Information-Theoretic analysis of a family of improper discrete constellations

Non-circular or improper Gaussian signaling has proven beneficial in several interference-limited wireless networks. However, all implementable coding schemes are based on finite discrete constellations rather than Gaussian signals. In this paper, we propose a new family of improper constellations g...

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Detalles Bibliográficos
Autores: Santamaria, I. (Ignacio)|||/items/8cff54ca-3d7e-46d6-b217-dcedfe5dbb7e, Lameiro, C. (Christian)|||/items/78a4ee89-776c-47cd-8e93-0b65325865d4, Schreier, P.J. (Peter J.)|||/items/de7714e1-8423-4acf-a2eb-de7a57249c62, Crespo-Bofill, P. (Pedro)|||/items/8293cea3-6f3d-4700-b266-5b467e6eabcd
Tipo de recurso: artículo
Fecha de publicación:2018
País:España
Institución:Universidad de Navarra
Repositorio:Dadun. Depósito Académico Digital de la Universidad de Navarra
Idioma:inglés
OAI Identifier:oai:dadun.unav.edu:10171/65401
Acceso en línea:https://hdl.handle.net/10171/65401
Access Level:acceso abierto
Palabra clave:Improper signals
Mutual information
Gaussian noise channels
Discrete constellations
Descripción
Sumario:Non-circular or improper Gaussian signaling has proven beneficial in several interference-limited wireless networks. However, all implementable coding schemes are based on finite discrete constellations rather than Gaussian signals. In this paper, we propose a new family of improper constellations generated by widely linear processing of a square M-QAM (quadrature amplitude modulation) signal. This family of discrete constellations is parameterized by κ, the circularity coefficient and a phase φ. For uncoded communication systems, this phase should be optimized as φ ∗ (κ) to maximize the minimum Euclidean distance between points of the improper constellation, therefore minimizing the bit error rate (BER). For the more relevant case of coded communications, where the coded symbols are constrained to be in this family of improper constellations using φ ∗ (κ), it is shown theoretically and further corroborated by simulations that, except for a shaping loss of 1.53 dB encountered at a high signal-to-noise ratio (snr), there is no rate loss with respect to the improper Gaussian capacity. In this sense, the proposed family of constellations can be viewed as the improper counterpart of the standard proper M-QAM constellations widely used in coded communication systems.