公开(公告)号：US20200028586A1

公开(公告)日：2020-01-23

申请号：US16497464

申请日：2018-03-26

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Seiji OKAMOTO ,  Yoshiaki KISAKA ,  Kengo HORIKOSHI ,  Mitsuteru YOSHIDA ,  Masahiro SUZUKI

IPC: H04B10/079 ,  H04J14/06

Abstract: A signal-to-noise ratio (SNR) estimation method includes an optical signal transmission step of inserting at least one pair of signal sequences into transmission data and transmitting the transmission data into which the at least one pair of signal sequences is inserted, a signal sequence extraction step of extracting the at least one pair of signal sequences from a received signal obtained by receiving the transmitted transmission data, an inner product calculation step of calculating an inner product value of the extracted at least one pair of signal sequences, a reception power calculation step of calculating reception power of the extracted at least one pair of signal sequences, and an SNR calculation step of calculating an SNR of the at least one pair of signal sequences on the basis of the calculated inner product value and the calculated reception power.

公开(公告)号：US20180175830A1

公开(公告)日：2018-06-21

申请号：US15553909

申请日：2017-01-16

Applicant: NTT ELECTRONICS CORPORATION ,  NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yasuharu ONUMA ,  Etsushi YAMAZAKI ,  Kazuhito TAKEI ,  Osamu ISHIDA ,  Kengo HORIKOSHI ,  Mitsuteru YOSHIDA ,  Yoshiaki KISAKA ,  Masahito TOMIZAWA

IPC: H03H17/02 ,  H04L7/00

CPC classification number: H03H17/0227 ,  H03H17/0213 ,  H03H17/0275 ,  H03H17/0685 ,  H03H2017/0214 ,  H03H2017/0245 ,  H03H2017/0247 ,  H03H2017/0298 ,  H04L7/0029 ,  H04L7/005 ,  H04L7/0087

Abstract: A parallel transfer rate converter inputs first parallel data with number of samples being S1 pieces in synchronism with a first clock, and outputs second parallel data with number of samples being S2=S1×(m/p) pieces (p is an integer equal to or larger than 1) in synchronism with a second clock having a frequency which is p/m times of a frequency of the first clock. A convolution operation device inputs the second parallel data in synchronism with the second clock, generates third parallel data with number of samples being S3=S2×(n/m) pieces (S3 is an integer equal to or larger than 1) by executing a convolution operation with a coefficient indicating a transmission characteristic to the second parallel data, and outputs the third parallel data in synchronism with the second clock.