Signaling of Precoding Granularity for LTE and LTE-A
A method for indicating a precoding granularity value. The method includes an access node performing at least one of dynamically signaling the precoding granularity value in downlink control information, semi-statically signaling the precoding granularity value through high-layer signaling, and implicitly signaling the precoding granularity value through a link with at least one parameter that the access node transmits for another purpose.
1 . A method for indicating a precoding granularity value, comprising:
an access node performing at least one of:
dynamically signaling the precoding granularity value in downlink control information (DCI),
semi-statically signaling the precoding granularity value through high-layer signaling, and
implicitly signaling the precoding granularity value through a link with at least one parameter that the access node transmits for another purpose.
2 . The method of claim 1 , wherein, when the precoding granularity value is dynamically signaled in the DCI, a first value of at least one bit in the DCI indicates a first precoding granularity value, and a second value of the at least one bit in the DCI indicates a second precoding granularity value.
3 . The method of claim 1 , wherein, when the precoding granularity value is semi-statically signaled through high-layer signaling, the high-layer signaling is at least one of:
radio resource control signaling; and
a medium access control (MAC) control element.
4 . The method of claim 1 , wherein, when implicit signaling is used, the at least one parameter that the access node transmits for another purpose is at least one of:
a feedback mode;
a transmission mode;
a transmission rank;
a resource allocation size;
a scrambling status of a cyclic redundancy check (CRC); and
a parity of the resource allocation size.
5 . The method of claim 4 , wherein the parameter is the transmission mode and wherein, when the transmission mode is closed-loop precoding, the access node signals a plurality of different precoding granularity values, and when the transmission mode is open-loop precoding, the access node signals a precoding granularity value of one resource block or a fixed number of resource blocks.
6 . The method of claim 4 , wherein the parameter is the transmission mode and wherein, when the access node determines that a user equipment (UE) is moving at a rate below a threshold, the access node signals a plurality of different precoding granularity values to the UE and uses a closed-loop precoding transmission mode, and when the access node determines that the UE is moving at a rate above the threshold, the access node signals a precoding granularity value of one resource block or a fixed number of resource blocks to the UE and uses an open-loop precoding transmission mode.
7 . The method of claim 4 , wherein the parameter is the transmission rank and wherein, when the transmission rank is below a threshold, precoding granularity is not enabled, and when the transmission rank is above a threshold, precoding granularity is enabled with a value that is at least one of predetermined and explicitly signaled.
8 . An access node in a wireless telecommunications system, comprising:
a processor configured such that the access node performs at least one of:
dynamically signaling a precoding granularity value in downlink control information (DCI),
semi-statically signaling the precoding granularity value through high-layer signaling, and
implicitly signaling the precoding granularity value through a link with at least one parameter that the access node transmits for another purpose.
9 . The access node of claim 8 , wherein, when the precoding granularity value is dynamically signaled in the DCI, a first value of at least one bit in the DCI indicates a first precoding granularity value, and a second value of the at least one bit in the DCI indicates a second precoding granularity value.
10 . The access node of claim 8 , wherein, when the precoding granularity value is semi-statically signaled through high-layer signaling, the high-layer signaling is at least one of:
radio resource control signaling; and
a medium access control (MAC) control element.
11 . The access node of claim 8 , wherein, when implicit signaling is used, the at least one parameter that the access node transmits for another purpose is at least one of:
a feedback mode;
a transmission mode;
a transmission rank;
a resource allocation size;
a scrambling status of a cyclic redundancy check (CRC); and
a parity of the resource allocation size.
12 . The access node of claim 11 , wherein the parameter is the transmission mode and wherein, when the transmission mode is closed-loop precoding, the access node signals a plurality of different precoding granularity values, and when the transmission mode is open-loop precoding, the access node signals a precoding granularity value of one resource block.
13 . The access node of claim 11 , wherein the parameter is the transmission mode and wherein, when the access node determines that a user equipment (UE) is moving at a rate below a threshold, the access node signals a plurality of different precoding granularity values to the UE and uses a closed-loop precoding transmission mode, and when the access node determines that the UE is moving at a rate above the threshold, the access node signals a precoding granularity value of one resource block or a fixed number of resource blocks to the UE and uses an open-loop precoding transmission mode.
14 . The access node of claim 11 , wherein the parameter is the transmission rank and wherein, when the transmission rank is below a threshold, precoding granularity is not enabled, and when the transmission rank is above a threshold, precoding granularity is enabled with a value that is at least one of predetermined and explicitly signaled.
15 . A user equipment (UE), comprising:
a processor configured such that the UE receives at least one of:
dynamic signaling of a precoding granularity value in downlink control information (DCI),
semi-static signaling of the precoding granularity value through high-layer signaling, and
implicit signaling of the precoding granularity value through a link with at least one parameter that was transmitted for another purpose.
16 . The UE of claim 15 , wherein, when the precoding granularity value is dynamically signaled in the DCI, a first value of at least one bit in the DCI indicates a first precoding granularity value, and a second value of the at least one bit in the DCI indicates a second precoding granularity value.
17 . The UE of claim 15 , wherein, when the precoding granularity value is semi-statically signaled through high-layer signaling, the high-layer signaling is at least one of:
radio resource control signaling; and
a medium access control (MAC) control element.
18 . The UE of claim 15 , wherein, when implicit signaling is used, the at least one parameter that was transmitted for another purpose is at least one of:
a feedback mode;
a transmission mode;
a transmission rank;
a resource allocation size;
a scrambling status of a cyclic redundancy check (CRC); and
a parity of the resource allocation size.
19 . The UE of claim 18 , wherein the parameter is the transmission mode and wherein, when the transmission mode is closed-loop precoding, the UE receives a plurality of different precoding granularity values, and when the transmission mode is open-loop precoding, the UE receives a precoding granularity value of one resource block.
20 . The UE of claim 18 , wherein the parameter is the transmission mode and wherein, when it is determined that the UE is moving at a rate below a threshold, the UE receives a plurality of different precoding granularity values and uses a closed-loop precoding transmission mode, and when it is determined that the UE is moving at a rate above the threshold, the UE receives a precoding granularity value of one resource block or a fixed number of resource blocks and uses an open-loop precoding transmission mode.
21 . The UE of claim 18 , wherein the parameter is the transmission rank and wherein, when the transmission rank is below a threshold, precoding granularity is not enabled, and when the transmission rank is above a threshold, precoding granularity is enabled with a value that is at least one of predetermined and explicitly signaled.
22 . The UE of claim 15 , wherein, when the UE receives a precoding granularity value that is different from a size of a resource block group that contains at least one resource block to which the precoding granularity value applies, the precoding granularity value is applied to as many resource blocks in the resource block group as possible, and any remaining resource block in the resource group assumes a precoding vector that is different from any precoding vector that was applied to any other resource block in the resource block group.
23 . The UE of claim 15 , wherein, when the UE receives a precoding granularity value that is different from a size of a resource block group that contains at least one resource block to which the precoding granularity value applies, the precoding granularity value is applied to as many resource blocks in the resource block group as possible, and any remaining resource block in the resource group assumes a precoding vector that is the same as the precoding vector of an adjacent resource block.
24 . The UE of claim 15 , wherein precoding granularity is applied on a resource block group basis.
25 . The UE of claim 15 , wherein precoding granularity is applied on a resource block group basis when a type 0 resource allocation is used, and precoding granularity is applied on a resource block basis when a resource allocation other than type 0 is used.