Search results for "modems"

showing 2 items of 2 documents

FLUMO: FLexible Underwater MOdem

2019

The last years have seen a growing interest in underwater acoustic communications because of its applications in marine research, oceanography, marine commercial operations, the offshore oil industry and defense. High-speed communication in the underwater acoustic channel has been challenging because of limited bandwidth, extended multipath, refractive properties of the medium, severe fading, rapid time variation and large Doppler shifts. In this paper, we show an implementation of a flexible Software-Defined Acoustic (SDA) underwater modem, where modulation parameters are completely tunable to optimize performance. In particular, we develop the system architecture following two key ideas. …

extended multipathSDAOrthogonal frequency-division multiplexingComputer sciencemarine commercial operationsUnderwater; acoustic ; software defined ; modem; JANUS; SDA; FSK; RedPitaya; WatermarkSettore ING-INF/01 - ElettronicaacousticFSKmodulate signalsDemodulationcontrolled testbedsUnderwaterunderwater acoustic channelOFDMFrequency-shift keyingFLUMOunderwater acoustic communicationsBandwidth (signal processing)Frequency shift keyingflexible Software-Definedoffshore oil industrysoftware definedRedPitayaflexible underwater MOdemmodulated signalsmodulation parameterstunable systemrefractive propertiesMultipath propagationStandardssystem architectureDoppler shiftsunderwater acoustic communicationhigh-speed communicationflexible systemElectronic engineeringDoppler shiftFadingoceanographymodemSettore ING-INF/03 - Telecomunicazionirapid time variationField programmable gate arraysmarine researchmodemsJANUSWatermarkSystems architectureUnderwater
researchProduct

A Channel-Aware Adaptive Modem for Underwater Acoustic Communications

2021

Acoustic underwater channels are very challenging, because of limited bandwidth, long propagation delays, extended multipath, severe attenuation, rapid time variation and large Doppler shifts. A plethora of underwater communication techniques have been developed for dealing with such a complexity, mostly tailoring specific applications scenarios which can not be considered as one-size-fits-all solutions. Indeed, the design of environment-specific solutions is especially critical for modulations with high spectral efficiency, which are very sensitive to channel characteristics. In this paper, we design and implement a software-defined modem able to dynamically estimate the acoustic channel c…

software radioGeneral Computer ScienceSettore ING-INF/03 - TelecomunicazioniOrthogonal frequency-division multiplexingComputer scienceBandwidth (signal processing)General EngineeringChannel estimationData_CODINGANDINFORMATIONTHEORYChannel estimation JANUS modems OFDM software radio underwater communication watermarkTK1-9971Delay spreadmodemsJANUSInterference (communication)underwater communicationModulationElectronic engineeringGeneral Materials ScienceElectrical engineering. Electronics. Nuclear engineeringUnderwater acoustic communicationMultipath propagationOFDMCommunication channelIEEE Access
researchProduct