Showing papers by "José Tribolet published in 1984"
TL;DR: In this paper, the equivalence among MEM, AR modeling, and predictive estimation is established, and a new classification method for the least-squares AR spectral estimation methods is introduced: the global and local minimization methods.
16 citations
01 Mar 1984
TL;DR: This study was prompted by direct observation of the structure of the excitation, where patterns of pulses may be found which are associated with phase-correcting mechanisms of the LPC impulse response, and developed a new multipulse technique based on a special ARMA model formed by cascading an all-pole with anall-pass network.
Abstract: Multipulse LPC, as is often designated the model proposed by Atal and Remae, has been directed towards 9.6 kb/s speech coding. However, at such bit rate, the speech quality is not yet generally acceptable. This paper has a double purpose - one is to investigate the role of short-time phase in multipulse LPC. The other is to look for different modelling structures to be used with this method. This study was prompted by direct observation of the structure of the excitation, where patterns of pulses may be found which are associated with phase-correcting mechanisms of the LPC impulse response. Consequently, a new multipulse technique was developed, based on a special ARMA model formed by cascading an all-pole with an all-pass network. This new model will be referred to as the MAPAP (Multipulse All-Pole All-Pass) method. Another one was tried in which the synthetic speech is formed by combination of several MAPAP signals. We therefore denoted it "multichannel multipulse" method. The potential advantages of both single and multichannel models seem rather promising.
15 citations
TL;DR: This paper deals with the problems associated with full-duplex scrambled speech communications over analog two-wire telephone networks by analyzing the situation in which the two users speak at the same time and each should hear the other.
Abstract: This paper deals with the problems associated with full-duplex scrambled speech communications over analog two-wire telephone networks. The goal is not to describe particular scrambling systems or methods, but to analyze the situation in which the two users speak at the same time and each should hear the other. Current telephone scrambling devices preclude this feature. A general half-duplex scrambling model is described as a base to the discussion of pseudo- and true full-duplex communications. Finally, a novel true full-duplex scrambling architecture based on a paper by Cox and Tribolet [11] is presented.
4 citations
19 Mar 1984
TL;DR: The purpose of this paper is to address, within a very general framework, the problem of choosing the "best" Spectral Analysis technique from within a set of available methods and for a given class of data signals, according to some pre- -specified criteria.
Abstract: The area of Spectral Analysis has grown considerably in recent years. A multitude of methods are now available and yet no tools have been developed to guide the naive user in the difficult process of choosing an adequate technique for his particular data problem. The purpose of this paper is to address, within a very general framework, the problem of choosing the "best" Spectral Analysis technique, from within a set of available methods and for a given class of data signals, according to some pre- -specified criteria. The foundations of the evaluation framework we propose are laid out in this paper. An in-depth study based on a particular evaluation methodology is reported, using a goodness of fit criterion derived from the works of Kedem and Slud [4,5]. Examples of this approach will be given for several data cases and several spectral analysis methods.
1 citations