US 11,894,962 B2
Guard interval adaptation for coordinated beamforming
Dennis Sundman, Sollentuna (SE); and Miguel Lopez, Solna (SE)
Assigned to Telefonaktiebolaget LM Ericsson (Publ), Stockholm (SE)
Appl. No. 17/624,475
Filed by Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
PCT Filed Jul. 10, 2020, PCT No. PCT/EP2020/069508
§ 371(c)(1), (2) Date Jan. 3, 2022,
PCT Pub. No. WO2021/005200, PCT Pub. Date Jan. 14, 2021.
Claims priority of provisional application 62/872,961, filed on Jul. 11, 2019.
Prior Publication US 2022/0294676 A1, Sep. 15, 2022
Int. Cl. H04L 27/26 (2006.01); H04B 7/024 (2017.01); H04B 7/06 (2006.01)
CPC H04L 27/2602 (2013.01) [H04B 7/024 (2013.01); H04B 7/0617 (2013.01); H04L 27/2607 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method of transmitting an Orthogonal Frequency Division Multiplexing, OFDM, symbol comprising a guard interval including a cyclically repeated part of an original symbol, the method comprising
applying a guard interval for the OFDM symbol, the guard interval comprising a first part, where the first part is a cyclic prefix;
determining whether to use the second part of the guard interval, and when it is determined that the second part of the guard interval is to be used:
including an indication that the applied guard interval comprises a second part, the second part being at least one of a cyclic prefix and a postfix;
applying the second part of the guard interval; and
transmitting the OFDM symbol; and
the determining whether to use the second part of the guard interval comprises:
determining whether coordinated beamforming transmission is performed between neighbouring access points;
estimating impact of transients emanating from changes in the coordinated beamforming; and
determining to apply the second part of the guard interval when estimated impact of transients has a timing within the second part of the guard interval.