Coded Multidimensional Index Modulation for 6G Wireless Networks

Index modulation (IM) schemes can be considered as possible candidates for use in sixth generation (6G) wireless networks due to the effective trade-offs they offer in terms of error characteristics, complexity and spectral efficiency, although there still remain interesting and at the same time difficult research problems to be solved in order to further improve the effectiveness of such schemes. The research objectives can be summarized as follows: development of generalized/improved IM schemes with higher spectral and/or energy efficiency, lower transmitter/receiver system complexity and better error characteristics; Integrating IM techniques into massive multiple-input/multiple-output (MIMO) systems to be used in 6G wireless networks; and exploring the potential of IM technologies in terms of practical implementation scenarios. Based on the research objectives of the proposed project, we plan to perform the following works:

• Development of a coded signal constellation for Generalized Multistream Spatial Modulation IM (GMSM-IM) systems, which includes construction of constant weight codes for antenna patterns, construction of lattice-based signal constellations for two or more active antennas, development of coding and decoding algorithms with low implementation complexity.
• The design of coded multidimensional signal constellations, encompassing the following objectives: refining constructions of coded multidimensional signal constellations utilizing frequency modulation, phase modulation, amplitude phase modulation, or hybrid modulations; contrasting them with conventional constellations; assessing their bit error probability characteristics within channels.
• Application of Generalized Cascading Codes (GCC) in OFDM-IM systems, including development of a GCC-OFDM-IM design rule. Application of frequency modulation, phase modulation, amplitude-phase modulation or other hybrid modulation in OFDM-IM systems, establishment of relationship between spatial separation gain and GCC code distance, development of multi-level/iterative decoding algorithms.

The scientific value of the proposed project lies in the development of a new methodology: this means that the new systems we have created will have characteristics (the ability to control channel errors, data transfer speed, energy and spectral efficiency, and complexity of implementation), which will ensure better quality compared to existing analogues in the world. Linear, combinatorial and algebraic coding methods, statistical and informational analysis of probabilistic characteristics of coded modulation systems, theory of algorithms and development of functional schemes will be used to solve the presented problems. Computer simulation and calculations will also be used extensively. The results obtained in the project will allow the user to make an informed choice between signal-code systems containing many similar parameters. The achieved concretization of encoding/decoding and modulation/demodulation algorithms provides an opportunity to directly use new constructions in solving various engineering tasks and will significantly reduce the design time of information transmission systems.

The project is funded by the Shota Rustaveli National Science Foundation of Georgia with a grant for fundamental research within the framework of the state scientific grant competition. Project leader Nodar Ughrelidze.