Downlink Throughput of 5G NR Using PUCCH HARQ Resource Assignment
A Radio Access Network (RAN) system includes a group of cell sites where each cell site includes multiple sectors, and each sector communicates with UE, the system including a Radio Resource Controller (RRC) in Central Unit (CU) controlling PUCCH resources for the sectors, and a Media Access Control (MAC) Scheduler in each sector allocating resources for PUCCH HARQ transmissions in an orthogonal manner separated in time or frequency or cyclic shift to minimize the inter-carrier interference across the sectors to improve system throughput.
1 . A Radio Access Network (RAN) system comprising:
a radio unit (RU) coupled to a plurality of user equipment (UE), the RU having a plurality of sectors;
a radio resource controller (RRC) in a control unit (CU) server controlling physical uplink control channel (PUCCH) resources for the plurality of sectors;
a media access control (MAC) scheduler for each of the plurality of sectors allocating resources for PUCCH hybrid automatic repeat request (HARQ) transmissions in an orthogonal manner, which are separated in time, frequency or cyclic shift to minimize the inter-carrier interference across the plurality of sectors.
2 . The RAN system of claim 1 , wherein the allocation of resources is selected from the group consisting of:
configuring a physical resource block index with an offset; or
configuring a cyclic shift index for each sector based on physical cell identity (PCI).
3 . The RAN system of claim 1 , wherein said RU comprises a plurality of RUs each RU having a plurality of sectors, said RRC controls PUCCH resources for all of the plurality of sectors, and wherein a MAC scheduler is provided for each the plurality of sectors where each MAC scheduler allocates the resources for PUCCH HARQ transmissions in an orthogonal manner across the plurality of sectors.
4 . The RAN system of claim 3 , wherein when the plurality of sectors comprises three sectors, said RRC configures different PUCCH resources separated by frequency and cyclic shift to the three sectors.
5 . The RAN system of claim 4 , wherein the system comprises a 10 MHz system and the three sectors comprise first, second and third sectors.
6 . The RAN system of claim 5 , wherein configurations of PUCCH HARQ F0 resources,
starts at index 11 for the first sector;
starts at index 15 for the second sector; and
starts at index 19 for the third sector.
7 . The RAN system of claim 4 , wherein the system comprises a 5 MHz system and the three sectors comprise first, second and third sectors.
8 . The RAN system of claim 7 , wherein configurations of PUCCH HARQ F0 resources,
starts at index 13 for the first sector;
starts at index 15 for the second sector; and
starts at index 17 for the third sector.
9 . The RAN system of claim 1 , wherein the RRC configures different PUCCH HARQ resources separated in frequency or cyclic shift to each sector in a RU.
10 . The RAN system of claim 1 , wherein said RRC does not configure PUCCH HARQ resources on the same frequency or cyclic shift for adjacent sectors to avoid causing interference in uplink HARQ detection.
11 . The RAN system of claim 1 , wherein said RRC configures an offset for HARQ resource blocks (RBs) based on physical cell identity (PCI) that is based on the overall available PUCCH resources in a system.
12 . The RAN system of claim 1 , wherein said RRC uses physical cell identity (PCI) to automatically configure frequency positions of PUCCH HARQ resources for each sector according to the following equation:
R
B
H
A
R
Q
-
FO
,
Start
i
=
R
B
H
A
R
Q
-
F
0
-
B
a
s
e
+
PCI
i
mod
N
*
K
where RB HARQ-FO,Start i is a start resource block index of HARQ-F0 resources for a sector i, PCI i is a PCI of a sector i, mod is a modulo operation that designates a remainder of PCI i divided by N, where N is a number of considered sectors for HARQ resource orthogonalization.
13 . The RAN system of claim 1 , wherein said MAC Scheduler in each of the plurality of sectors assigns PUCCH HARQ resources through a resource indicator field in downlink control information (DCI) to transmit acknowledgement status for physical downlink shared channel (PDSCH).
14 . The RAN system of claim 1 , wherein the system comprises a plurality of RUs where each RU has an RRC;
wherein the allocation of resources comprises using one symbol x in a slot reserved for PUCCH HARQ transmission, which symbol will not be used for PUSCH in any RU and that symbol will be shared among adjacent RUs.
15 . The RAN system of claim 14 wherein the plurality of RUs comprises Cell 0, Cell 1, and Cell 2, and wherein,
Cell 0 uses symbol x in slot 0,
Cell 1 uses symbol x in slot 1, and
Cell 2 uses symbol x in slot 2.