Delay spread statistics in simulcast transmission system

Alshamali, Ahmad; Al-Oqleh, M.S.

doi:10.1049/el:20020651

Cited by 6 publications

(5 citation statements)

References 4 publications

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“…These two values generally quantify the time dispersion properties of multipath channel. , · …(1) A simulcast radio system that consists of two or more base stations with overlapped coverage was introduced and closedform equations for the statistics of the delay spread in a simulcast mobile radio system were derived [16]. A receiver in the overlap areas may receive two or more signals with different delays.…”

Section: Feasibility Analysis Of Multiple Sendersmentioning

confidence: 99%

Ripple flooding in wireless sensor networks

Yuan

Yang

Kim

2011

Proceedings of the 8th ACM Symposium on Performance Evaluation of Wireless Ad Hoc, Sensor, and Ubiquitous Networks

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Flooding is a fundamental operation to support route discovery and time synchronization in wireless sensor networks. A simple flooding causes the broadcast storm problem and leads to long latency to complete the broadcast. This paper presents the Ripple flooding scheme (RFS) for wireless sensor networks (WSNs). The proposed scheme improves the convergence speed of flooding by using a synchronized packet rebroadcasting instead of using a CSMA (Carrier Sense Multiple Access) MAC based packet rebroadcasting. We analyse the multipath delay spread feasibility on a receiver for the packets from multiple senders. The theoretical upper bound of packet loss rate (PLR) is less than 13%. The experimental result shows the same as the PLR of the theoretical analysis. We implement the RFS on the sensor node with the MSP430 microcontroller and the CC2420 transceiver and evaluate the major performance metrics including the convergence time and the reliability in various network scales and densities. The convergence time is at least 3.5 times faster than the CSMA MAC based flooding in the dense network environments. The transmission reliability of the RFS is slightly better than the reliability of the CSMA MAC based flooding because of the implicit overhearing scheme provided by the RFS.

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Section: Feasibility Analysis Of Multiple Sendersmentioning

confidence: 99%

Ripple flooding in wireless sensor networks

Yuan

Yang

Kim

2011

Proceedings of the 8th ACM Symposium on Performance Evaluation of Wireless Ad Hoc, Sensor, and Ubiquitous Networks

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“…Following our approach presented in [11], the probability density function of the local rms delay spread can be found by performing the required random variables transformation on Eq. (3):…”

Section: Pdf and Cdf Of Local Rms Delay Lmentioning

confidence: 99%

“…The statistical properties of the rms delay spread for simulcast and similar environments have been studied for non-dispersive channel [7][8][9] and for dispersive channel considering lognormal fading [10] and Rayleigh fading [11,12]. In this paper we have studied the statistical properties of the rms delay spread for a simple simulcast transmission system that contains two base stations.…”

Section: Introductionmentioning

confidence: 99%

Statistical properties of the delay spread in a two path mobile radio with Nakagami fading channel

Alshamali

Al-Oqleh

2005

AEU - International Journal of Electronics and Communications

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“…Paralelamente, desenvolviam-se modelos de canal de RF cada vez mais precisos, uma tarefa que se iniciou em 1963 com Bello [11] e se estende até os dias de hoje [12], [13], [14] e [15]. Já em 1967, Saltzberg [16] alertava para a importância em lidar com o problema da interferência entre símbolos ocasionada pela dispersão do sinal.…”

Section: Breve História Do Ofdmunclassified

“…Repetiremos este truque mais adiante. 12 Não confunda com os símbolos de m bits com os quais estamos lidando nesta seção.…”

Section: Taxa Do Códigounclassified

Equalização pré-FFT de sistemas baseados em orthogonal frequency-division multiplexing.

Acácio¹

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AGRADECIMENTOSAo amigo e orientador Prof. Dr. Vítor Heloiz Nascimento pelo incentivo e orientação, bem como pelos longos períodos dedicados a esta tarefa em detrimento de seus próprios afazeres.Aos meus pais pela paciência que tiveram em meus momentos de exaltação durante as várias etapas que tiveram de ser superadas até a conclusão desta dissertação.A Itautec Philco S.A., empresa em que trabalho, pelas horas e esforços que me permitiram desviar a este trabalho. ABSTRACTThis dissertation deals with time-domain equalization of digital communications systems based on orthoghonal frequency-division multiplexing (OFDM), usually referred as pre-FFT equalization in the technical literature. Such systems were originally designed to require no time equalization but can profit from its use, as is shown in this work. An uncoded simulator of the OFDM-based European system for terrestrial digital television transmission, the digital video broadcasting (DVB-T), was implemented in software. Many simulations were run to compare the performance of the traditional DVB-T reception method with the equalized version proposed. Several digital signal processing techniques were used to simulate as diverse fenomena as: generation of the source signal, effect of multipath communications channels, presence of additive white Gaussian noise, LMS (Least Mean Square) equalization, among others. In order to develop a solid base, the work includes mathematical studies about the general OFDM theory, models of communications channels and the basic principle of operation of the LMS algorithm. Since the DVB-T was used as a practical study case, a technical description of the system is presented, in which many problems and aspects about its generation and reception are discussed. To provide the reader with a historical and technological insight on the subject, this work also includes a summary of the landmarks in the development of the OFDM since the first experiments.

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Delay spread statistics in simulcast transmission system

Cited by 6 publications

References 4 publications

Ripple flooding in wireless sensor networks

Ripple flooding in wireless sensor networks

Statistical properties of the delay spread in a two path mobile radio with Nakagami fading channel

Equalização pré-FFT de sistemas baseados em orthogonal frequency-division multiplexing.

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