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Sueli Irene Rodrigues Costa

Publications and source records attributed to Sueli Irene Rodrigues Costa.

5 recordsLinked to original sources

Construction $C^\star$ from Self-Dual Codes

Construction $C^\star$ was recently introduced as a generalization of the multilevel Construction C (or Forney's code-formula), such that the coded levels may be dependent. Both constructions do not produce a lattice in general, hence the central idea of this paper is to present a 3-level lattice Construction $C^\star$ scheme that admits an efficient nearest-neighborhood decoding. In order to achieve this objective, we choose coupled codes for levels 1 and 3, and set the second level code C2 as an independent linear binary self-dual code, which is known to have a rich mathematical structure among families of linear codes. Our main result states a necessary and sufficient condition for this construction to generate a lattice. We then present examples of efficient lattices and also non-lattice constellations with good packing properties.

cs.IT↗

Multilevel constructions: coding, packing and geometric uniformity

Lattice and special nonlattice multilevel constellations constructed from binary codes, such as Constructions A, C, and D, have relevant applications in Mathematics (sphere packing) and in Communication (multi-stage decoding and efficient vector quantization). In this work, we explore some properties of Construction C, in particular its geometric uniformity. We then propose a new multilevel construction, inspired by bit interleaved coded modulation (BICM), that we call Construction C*. We investigate the geometric uniformity, laticeness, and minimum distance properties of Construction C* and discuss its superior packing efficiency when compared to Construction C.

cs.IT↗

Construction C*: an inter-level coded version of Construction C

Besides all the attention given to lattice constructions, it is common to find some very interesting nonlattice constellations, as Construction C, for example, which also has relevant applications in communication problems (multi-level coding, multi-stage decoding, good quantization efficieny). In this work we present a constellation which is a subset of Construction C, based on inter-level coding, which we call Construction C*. This construction may have better immunity to noise and it also provides a simple way of describing the Leech lattice $Λ_{24}.$ A condition under which Construction C* is a lattice constellation is given.

cs.IT↗

On the existence of rotated $D_n$-lattices constructed via Galois extensions

In this paper we construct families of rotated $D_n$-lattices which may be suitable for signal transmission over both Gaussian and Rayleigh fading channels via subfields of cyclotomic fields. These constructions exhibit full diversity and good minimum product distance which are important parameters related to the signal transmission error probability. It is also shown that for some Galois extensions $\matK|\matQ$ it is impossible to construct rotated $D_n$-lattices via fractional ideals of $\mathcal O_{\mattK}$.

math.NT↗

Rotated Dn-lattices

Based on algebraic number theory we construct some families of rotated Dn-lattices with full diversity which can be good for signal transmission over both Gaussian and Rayleigh fading channels. Closed-form expressions for the minimum product distance of those lattices are obtained through algebraic properties.

math.NT↗