Sumitomo Electric Industries, Limited

Sumitomo Wiring Systems, Limited

Autonetworks Technologies, Limited

Nippon Telegraph and Telephone Corporation

Daisuke Umehara

Satoshi Horihata

Shinichi Ishiko

Masahiro Morikura

Toshiya Hisada

Yasuhiro Yabuuchi

Takatoshi Sugiyama

Tetsuo Morita

Masaaki Tanaka

A power line communication system is provided in which the influence of the impulsive noise unexpectedly generated on a power line which is a communication medium can be reduced according to the characteristics of the impulsive noise by an existing method and power line communication can be realized without a hindrance. A transmitter is constituted by: a modulator for conveying a LIN data signal by a power line; a filter that allows a signal of a predetermined band to pass therethrough; and a sinusoidal wave outputter (sinusoidal wave in the figure). In contrast, the receiver is constituted by the sinusoidal wave outputter, the filter and a demodulator that performs demodulation. To the power line, a limiter that limits the amplitude of the propagating signal to a predetermined amplitude (reception signal amplitude) is connected.

Power line communication system

Provided is a wireless relay system that improves system throughput between terminal stations and flexibly makes system throughput variable with respect to short-term traffic fluctuations. In the wireless relay system, a plurality of relay stations relay communication between two terminal stations that perform random access. The terminal stations and the relay stations include a slot synchronization unit, a time synchronization unit, and a transmission unit. The slot synchronization unit synchronizes slot timing of a time slot indicating a unit time. The time synchronization unit performs time synchronization for synchronization of the slot timing. The transmission unit transmits a transmission packet to a wireless line in synchronization with the slot timing. A transmission right is allocated for at least one time slot to each of a plurality of groups which are configured so that a group of a terminal station or a relay station and a group of an adjacent terminal station or an adjacent relay station are different from each other. The transmission unit transmits the transmission packet to the wireless line only in a time slot in which the transmission right is allocated to the group to which the terminal station or the relay station belongs.

Relay station, wireless relay system, and access control method in the system that perform random access in accordance with transmission right

For voltage values (observed noise sequence) in an electronic power line (communication medium) which are obtained at a predetermined interval, initial values of noise characteristics based on a statistic of the observed noise sequence itself are decided by a moment method (Sto S), the noise characteristics (state transition probabilities and state noise power) for maximization of the likelihood of the observed noise sequence are obtained from the initial values by MAP (Maximum A Posteriori) estimation using a Baum-Welch algorithm (Sto S), a state sequence is estimated from the obtained noise characteristics, and an impulsive noise at each time point is detected.

Noise detection method, noise detection apparatus, simulation method, simulation apparatus, and communication system

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Kyoto, Japan

Daisuke Umehara