Uchechi, who is a Nigerian Under-20 and Under-23 international, moved to England in 2002 and was on the books at Charlton Athletic and West Ham.
He becomes manager Sven-Goran Eriksson's fifth January signing.
Defender Ben Mee and striker Yakubu have both joined on loan, while Kyle Naughton's loan deal has been extended and there has been a permanent deal for Sol Bamba.
Source: BBC Sport
Source: BBC Sport