  This paper describes a novel approach to solving unstructured search problems
using a classical, signal-based emulation of a quantum computer. The classical
nature of the representation allows one to perform subspace projections in
addition to the usual unitary gate operations. Although bandwidth requirements
will limit the scale of problems that can be solved by this method, it can
nevertheless provide a significant computational advantage for problems of
limited size. In particular, we find that, for the same number of noisy oracle
calls, the proposed subspace projection method provides a higher probability of
success for finding a solution than does an single application of Grover's
algorithm on the same device.
