What is the difference between the V-OFDM and OSDM I am trying to understand the difference(s) between V-OFDM (Vector Orthogonal Frequency Division Multiplexing) and OSDM (Orthogonal Signal Division Multiplexing) which are used as a multicarrier modulation techniques in wireless communication. Based on what I understand both are dividing the sub-carriers into  groups of sub-carriers vertically, and then process the $DFT$ horizontally. But when checking online and read different papers and books, some are talking about V-OFDM and others OSDM !! 

Could anyone please explain further about differences between them ? design and differences  of OSDM from V-OFDM? Or they are similar, only two different names with same technology !!!

Thanks in Advance!
They are little bit different in performing the $DFT$ and the adding of $CP$. her you can read more details about those differences : https://sci-hub.tw/10.1109/ICC.2009.5198846  

Good luck