Search results for " Multipath"
showing 3 items of 3 documents
A Novel Method of Distance Measurement Based on Pulse Position Modulation and Synchronization of Chaotic Signals Using Ultrasonic Radar Systems
2009
This paper deals with a novel method of transmission and receipt of a signal based on both the property of two chaotic systems generating the same chaotic signal when they are synchronized and the property of pulse position modulation (PPM) to be insensitive to the distortions of the transmission channel. The method is discussed in the context of ultrasonic radar systems, in which the transmitter and receiver, which consist of ultrasonic sensors, are near each other, and the received signal consists of the transmitted signal reflected by an obstacle. A reference sinusoidal signal is superimposed to a chaotic signal generated by a master chaotic system, and the whole signal is modulated acco…
Signal Quality Monitoring: Correlation mask based on Ratio Test metrics for multipath detection
2009
In any measurement process, the observation is error affected: calibration and careful measuring procedures can reduce the error components but are unable to completely eliminate them. The capability to monitor and to detect any disturbances on the spreading sequences transmitted by the satellites is then of primary importance. Quality Control techniques based on a modified tracking architecture, which provides a certain number of correlator outputs, are analysed in this paper. Such outputs are used to build a metric used to monitor in real-time the reliability of the signal being tracked. In literature, several definitions of metrics can be found. The mainly used metrics are based on the f…
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. …