Lattice Structures of Precoders Maximizing the Minimum Distance in Linear Channels
2015 (English)In: IEEE Transactions on Information Theory, ISSN 0018-9448, E-ISSN 1557-9654, Vol. 61, no 2, 908-916 p.Article in journal (Refereed) Published
This paper investigates linear precoding over nonsingular linear channels with additive white Gaussian noise, with lattice-type inputs. The aim is to maximize the minimum distance of the received lattice points, where the precoder is subject to an energy constraint. It is shown that the optimal precoder only produces a finite number of different lattices, namely perfect lattices, at the receiver. The well-known densest lattice packings are instances of perfect lattices, but are not always the solution. This is a counter-intuitive result as previous work in the area showed a tight connection between densest lattices and minimum distance. Since there are only finite many different perfect lattices, they can theoretically be enumerated offline. A new upper bound on the optimal minimum distance is derived, which significantly improves upon a previously reported bound, and is useful when actually constructing the precoders.
Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE) , 2015. Vol. 61, no 2, 908-916 p.
MIMO; modulation; lattices
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:liu:diva-114573DOI: 10.1109/TIT.2014.2367004ISI: 000348298400017OAI: oai:DiVA.org:liu-114573DiVA: diva2:791468
Funding Agencies|Swedish Foundation for Strategic Research; Centers for High Speed Wireless Communications and Distributed Antenna Systems through the Lund University, Lund, Sweden; Research Grants Council Areas of Excellence Scheme [E-02/08]; University Grants Committee, Hong Kong2015-02-272015-02-262016-05-31