If you of Jewish origin or predisposition, then your name is probably is derived from aviv, meaning "spring." (check out http://www.uahc.org/torah/issue/981122.shtml). Otherwise, Aviva may be related to the Latin word viva, meaning life, and is used to convey a sense of wellbeing and vitality. Either way, your name emits, like, positive vibes (peace sign).
P.S. If on the other hand you are a nihilist goth dom 'n' gloomer hanging out in graveyards and listening to "The Dead Can Dance", rejoice! Your name might also be interpreted as meaning "dead," if the "a-" in Aviva is interpreted as a negation of Viva (life).