Vector Representation of Signal Signal can be represented by its projection onto the basis x(t)=∑r,(t) ·中，(t)is the basis(orthogonal to each other) .x the coefficient of the projection .x(is uniquely described by xVector Representation of Signal x(t) = X 1 i=¡1 xiÁi (t) 11 Signal can be represented by its projection onto the basis is the basis (orthogonal to each other) xi the coefficient of the projection Ái (t) x(t) is uniquely described by xi