1. A processing method comprising: receiving a signal over at least one antenna corresponding to an input vector y that represents a noisy observation of Ax, where A is a data matrix and x is a vector of unknown variables; recovering x from said received input vector y via an iterative method; wherein said recovering comprises determining an inference of a vector of marginal means over a graph G, where the graph G is of a joint Gaussian probability density function p(x) associated with noise in said received input vector y.