Receiver in-phase and quadrature skew tolerant baud-rate timing recovery scheme for short-reach coherent optical interconnection.
Opt Lett
; 49(10): 2845-2848, 2024 May 15.
Article
in En
| MEDLINE
| ID: mdl-38748177
ABSTRACT
A baud-rate sampling timing recovery (TR) scheme with receiver IQ skew tolerance is proposed and experimentally demonstrated. The proposed scheme performs independent TR for the in-phase and quadrature (IQ) tributary signals, thereby tracking the sampling phase error while naturally compensating for receiver IQ skew. The robustness of the IQ-independent TR to frequency offset (FO) and phase noise is theoretically analyzed. To address IQ misalignment caused by the IQ-independent TR, the use of pseudo-noise (PN) sequences for IQ frame synchronization is proposed. The proposed scheme achieves accurate timing recovery with hardware-efficient baud-rate sampling in the presence of receiver IQ skew, laying the foundation for stable performance of subsequent baud-rate equalization. The performance of the scheme is validated in a 56 GBaud polarization division multiplexed (PDM) 16QAM coherent experimental system. Experimental results demonstrate that the proposed scheme achieves similar BER performance to the modified Gardner + real-valued multiple-input multiple-output (RVMIMO) (@2 SPS) scheme. Moreover, the proposed scheme exhibits robustness to arbitrary IQ skew compared to the ABSPD + RVMIMO (@1 SPS) scheme.
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01-internacional
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MEDLINE
Language:
En
Journal:
Opt Lett
/
Opt. lett. (Online)
/
Optics letters (Online)
Year:
2024
Document type:
Article
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