I don't think communism and democracy necessarily go against each-other ideologically. Like the idea of equalizing everyone through the government could also include everyone having a vote. The revolution most likely couldn't be done through peaceful means (either the vote never passes or once it passes those negatively effected revolt), but afterwards couldn't the authoritarian revolutionist government establish a democracy? Or is communism always doomed to devolve into a dictatorship from the revolutionist government leaders wanting to maintain power? Are there any historical examples of Democratic Communism?
This is more of a question about political theory, so maybe something like /r/Socialism101 might be a better place to ask; And AFAIK "Has there ever been..?" questions aren't generally allowed here.
If your question is "Was the Soviet system democratic?" or anything similar, then there are threads to be found in the searchbar, friend - A "Soviet" in itself is a worker's council, to get you started, while we wait for an answer.