Pulse or digital communications – Systems using alternating or pulsating current – Plural channels for transmission of a single pulse train
Reexamination Certificate
2011-06-14
2011-06-14
Liu, Shuwang (Department: 2611)
Pulse or digital communications
Systems using alternating or pulsating current
Plural channels for transmission of a single pulse train
C375S340000, C375S289000, C375S312000, C370S499000, C398S098000, C398S076000, C398S172000, C398S077000
Reexamination Certificate
active
07961798
ABSTRACT:
Wired/wireless optical signal modulation and demodulation apparatuses and methods using an intensity modulation/direct detection method and an orthogonal frequency division multiplexing (OFDM) method are provided. A unipolar OFDM symbol frame is generated by determining the polarity of each of a plurality of sub-frames of a bipolar OFDM symbol frame which comprises both a plurality of positive pulses and a plurality of negative pulses, inverting the polarity of the sub-frames which are determined to be negative, delaying one of the positive sub-frame and a positive sub-frame obtained through the inversion by the duration of the sub-frames, and multiplexing the result of the delaying and whichever of the positive sub-frame and the positive sub-frame obtained through the inversion is not the result of the delaying. The unipolar OFDM symbol frame can guarantee high power amplification efficiency and high transmission power efficiency, and is robust against a multi-path channel environment. Therefore, the unipolar OFDM symbol frame can be used in various optical signal modulation/demodulation methods for wireless indoor broadband optical transmission devices, wired broadband optical transmission devices using multi-mode optical fibers, and radio-over-fiber devices which transmit baseband analog signals as optical signals.
REFERENCES:
patent: 5754322 (1998-05-01), Ishikawa et al.
patent: 6442211 (2002-08-01), Hampel et al.
patent: 6470030 (2002-10-01), Park et al.
patent: 7054375 (2006-05-01), Kannan et al.
patent: 2003/0128751 (2003-07-01), Vandenameele-Lepla
patent: 2004/0018018 (2004-01-01), Izadpanah
patent: 0 788 264 (1997-06-01), None
patent: 1020050089709 (2005-08-01), None
patent: WO 03/041330 (2003-05-01), None
Lowery, A., “10 Gbit/s multimode fiber link usingpower efficient orthogonal-frequency-division multiplexing”, 2005, Optics Express, vol. 13, 10003-10009.
Gonzalez, O., “OFDM over indoor wireless optical channel”, 2005, Optoelectron, vol. 152, p. 199-204.
Ahn Sung
Blakely , Sokoloff, Taylor & Zafman LLP
Electronics and Telecommunications Research Institute
Liu Shuwang
LandOfFree
Modulation and demodulation apparatuses and methods for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Modulation and demodulation apparatuses and methods for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Modulation and demodulation apparatuses and methods for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2635992