PSG are back in the last eight for the first time in 18 years but face the ultimate challenge, taking on the title favourites.
"We may not have a lot of possession but as soon as we get the ball I want my team to show character and inspiration to go forward and score," Ancelotti told a news conference on the eve of the game.
"We have defended very well so far this term and we've done well on the counter-attack. This is what we want to do tomorrow because we'll need it if we are to get a good result."
PSG, who have a seven-point lead at the top of Ligue 1, will be without midfielder Thiago Motta because of a groin injury.
Ancelotti's team will take heart from AC Milan's first-leg performance in the previous record, the Italians having won 2-0 before Barca turned the tie around in the return match.
"Milan played a good tactical game. They made it difficult for Barcelona to play like they wanted to," said PSG's hot-shot marksman Zlatan Ibrahimovic.
"Barca like to keep the ball but we want to have possession because we are at home. We want to find a solution to upset them."
Ibrahimovic seemed to relish PSG's underdog status for the clash with World Player of the Year Lionel Messi and company.
"We are up against probably the best team that has ever played on this planet," said former Barca striker Ibrahimovic. "But the team that makes the fewest mistakes is the team that will win."
