Patent attributes
A digital matched filter receives an input signal in natural order, correlates the input signal against a code and generates a filtered output signal in a permuted order with respect to the input signal. The code is a factorization of a first and second patterns. The filter includes a first filter to correlate against the first code and a second filter to correlate against the second pattern. A memory is included to store intermediate values produced from the first filter correlation operation. Certain ones of the intermediate values are selectively retrieved from memory in accordance with a unique addressing scheme for each second filter correlation operation. More specifically, the addressing scheme allows retrieved intermediate values to be reused in successive second filter correlations. The permuted order outputs of the filter are of no concern in many applications, like cell searching, where buffering is available.
