Development of low-cost high-resolution APD measuring equipment

摘要

Given that amplitude probability distribution (APD) is an effective means of estimating the effects of electromagnetic disturbance on digital communications, we are now testing low-cost equipment for measuring APD at high resolution. The equipment combines multiple M-sequence counters having relatively prime periods and makes use of residue number systems (RNS) so that most of the circuits can be formed on one IC chip and a low-cost configuration can be achieved. In addition, the size of the discrete logarithm table, which is essential to restoring the enumerated value from the bit pattern output of the M-sequence counters, need be only 10/sup -5/ the size of a single M-sequence counter. By therefore arranging units of this APD measuring equipment into a parallel configuration, the processing speed can be increased by n times.