  In this paper we consider the problem of transmitting a continuous alphabet
discrete-time source over an AWGN channel. We propose a constructive scheme
based on a set of curves on the surface of a N-dimensional sphere. Our approach
shows that the design of good codes for this communication problem is related
to geometrical properties of spherical codes and projections of N-dimensional
rectangular lattices. Theoretical comparisons with some previous works in terms
of the mean square error as a function of the channel SNR as well as
simulations are provided.
