547 research outputs found
Cross Z-Complementary Pairs for Optimal Training in Spatial Modulation Over Frequency Selective Channels
The contributions of this article are twofold: Firstly, we introduce a novel class of sequence pairs, called “cross Z-complementary pairs (CZCPs),” each displaying zero-correlation zone (ZCZ) properties for both their aperiodic autocorrelation sums and crosscorrelation sums. Systematic constructions of perfect CZCPs based on selected Golay complementary pairs (GCPs) are presented. Secondly, we point out that CZCPs can be utilized as a key component in designing training sequences for broadband spatial modulation (SM) systems. We show that our proposed SM training sequences derived from CZCPs lead to optimal channel estimation performance over frequency-selective channels
Spread Spectrum Modulation with Grassmannian Constellations for Mobile Multiple Access Underwater Acoustic Channels
The objective of this study is to evaluate Grassmannian constellations combined with a spread spectrum multiple access scheme for underwater acoustic mobile multiple access communication systems. These communication systems enable the coordination of a fleet of Autonomous Underwater Vehicles (AUVs) from a surface or bottom control unit, e.g., a boat. Due to its robustness against phase rotation, the demodulator of Grassmannian constellations uses non-coherent detection, and the main advantage of such modulation lies in the spectrum efficiency gain with respect to conventional differential modulation. The communication system under study in this paper consists of (i), at the transmitter side, a Grassmannian modulation used in an orthogonal spread spectrum multiple access scheme called Multiuser Hyperbolic Frequency Modulation (MU-HFM) and (ii), at the receiver side, a non-coherent array decoder. The modulation and demodulation are presented as well as the considered spreading sequences. Finally, performances of the proposed transmission scheme are evaluated over replayed underwater acoustic channel responses collected at sea by a multi-sensor acoustic acquisition system.Spread Spectrum Modulation with Grassmannian Constellations for Mobile Multiple Access Underwater Acoustic ChannelspublishedVersio
Design of a simulation platform to test next generation of terrestrial DVB
Digital Terrestrial Television Broadcasting (DTTB) is a member of our daily life
routine, and nonetheless, according to new users’ necessities in the fields of
communications and leisure, new challenges are coming up. Moreover, the current Standard is not able to satisfy all the potential requirements.
For that reason, first of all, a review of the current Standard has been performed
within this work. Then, it has been identified the needing of developing a new
version of the standard, ready to support enhanced services, as for example
broadcasting transmissions to moving terminals or High Definition Television
(HDTV) transmissions, among others.
The main objective of this project is the design and development of a physical
layer simulator of the whole DVB-T standard, including both the complete transmission and reception procedures. The simulator has been developed in Matlab. A detailed description of the simulator both from a functional and an architectural point of view is included. The simulator is the base for testing any
possible modifications that may be included into the DVB-T2 future standard. In fact, several proposed enhancements have already been carried out and their performance has been evaluated. Specifically, the use of higher order modulation schemes, and the corresponding modifications in all the system
blocks, have been included and evaluated. Furthermore, the simulator will allow
testing other enhancements as the use of more efficient encoders and
interleavers, MIMO technologies, and so on.
A complete set of numerical results showing the performance of the different parts of the system, are presented in order to validate the correctness of the implementation and to evaluate both the current standard performance and the
proposed enhancements.
This work has been performed within the context of a project called FURIA,
which is a strategic research project funded by the Spanish Ministry of Industry, Tourism and Commerce. A brief description of this project and its consortium
has been also included herein, together with an introduction to the current situation of the DTTB in Spain (called TDT in Spanish)
Design of a simulation platform to test next generation of terrestrial DVB
Digital Terrestrial Television Broadcasting (DTTB) is a member of our daily life
routine, and nonetheless, according to new users’ necessities in the fields of
communications and leisure, new challenges are coming up. Moreover, the current Standard is not able to satisfy all the potential requirements.
For that reason, first of all, a review of the current Standard has been performed
within this work. Then, it has been identified the needing of developing a new
version of the standard, ready to support enhanced services, as for example
broadcasting transmissions to moving terminals or High Definition Television
(HDTV) transmissions, among others.
The main objective of this project is the design and development of a physical
layer simulator of the whole DVB-T standard, including both the complete transmission and reception procedures. The simulator has been developed in Matlab. A detailed description of the simulator both from a functional and an architectural point of view is included. The simulator is the base for testing any
possible modifications that may be included into the DVB-T2 future standard. In fact, several proposed enhancements have already been carried out and their performance has been evaluated. Specifically, the use of higher order modulation schemes, and the corresponding modifications in all the system
blocks, have been included and evaluated. Furthermore, the simulator will allow
testing other enhancements as the use of more efficient encoders and
interleavers, MIMO technologies, and so on.
A complete set of numerical results showing the performance of the different parts of the system, are presented in order to validate the correctness of the implementation and to evaluate both the current standard performance and the
proposed enhancements.
This work has been performed within the context of a project called FURIA,
which is a strategic research project funded by the Spanish Ministry of Industry, Tourism and Commerce. A brief description of this project and its consortium
has been also included herein, together with an introduction to the current situation of the DTTB in Spain (called TDT in Spanish)
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