Signal transmission apparatus and optical modem modulation method
First Claim
1. A modulation method for an optical modem, wherein the method runs on a processor of the optical modem, comprising:
- providing a signal to a light source;
receiving light reflected by an optical link when light output from the light source based on the provided input signal is reflected by the optical link;
determining an characteristic of the optical link using the reflected light; and
selecting a power level and a modulation method for each of a plurality of subcarriers in which optical signals are transmitted based on the determined characteristic of the optical link.
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Accused Products
Abstract
A modulation method of an optical modem and a signal transmission apparatus performing the method are disclosed. The modulation method of the optical modem includes an optical interface providing a signal to a light source, a photo detector receiving reflected light by an optical link when output light from the light source based on the provided signal is reflected by the optical link, the photo detector measuring and determining characteristics of the optical link using the reflected light, and the optical modem determining a power level and a modulation method for each subcarrier based on the characteristics of the optical link.
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Citations
17 Claims
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1. A modulation method for an optical modem, wherein the method runs on a processor of the optical modem, comprising:
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providing a signal to a light source; receiving light reflected by an optical link when light output from the light source based on the provided input signal is reflected by the optical link; determining an characteristic of the optical link using the reflected light; and selecting a power level and a modulation method for each of a plurality of subcarriers in which optical signals are transmitted based on the determined characteristic of the optical link. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A signal transmission apparatus comprising:
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a light source to emit an output light; an optical interface to provide a signal so that the light source emits the output light; an optical splitter to change an optical path of light reflected by an optical link when the output light emitted from the light source is reflected by the optical link; a photo detector unit comprising a photo detector to receive the light reflected by the optical link, transmitted from the optical splitter and to determine characteristics of the optical link; and an optical modem to select a power level and a modulation method for each of a plurality of OFDM subcarriers in which optical signals are transmitted based on the characteristics of the optical link. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A modulation method of an optical modem included in an optical line terminal (OLT) or an optical network unit (ONU) consisted of an orthogonal frequency division multiple access-passive optical network (OFDMA-PON), wherein the modulation method runs on a processor of the optical modem, the modulation method comprising:
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emitting, an output light; receiving light reflected by an optical link when the output light is reflected by the optical link; determining, using the reflected light, a length and a loss characteristic of an optical fiber included in the optical link through which the output light is transmitted; and controlling, a power level and a bit allocated to a subcarrier for an optical OFDM signal based on the length and the loss characteristic of the optical fiber. - View Dependent Claims (16, 17)
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Specification