Wireless communications device providing time and frequency-domain channel estimates interpolation and related methods
View Patent ↗A wireless communications device which may include a wireless receiver for receiving wireless signals comprising unknown data portions over a channel, and a demodulator connected to the wireless receiver. The demodulator may be for estimating a delay spread and a fade rate associated with the channel, determining a desired time-domain interpolation filter based upon the estimated fade rate, and determining a desired frequency-domain interpolation filter based upon the estimated delay spread. The demodulator may further generate channel estimates for the unknown data portions based upon the desired time-domain interpolation filter and the desired frequency-domain interpolation filter, and determine the unknown data portions based upon the channel estimates.
1. A wireless communications device comprising:
a wireless receiver for receiving wireless signals comprising unknown data portions over a channel, the wireless signals comprising guard bands separating the unknown data portions; and
a demodulator connected to said wireless receiver for
estimating a delay spread and a fade rate associated with the channel based upon the guard bands,
determining a desired time-domain interpolation filter from a plurality of predetermined time-domain interpolation filters each associated with a different fade rate based upon the estimated fade rate,
determining a desired frequency-domain interpolation filter based upon the estimated delay spread,
generating channel estimates for the unknown data portions based upon the desired time-domain interpolation filter and the desired frequency-domain interpolation filter, and
determining the unknown data portions based upon the channel estimates.
2. The wireless communications device of claim 1 wherein the wireless signals further comprise a plurality of pilot symbols interspersed with data in the unknown data portions, and wherein said demodulator estimates the delay spread based upon the pilot symbols.
3. The wireless communications device of claim 1 wherein the wireless signals further comprise a plurality of pilot symbols interspersed with data in the unknown data portions, and wherein said demodulator further estimates the fade rate based upon the pilot symbols.
4. The wireless communications device of claim 1 wherein said demodulator generates the channel estimates based upon an average of the time-domain and frequency-domain interpolations of the channel estimates.
5. The wireless communications device of claim 1 wherein said demodulator generates the channel estimates based upon a weighted average of the time-domain and frequency-domain interpolations of the channel estimates.
6. The wireless communications device of claim 1 wherein said demodulator determines the desired frequency-domain interpolation filter from a plurality of predetermined frequency-domain interpolation filters each associated with a different delay spread.
7. The wireless communications device of claim 1 wherein the wireless signals comprise orthogonal frequency division multiplexing (OFDM) signals.
8. A wireless communications device comprising:
a wireless receiver for receiving wireless signals over a channel, the wireless signals comprising unknown data portions, a plurality of pilot symbols interspersed with unknown data in the unknown data portions, and guard bands separating the unknown data portions; and
a demodulator connected to said wireless receiver for
estimating a delay spread and a fade rate associated with the channel based upon the pilot symbols and the guard bands,
determining a desired time-domain interpolation filter from a plurality of predetermined time-domain interpolation filters each associated with a different fade rate based upon the estimated fade rate,
determining a desired frequency-domain interpolation filter based upon the estimated delay spread,
generating channel estimates for the unknown data portions based upon the desired time-domain interpolation filter and the desired frequency-domain interpolation filter, and
determining the unknown data portions based upon the channel estimates.
9. The wireless communications device of claim 8 wherein said demodulator generates the channel estimates based upon an average of the time-domain and frequency-domain interpolations of the channel estimates.
10. The wireless communications device of claim 8 wherein said demodulator generates the channel estimates based upon a weighted average of the time-domain and frequency-domain interpolations of the channel estimates.
11. The wireless communications device of claim 8 wherein said demodulator determines the desired frequency-domain interpolation filter from a plurality of predetermined frequency-domain interpolation filters each associated with a different delay spread.
12. The wireless communications device of claim 8 wherein the wireless signals comprise orthogonal frequency division multiplexing (OFDM) signals.
13. A wireless communications system comprising:
a plurality of wireless communications devices each comprising
a wireless receiver for receiving wireless signals comprising unknown data portions over a channel, the wireless signals comprising guard bands separating the unknown data portions; and
a demodulator connected to said wireless receiver for
estimating a delay spread and a fade rate associated with the channel based upon the guard bands,
determining a desired time-domain interpolation filter based upon the estimated fade rate,
determining a desired frequency-domain interpolation filter from a plurality of predetermined frequency-domain interpolation filters each associated with a different delay spread based upon the estimated delay spread,
generating channel estimates for the unknown data portions based upon the desired time-domain interpolation filter and the desired frequency-domain interpolation filter, and
determining the unknown data portions based upon the channel estimates.
