0
$\begingroup$

I am trying to figure out the channel capacity of OFDM with index modulation (OFDM-IM). One of the article reports that the conditional channel capacity of OFDM-IM is $\mathcal{C}_{\mathrm{OFDM-IM}}(\gamma) = \frac{1}{L}\left[I(\boldsymbol{x}_s;\boldsymbol{y}\vert \boldsymbol{x}_c)+I(\boldsymbol{x}_c;\boldsymbol{y})\right]$, where $\gamma$ is the SNR, $L$ is the number of subcarriers available for modulation in one group, $I(\boldsymbol{x}_s;\boldsymbol{y}\vert \boldsymbol{x}_c)$ provides constellation domain information, $I(\boldsymbol{x}_c;\boldsymbol{y})$ is the index domain information and $\boldsymbol{y}$ is the vector of received symbol. I was wondering whether this relation is only valid when we expect a complex-valued signal after IFFT? Secondly, how would this relation change if we need a real-valued signal after IFFT, i.e., when Hermitian symmetry is enforced in the frequency domain prior to IFFT?

$\endgroup$
2

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.