US 12,323,199 B2
System and method for Doppler frequency shift compensation in free space optical links
Michael Y. Frankel, Pikesville, MD (US); and Vladimir Pelekhaty, Baltimore, MD (US)
Assigned to Ciena Corporation, Hanover, MD (US)
Filed by Ciena Corporation, Hanover, MD (US)
Filed on Sep. 26, 2022, as Appl. No. 17/952,496.
Prior Publication US 2024/0113747 A1, Apr. 4, 2024
Int. Cl. H04B 7/01 (2006.01); H04B 7/185 (2006.01)
CPC H04B 7/01 (2013.01) [H04B 7/185 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A coherent transceiver for use in a first satellite comprising:
a transmitter including a modulator configured to modulate a light transmitted by laser;
a receiver including a Local Oscillator (LO) laser configured to provide a down conversion signal for received signal; and
circuitry configured to tune a frequency of the transmitter laser and the LO laser based on an amount of Doppler frequency shift to be compensated, wherein only the LO laser is tuned responsive to a maximum Doppler frequency shift not exceeding a maximum frequency tuning range of the LO laser.