In this paper, a symmetric training sequence-based (STSB) copyright frequency offset estimation (FOE) scheme for coherent free-space optical (CFSO) communication is proposed.In the proposed technique, we exploit the training-sequence-based (TSB) copyright FOE algorithm to the CFSO communication system in the quadrature phase-shift keying (QPSK) modulation format.A symmetric training sequence, tailored to the copyright FOE algorithm for atmospheric turbulence channel, is formulated to accurately identify the correct temporal position of a data frame from received signals.
Unlike the 4th power algorithm, the proposed algorithm Stoves STBI900G Built-In Double Gas Oven requires only the identified training sequence and the symmetric sequence of the original training sequence in the FOE stage, performing a single multiplication to accurately remove the signal modulation phase.In this way, the proposed technique significantly improves the estimation accuracy.Furthermore, by avoiding the time-consuming 4th power operation, the proposed method reduces the computational complexity while expanding the FOE range.
Therefore, when compared with existing algorithms, our proposed technique can achieve more accurate timing, a wider estimation range, and lower complexity.A 10-Gbps QPSK CFSO communication transmission experiment with different turbulence channels was carried out to validate Ear Care the proposed technique and the improvement in receiver sensitivity.