Ephraim heads to London Road looking to play regular first-team football having found opportunities limited at his parent club.
He told the club's official website: "It was time for me to get out and play a bit of first team football.
"I have played at this level with Leeds United and Charlton, so I know what to expect. The team like to play attacking football, so I am looking forward to it.
"I have played at London Road before and was on the losing side and know exactly how loud the home fans can be.
"I can play in a number of positions, in midfield or behind the strikers, but obviously I am just looking to play.
"It is up to me to impress in training."