Pseudonoise with Arbitrary Amplitude Distribution--Part II: Hardware Implementation

Abstract

A hardwired device that produces a voltage with arbitrary amplitude distribution was constructed using a "conditional bit" algorithm to sample from an arbitrary voltage amplitude distribution. The sampling algorithm and hardware processor are independent of the distribution sampled. Only a small read-only memory ROM needs to be changed to alter the distribution sampled. It is possible to compute the accuracy of the sampled random variables from knowledge of the read-only memory contents. The sampling accuracy of the device may be arbitrarily increased by varying any of several design parameters. Our particular pseudonoise generator produced 200 000 random seven-bit variables/s. Contents of read-only memories for both a Gaussian and an arbitrary density were computed so that the maximum error was less than 2.73 percent. Both the sampling speed and accuracy of a conditional bit pseudonoise generator can be increased much in excess of our implementation.