Patent
Optical transmission system for radio access and high frequency optical transmitter
Hiroyuki Sasai,Masaru Fuse +1 more
TLDR
In this paper, an optical branching portion branches the intensity-modulated optical signal and respectively outputs branched optical signals to radio base stations to obtain an RF signal by frequency-converting the IF signal.Abstract:
Modulators respectively modulate baseband signals into IF signals having different frequencies. A multiplexer multiplexes the IF signals. An electrical-optical converter intensity modulates the multiplexed IF signals into optical signals. A local oscillation signal source outputs a predetermined local oscillation signal. An external modulator intensity-modulates the optical signal using the local oscillation signal. An optical branching portion branches the intensity-modulated optical signal and respectively outputs branched optical signals to radio base stations. An optical-electrical converter converts the optical signal into an electric signal, to obtain an RF signal by frequency-converting the IF signal. An antenna only transmits a component having a desired radio frequency extracted in a band filter from the RF signal to a subscriber terminal. Frequency conversion from the IF signal to the RF signal is thus optically performed, whereby the frequency or electrical-optical converter is shared among the radio base stations.read more
Citations
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Patent
Wireless power transmission systems and methods
TL;DR: In this paper, a wireless base unit obtains a request for wireless power and determines a power requirement associated with a wireless field unit and compares the power requirement to a remaining power capacity of the base unit.
Patent
Optical fiber-based distributed antenna systems, components, and related methods for calibration thereof
TL;DR: In this paper, the authors present an indoor distributed antenna system (IDAS) to provide wireless communication services to clients inside a building or other facility, where the communications can be distributed between a head end unit (HEU) that receives carrier signals from one or more service or carrier providers and converts the signals to Radio-over-Fiber (RoF) signals for distribution over optical fibers to end points.
Patent
Systems, methods, and devices for increasing radio frequency (RF) power in distributed antenna systems
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Hybrid data transport for a virtualized distributed antenna system
TL;DR: In this paper, a distributed antenna system (DAS) consisting of a plurality of remote Digital Access Units (DAUs) located at a remote location is described, where each of the remote DAUs is coupled to each other and operable to transport digital signals between the plurality of Remote DAUs.
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Providing digital data services as electrical signals and radio-frequency (RF) communications over optical fiber in distributed communications systems, and related components and methods
Igor Berlin,William Patrick Cune,Jason Elliott Greene,Christian Heidler,James Arthur Register,Wolfgang Gottfried Tobias Schweiker +5 more
TL;DR: In this article, the authors describe a distributed communications system providing and supporting radio frequency (RF) communication services and digital data services, and related components and methods are disclosed, where RF communication services can be distributed over optical fiber to client devices, such as remote units for operation.
References
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Patent
Method and apparatus for interleaved optical single sideband modulation
TL;DR: In this article, an optical carrier notch filter is coupled to a port of the optical coupler, which separates the output into a transmitted signal that contains the optical carrier and a reflected signal that includes the interleaved optical single sideband signals.
Journal ArticleDOI
Full-duplex fiber-optic RF subcarrier transmission using a dual-function modulator/photodetector
TL;DR: In this article, an electroabsorption waveguide device is presented as a dual-function modulator/photodetector for application as a cost-effective full-duplex transceiver in radio-frequency (RF) fiber-optic links.
Patent
Optical communication system
TL;DR: In this paper, an optical communication system by which an optical axis is easily adjusted between a transmitting part and a receiving part was proposed. But the optical axis was not adjusted between the transmitting and receiving parts.
Patent
Optical modulation apparatus and method of controlling optical modulator
TL;DR: In this article, a low-frequency superimposing unit superimposes a prescribed lowfrequency signal on the modulator driving voltage signal, and an operating point controller controls the operating point of the optical modulator by detecting operating point drift.
Patent
System and method of high-speed transmission and appropriate transmission apparatus
TL;DR: In this paper, a high-speed optical transmission system is rendered independent of the type of transmitter or of signals sent to it if it comprises an adaptation unit (32) receiving the original optical pulses (30) and capable of generating corresponding pulsed signals of RZ type.