Approach in companding‐quantisation‐inspired PAM constellation design. Issue 18 (4th October 2018)

• Record Type: Journal Article
• Authors: Vlajkov, Slobodan; Jovanović, Aleksandra; Perić, Zoran
• Is Part Of: IET communications. Volume 12:Issue 18(2018)
• Page Start: 2305
• Page End: 2314
• Publication Date: 2018-10-04
• Subjects: quantisation (signal) -- error statistics -- probability -- pulse amplitude modulation; companding‐quantisation‐inspired PAM constellation design -- pulse‐amplitude modulation constellations -- nonequiprobable symbols -- nonuniformly distributed constellations points -- piecewise‐linear constellation design function -- constellation points -- uniform subsets -- symbol error probability -- conventional uniform PAM constellation -- piecewise‐uniform PAM constellations -- signal energy; Telecommunication systems -- Periodicals; Speech processing systems -- Periodicals; 621.38205
• DOI: 10.1049/iet-com.2018.5439
• Languages: English
• ISSNs: 1751-8628

Abstract

Abstract : In this study, a very simple but successful method for designing the pulse‐amplitude modulation (PAM) constellations with non‐equiprobable symbols and not equally spaced amplitudes is presented. The method, inspired by companding quantisation, introduces a constellation design function having a feature that maps the non‐uniformly distributed constellations points into uniform ones. In particular, two classes of piecewise‐linear constellation design function having two segments are provided. In PAM constellation designed by the proposed method, the set of constellation points is divided into two uniform subsets. Each of these subsets is characterised by a certain probability of constellation points and by a constant distance between adjacent points. For this model of PAM constellation, the formulas that enable the elegant assessment of the signal energy and the symbol error probability are derived. Results obtained analytically and verified through simulations show that, in terms of the symbol error probability, the proposed PAM constellations outperforms conventional uniform PAM constellation as well as the other models of piecewise‐uniform PAM constellations.