Koren, a free summer signing from West Brom, hit his fourth goal of the season in the 77th minute as Nigel Pearson's side overcame Ipswich 1-0 to move four points clear of the bottom three.
The Slovenia international said: "It's good to have gone three games unbeaten.
"We went through a difficult period, but now we have seven points from a possible nine and that has helped to build confidence.
"The atmosphere in the squad is getting better and better and hopefully that will continue. We can't wait for the next game to come along now."
Koren added: "The goal was a good moment from everybody in the team because everybody played their part."
Source: PA
Source: PA