Dept. of Electrical Engineering;
Sohag University;
Sohag;
Egypt;
Dept. of Electrical Engineering;
Aswan University Aswan 81542;
Egypt;
Dept. of Electrical Engineering;
Assiut University;
Assiut;
Egypt;
Dept. of Electronics & Comm. Engineering;
Arab Academy for Science;
Technology and Maritime Transport;
Aswan;
indexed modulation; combinatorial modulation; double sparsity; critical sparsity; sparsely indexed modulation; OFDM-IM;