System and method for an adaptive frame structure with filtered OFDM
Different filtered-orthogonal frequency division multiplexing (f-OFDM) frame formats may be used to achieve the spectrum flexibility. F-OFDM waveforms are generated by applying a pulse shaping digital filter to an orthogonal frequency division multiplexed (OFDM) signal. Different frame formats may be used to carry different traffic types as well as to adapt to characteristics of the channel, transmitter, receiver, or serving cell. The different frame formats may utilize different sub-carrier (SC) spacings and/or cyclic prefix (CP) lengths. In some embodiments, the different frame formats also utilize different symbol durations and/or transmission time interval (TTI) lengths.
1. A method for transmitting signals in a wireless network, the method comprising:
communicating, by a wirelessly-enabled device, a first orthogonal frequency division multiplexing (OFDM) signal using a first frame structure configuration; and
communicating, by the wirelessly-enabled device, a second OFDM signal using a second frame structure configuration, the first OFDM signal at least partially overlapping the second OFDM signal in the time-domain, wherein the first frame structure configuration is at least partially misaligned with the second frame structure configuration in the time domain such that at least some pairs of overlapping slots in the first and second frame structure configurations have different starting or ending slot locations.
2. The method of claim 1 , wherein the first OFDM signal and the second OFDM signal carry symbols having different cyclic prefix (CP) lengths than one another.
3. The method of claim 1 , wherein the first OFDM signal and the second OFDM signal are transmitted over different frequency sub-bands.
4. The method of claim 1 , wherein starting locations of all slots in the first frame structure configuration are offset from starting locations of all slots in the second frame structure.
5. The method of claim 4 , wherein slots in the first frame structure configuration have the same periodic duration as slots in the second frame structure configuration.
6. The method of claim 4 , wherein slots in the first frame structure configuration have a different periodic duration as slots in the second frame structure configuration.
7. The method of claim 1 , wherein the wirelessly-enabled device is a mobile device or an access point.
8. An apparatus comprising:
a processor; and
a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions to:
communicate a first orthogonal frequency division multiplexing (OFDM) signal using a first frame structure configuration; and
communicate a second OFDM signal using a second frame structure configuration, the first OFDM signal at least partially overlapping the second OFDM signal in the time-domain, wherein the first frame structure configuration is at least partially misaligned with the second frame structure configuration in the time domain such that at least some pairs of overlapping slots in the first and second frame structure configurations have different starting or ending slot locations.
9. The apparatus of claim 8 , wherein the first OFDM signal and the second OFDM signal carry symbols having different cyclic prefix (CP) lengths than one another.
10. The apparatus of claim 8 , wherein the first OFDM signal and the second OFDM signal are transmitted over different frequency sub-bands.
11. The apparatus of claim 8 , wherein starting locations of all slots in the first frame structure configuration are offset from starting locations of all slots in the second frame structure.
12. The apparatus of claim 11 , wherein slots in the first frame structure configuration have the same periodic duration as slots in the second frame structure configuration.
13. The apparatus of claim 12 , wherein slots in the first frame structure configuration have a different periodic duration as slots in the second frame structure configuration.
14. The apparatus of claim 8 , wherein the apparatus is a mobile device or an access point.
15. A computer program product comprising a non-transitory computer readable storage medium storing programming, the programming including instructions to:
communicate a first orthogonal frequency division multiplexing (OFDM) signal using a first frame structure configuration; and
communicate a second OFDM signal using a second frame structure configuration, the first OFDM signal at least partially overlapping the second OFDM signal in the time-domain, wherein the first frame structure configuration is at least partially misaligned with the second frame structure configuration in the time domain such that at least some pairs of overlapping slots in the first and second frame structure configurations have different starting or ending slot locations.
16. The computer program product of claim 15 , wherein the first OFDM signal and the second OFDM signal carry symbols having different cyclic prefix (CP) lengths than one another.
17. The computer program product of claim 15 , wherein the first OFDM signal and the second OFDM signal are transmitted over different frequency sub-bands.
18. The computer program product of claim 15 , wherein starting locations of all slots in the first frame structure configuration are offset from starting locations of all slots in the second frame structure.
19. The computer program product of claim 15 , wherein slots in the first frame structure configuration have the same periodic duration as slots in the second frame structure configuration.
20. The computer program product of claim 19 , wherein slots in the first frame structure configuration have a different periodic duration as slots in the second frame structure configuration.