Simple Self-Homodyne Detection Scheme for Optical OFDM With Inserted Pilot Subframes and Application in Optical Access Networks

Autor: Guo-Wei Lu, Xun Guan, Takahide Sakamoto, Naokatsu Yamamoto, Calvin Chun-Kit Chan
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: IEEE Access, Vol 5, Pp 24602-24607 (2017)
Druh dokumentu: article
ISSN: 2169-3536
DOI: 10.1109/ACCESS.2017.2765336
Popis: In this paper, a simple self-homodyne detection scheme is proposed and experimentally demonstrated for applications in optical access networks. Unmodulated pilot subframes are periodically inserted and interleaved with data subframes to form an orthogonal frequency-division multiplexing (OFDM) signal. Owing to the coherence between the embedded pilot and data subframes, a Mach-Zehnder delay interferometer with a free spectral range equal to the frequency of the subframe is deployed for the self-homodyne detection of the OFDM signal. It saves the local oscillator and optical hybrid, which are usually used in a conventional coherent receiver, thus reducing the hardware complexity and implementation cost. Meanwhile, the digital signal processing (DSP) for the self-homodyne detection is free from carrier-frequency-offset compensation and carrier-phase estimation, reducing the complexity, power consumption, and latency of the system. It also allows the use of a low-cost laser source as the source for the downstream signal. The proposed scheme provides a cost-effective and energy-efficient downstream solution for optical access networks, owing to the hardware saving and complexity reduction in DSP. A 10-Gb/s OFDM downstream transmission over a 20-km standard single-mode fiber is experimentally demonstrated with an error-free operation, using both a 10-MHz distributed feedback laser and a 100-kHz external cavity laser as downstream laser sources.
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