1. A method for operating signal processing circuitry to form output signals from a plurality of input signals comprising using the signal processing circuitry for: accepting the plurality of input signals; using a prototype generator to determine a characterization of one or more prototype signals from multiple of the input signals; and using an estimator to process each prototype signal of the one or more prototype signals including processing said prototype signal to form a corresponding output signal as an estimate of said prototype signal, the output signal comprising a combination of one or more of the input signals; wherein forming the output signal as an estimate of a corresponding one of the one or more prototype signals as a combination of one or more of the input signals includes computing statistics relating the prototype signal and the one or more input signals, and determining a weighting coefficient to apply to each of said input signals.