The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 19, 2026
Filed:
Jun. 23, 2021
Ntt, Inc., Tokyo, JP;
Masanori Nakamura, Musashino, JP;
Takeo Sasai, Musashino, JP;
Etsushi Yamazaki, Musashino, JP;
Yoshiaki Kisaka, Musashino, JP;
NTT, Inc., Tokyo, JP;
Abstract
A transmission apparatus causes a digital-to-analog conversion unit to perform digital-to-analog conversion on transmission signals pre-equalized by using a compensation filter, then converts electrical signals into optical signals, and outputs the optical signals. A receiving apparatus converts the received optical signals into received electrical signals, then performs analog-to-digital conversion, and demodulates the received signals. A scale estimation unit calculates a slope near an amplitude 0 in a correlation between an amplitude distribution of the pre-equalized transmission signals and an amplitude distribution of the received signals. A scale unit scales amplitude of the received signals on the basis of the calculated slope. A coefficient estimation unit calculates a filter coefficient of the compensation filter on the basis of the pre-equalized transmission signals and the scaled received signals. An output amplitude level determination unit determines output levels of the transmission signals from the digital-to-analog conversion unit on the basis of a correlation between distributions of amplitudes of non-pre-equalized and pre-equalized transmission signals.