Allocation and logical to physical mapping of scheduling request indicator channel in wireless networks
A method for allocating resources for a scheduling request indicator (SRI) is disclosed. An SRI cycle period for use by user equipment (UE) within a cell is transmitted from a NodeB in a cell to UE within the cell. The NodeB transmits a specific SRI subframe offset and an index value to the particular UE within the cell. The specific SRI subframe offset and the index value enable the UE to determine a unique combination of cyclic shift, RS orthogonal cover, data orthogonal cover, and resource block number for the UE to use as a unique physical resource for an SRI in the physical uplink control channel (PUCCH).
1. A method for sending a scheduling request indicator (SRI) by a user equipment (UE), comprising:
transmitting the SRI at a determined SRI subframe offset and a SRI cycle period, the determined SRI subframe offset being equal to n for values of n from 0 to 4, equal to n-5 for values of n from 5 to 14, equal to n-15 for values of n from 15 to 34, equal to n-35 for values of n from 35-74, and equal to n-75 for values of n from 75 to 154, where n is a received index value.
2. The method of claim 1 wherein the SRI cycle period extends the unique physical resource to a persistent periodic physical resource.
3. The method of claim 1 wherein the index value n is received in higher level signaling.
4. The method of claim 1 wherein the higher level signaling is radio resource control (RRC) signaling.
5. The method of claim 1 , wherein the SRI subframe offset and the index value n enable the UE to determine a unique combination, wherein an SRI resource indexed by n is located in a physical uplink control channel (PUCCH) resource block (RB) number, wherein the PUCCH RB number is └n/N SRI SFRB N SRI ┘;
wherein a subframe S 0 +└(n mod N SRI SFRB N SRI )/N SRI SFRB ┘indicates where an SRI resource is located on a channelization resource indexed by n SRI (SRI resource index)=(n mod N SRI SFRB );
wherein the acronym SFRB means subframe resource block;
wherein N SRI SFRB is the SRI multiplexing capacity in one subframe of a RB; and
wherein N SRI is the SRI period expressed in number of subframes, and S 0 is the number of a first subframe of an SRI period, and assuming a PUCCH RB indexing starts from an upper edge of the PUCCH down to a lower edge.
6. The method of claim 1 , wherein N SRI SFRB is the SRI multiplexing capacity in one subframe of a RB, given a cyclic shift separation Δ shift PUCCH between resources using the same orthogonal covering code,
N
SRI
SFRB
=
{
6
N
SC
RB
/
Δ
shift
PUCCH
for
normal
cyclic
prefix
4
N
SC
RB
/
Δ
shift
PUCCH
for
extended
cyclic
prefix
,
wherein N SC RB is the number N of sub-carriers (SC) in one resource block (RB).
7. The method of claim 1 , wherein resources used for the SRI transmission on PUCCH in a given RB/subframe are identified by the resource index n SRI from which the orthogonal sequence indexes n OC,1 (n s) , n OC,2 (n s) , n OC,3 (n s) of the block spreading codes 1, 2 and 3 respectively, and a cyclic shift α(1) are determined according to:
n OC,1 (n s) =( n OC,1 (0) +f 1 ( n s ))mod 3
n OC,2 (n s) =( n OC,2 (0) +f 2 ( n s ))mod 3
n OC,3 (n s) =( n OC,3 (0) +f 3 ( n s ))mod 3
α( l )=(α (0) +f 4 ( l ))mod N SC RB
where N SC RB =12 is the number of sub-carriers in one resource block (RB) and
n
OC
,
1
(
0
)
=
{
⌊
(
n
SRI
mod
(
N
SRI
SFRB
/
2
)
)
Δ
shift
PUCCH
/
N
SC
RB
⌋
for
normal
cyclic
prefix
2
⌊
(
n
SRI
mod
(
N
SRI
SFRB
/
2
)
)
Δ
shift
PUCCH
/
N
SC
RB
⌋
for
extended
cyclic
prefix
n
OC
,
2
(
0
)
=
⌊
(
n
SRI
mod
(
N
SRI
SFRB
/
2
)
)
Δ
shift
PUCCH
/
N
SC
RB
⌋
n
OC
,
3
(
0
)
=
⌊
2
n
SRI
/
N
SRI
SFRB
⌋
α
(
0
)
=
{
(
(
n
SRI
mod
(
N
SRI
SFRB
/
2
)
)
Δ
shift
PUCCH
+
δ
offset
PUCCH
+
(
n
OC
,
1
(
0
)
mod
Δ
shift
PUCCH
)
)
mod
N
SC
RB
normal
cp
(
(
n
SRI
mod
(
N
SRI
SFRB
/
2
)
)
Δ
shift
PUCCH
+
δ
offset
PUCCH
+
n
OC
,
2
(
0
)
)
mod
N
SC
RB
extended
cp
and f 1 (n s ), f 2 (n s ), f 3 (n s ) represent index hopping functions varying per slot and f 4 (l) represents index hopping function varying per symbol.
8. The method of claim 1 , further comprising:
receiving the index value n;
determining the SRI cycle period; and
determining the SRI subframe offset, wherein the SRI subframe offset equals n for values of n from 0 to 4, equals n-5 for values of n from 5 to 14, equals n-15for values of n from 15 to 34, equals n-35 for values of n from 35-74, and equals n-75 for values of n from 75 to 154.