Apparatus and method for multefire industry release (MFIR)

1. A user equipment (UE), comprising:

a memory; and

baseband circuitry comprising

a radio frequency (RF) interface configured to receive downlink (DL) signals and transmit uplink (UL) signals during a succession of long-term evolution (LTE)—time division duplex (TDD) radio frames, and

one or more processors configured to, when executing instructions stored in the memory, cause the UE to:

determine, based on a DL signal in a radio frame, that an eNB has assessed, based on a Cat-2 listen before talk (LBT) procedure, that a radio frame is valid; and

in response to determining that the radio frame is valid, without performing an LBT procedure, transmit, by way of the RF interface, a UL burst with a timing advance within a predetermined period of time after a DL burst in the radio frame, wherein the timing advance creates an interval at an end of a UL signal during which an eNB performs a LBT operation,

process the DL signal in a downlink pilot timeslot (DwPTS) of the radio frame and refrain from processing an additional DL signal following the DwPTS in the same subframe and prior to a guard period preceding the UL burst, wherein a length of the guard period does not exceed 16 us.

2. The UE of claim 1 , wherein the one or more processors are configured to determine that the eNB has determined that the radio frame is valid by, in a first DL subframe of a LTE-TDD radio frame, detecting a presence of a signal indicative of an eNB transmitting a DL signal to the UE, further wherein a fixed frame period within the radio frame begins with a DL burst and ends with a UL burst independent of a radio frame structure.

3. The UE of claim 2 , wherein the signal indicative of the eNB transmitting the DL signal comprises a cell-specific reference signal (CRS).

4. UE of claim 1 , wherein the one or more processors are configured to cause transmission of the UL burst beginning at an uplink pilot timeslot (UpPTS) boundary.

5. UE of claim 1 , wherein the timing advance is 0.25 ms for a 5 ms frame period or the timing advance is 0.5 ms for a 10 ms frame period.

6. The UE of claim 1 , wherein the one or more processors are configured to send UL data using a Physical Random Access Channel (PRACH), wherein the PRACH comprises 12 resource blocks.

7. The UE of claim 1 , wherein the one or more processors are configured to send UL data using a legacy LTE PRACH that spans over 6 resource blocks, and wherein the UL data is repeated over adjacent 6 resource blocks.

8. The UE of claim 1 , wherein UL control information is carried on PUSCH.

9. An apparatus for an evolved node B (eNB) device, comprising baseband circuitry having a radio frequency (RF) interface configured to receive uplink (UL) signals and transmit downlink (DL) signals during a succession of LTE-TDD radio frames, and one or more processors configured to:

performing a Cat-2 listen before talk (LBT) operation on an unlicensed channel during a radio frame; and

in response to determining that the unlicensed channel is clear, transmitting, within a predetermined time period, a DL burst to a user equipment device (UE) in one or more radio frames, wherein the one or more processors are configured to transmit subframes corresponding to an LBT frame starting at a first DL frame after an UL frame in the radio frame, such that alignment of transmission of the LBT frame is independent of a first subframe of the radio frame, wherein the one or more processors are configured to continue to transmit an additional DL signal beyond a downlink pilot timeslot (DwPTS) and prior to a guard period of the radio frame to create a gap corresponding to the predetermined time period, wherein the guard period has a maximum length of 16 us, further wherein the LBT frame has a duration of 5 ms, wherein the one or more processors are configured to:

select an LTE-TDD UL/DL configuration of 0, 1, or 2;

configure a timing advance for UL transmission of 0.25 ms; and

perform an LBT operation every 5 ms during the radio frame after an end of each UL burst.

10. The apparatus of claim 9 , wherein the one or more processors are configured to drop a radio transmission in response to determining that the unlicensed channel is not clear.

11. The apparatus of claim 9 , wherein the LBT frame has a duration of 10 ms.

12. The apparatus of claim 11 , wherein the one or more processors are configured to:

select an LTE-TDD UL/DL configuration of 3, 4, or 5; and

configure a timing advance for UL transmission of 0.5 ms.

13. The apparatus of claim 11 , wherein the one or more processors are configured to select a LTE-TDD special subframe configuration of 0 or 5.

14. The apparatus of claim 11 , wherein the one or more processors are configured to:

select an LTE-TDD UL/DL configuration 6; and

perform an LBT operation every 5 ms during the radio frame after an end of each UL burst;

configure a timing advance for UL transmission of 0.5 ms; and

begin transmission of a DL signal the predetermined time period after a first DL/UL switching, such that there is no gap between the UL burst and the DL signal.

15. The apparatus of claim 9 , wherein the one or more processors are configured to select a LTE-TDD special subframe configuration of 0, 1, 5, or 9.

16. The apparatus of claim 9 , wherein the one or more processors are configured to begin transmission of the DL burst at a subframe boundary.

17. The apparatus of claim 9 , wherein the eNB device receives a UpPTS after the guard period.

18. The apparatus of claim 17 , wherein the UpPTS is in the same subframe as the guard period.