The 27-year-old had been a free agent after leaving Millwall at the end of last season, but will now represent the Sky Blues in the 2014-15 campaign.
Head coach Steven Pressley told the club's official website: "Simeon is a player that has played at the highest level, scored at the highest level and has a track record of being an individual that teammates can depend on when the time comes. All of those attributes are the kind I want in my players.
"He's got a great attitude, he's hungry, he's a very good age and he knows what promotion requires whether that be into League One or the Premier League and his experience will be a huge benefit to the younger players in the dressing room.
"His goal-scoring record throughout the leagues also speaks for itself and I'm looking forward to his arrival taking the competition for places among the strikers up another gear."
Jackson has also played for Norwich City during a well-travelled career.