Patent ID: 7436876

Claim:
An ultra wideband receiver comprising: an ultra wideband antenna; an ultra wideband receiver coupled to the ultra wideband antenna for receiving an input signal, said ultra wideband receiver further comprising: a sampling stage for sampling the input signal and generating a sampled signal; a summation stage for summing a plurality of sampled signals and generating a sum signal; an evaluation stage for evaluating one or more sum signals to generate an evaluation result; a threshold comparator to compare the evaluation result with a threshold; wherein the threshold is varied based on a performance criterion, wherein the evaluation stage and threshold comparator utilize a plurality of ramps in accordance with one or more of the following relationships: Number Threshold Equation 0 MaxR > C 1 N * MaxR / MA_meanV > C 2 MaxR / NextR > C 3 Logic AND of equation 1 and 2 4 Logic OR of equation 1 and 2 5 N * MaxR / MaxV > C 6 N * (MaxR / MA_meanV) * (MinV / MaxV) > C 7 N * (MaxR / MA_meanV) * [FORCE_ZERO(MinV − MA_MinV) / FORCE_ONE(MaxV − MA_MinV)] > C 8 N * (MaxR − NextR) / MA_meanV > C 9 N * [(MaxR − NextR) / MA_meanV] * (MinV / MaxV) > C. wherein N represents the acquisition integration length, C is some programmable constant, and the performance criterion is described as the following: Quantity Description MaxR 1 st largest acquisition ramp NextR 2 nd largest acquisition ramp MaxV Maximum correlator variance MinV Minimum correlator variance MeanV Mean correlator variance MA_MeanV Moving (historical) average of the mean correlator varience MA_MinV Moving (historical) average of the minimum correlator varience Logic_1 Constant value 1 Logic_0 Constant value 0.