US 12,476,714 B2
Electrical duobinary soft information receiver for NRZ modulation fiber transmission
Rainer Strobel, Munich (DE)
Assigned to MAXLINEAR, INC., Carlsbad, CA (US)
Filed by MAXLINEAR, INC., Carlsbad, CA (US)
Filed on Feb. 13, 2024, as Appl. No. 18/440,933.
Application 18/440,933 is a division of application No. 17/594,357, granted, now 11,901,954, issued on Feb. 13, 2024, previously published as PCT/US2020/027367, filed on Apr. 9, 2020.
Claims priority of provisional application 62/833,108, filed on Apr. 12, 2019.
Prior Publication US 2024/0187108 A1, Jun. 6, 2024
Int. Cl. H04B 10/69 (2013.01); H04B 10/516 (2013.01); H04B 10/40 (2013.01)
CPC H04B 10/69 (2013.01) [H04B 10/5167 (2013.01); H04B 10/40 (2013.01)] 11 Claims
OG exemplary drawing
 
1. An electrical duobinary receiver circuit configured to receive an optical signal, comprising:
a receive circuit configured to perform an electrical duobinary demodulation by processing the optical signal, and converting the optical signal into a binary signal based on three or more decision thresholds with distances therebetween that are unequally spaced from one another; and
a decoder circuitry comprising a log-likelihood ratio circuit configured to process samples from a clock data recovery circuit, and generate a soft information output signal in terms of log-likelihood ratios based on the samples, wherein the samples are based on different bit positions and one or more intermediate positions between the bit positions based on an offset.