OFDM system and method for supporting a wide range of mobility speeds
View Patent ↗A method and apparatus for wireless communication in which groups of expected mobile device mobility speed ranges are established. A first sub-carrier block arrangement for the group having the lowest expected mobility speed range is determined. The first sub-carrier block arrangement is comprised of a plurality of sub-carriers. A second sub-carrier block arrangement for a group having an expected mobility speed range faster than the expected speed range of the lowest expected speed range group is determined. The second sub-carrier block arrangement is comprised of the plurality of sub-carriers. The first and second sub-carrier block arrangements are different but use the same sub-carrier spacing and symbol duration.
1. A wireless communication method, comprising:
establishing groups of expected mobile device mobility speed ranges;
determining a first sub-carrier block arrangement for the group having the lowest expected mobility speed range, the first sub-carrier block arrangement being comprised of a plurality of sub-carriers; and
determining a second sub-carrier block arrangement for a group having an expected mobility speed range faster than the expected speed range of the lowest expected speed range group, the second sub-carrier block arrangement being comprised of the plurality of sub-carriers, the first and second sub-carrier block arrangements being different but using a same sub-carrier spacing and symbol duration, wherein the second sub-carrier block arrangement includes at least one disabled sub-carrier.
2. The method of claim 1 , further comprising
disabling additional sub-carriers within sub-carrier blocks supporting mobility speed range groups beyond that for the group supported by the second sub-carrier block arrangement.
3. The method of claim 1 , wherein the second sub-carrier block arrangement includes a modulation symbol mapped on at least two consecutive sub-carriers in the frequency domain.
4. The method of claim 3 , wherein additional modulation symbol mappings are made in consecutive sub-carriers in the frequency domain within sub-carrier blocks supporting mobility speed range groups beyond that for the group supported by the second sub-carrier block arrangement.
5. The method of claim 3 , wherein the first sub-carrier block arrangement includes at least one disabled sub-carrier.
6. The method of claim 1 , further comprising using different FFT sizes for wireless communication between types of devices, wherein mobile devices use a smaller FFT than stationary devices.
7. The method of claim 1 , further comprising creating a diversity channel comprised of the first sub-carrier block arrangement the second sub-carrier block arrangement.
8. A computer program product, tangibly embodied in a computer storage medium for executing instructions on a processor, the computer program product being operable to cause a machine to:
establish groups of expected mobile device mobility speed ranges;
determine a first sub-carrier block arrangement for the group having the lowest expected mobility speed range, the first sub-carrier block arrangement being comprised of a plurality of sub-carriers; and
determine a second sub-carrier block arrangement for a group having an expected mobility speed range faster than the expected speed range of the lowest expected speed range group, the second sub-carrier block arrangement being comprised of the plurality of sub-carriers, the first and second sub-carrier block arrangements being different but using a same sub-carrier spacing and symbol duration, wherein the second sub-carrier block arrangement includes at least one disabled sub-carrier.
9. The method of claim 8 , further comprising disabling additional sub-carriers within sub-carrier blocks supporting mobility speed range groups beyond that for the group supported by the second sub-carrier block arrangement.
10. The method of claim 8 , wherein the second sub-carrier block arrangement includes a modulation symbol mapped on at least two consecutive sub-carriers in the frequency domain.
11. The method of claim 10 , wherein additional modulation symbol mappings are made in consecutive sub-carriers in the frequency domain within sub-carrier blocks supporting mobility speed range groups beyond that for the group supported by the second sub-carrier block arrangement.
12. The method of claim 10 , wherein the first sub-carrier block arrangement includes at least one disabled sub-carrier.
13. The method of claim 8 , further comprising using different FFT sizes for wireless communication between types of devices, wherein mobile devices use a smaller FFT than stationary devices.
14. A wireless communication apparatus supporting groups of expected mobile device mobility speed ranges, the apparatus comprising a processor, the processor operating to:
use a first sub-carrier block arrangement to engage in wireless communications with the group having the lowest expected mobility speed range, the first sub-carrier block arrangement being comprised of a plurality of sub-carriers; and
use a second sub-carrier block arrangement to engage in wireless communications with a group having an expected mobility speed range faster than the expected speed range of the lowest expected speed range group, the second sub-carrier block arrangement being comprised of the plurality of sub-carriers, the first and second sub-carrier block arrangements being different but using a same sub-carrier spacing and symbol duration, wherein the second sub-carrier block arrangement includes at least one disabled sub-carrier.
15. The apparatus of claim 14 , wherein the processor is part of a base station.
16. The apparatus of claim 14 , wherein the processor further disables additional sub-carriers within sub-carrier blocks supporting mobility speed range groups beyond that for the group supported by the second sub-carrier block arrangement.
17. The apparatus of claim 14 , wherein the second sub-carrier block arrangement includes a modulation symbol mapped on at least two consecutive sub-carriers in the frequency domain.
18. The apparatus of claim 17 , wherein the processor further makes additional modulation symbol mappings in consecutive sub-carriers in the frequency domain within sub-carrier blocks supporting mobility speed range groups beyond that for the group supported by the second sub-carrier block arrangement.
19. The apparatus of claim 14 , wherein the processor uses different FFT sizes for wireless communication with other types of other devices, wherein communication with mobile devices use a smaller FFT than communication with stationary devices.
20. The apparatus of claim 14 , wherein the processor creates a diversity channel comprised of the first sub-carrier block arrangement the second sub-carrier block arrangement.