Nippon Telegraph and Telephone Corporation

Noriko Iiyama

Masamichi Fujiwara

Junichi Kani

Takeshi Sakamoto

Satoshi Shigematsu

Jun Terada

Nobuyuki Tanaka

Naotaka Shibata

Hiroo Suzuki

Jun-ichi Kani

Shigeru Kuwano

Jun-Ichi Kani

A communication device includes: a MAC unit that processes a main signal including a payload, and determines a communication timing of the main signal; a communication unit that performs, based on the communication timing, at least one of transmission processing for E/O converting the main signal acquired from the MAC unit, and transmitting the main signal to a communication counterpart device, and reception processing for O/E converting the main signal received from the communication counterpart device; a main signal transmission line through which the main signal is transmitted between the MAC unit and the communication unit; and a control information transmission line that is provided separately from the main signal transmission line, and through which communication timing data that is data indicating the communication timing is transmitted from the MAC unit to the communication unit.

Communication apparatus and communication method

An ADC () in an optical receiver () generates a sample signal composed of time series samples by oversampling a received signal that is an electrical signal converted from an optical signal by a light receiving unit (). A symbol timing detection unit () of a DSP unit () detects a symbol timing in the sample signal. When it is determined that a symbol timing is appearing at a longer interval than a predetermined interval based on this detection result, a symbol timing adjusting unit () skips one or more samples included in the sample signal to read out samples at the predetermined interval, while when it is determined that the symbol timing is appearing at a shorter interval than the predetermined interval, the symbol timing adjusting unit inserts the same samples as one or more samples included in the sample signal immediately after the one or more samples to read out the samples at the predetermined interval.

Signal processing apparatus and optical receiver

A signal processing device included in an optical reception device configured to receive a burst optical signal transmitted by one of a plurality of optical transmission devices, includes a symbol timing detecting unit configured to detect a symbol timing based on sample signals obtained by oversampling the burst optical signal converted into an electric signal with a sampling rate higher than a symbol rate, an adaptive equalization filter unit configured to perform an equalization process on the sample signals, and a timing matching unit configured to match timing such that, when the adaptive equalization filter unit takes in the sample signals, one of the taken-in sample signals corresponding to the symbol timing is given to a tap of which a tap coefficient has a maximum value among taps included in the adaptive equalization filter unit.

Signal processing apparatus and optical receiving apparatus

An OLT of a PON obtains information on discontinuous reception of a UE from a BBU of LTE, and adjusts a sleep start timing and a sleep cycle of an ONU so that a recovery waiting time in the OLT with respect to downlink data transmitted from the BBU to the UE can be minimized.

Optical wireless access system

A communication system and method comprising a higher-network apparatus and a lower-network apparatus connected through a PON system, which transfers uplink data from the lower-network apparatus to the higher-network apparatus at high speed so as to meet severe conditions required for a delay time between the higher-network apparatus and the lower-network apparatus. The method including a scheduling execution process in which a higher-network apparatus performs scheduling for uplink communication from each of the lower-network apparatus to the device itself and an uplink data transmission permission process in which the higher-network apparatus calculates a transmission time and a transmission permission amount of uplink data transmitted from an ONU to OLT based on the scheduling for uplink communication and notifies the OLT.

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Tokyo, Japan

Noriko Iiyama