Techniques for use in reverse time alignment
The present disclosure describes a method, an apparatus, and a computer-readable medium for use in providing reverse time alignment in a wireless network. For example, the method may include obtaining a first timing value from a serving node and a second timing value from each of one or more non-serving nodes of the UE, computing one or more timing differences between the first timing value and each of one or more second timing values, and reporting the one or more timing differences to the serving node. Additionally, the disclosure describes a method, an apparatus and a computer-readable medium for use in providing time alignment in a coordinated multi-point (CoMP) transmission network by obtaining of a CoMP transmission network timing information from a plurality of user equipments (UEs) and storing the timing information for each of the plurality of UEs for communicating with the first node.
1. A method for use in providing reverse time alignment in a wireless network, comprising:
obtaining, at a user equipment (UE), a first timing value from a serving node and a second timing value from each of one or more non-serving nodes of the UE;
computing, at the UE, timing differences between the first timing value and each of one or more second timing values;
reporting, by the UE, the timing differences to the serving node;
obtaining a third timing value from the serving node, wherein the third timing value is a UE specific timing value that is based on the reported timing differences and is different than the first timing value;
synchronizing timing at the UE to the third timing value received from the serving node; and
receiving a coordinated multi-point (CoMP) transmission at the UE from the serving node and the one or more non-serving nodes according to the third timing value,
wherein the third timing value addresses propagation delays between at least one of the serving node and the UE or one or more non-serving nodes and the UE.
2. The method of claim 1 , wherein at least one of the first timing value or the second timing value are obtained from primary or secondary synchronization signals received, respectively, from the serving node and the one or more non-serving nodes.
3. The method of claim 1 , wherein at least one of the first timing value or the second timing value are obtained from system information block (SIB) messages received, respectively, from the serving node and the one or more non-serving nodes.
4. The method of claim 3 , wherein at least one of the first timing value or the second timing value is obtained from the system information block (SIB) messages, and wherein system information block (SIB) messages comprise a coordinated universal time (UTC).
5. The method of claim 1 , wherein at least one of the first timing value or the second timing value are obtained by the UE from measurements in an idle or a connected mode.
6. The method of claim 1 , wherein the UE reports the timing differences to the serving node via an uplink control channel, a data channel, or a combination thereof.
7. The method of claim 6 , wherein the uplink control channel comprises a physical uplink control channel (PUCCH) and the uplink data channel comprises a physical uplink shared channel (PUSCH).
8. The method of claim 1 , further comprising:
reporting at least one propagation delays associated with the serving node or the one or more non-serving nodes to the serving node.
9. The method of claim 1 , wherein a multipath delay experienced by the UE for the CoMP transmission is less than a cyclic prefix length.
10. An apparatus for use in providing reverse time alignment in a wireless network, comprising:
means for obtaining, at a user equipment (UE), a first timing value from a serving node and a second timing value from each of one or more non-serving nodes of the UE;
means for computing, at the UE, timing differences between the first timing value and each of one or more second timing values;
means for reporting, by the UE, the timing differences to the serving node;
means for obtaining a third timing value from the serving node, wherein the third timing value is a UE specific timing value that is based on the reported timing differences and is different than the first timing value;
means for synchronizing timing at the UE to the third timing value received from the serving node; and
means for receiving a coordinated multi-point (CoMP) transmission at the UE from the serving node and the one or more non-serving nodes according to the third timing value,
wherein the third timing value addresses propagation delays between at least one of the serving node and the UE or one or more non-serving nodes and the UE.
11. The apparatus of claim 10 , wherein at least one of the first timing value or the second timing value are obtained from primary or secondary synchronization signals received, respectively, from the serving node and the one or more non-serving nodes.
12. The apparatus of claim 10 , wherein at least one of the first timing value or the second timing value are obtained from system information block (SIB) messages received, respectively, from the serving node and the one or more non-serving nodes.
13. The apparatus of claim 12 , wherein at least one of the first timing value or the second timing value is obtained from the system information block (SIB) messages, and wherein system information block (SIB) messages comprise a coordinated universal time (UTC).
14. The apparatus of claim 10 , wherein at least one of the first timing value or the second timing value are obtained by the UE from measurements in an idle or a connected mode.
15. The apparatus of claim 10 , wherein the UE reports the timing differences to the serving node via an uplink control channel or a data channel.
16. The apparatus of claim 15 , wherein the uplink control channel comprises a physical uplink control channel (PUCCH) and the uplink data channel comprises a physical uplink shared channel (PUSCH).
17. The apparatus of claim 10 , further comprising:
means for reporting at least one propagation delays associated with the serving node or the one or more non-serving nodes to the serving node.
18. An apparatus for use in providing reverse time alignment in a wireless network, comprising:
a memory; and
at least one processor coupled with the memory, wherein the at least one processor and the memory are configured to:
obtain, at a user equipment (UE), a first timing value from a serving node and a second timing value from each of one or more non-serving nodes of the UE;
compute, at the UE, timing differences between the first timing value and each of one or more second timing values;
report, by the UE, the timing differences to the serving node;
obtain a third timing value from the serving node, wherein the third timing value is a UE specific timing value that is based on the reported timing differences and is different than the first timing value;
synchronize timing at the UE to the third timing value received from the serving node; and
receive a coordinated multi-point (CoMP) transmission at the UE from the serving node and the one or more non-serving nodes according to the third timing value,
wherein the third timing value addresses propagation delays between at least one of the serving node and the UE or one or more non-serving nodes and the UE.
19. The apparatus of claim 18 , wherein at least one of the first timing value or the second timing value are obtained from primary or secondary synchronization signals received from the serving node and the one or more non-serving nodes.
20. The apparatus of claim 18 , wherein at least one of the first timing value or the second timing value are obtained from system information block (SIB) messages received from the serving node and the one or more non-serving nodes.
21. The apparatus of claim 20 , wherein at least one of the first timing value or the second timing value is obtained from the system information block (SIB) messages, and wherein system information block (SIB) messages comprise a coordinated universal time (UTC).
22. The apparatus of claim 18 , wherein at least one of the first timing value or the second timing value are obtained by the UE from measurements in an idle or a connected mode.
23. The apparatus of claim 18 , wherein the UE reports the timing differences to the serving node via an uplink control channel, a data channel, or some combination thereof.
24. The apparatus of claim 23 , wherein the uplink control channel comprises a physical uplink control channel (PUCCH) and the uplink data channel comprises a physical uplink shared channel (PUSCH).
25. The apparatus of claim 18 , wherein the memory and the processor are further configured to:
report at least one propagation delays associated with the serving node or the one or more non-serving nodes to the serving node.
26. The apparatus of claim 18 , wherein a multipath delay experienced by the UE for the CoMP transmission is less than a cyclic prefix length.