Transmitter management under transmitter uncertainty
Management of transmitters is disclosed for conditions of transmission uncertainty that arises in operating over non-guaranteed transmission carriers that are required to perform listen-before-talk (LBT) processes and guaranteed transmission carriers that are LBT-exempt. Due to the hardware and software constraints, techniques are described to pre-prepare data and control transmissions or provide the transmitters additional time to prepare for such data and control transmissions based on the results of clear channel assessment (CCA) checks of the non-guaranteed transmission carriers.
1. A method of wireless communication, comprising:
pre-preparing, at a transmitter, a plurality of candidate combined transmission waveforms of cross-carrier control information for one of at least one non-guaranteed transmission carriers and one or more of: control information and data for a guaranteed transmission carrier before detecting a result of a clear channel assessment (CCA);
receiving, at the transmitter, a transmission status for the at least one non-guaranteed transmission carriers, wherein the transmission status is the result of the CCA to indicate clear transmission or no transmission on the at least one non-guaranteed transmission carriers;
selecting, by the transmitter, a transmission waveform from the plurality of candidate combined transmission waveforms based on the transmission status; and
transmitting, by the transmitter, the selected transmission waveform to a receiver.
2. The method of claim 1 , wherein the selecting the transmission waveform is performed in response to the received transmission status of the at least one non-guaranteed transmission carriers indicates the clear transmission on the at least one non-guaranteed transmission carriers.
3. The method of claim 1 , wherein the plurality of candidate combined transmission waveforms includes:
a cross-carrier control transmission waveform for each of the at least one non-guaranteed transmission carriers, the cross-carrier control transmission wave form including cross-carrier control information associated with the related at least one non-guaranteed transmission carriers; and
a local carrier transmission waveform for the guaranteed transmission carrier, the local carrier transmission waveform including one or more of: control information and data for the guaranteed transmission carrier.
4. The method of claim 3 , wherein each of the plurality of candidate combined transmission waveforms is formed using a different transform operation.
5. The method of claim 3 , wherein the selecting the transmission waveform includes combining the local carrier transmission waveform with the cross-carrier control transmission waveform for each of the at least one non-guaranteed transmission carriers in which the transmission status received indicates the clear transmission.
6. The method of claim 3 , wherein the selecting the transmission waveform includes selecting only the local carrier transmission waveform in response to the received transmission status of the at least one non-guaranteed transmission carriers indicating the no transmission.
7. The method of claim 1 , wherein the pre-preparing, the receiving, the selecting, and the transmitting the selected transmission waveform is performed in one of:
a subframe prior to receiving the transmission status; and
a first subframe after a predetermined time from the receiving the transmission status.
8. A method of wireless communication, comprising:
pre-preparing, at a transmitter, a plurality of candidate singular transmission waveforms of one or more of: control information and data for a guaranteed transmission carrier before detecting a result of a clear channel assessment (CCA);
receiving, at the transmitter, a transmission status for at least one non-guaranteed transmission carriers, wherein the transmission status is the result of the CCA to indicate clear transmission or no transmission on the at least one non-guaranteed transmission carriers;
selecting, by the transmitter, a transmission waveform from the plurality of candidate singular transmission waveforms based on the transmission status; and
transmitting, by the transmitter, the selected transmission waveform to a receiver.
9. The method of claim 8 , wherein the selecting the transmission waveform is performed in response to the received transmission status of the at least one non-guaranteed transmission carriers indicates the no transmission on the at least one non-guaranteed transmission carriers.
10. The method of claim 8 , wherein the pre-preparing, the receiving, the selecting, and the transmitting the selected transmission waveform is performed in one of:
a subframe prior to receiving the transmission status; and
a first subframe after a predetermined time from the receiving the transmission status.
11. A method of wireless communication, comprising:
entering, by a transmitter, a first subframe of a transmission frame;
receiving, at the transmitter, a transmission status for at least one non-guaranteed transmission carriers associated with the transmitter, wherein the transmission status is a result of a clear channel assessment (CCM to indicate clear transmission or no transmission on the at least one non-guaranteed transmission carriers;
transmitting, by the transmitter, a non-time critical signal over a non-guaranteed transmission carrier for a fixed number of symbols of the first subframe after the receiving the transmission status; and
transmitting, by the transmitter, a transmission waveform generated in response to the transmission status beginning at a first transmission symbol after the fixed number of symbols in the first subframe, wherein the transmission waveform is based on the transmission status.
12. The method of claim 11 , wherein the transmission waveform waveforms includes one of:
a combined transmission waveform of cross-carrier control information for each of the at least one non-guaranteed transmission carriers having the transmission status indicating the clear transmission and one or more of: control information and data for a guaranteed transmission carrier; or
a singular transmission waveform of the one or more of: control information and data for the guaranteed transmission carrier, when each of the at least one non-guaranteed transmission carriers has the transmission status indicating the no transmission.
13. The method of claim 11 , wherein the non-time critical signal includes one or more of: a common reference signal (CRS), a channel usage pilot signal (CUPS), a channel usage beacon signal (CUBS), synchronization signal, CSI-RS, or a combination thereof.
14. A method of wireless communication, comprising:
entering, by a transmitter, a first subframe of a transmission frame;
receiving, at the transmitter, a transmission status for at least one non-guaranteed transmission carriers associated with the transmitter, wherein the transmission status is a result of a clear channel assessment (CCA) to indicate clear transmission or no transmission on the at least one non-guaranteed transmission carriers;
transmitting, by the transmitter, a non-time critical signal over a guaranteed transmission carrier for a fixed number of symbols of the first subframe after the receiving the transmission status; and
transmitting, by the transmitter, a transmission waveform generated in response to the transmission status beginning at a first transmission symbol after the fixed number of symbols in the first subframe, wherein the transmission waveform is based on the transmission status.
15. The method of claim 14 , wherein the transmission waveform waveforms includes a singular transmission waveform of the one or more of: control information and data for the guaranteed transmission carrier, when each of the at least one non-guaranteed transmission carriers has the transmission status indicating the no transmission.
16. The method of claim 14 , wherein the non-time critical signal includes one or more of: a common reference signal (CRS), a channel usage pilot signal (CUPS), a channel usage beacon signal (CUBS), synchronization signal, CSI-RS, or a combination thereof.