US 12,451,945 B2
Methods for adapting density of demodulation reference signals
Lars Lindbom, Karlstad (SE); Mattias Frenne, Uppsala (SE); Martin Hessler, Linköping (SE); and Karl Werner, Segeltorp (SE)
Assigned to TELEFONAKTIEBOLAGET LM ERICSSON (PUBL), Stockholm (SE)
Filed by Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
Filed on Dec. 29, 2023, as Appl. No. 18/399,952.
Application 18/399,952 is a continuation of application No. 17/579,781, filed on Jan. 20, 2022, granted, now 11,956,047.
Application 17/579,781 is a continuation of application No. 17/112,455, filed on Dec. 4, 2020, granted, now 11,233,555, issued on Jan. 25, 2022.
Application 17/112,455 is a continuation of application No. 16/308,203, granted, now 10,879,986, issued on Dec. 29, 2020, previously published as PCT/EP2017/075700, filed on Oct. 9, 2017.
Claims priority of provisional application 62/406,753, filed on Oct. 11, 2016.
Prior Publication US 2024/0137094 A1, Apr. 25, 2024
Int. Cl. H04L 5/00 (2006.01); H04B 7/06 (2006.01); H04L 5/10 (2006.01); H04L 25/02 (2006.01); H04B 7/0413 (2017.01)
CPC H04B 7/0684 (2013.01) [H04L 5/0016 (2013.01); H04L 5/0023 (2013.01); H04L 5/0051 (2013.01); H04L 5/0092 (2013.01); H04L 5/10 (2013.01); H04L 25/0224 (2013.01); H04B 7/0413 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A method, in a first wireless node, the method comprising:
selecting a set of demodulation reference signal antenna ports for use in transmitting data to or receiving data from a plurality of User Equipments, UEs, in a given transmit time interval, from a plurality of sets of demodulation reference signal antenna ports that are available for use, wherein at least two of sets of the plurality of sets of demodulation reference signal antenna ports have different demodulation reference signal densities in frequency dimension; and
sending a message to a UE indicating the selected set of demodulation reference signal antenna ports, wherein the message indicates the selected set from a plurality of possible sets of available ports, the possible sets of available ports comprising:
a first set of demodulation reference signal antenna ports comprising each odd subcarrier of a first physical resource block, wherein the first set of demodulation reference signal antenna ports comprises one port or two antenna ports being separated from one another by orthogonal cover codes;
a second set of demodulation reference signal antenna ports comprising each even subcarrier of a second physical resource block, wherein the second set of demodulation reference signal antenna ports comprises one port or two antenna ports being separated from one another by orthogonal cover codes, wherein the demodulation reference signal antenna ports of the first set and second set are different; and
a third set of demodulation reference signal antenna ports corresponding to a merger in at least one physical resource block of the first set of demodulation reference signal antenna ports and the second set of demodulation reference signal antenna ports, wherein the third set of demodulation reference signal antenna ports comprises one port or two antenna ports being separated from one another by orthogonal cover codes.