US 11,996,879 B2
Removal of passive intermodulation in antenna systems
Jin Ellgardt, Sundbyberg (SE); Spendim Dalipi, Sollentuna (SE); Mats Gan Klingberg, Enebyberg (SE); and Haiying Cao, Beijing (CN)
Assigned to TELEFONAKTIEBOLAGET LM ERICSSON (PUBL), Stockholm (SE)
Appl. No. 17/911,705
Filed by Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
PCT Filed Mar. 18, 2020, PCT No. PCT/CN2020/079862
§ 371(c)(1), (2) Date Sep. 15, 2022,
PCT Pub. No. WO2021/184232, PCT Pub. Date Sep. 23, 2021.
Prior Publication US 2023/0179252 A1, Jun. 8, 2023
Int. Cl. H04B 1/525 (2015.01); H04B 7/06 (2006.01)
CPC H04B 1/525 (2013.01) [H04B 7/0617 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method for passive intermodulation (PIM) removal in an antenna system, the method being performed by a controller of the antenna system, the method comprising:
identifying, during transmission using codebook based beamforming, which transmission radio chains of the antenna system that cause a signal received by receiver radio chains of the antenna system to be impacted by PIM, wherein these transmission radio chains are identified based on which codeword in the codebook is used for the beamforming;
determining a correction signal by subjecting the signals only as transmitted by the identified transmission radio chains to a model of the PIM; and
removing PIM from the signal received by the receiver radio chains by subtracting the correction signal from the signal received by the receiver radio chains.