2002 International Telecommunications Symposium

"This paper presents a performance analysis of two QPSK detection schemes for flat Rayleigh fading channels. Closed-form expressions for the bit error probability of both schemes are obtained. It is shown that they present the same error probability and a complexity analysis is carried out to determine the best scheme in terms of the number of operations...

"Lately, the actual statistical behavior of LAN/WAN trafc is being confronted against classical Markovian-based models. Many theoretical and simulation work have been done to date. Almost all such disagreements are based on software simulations. In this article we show a simple yet reliable tool that can emulate in an efcient manner many LAN/WAN trafc...

"The design of a reliable multicast protocol using a methodology based on performance analysis techniques and genetic algorithms is presented. The main objective of this work is to find a faster implementation with lower costs from the HW/SW Codesign technique. The process requires a choice between the tasks to be implemented in hardware and those to be...

"In this paper the emerging role of Java in Telecommunications is surveyed. In particular, attention is drawn to the advantages and disadvantages of the language for application and service development. The JINI framework for the construction of robust and self-configuring distributed systems is briefly described. Replication (of processes/data) is a...

"Generally, real-time applications based on UDP protocol generate large volumes of data and are not sensitive to network congestion. In contrast, TCP traffic is considered \u201cwell-behaved\u201d because it prevents the network from congestion by means of closed- loop control of packet-loss and round-trip-time. The integration of both sorts of traffic...

"This article investigates pattern sequences for Direct Sequence Code Division Multiple Access (DS-CDMA) spread spectrum communication of image watermarks. The problem is stated and three choices of sequence generation are proposed, namely: traditional pseudorandom generation, deterministic sequences from Walsh and Hadamard basis, and generation by...

"Nowadays, data security is an important issue in telecommunication network to be considered in its implementation and operation. This paper presents the GODZUK cryptographic algorithm in a civilian and military mobile communication applications, as a possible standards chosen by 3GPP for the third generation of cellular telephony and by the Brazilian...

"We introduce a method for audio-integrity verification based on a combination of watermarking and fingerprinting. The fingerprint is a sequence of symbols (“audio descriptor units”) that enables one to identify an audio signal Integrity verification is performed by embedding the fingerprint into the audio signal itself by means of a watermark. The...

"This paper establishes the condition for the Rocha-Massey homophonic coding scheme to have lower redundancy than the Jendal-Kuhn-Massey scheme, for sources whose symbol probabilities are rational numbers. The condition is that each probability, in the probability distribution of the symbols of a discrete memoryless source, must contain only countably...

"The first aim of this work is to extend some recent and important results on the equivalence between Shalvi-Weinstein and Constant Modulus methods, by including the so called Generalized Constant Modulus criterion and its corresponding stochastic algorithm. Such method avoid the power restriction on the optimization process, based on the idea that any...