Constant-Weight Convolutional Codes for Index Modulation

Conference: WSA 2021 - 25th International ITG Workshop on Smart Antennas
11/10/2021 - 11/12/2021 at French Riviera, France

Proceedings: ITG-Fb. 300: WSA 2021

Pages: 6Language: englishTyp: PDF

Authors:
Bailon, Daniel Nicolas; Freudenberger, Juergen (Institute for System Dynamics, HTWG Konstanz, University of Applied Sciences, Germany)
Kuehn, Volker (Institute of Communications Engineering, Faculty of Computer Science and Electrical Engineering, University of Rostock, Germany)

Abstract:
The encoding of antenna patterns with generalized spatial modulation as well as other index modulation techniques require w-out-of-n encoding where all binary vectors of length n have the same weight w. This constant-weight property cannot be obtained by conventional linear coding schemes. In this work, we propose a new class of constant-weight codes that result from the concatenation of convolutional codes with constant-weight block codes. These constant-weight convolutional codes are nonlinear binary trellis codes that can be decoded with the Viterbi algorithm. Some constructed constant-weight convolutional codes are optimum free distance codes. Simulation results demonstrate that the decoding performance with Viterbi decoding is close to the performance of the best-known linear codes. Similarly, simulation results for spatial modulation with a simple on-off keying show a significant coding gain with the proposed coded index modulation scheme.