US 12,255,837 B2
Configuration and resource allocation for downlink demodulation reference signals
Hong Ren, Kanata (CA); Chandra Sekhar Bontu, Nepean (CA); Mattias Frenne, Uppsala (SE); and Jagadish Ghimire, Kanata (CA)
Assigned to Telefonaktiebolaget LM Ericsson (Publ), Stockholm (SE)
Appl. No. 17/415,926
Filed by Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
PCT Filed Dec. 26, 2018, PCT No. PCT/IB2018/060627
§ 371(c)(1), (2) Date Jun. 18, 2021,
PCT Pub. No. WO2020/136416, PCT Pub. Date Jul. 2, 2020.
Prior Publication US 2022/0085929 A1, Mar. 17, 2022
Int. Cl. H04L 5/00 (2006.01); H04L 1/00 (2006.01); H04L 27/26 (2006.01); H04B 7/0452 (2017.01)
CPC H04L 5/0016 (2013.01) [H04L 1/0027 (2013.01); H04L 5/0051 (2013.01); H04L 27/2613 (2013.01); H04B 7/0452 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A network node, comprising:
processing circuitry configured to:
allocate resources for a reference signal signaling for a first wireless device, the allocated resources configured to separate, in a slot, at least one transmission layer of the first wireless device from at least one transmission layers of a second wireless device by:
scheduling the first wireless device and second wireless device on at least one shared reference signal port using the same resource elements and CDM code, the first wireless device and second wireless device having different scrambling sequences, and the first wireless device and the second wireless device having the at least one shared reference signal port being part of a wireless device sub-group, the wireless device sub-group meeting at least one predefined spatial condition, the at least one predefined spatial condition including a spatial metric associated with each wireless device within the subgroup that meets a predefined criterion with respect to all other wireless devices in the same subgroup;
the first wireless device scheduled for a reference signal port combination for one selected from a group consisting of:
a one front-load reference signal symbol configuration; and
a two front-load reference signal symbol configuration; and
determine resources for a downlink, DL, demodulation reference signal, DMRS, by:
dividing a plurality of scrambling sequence identifiers, IDs, into a plurality of non-overlapping groups;
allocating a group of scrambling sequence IDs to a set of wireless devices;
selecting one scrambling sequence ID from the plurality of scrambling sequence IDs and configuring the selected one scrambling sequence ID for all wireless devices in the set of wireless devices;
trying to use orthogonal demodulation antenna ports to separate one or both layers or wireless devices in the set of wireless devices; and
allocating a same orthogonal demodulation antenna port to those of the set of wireless devices that have spatial separation above a first threshold if those of the set of wireless devices can use different scrambling sequences when a number of available orthogonal demodulation antenna ports is below a target number.