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Shin KANEKO Noriki MIKI Hideaki KIMURA Hisaya HADAMA
This paper presents spectral multi-level (M-ary) amplitude shift keying (ASK) optical code-division-multiplexing (OCDM) as a key technology for future optical access network. A novel transmitter configuration to achieve flexible scalability that is required in future optical access network is proposed. The transmitter employs pre-biasing circuits and dummy data input. Pre-biasing circuits enable us to achieve high tolerance to multiple access interference by compensating for the nonlinearity of the M-ary ASK and increase the number of multiplexed binary data streams. By inputting the dummy data into the transmitter so that the total number of multiplexed binary data streams including those that actually accommodate users/services and the dummy streams remains constant, the number of users/services can be increased up to the total number of data streams without changing the parameters for pre-biasing. Therefore, the proposed transmitter can flexibly enhance the scalability of the spectral M-ary ASK OCDM. The formulas for calculating the bit error rate characteristics are described when using the conventional and proposed transmitters. The feasibility of the proposed transmitter is verified theoretically using the established formulas.
Hideaki KIMURA Noriko IIYAMA Yoshihito SAKAI Kiyomi KUMOZAKI
We propose the network on demand concept to yield the optical access network system that well handles the diversity in user demands and support technologies such as module and devices configuration. In this proposal, the network accommodation equipment, such as OLT needed for each service, is installed ‘virtually' using WDM, and the physical rate can adapt to the user-demanded service rate by using the WDM parallel transmission technique. It well handles the diversity in user demands/services and lowers system power consumption.
Kazuhiko KINOSHITA Yukio ITO Hideaki KIMURA Yuji MAEDA
This letter summarizes three talks in the tutorial session of the 13th Asia-Pacific Network Operations and Management Symposium (APNOMS2011), which focused on the disaster recovery and further emergency management regarding the Great East Japan Earthquake of 2011. We present the damage and restoration of communication networks and points to a future disaster-resilient society.
Takeshi KUROSAKI Toshikazu HASHIMOTO Noboru ISHIHARA Yasuhiro SUZUKI Masahiro YANAGISAWA Hideaki KIMURA Makoto NAKAMURA Yuichi TOHMORI Kazutoshi KATO Yoshihiro KAWAGUCHI Yuji AKAHORI Yasufumi YAMADA Kuniharu KATO Hiromu TOBA Junichi YOSHIDA
This paper describes design techniques for suppressing crosstalk in an optical transceiver module using PLC-hybrid-integration technologies and for achieving burst-mode operation with high sensitivity and wide dynamic range using CMOS-IC technologies. An arrangement that reduces the electrical crosstalk to less than -100 dB was designed using three-dimensional electromagnetic field analysis. The configurations of a newly developed instantaneous-response CMOS LD driver circuit is also described and instantaneous-response CMOS receiver circuit techniques are reviewed. With these techniques, we have succeeded in building optical transceiver modules for ATM-PON systems using PLC-hybrid-integration and inexpensive standard CMOS-IC fabrication processes. Under full-duplex operation at 156 Mb/s, fabricated transceiver modules showed receiver sensitivity of better than -34 dBm and dynamic range of over 28 dB, which satisfy both the class-B and class-C specifications recommended by ITU-T (International Telecommunication Union-Telecommunication standardization sector) G983.1 for the optical transceiver module for an ONU (optical network unit).
Shin KANEKO Sang-Yuep KIM Noriki MIKI Hideaki KIMURA Hisaya HADAMA Koichi TAKIGUCHI Hiroshi YAMAZAKI Takashi YAMADA Yoshiyuki DOI
We propose frequency-domain optical code-division-multiplexing (CDM) employing quadrature-amplitude-modulation (QAM) using two of multi-level (M-ary) data generated based on electrical-domain spatial code spreading. Its spectral efficiency is enhanced compared to the conventional scheme with amplitude-shift-keying (ASK) using only one of M-ary data. Although it demands the recovery of amplitude and optical phase information, the practicality of the receiver is retained with self-homodyne detection using a phase-shift-keying (PSK) pilot light. Performance is theoretically evaluated and the optimal parameters are derived. Finally, the feasibility of the proposed technique is experimentally confirmed.
