Adaptive techniques for automatic frequency determination and measurement

摘要

Various implementations of a technique are presented for capitalizing on signal correlation in a manner for providing usable frequency information. In a specific embodiment, a filter (51) is adapted to a signal component of an input signal using a variable generated by an adapter 58. The variable has a prescribed relationship to the frequency of the signal component. The variable is used to weight a combination of signal values derived from past signal history to form a prediction of a future signal. An adder 56 combines the new signal value with the prediction to form an error signal which is used by the filter (51) and the adapter (58). When the filter converges, a frequency indicator (59) using the variable provides an output signal indicative of the frequency of the signal component.