Patent ID: 7148830

Claim:
A method of processing input signal data using a look-ahead delta sigma modulator of depth N using natural and pruned pattern loop filter responses, wherein N is greater than or equal to two, the method comprising: determining a set of pattern responses of a loop filter of the look-ahead delta sigma modulator for each output candidate vector by setting signal input data to the loop filter of the delta sigma modulator to at least approximately zero and filtering a set of output candidate vectors; determining a natural response of the loop filter of the look-ahead delta sigma modulator by setting feedback data to the loop filter to at least approximately zero and filtering a set of input data signal samples; pruning the set of pattern responses to determine a set of one or more pruned pattern responses; and quantizing each input signal data sample by applying predetermined decision criteria to determine a best match between a member of the set of one or more pruned pattern responses and the natural response and selecting quantization output data from the output candidate vector associated with the pruned pattern response used to determine the best match.