Generalized OFDM (GOFDM) for ultra-high-speed optical transmission

Ivan B Djordjevic, Murat Arabaci, Lei Xu, Ting Wang

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

We propose a coded N-dimensional modulation scheme suitable for ultra-high-speed serial optical transport. The proposed scheme can be considered as a generalization of OFDM, and hence, we call it as generalized OFDM (GOFDM). In this scheme, the orthogonal subcarriers are used as basis functions and the signal constellation points are defined over this N-dimensional linear space. To facilitate implementation, we propose using N-dimensional pulse-amplitude modulation (ND-PAM) as the signal constellation diagram, which is obtained as the N-ary Cartesian product of one-dimensional PAM. In conventional OFDM, QAM/PSK signal constellation points are transmitted over orthogonal subcarriers and then they are multiplexed together in an OFDM stream. Individual subcarriers, therefore, carry N parallel QAM/PSK streams. In the proposed GOFDM scheme instead, an N-dimensional signal constellation point is transmitted over all N subcarriers simultaneously. When some of the subcarriers are severely affected by channel impairments, the constellation points carried by those subcarriers may be lost in the conventional OFDM. In comparison, under such conditions, the overall signal constellation point will face only small distortion in GOFDM and it can be recovered successfully using the information on the other high fidelity subcarriers. Furthermore, because the channel capacity is a logarithmic function of signal-to-noise ratio but a linear function of the number of dimensions, the spectral efficiency of optical transmission systems can be improved with GOFDM.

Original languageEnglish (US)
Pages (from-to)6969-6979
Number of pages11
JournalOptics Express
Volume19
Issue number7
DOIs
StatePublished - Mar 28 2011

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constellations
high speed
pulse amplitude modulation
quadrature amplitude modulation
channel capacity
impairment
signal to noise ratios
diagrams
modulation
products

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Generalized OFDM (GOFDM) for ultra-high-speed optical transmission. / Djordjevic, Ivan B; Arabaci, Murat; Xu, Lei; Wang, Ting.

In: Optics Express, Vol. 19, No. 7, 28.03.2011, p. 6969-6979.

Research output: Contribution to journalArticle

Djordjevic, Ivan B ; Arabaci, Murat ; Xu, Lei ; Wang, Ting. / Generalized OFDM (GOFDM) for ultra-high-speed optical transmission. In: Optics Express. 2011 ; Vol. 19, No. 7. pp. 6969-6979.
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