim 3 , wherein removing said bias further comprising:

removing a term causing said bias before detecting said plurality of pilot symbols to remove a correlation between the channel estimate and said received plurality of pilot symbols.

6. A method, as set forth in claim 3 , wherein removing said bias further comprising:

measuring a correlation coefficient external to the channel estimate to provide a first input for bias removal in said receiver.

7. A method, as set forth in claim 3 , wherein removing said bias further comprising:

performing channel estimation of the channel to determine a plurality of filter coefficients for the channel estimate; and

computing a correlation coefficient from said plurality of filter coefficients to provide in said receiver a first input for bias removal.

8. A method, as set forth in claim 6 , wherein removing said bias further comprising:

providing in said receiver a second input representing one or more pre-defined pilot symbols for bias removal.

9. A method, as set forth in claim 8 , wherein removing said bias further comprising:

providing in said receiver a third input representing a received signal for bias removal.

10. A method, as set forth in claim 9 , further comprising:

applying in said receiver a composite input signal based on said first, second and third inputs before detecting said plurality of pilot symbols.

11. A receiver comprising:

a storage storing instructions to remove a substantial portion of a bias from at least a portion of a plurality of received pilot symbols for measuring a reception quality on a wireless communication link based on an error rate of said plurality of pilot symbols said storage storing a bias removal module that extracts a plurality of channel coefficients from said wireless propagation channel to remove said bias before detecting said plurality of pilot symbols; and

a detector coupled to said storage to receive said plurality of pilot symbols in a data stream to derive the reception quality for said wireless communication link using said plurality of pilot symbols with said bias substantially removed therefrom.

12. A receiver, as set forth in claim 11 , further comprising:

a channel estimator coupled to said detector to obtain a channel estimate for a channel based on a channel estimation method such that channel estimation is based on said plurality of pilot symbols.

13. A receiver comprising:

a storage storing instructions to remove a substantial portion of a bias from at least a portion of a plurality of received pilot symbols for measuring a reception quality on a wireless communication link based on an error rate of said plurality of pilot symbols;

a detector coupled to said storage to receive said plurality of pilot symbols in a data stream to derive the reception quality for said wireless communication link using said plurality of pilot symbols with said bias substantially removed therefrom; and

a rake receiver, wherein for said rake receiver said storage storing a bias removal module to enable a maximum ratio combiner having a multiplicity of inputs and an output to compute for each input to said maximum ratio combiner a bias removal parameter and apply the bias removal parameter to the output of said maximum ratio combiner.

14. A receiver, as set forth in claim 13 , wherein said rake receiver further comprising:

a receive antenna with diversity combining.

15. A receiver, as set forth in claim 13 , wherein said rake receiver further comprising:

a receive structure with multipath support.

16. A receiver, as set forth in claim 13 , wherein said wireless communication link is a wireless propagation channel.

17. A receiver, as set forth in claim 13 , wherein said rake receiver is disposed in a base station transceiver associated with a wireless mobile communication system.

18. A receiver, as set forth in claim 13 , wherein said base station transceiver is being defined at least in part by a Universal Mobile Telecommunication System (UMTS) standard.

19. An apparatus for measuring a reception quality on a wireless communication link to a receiver, the apparatus comprising:

means for receiving at said receiver a plurality of pilot symbols in a data stream to obtain a channel estimate for a channel;

means for removing a substantial portion of a bias from at least a portion of said plurality of received pilot symbols comprising means for removing said bias before detecting said plurality of pilot symbols; and

means for deriving the reception quality for said wireless communication link using said plurality of pilot symbols with said bias substantially removed therefrom.

20. An apparatus for measuring a reception quality on a wireless communication link to a receiver, the apparatus comprising:

means for receiving at said receiver a plurality of pilot symbols in a data stream to obtain a channel estimate for a channel;

means for removing a substantial portion of a bias from at least a portion of said plurality of received pilot symbols;

means for deriving the reception quality for said wireless communication link using said plurality of pilot symbols with said bias substantially removed therefrom;

means for demodulating said received plurality of pilot symbols while neglecting other channel estimation errors; and

means for correlating the channel estimate to said received plurality of pilot symbols to derive an indication of correlation between the channel estimate and said corresponding demodulated received plurality of pilot symbols.

21. An apparatus, as set forth in claim 19 , further comprising:

means for providing channel estimation for said channel based on said plurality of pilot symbols.