Nuestros investigadores

Xabier Insausti Sarasola

Departamento
Departamento de Ingeniería Biomédica y Ciencias
Escuela de Ingenieros (TECNUN). Universidad de Navarra
Líneas de investigación
Teoría de la información, Esquemas de codificación y compresión para sistemas de comunicaciones, Computación distribuida en redes de sensores
Índice H
2, (Scopus, 11/07/2018)
3, (Google Scholar, 11/07/2018)

Publicaciones científicas más recientes (desde 2010)

Autores: Zárraga-Rodríguez, M.; Gutiérrez-Gutiérrez, Jesús, (Autor de correspondencia); Insausti, Xabier;
Revista: ENTROPY
ISSN 1099-4300  Vol. 21  Nº 10  2019  págs. 965
In this paper, we present a low-complexity coding strategy to encode (compress) finite-length data blocks of Gaussian vector sources. We show that for large enough data blocks of a Gaussian asymptotically wide sense stationary (AWSS) vector source, the rate of the coding strategy tends to the lowest possible rate. Besides being a low-complexity strategy it does not require the knowledge of the correlation matrix of such data blocks. We also show that this coding strategy is appropriate to encode the most relevant Gaussian vector sources, namely, wide sense stationary (WSS), moving average (MA), autoregressive (AR), and ARMA vector sources.
Autores: Gutiérrez-Gutiérrez, Jesús, (Autor de correspondencia); Villar-Rosety, F. M.; Zárraga-Rodríguez, M.; et al.
Revista: IEEE COMMUNICATIONS LETTERS
ISSN 1089-7798  Vol. 23  Nº 5  2019  págs. 773 - 776
In this letter, we give a low-complexity analog linear coding scheme for transmitting finite-length data blocks of asymptotically wide sense stationary (AWSS) autoregressive (AR) sources through additive white Gaussian noise (AWGN) channels.
Autores: Gutiérrez-Gutiérrez, Jesús, (Autor de correspondencia); Zárraga-Rodríguez, M.; Villar-Rosety, F. M.; et al.
Revista: ENTROPY
ISSN 1099-4300  Vol. 20  Nº 6  2018 
In this paper, we give upper bounds for the rate-distortion function (RDF) of any Gaussian vector, and we propose coding strategies to achieve such bounds. We use these strategies to reduce the computational complexity of coding Gaussian asymptotically wide sense stationary (AWSS) autoregressive (AR) sources. Furthermore, we also give sufficient conditions for AR processes to be AWSS.
Autores: Gutiérrez-Gutiérrez, Jesús, (Autor de correspondencia); Zárraga-Rodríguez, M.; Insausti, Xabier;
Revista: SENSORS
ISSN 1424-8220  Vol. 18  Nº 4  2018 
In this paper, we compare six known linear distributed average consensus algorithms on a sensor network in terms of convergence time (and therefore, in terms of the number of transmissions required). The selected network topologies for the analysis (comparison) are the cycle and the path. Specifically, in the present paper, we compute closed-form expressions for the convergence time of four known deterministic algorithms and closed-form bounds for the convergence time of two known randomized algorithms on cycles and paths. Moreover, we also compute a closed-form expression for the convergence time of the fastest deterministic algorithm considered on grids.
Autores: Gutiérrez-Gutiérrez, Jesús, (Autor de correspondencia); Zárraga-Rodríguez, M.; Crespo, Pedro M.; et al.
Revista: ENTROPY
ISSN 1099-4300  Vol. 20  Nº 9  2018  págs. 719
Autores: Insausti, Xabier; Crespo, Pedro M.; Gutiérrez-Gutiérrez, Jesús; et al.
Revista: IEEE COMMUNICATIONS LETTERS
ISSN 1089-7798  Vol. 22  Nº 9  2018  págs. 1754 - 1757
In this letter, we design a low-latency, low-complexity, and low-transmission power analog linear coding scheme to estimate the finite-length data blocks under a mean-square-error (distortion) criterion. The proposed scheme is based on the analog linear coding and the discrete Fourier transform. A remarkable feature of our scheme is that it does not require knowing the correlation matrix of the data blocks, and therefore, it can be used even if the correlation matrix changes slowly with time.
Autores: Insausti, Xabier; Saez, A.; Crespo, Pedro M.;
Revista: WIRELESS NETWORKS
ISSN 1572-8196  2017  págs. 1 - 9
This paper proposes a novel scheme for the slow block fading Gaussian multiple access relay channel inspired by the compute-and-forward (CoF) relaying strategy. The CoF relaying strategy exploits interference to obtain significantly higher rates between users in a network by decoding linear functions of the transmitted messages. Unlike other approaches in the literature, our approach is valid for any number of transmitters and, most importantly, it only requires channel state information at the receiver side, while it still attains similar or higher rates than the other approaches found in the literature
Autores: Gutiérrez-Gutiérrez, Jesús, (Autor de correspondencia); Zárraga-Rodríguez, M.; Insausti, Xabier;
Revista: ENTROPY
ISSN 1099-4300  Vol. 19  Nº 554  2017 
In this paper, we present upper bounds for the rate distortion function (RDF) of finite-length data blocks of Gaussian wide sense stationary (WSS) sources and we propose coding strategies to achieve such bounds. In order to obtain those bounds, we previously derive new results on the discrete Fourier transform (DFT) of WSS processes.
Autores: Gutiérrez-Gutiérrez, Jesús, (Autor de correspondencia); Zárraga-Rodríguez, M.; Insausti, Xabier; et al.
Revista: ENTROPY
ISSN 1099-4300  Vol. 19  Nº 95  2017 
In the present paper, we obtain a result on the rate-distortion function (RDF) of wide sense stationary (WSS) vector processes that allows us to reduce the complexity of coding those processes. To achieve this result, we propose a sequence of block circulant matrices. In addition, we use the proposed sequence to reduce the complexity of filtering WSS vector processes.
Autores: Insausti, Xabier, (Autor de correspondencia); Gutiérrez-Gutiérrez, Jesús; Zárraga-Rodríguez, M.; et al.
Revista: SENSORS
ISSN 1424-8220  Vol. 17  Nº 1702  2017 
In a network, a distributed consensus algorithm is fully characterized by its weighting matrix. Although there exist numerical methods for obtaining the optimal weighting matrix, we have not found an in-network implementation of any of these methods that works for all network topologies. In this paper, we propose an in-network algorithm for finding such an optimal weighting matrix.
Autores: Insausti, Xabier; Camaro, F.; Crespo, Pedro M.; et al.
Revista: IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING
ISSN 1932-4553  Vol. 7  Nº 2  2013  págs. 163 - 174
In this paper, we design a practical power-efficient algorithm for Wireless Sensor Networks (WSN) in order to obtain, in a distributed manner, the projection of an observed sampled spatial field on a subspace of lower dimension. This is an important problem that is motivated in various applications where there are well defined subspaces of interest (e. g., spectral maps in cognitive radios). As opposed to traditional Gossip Algorithms used for subspace projection, where separation of channel coding and computation is assumed, our algorithm combines binary finite-length Computational Coding and a novel gossip-like protocol with certain communication rules, achieving important savings in convergence time and yielding a decrease in energy consumption as the density of the network increases, as compared to a separation scheme.

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