14. The wireless communications system of claim 13 wherein the wireless signals further comprise a plurality of pilot symbols interspersed with data in the unknown data portions, and wherein said demodulator further estimates at least one of the delay spread and the fade rate based upon the pilot symbols.
15. The wireless communications system of claim 13 wherein said demodulator generates the channel estimates based upon an average of the time-domain and frequency-domain interpolations of the channel estimates.
16. The wireless communications system of claim 15 wherein said demodulator generates the channel estimates based upon a weighted average of the time-domain and frequency-domain interpolations of the channel estimates.
17. The wireless communications system of claim 13 wherein said demodulator determines the desired time-domain interpolation filter from a plurality of predetermined time-domain interpolation filters each associated with a different fade rate.
18. The wireless communications system of claim 13 wherein the wireless signals comprise orthogonal frequency division multiplexing (OFDM) signals.
19. A wireless communications method comprising:
receiving wireless signals comprising unknown data portions over a channel, the wireless signals comprising guard bands separating the unknown data portions;
estimating a delay spread and a fade rate associated with the channel based upon the guard bands;
determining a desired time-domain interpolation filter from a plurality of predetermined time-domain interpolation filters each associated with a different fade rate based upon the estimated fade rate;
determining a desired frequency-domain interpolation filter based upon the estimated delay spread;
generating channel estimates for the unknown data portions based upon the desired time-domain interpolation filter and the desired frequency-domain interpolation filter; and
determining the unknown data portions based upon the channel estimates.
20. The method of claim 19 wherein the wireless signals further comprise a plurality of pilot symbols interspersed with data in the unknown data portions, and wherein estimating further comprises estimating at least one of the delay spread and the fade rate based upon the pilot symbols.
21. The method of claim 19 wherein generating the channel estimates comprises, generating the channel estimates based upon an average of the time-domain and frequency-domain interpolations of the channel estimates.
22. The method of claim 21 wherein generating the channel estimates comprises generating the channel estimates based upon a weighted average of the time-domain and frequency-domain interpolations of the channel estimates.
23. The method of claim 19 wherein determining the desired frequency-domain interpolation filter comprises determining the desired frequency-domain interpolation filter from a plurality of predetermined frequency-domain interpolation filters each associated with a different delay spread.
24. The method of claim 19 wherein the wireless signals comprise orthogonal frequency division multiplexing (OFDM) signals.
25. A wireless communications device comprising:
a wireless receiver for receiving wireless signals comprising unknown data portions over a channel, the wireless signals comprising guard bands separating the unknown data portions; and
a demodulator connected to said wireless receiver for
estimating a delay spread and a fade rate associated with the channel based upon the guard bands,
determining a desired time-domain interpolation filter based upon the estimated fade rate,
determining a desired frequency-domain interpolation filter from a plurality of predetermined frequency-domain interpolation filters each associated with a different delay spread based upon the estimated delay spread,
generating channel estimates for the unknown data portions based upon the desired time-domain interpolation filter and the desired frequency-domain interpolation filter, and
determining the unknown data portions based upon the channel estimates.
26. The wireless communications device of claim 25 wherein the wireless signals further comprise a plurality of pilot symbols interspersed with data in the unknown data portions, and wherein said demodulator further estimates the delay spread based upon the pilot symbols.
27. The wireless communications device of claim 25 wherein the wireless signals further comprise a plurality of pilot symbols interspersed with data in the unknown data portions, and wherein said demodulator estimates the fade rate based upon the pilot symbols.
28. A wireless communications method comprising:
receiving wireless signals comprising unknown data portions over a channel, the wireless signals comprising guard bands separating the unknown data portions;
estimating a delay spread and a fade rate associated with the channel based upon the guard bands;
determining a desired time-domain interpolation filter based upon the estimated fade rate;
determining a desired frequency-domain interpolation filter from a plurality of predetermined frequency-domain interpolation filters each associated with a different delay spread based upon the estimated delay spread;
generating channel estimates for the unknown data portions based upon the desired time-domain interpolation filter and the desired frequency-domain interpolation filter; and
determining the unknown data portions based upon the channel estimates.
29. The method of claim 28 wherein the wireless signals further comprise a plurality of pilot symbols interspersed with data in the unknown data portions, and wherein estimating further comprises estimating at least one of the delay spread and the fade rate based upon the pilot symbols.
30. The method of claim 28 wherein generating the channel estimates comprises generating the channel estimates based upon an average of the time-domain and frequency-domain interpolations of the channel estimates.
31. The method of claim 28 wherein generating the channel estimates comprises generating the channel estimates based upon a weighted average of the time-domain and frequency-domain interpolations of the channel estimates.