Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 10 of 10 for “"time-hopping"”.
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Mitigating radar interference via time hopping
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2024-05-01
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Slow frequency and time hopping in wireless communication
… in the scheme called SFH/TDMA (Slow Frequency Hopping/Time Division Multiple Access). Comparing the performance of SFH/TDMA with that of CDMA (Code Division Multiple Access) is a problem of both practical and theoretical interest. We contribute to the understanding of the problem by comparing a …
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Channel-coded time-hopping and direct-sequence ultrawideband systems
… channel estimation. Then the z-domain Discrete Time Transfer Function (DTTF) of UWB channels is derived based on the specifications presented in the preceding sections. This transfer function forms the basis of the proposed memory-efficient implementation of the equalizer advocated. Furthermore, …
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Simulation and analysis of a time hopping spread spectrum communication system
… access systems. Direct sequence and frequency hopping systems have been the primary spread spectrum techniques used in practice. One technique which has not received much attention until recently is time hopping. In time hopping, a symbol is transmitted at a random position within the symbol …
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Enhancing the bit error rate performance of ultra wideband systems using time-hopping pulse position modulation in multiple access environments
… the performance of PPM system, combined with Time Hopping Spread Spectrum (THSS) multiple access technique is evaluated in an asynchronous multiple access free space environment. The multiple access interference is first assumed to be a zero mean Gaussian random process to simulate the …
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Data transmission by frequency-hopped multilevel frequency shift keying
… systems. It is a combination of frequency hopping and time hopping. In this system many users share a common frequency band using code division multiplexing. Each user is assigned an address and the message is modulated into the address. The receiver, knowing the address, decodes the …
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Adaptive detection in ultrawide bandwidth wireless communication systems
… UWB system, namely the hybrid direct-sequence time-hopping (DS-TH) UWB system. This novel pulse-based UWB system is capable of inheriting the advantages of both the pure direct-sequence (DS)-UWB and pure time-hopping (TH)-UWB systems, while avoiding their disadvantages. Furthermore, this hybrid …
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Analysis of Lightweight Cryptographic Primitives
… range, but is costly enough in terms of memory, time, and energy consumption that some devices opt to use no security. Short development and a strong drive to market also contribute to a lack in security. Recent work in lightweight cryptography has analyzed the suitability of custom protocols …
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Synchronization in Impulse Based Ultra Wideband Systems
… using various metrics that include time of arrival and BER measurements. A comprehensive study of the synchronization problem using Probability of False Alarm is limited. The current thesis attempts to characterize the synchronization problem using Probability of False Alarm and …
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On the Development of a Very Fast Simulator for TH-UWB Systems = Sobre el Desarrollo de un Simulador Rápido para los Sistemas TH-UWB
Impulse Radio-Time Hopping-Ultra Wideband (IR-TH-UWB) is a relatively new technology that might have a big effect on improving wireless communication. Multipath resistance, low power, high capacity, coexistence with other systems, ability of penetrating walls are some of the characteristics that …