# Active Indices Database¶

This webpage introduces a comprehensive database of the active indices designed for the generalized spatial modulation and the subcarrier index modulation schemes, which are representative members of index modulation family. The designed active indices are provided in three formats: pure indices, activation tensor, and its vector representation. In this webpage, $$M$$ denotes the number of transmit antennas or subcarriers, $$K$$ denotes the number of activated antennas or subcarriers, and $$Q$$ denotes the number of activation patterns, where we have the constraint of $$2 \leq Q \leq 2^{\left\lfloor \log_2{M \choose K} \right\rfloor}$$.

Note that the designed active indices in the $$Q > 1024$$ case are omitted in this database, although they are supported by this toolkit. Additionally, the activation tensor is omitted in the $$Q > 128$$ case due to its large file size.

This database currently supports 100.00% of the possible IM parameters for $$M \leq 20$$ and 75.53% of parameters for $$M \leq 32$$.

One can also obtain the designed active indices by the VIEWIM mode of the imtoolkit command. For example, in the $$(M,K,Q)=(16,8,16)$$ case, the corresponding active indices are obtained by executing the following command.

> imtoolkit VIEWIM_code=index_dm=opt_M=16_K=8_Q=16
[[1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0]
[1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0]
[1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1]
[1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0]
[1 1 0 0 1 1 0 0 0 0 1 1 0 0 1 1]
[1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0]
[1 0 0 1 0 1 1 0 1 0 0 1 0 1 1 0]
[1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1]
[0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0]
[0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 1]
[0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1]
[0 0 1 1 0 0 1 1 1 1 0 0 1 1 0 0]
[0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1]
[0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0]
[0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1]
[0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1]]
Minimum Hamming distance = 8
Inequality L1 = 0