US 12,470,450 B2
Method of large frequency offset estimation for an OFDM communications system using reference signals
Zhonghui Zhang, Shatin (HK); Yuxian Zhang, Tai Po (HK); and Yibing Yao, Shatin (HK)
Assigned to Hong Kong Applied Science And Technology Research Institute Co., Ltd., Shatin (HK)
Filed by Hong Kong Applied Science And Technology Research Institute Co., Ltd., Shatin (HK)
Filed on Jan. 27, 2023, as Appl. No. 18/102,323.
Prior Publication US 2024/0259248 A1, Aug. 1, 2024
Int. Cl. H04L 27/26 (2006.01); H04L 25/02 (2006.01); H04L 27/00 (2006.01)
CPC H04L 27/2666 (2013.01) [H04L 25/0224 (2013.01); H04L 27/0014 (2013.01); H04L 27/2675 (2013.01); H04L 2027/0026 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of performing carrier frequency offset (CFO) estimation of physical channels in a mobile communications system, the method comprising:
performing channel estimation of a received signal on a physical channel based on multiple orthogonal frequency division multiplex (OFDM) symbols in one or more reference signals (RSs);
determining multiple phase rotation values Φ and corresponding time differences s between different OFDM symbols in the one or more RSs over a base phase rotation range comprising +/−π to obtain a first CFO estimation candidate ƒ0; and
extending the base phase rotation range to provide an extended phase rotation range of greater than +/−π to obtain additional CFO estimation candidates ƒ1, ƒ2 . . . ƒn within the extended phase rotation range;
wherein the first CFO estimation candidate ƒ0 corresponds to a base phase rotation value Φ0=Φori where Φori is an original phase rotation value and the additional CFO estimation candidates ƒ1, ƒ2 . . . ƒn within the extended phase rotation range correspond respectively to phase rotation values Φ1, Φ2 . . . Φn=[Φori+/−2 mπ] where m is a positive integer.