US 12,262,338 B2
Radio synchronization
Wei Li, Trondheim (NO); and Eivind Sjøgren Olsen, Trondheim (NO)
Assigned to Nordic Semiconductor ASA, Trondheim (NO)
Filed by Nordic Semiconductor ASA, Trondheim (NO)
Filed on Jul. 14, 2022, as Appl. No. 17/865,185.
Claims priority of application No. 2110906 (GB), filed on Jul. 29, 2021.
Prior Publication US 2023/0031301 A1, Feb. 2, 2023
Int. Cl. H04L 7/00 (2006.01); H04W 56/00 (2009.01)
CPC H04W 56/001 (2013.01) [H04L 7/0087 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A radio receiver device configured to receive a digital radio signal and to determine whether said digital radio signal includes a predetermined cyclic preamble having a period, the radio receiver device comprising:
an input portion configured to sample the received digital radio signal and to generate therefrom a plurality of samples;
a buffer configured to store the plurality of samples;
a first autocorrelator configured to correlate a first subset of the plurality of samples with a second subset of the plurality of samples to generate a first correlation metric, said second subset of samples having been stored in the buffer earlier than said first subset of samples by a first delay equal to an even integer multiple of half of the preamble period;
a second autocorrelator configured to correlate the first subset of the plurality of samples with a third subset of the plurality of samples to generate a second correlation metric, said third subset of samples having been stored in the buffer earlier than said first subset of samples by a second delay equal to an odd integer multiple of half of the preamble period; and
a processing portion configured to calculate a difference between the first and second correlation metrics and to determine that the radio signal includes the predetermined cyclic preamble when said difference is greater than a threshold value.