Patents Assigned to NATL. INSTITUTE OF INFO. AND COMMUNICATIONS TECH.
  • Publication number: 20050180750
    Abstract: A method for routing optical packets using multiple wavelength labels includes converting optical packet address signals to a plurality of optical pulses having different time-deviated wavelengths by executing a first operation to impart a wavelength dependent delay time with respect to a plurality of optical pulses having different wavelengths at a same time axis position. When the optical pulses are transmitted along a predetermined optical path having dispersion the dispersion is compensated for by executing a second operation on the optical pulses corresponding to a reverse process of the operation to impart a wavelength dependent delay time. This second operation results in the generation of a plurality of optical pulses having different wavelengths at a given point on the time axis. The pulse signals thus generated are used to determine the packet transmission route.
    Type: Application
    Filed: April 1, 2005
    Publication date: August 18, 2005
    Applicant: NATL. INSTITUTE OF INFO. AND COMMUNICATIONS TECH.
    Inventors: Naoya Wada, Hiroaki Harai, Wataru Chujo, Fumito Kubota
  • Publication number: 20050105649
    Abstract: This invention has as its object to implement the constitution of a receiver that receives signals sent by performing multi-valued pulse modulation and performs iterative decoding. The constitution includes: (1) a bank of pulse correlators that achieves correlation with all predetermined sent pulse waveforms, (2) a pulse demapper that calculates the log likelihood ratio for each bit of the interleaved code word from said pulse correlator outputs and a priori information for each bit, (3) a deinterleaver that performs deinterleaving on the output from said pulse demapper, (4) a decoder that calculates likelihood information for the deinterleaved code word bits and information bits, respectively, (5) an interleaver that interleaves the output of the decoder in the same manner as on the sending side, and (6) a feedback circuit that provides feedback of the output of said interleaver as a priori probability to the pulse demapper.
    Type: Application
    Filed: September 9, 2004
    Publication date: May 19, 2005
    Applicant: NATL. INSTITUTE OF INFO. AND COMMUNICATIONS TECH.
    Inventors: Kenichi Takizawa, Ryuji Kohno