Miaowen Wen received his Ph.D. degree from Peking University, Beijing, in 2014. From 2012 to 2013, he was a Visiting Student Research Collaborator with Princeton University, NJ, USA. He is currently an Associate Professor at the South China University of Technology, Guangzhou, China. He has published one book and more than 100 IEEE journal papers. His research interests include a variety of topics in the areas of wireless and molecular communications.Qiang Li received his Ph.D. degree from South China University of Technology, Guangzhou, in 2020. From 2018 to 2019, he was a Visiting Student Research Collaborator with Princeton University, NJ, USA. He is currently a faculty member at the Jinan University, Guangzhou, China. His research interests include index modulation and reconfigurable intelligent surfaces.Xiang Cheng received his Ph.D. degree from Heriot-Watt University and The University of Edinburgh, U.K., in 2009, where hewas awarded the Postgraduate Research Thesis Prize. He is currently a Professor at Peking University. His general research interests are in areas of channel modeling, wireless communications and data analytics, subjects on which he has published more than 200 journal and conference papers, five books, and holds 10 patents.

• 1 Introduction.- 2 Constellation-Based Index Modulation: A Combinatorial Approach.- 3 Constellation-Based Index Modulation: A Permutational Approach.- 4 Code-Based Index Modulation.- 5 Pilot-Based Index Modulation.- 6 Conclusions and Future Directions.

Miaowen Wen received his Ph.D. degree from Peking University, Beijing, in 2014. From 2012 to 2013, he was a Visiting Student Research Collaborator with Princeton University, NJ, USA. He is currently an Associate Professor at the South China University of Technology, Guangzhou, China. He has published one book and more than 100 IEEE journal papers. His research interests include a variety of topics in the areas of wireless and molecular communications.Qiang Li received his Ph.D. degree from South China University of Technology, Guangzhou, in 2020. From 2018 to 2019, he was a Visiting Student Research Collaborator with Princeton University, NJ, USA. He is currently a faculty member at the Jinan University, Guangzhou, China. His research interests include index modulation and reconfigurable intelligent surfaces.Xiang Cheng received his Ph.D. degree from Heriot-Watt University and The University of Edinburgh, U.K., in 2009, where hewas awarded the Postgraduate Research Thesis Prize. He is currently a Professor at Peking University. His general research interests are in areas of channel modeling, wireless communications and data analytics, subjects on which he has published more than 200 journal and conference papers, five books, and holds 10 patents.

• 1 Introduction.- 2 Constellation-Based Index Modulation: A Combinatorial Approach.- 3 Constellation-Based Index Modulation: A Permutational Approach.- 4 Code-Based Index Modulation.- 5 Pilot-Based Index Modulation.- 6 Conclusions and Future Directions.

Miaowen Wen received his Ph.D. degree from Peking University, Beijing, in 2014. From 2012 to 2013, he was a Visiting Student Research Collaborator with Princeton University, NJ, USA. He is currently an Associate Professor at the South China University of Technology, Guangzhou, China. He has published one book and more than 100 IEEE journal papers. His research interests include a variety of topics in the areas of wireless and molecular communications.Qiang Li received his Ph.D. degree from South China University of Technology, Guangzhou, in 2020. From 2018 to 2019, he was a Visiting Student Research Collaborator with Princeton University, NJ, USA. He is currently a faculty member at the Jinan University, Guangzhou, China. His research interests include index modulation and reconfigurable intelligent surfaces.Xiang Cheng received his Ph.D. degree from Heriot-Watt University and The University of Edinburgh, U.K., in 2009, where hewas awarded the Postgraduate Research Thesis Prize. He is currently a Professor at Peking University. His general research interests are in areas of channel modeling, wireless communications and data analytics, subjects on which he has published more than 200 journal and conference papers, five books, and holds 10 patents.

• 1 Introduction.- 2 Constellation-Based Index Modulation: A Combinatorial Approach.- 3 Constellation-Based Index Modulation: A Permutational Approach.- 4 Code-Based Index Modulation.- 5 Pilot-Based Index Modulation.- 6 Conclusions and Future Directions.