Sang-Yuep KIM Jun-ichi KANI Hideaki KIMURA
This paper presents a scheme that digitally cancels the unwanted phase components generated by the transmitter's laser and the receiver's local oscillator laser; such components place a substantial limit on the performance of coherent transceivers monolithically integrated with lasers in a photonic integrated circuit (PIC). Our cancellation proposal adopts the orthogonal polarization approach to provide a reference that is uncorrelated with the data signal. We elaborate on the principle of our proposal and its digital signal processing (DSP) algorithm. Experiments on a VCSEL with a linewidth of approximately 300MHz verify that our proposal can overcome the inherent phase noise limitations indicated by simulations and experiments. Our cancellation algorithm in conjunction with CMA-based polarization control is demonstrated and evaluated to confirm the feasibility of our proposal. The achievement of greatly relaxed laser linewidth will offer a significant benefit in offsetting the technical and cost requirements of coherent transceiver PICs with lasers. Therefore, our cancellation proposal is an enabling technology for the successful deployment of future coherent-based passive optical network (PON) systems.
Takeshi KUROSAKI Toshikazu HASHIMOTO Noboru ISHIHARA Yasuhiro SUZUKI Masahiro YANAGISAWA Hideaki KIMURA Makoto NAKAMURA Yuichi TOHMORI Kazutoshi KATO Yoshihiro KAWAGUCHI Yuji AKAHORI Yasufumi YAMADA Kuniharu KATO Hiromu TOBA Junichi YOSHIDA
This paper describes design techniques for suppressing crosstalk in an optical transceiver module using PLC-hybrid-integration technologies and for achieving burst-mode operation with high sensitivity and wide dynamic range using CMOS-IC technologies. An arrangement that reduces the electrical crosstalk to less than -100 dB was designed using three-dimensional electromagnetic field analysis. The configurations of a newly developed instantaneous-response CMOS LD driver circuit is also described and instantaneous-response CMOS receiver circuit techniques are reviewed. With these techniques, we have succeeded in building optical transceiver modules for ATM-PON systems using PLC-hybrid-integration and inexpensive standard CMOS-IC fabrication processes. Under full-duplex operation at 156 Mb/s, fabricated transceiver modules showed receiver sensitivity of better than -34 dBm and dynamic range of over 28 dB, which satisfy both the class-B and class-C specifications recommended by ITU-T (International Telecommunication Union-Telecommunication standardization sector) G983.1 for the optical transceiver module for an ONU (optical network unit).
Tomoaki YOSHIDA Hideaki KIMURA Shuichiro ASAKAWA Akira OHKI Kiyomi KUMOZAKI
We developed a compact, 16-channel integrated optical subscriber module for one-fiber bi-directional optical access systems. They can support more subscribers in a limited mounting space. For ultimate compactness, we created 8-channel integrated super-compact optical modules, 4-channel integrated limiting amplifiers, and 4-channel integrated LD drivers for Fast Ethernet. We introduce a new simulation method to analyze the electrical crosstalk that degrades sensitivity of the optical module. A new IC architecture is applied to reduce electrical crosstalk. We manufactured the optical subscriber module with these optical modules and ICs. Experiments confirm that the module offers a sensitivity of -27.3 dBm under 16-channel 125 Mbit/s simultaneous operation.
Yasumasa SUZAKI Masanobu OKAYASU Takeshi KUROSAKI Makoto NAKAMURA Yasuhiro SUZUKI Hideaki KIMURA Hiromu TOBA
We developed an optical transceiver diode (TRAD) module for bi-directional time-compression-multiplexing (TCM) transmission systems. A wavelength-insensitive structure as a receiver and a low-capacitance configuration in the module provide a high sensitivity. Stable switching of 156 Mbit/s NRZ burst signals between the transmitter and receiver modes is achieved. In addition, it is shown that optical module cost can be further reduced by using passive alignment on a Si bench.
Yasumasa SUZAKI Masanobu OKAYASU Takeshi KUROSAKI Makoto NAKAMURA Yasuhiro SUZUKI Hideaki KIMURA Hiromu TOBA
We developed an optical transceiver diode (TRAD) module for bi-directional time-compression-multiplexing (TCM) transmission systems. A wavelength-insensitive structure as a receiver and a low-capacitance configuration in the module provide a high sensitivity. Stable switching of 156 Mbit/s NRZ burst signals between the transmitter and receiver modes is achieved. In addition, it is shown that optical module cost can be further reduced by using passive alignment on a Si bench.
Norio TAMAKI Hideaki KIMURA Ryuichi WATANABE
Minimizing the guard time, Tguard, in the TCM-TDMA PDS scheme is essential in maximizing TCM transmission efficiency. As a replacement for the commonly adopted worst-case approach to TCM-TDMA PDS system estimation, this paper proposes a statistical approach. The level distributions of losses and n-th order Fresnel reflections are determined from published measurements. The proposed approach estimates the reflection of the optical access network.