  Using coordinate-free basic operators on toy Fock spaces \cite{AP}, quantum
random walks are defined following the ideas in \cite{LP,AP}. Strong
convergence of quantum random walks associated with bounded structure maps is
proved under suitable assumptions, extendings the result obtained in \cite{KBS}
in case of one dimensional noise. To handle infinite dimensional noise we have
used the coordinate-free language of quantum stochastic calculus developed in
\cite{GS1}.
