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:
transmitting, by a transmitter, a first filtered-orthogonal frequency division multiplexing (f-OFDM) signal;
transmitting, by the transmitter, a second f-OFDM signal, the first f-OFDM signal and the second f-OFDM signal being communicated in accordance with different sub-carrier spacings than one another; and
assigning a first frame format to the first f-OFDM signal and a second frame format to the second f-OFDM signal, wherein the first frame format requires a different cyclic prefix (CP) length and a different sub-carrier spacing than the second frame format, wherein assigning the first frame format to the first f-OFDM signal comprises selecting the first frame format based on a serving region size of the transmitter.
2. A method for transmitting signals in a wireless network, the method comprising:
transmitting, by a transmitter, a first filtered-orthogonal frequency division multiplexing (f-OFDM) signal;
transmitting, by the transmitter, a second f-OFDM signal, the first f-OFDM signal and the second f-OFDM signal being communicated in accordance with different sub-carrier spacings than one another; and
assigning a first frame format to the first f-OFDM signal and a second frame format to the second f-OFDM signal, wherein the first frame format requires a different cyclic prefix (CP) length and a different sub-carrier spacing than the second frame format, wherein assigning the first frame format to the first f-OFDM signal comprises selecting the first frame format based on a characteristic of a receiver associated with the first f-OFDM signal, wherein the characteristic of the receiver associated with the first f-OFDM signal comprises a mobility speed of the receiver.
3. A method for transmitting signals in a wireless network, the method comprising:
transmitting, by a transmitter, a first transmission in a default sub-band with default frame structure parameters to a first user equipment (UE);
transmitting, by the transmitter, a signaling to the first UE, wherein the signaling indicates additional frame structure parameters; and
transmitting, by the transmitter, a second transmission to the first UE with the additional frame structure parameters in the default sub-band or an additional sub-band;
wherein the default frame structure parameters comprise a different sub-carrier spacing than a sub-carrier spacing in the additional frame structure parameters, and the sub-carrier spacing in the default frame structure parameters comprises at least one of 7.5 kHz, 15 kHz, 30 kHz, and 60 kHz.
4. The method of claim 3 , wherein the default sub-band is a default filtered-orthogonal frequency-division multiplexing (f-OFDM) sub-band, and the additional sub-band is an additional f-OFDM sub-band.
5. The method of claim 3 , wherein the default frame structure parameters comprise different cyclic prefix (CP) lengths than CP lengths in the additional frame structure parameters.
6. The method of claim 3 , wherein the default sub-band and the additional sub-band have a same frequency sub-band during different transmission time intervals (TTIs) or have different frequency sub-bands during a same time period.
7. The method of claim 3 , further comprising:
transmitting, by the transmitter, a downlink (DL) related signaling to the first UE when the first UE initially accesses the wireless network, wherein the DL related signaling that indicates the default frame structure parameters; or
transmitting, by the transmitter, the first transmission to the first UE in the default sub-band with the default frame structure parameters without signaling the default frame structure parameters to the first UE.
8. A transmitter comprising:
a processor; and
a computer readable storage medium storing programming for execution by the processor, the programming including instructions to:
transmit a first transmission in a default sub-band with default frame structure parameters to a first user equipment (UE);
transmit a signaling to the first UE, wherein the signaling indicates additional frame structure parameters; and
transmit a second transmission to the first UE with the additional frame structure parameters in the default sub-band or an additional sub-band;
wherein the default frame structure parameters comprise a different sub-carrier spacing than a sub-carrier spacing in the additional frame structure parameters, and the sub-carrier spacing in the default frame structure parameters comprises at least one of 7.5 kHz, 15 kHz, 30 kHz, and 60 kHz.
9. The transmitter of claim 8 , wherein the default sub-band is a default filtered-orthogonal frequency-division multiplexing (f-OFDM) sub-band, and the additional sub-band is an additional f-OFDM sub-band.
10. The transmitter of claim 8 , wherein the default frame structure parameters comprise different cyclic prefix (CP) lengths than CP lengths in the additional frame structure parameters.
11. The transmitter of claim 8 , wherein the default sub-band and the additional sub-band have a same frequency sub-band during different transmission time intervals (TTIs) or have different frequency sub-bands during a same time period.
12. The transmitter of claim 8 , the programming further including instructions to transmit a higher layer signaling that indicates the additional frame structure parameters.
13. A method for receiving signals in a wireless network, the method comprising:
receiving, by a user equipment (UE), a first transmission in a default sub-band with default frame structure parameters when the UE initially accesses a network;
receiving, by the UE, a signaling from a transmitter, wherein the signaling indicates additional frame structure parameters; and
receiving, by the UE, a second transmission with additional frame structure parameters in an additional sub-band or the default sub-band,
wherein the default frame structure parameters comprise a different sub-carrier spacing than a sub-carrier spacing in the additional frame structure parameters, and the sub-carrier spacing in the default frame structure parameters comprises at least one of 7.5 kHz, 15 kHz, 30 kHz, and 60 kHz.
14. The method of claim 13 , wherein the default sub-band is a default filtered-orthogonal frequency-division multiplexing (f-OFDM) sub-band, and the additional sub-band is an additional f-OFDM sub-band.
15. The method of claim 13 , wherein the default frame structure parameters comprise different cyclic prefix (CP) lengths than CP lengths in the additional frame structure parameters.
16. The method of claim 13 , wherein the default sub-band and the additional sub-band have a same frequency sub-band during different transmission time intervals (TTIs) or have different frequency sub-bands during a same time period.
17. The method of claim 13 , further comprising:
receiving, by the UE, a downlink (DL) related signaling from the transmitter when the UE initially accesses the wireless network, wherein the DL related signaling indicates the default frame structure parameters; or
receiving, by the UE, the first transmission in the default sub-band with default frame structure parameters to the UE without receiving the default frame structure parameters from the transmitter.
18. A user equipment (UE) comprising:
a processor; and
a computer readable storage medium storing programming for execution by the processor, the programming including instructions to:
receive a first transmission in a default sub-band with default frame structure parameters when the UE initially accesses a network;
receive a signaling from a transmitter, wherein the signaling indicates additional frame structure parameters; and
receive a second transmission with additional frame structure parameters in an additional sub-band or the default sub-band,
wherein the default frame structure parameters comprise a different sub-carrier spacing than a sub-carrier spacing in the additional frame structure parameters, and the sub-carrier spacing in the default frame structure parameters comprises at least one of 7.5 kHz, 15 kHz, 30 kHz, and 60 kHz.
19. The UE of claim 18 , wherein the default sub-band is a default filtered-orthogonal frequency-division multiplexing (f-OFDM) sub-band, and the additional sub-band is an additional f-OFDM sub-band.
20. The UE of claim 18 , wherein the default frame structure parameters comprise different cyclic prefix (CP) lengths than CP lengths in the additional frame structure parameters.
21. The UE of claim 18 , wherein the default sub-band and the additional sub-band have a same frequency sub-band during different transmission time intervals (TTIs) or have different frequency sub-bands during a same time period.
22. The UE of claim 18 , the programming further including instructions to receive a higher layer signaling that indicates the additional frame structure parameters.