IEEE Transaction on Circuits and Systems Review Process
It means that the reviewers already submitted their scores and now the paper is with the associate editor who will make a recommendation to the Editor-in-Chief.

The next step will be "awaiting final decision" which will be made by the Editor-in-Chief.

It will take probably a week or less to get a decision now based on my experience. 

At this point, the paper could get accepted or rejected. You cannot infer anything from this status.

I recently submitted a TCAS journal paper and went through this process.