Computer Simulation and Receiver Study at VLF

Design of efficient communications receivers for use at Very Low Frequencies (VLF) is difficult due to the impulsive atmospheric noise commonly found at VLF. This study develops a computer simulation of the atmospheric noise process in the VLF band. This simulation is then combined with simulations of a proposed receiver design and used to adjust the parameters of the proposed receiver. The resulting receiver is distinguished by a wideband front end and three stages of Automatic Gain Control (AGC) combined with clippers, each operating in an independent bandwidth. Finally, the proposed receiver is compared with an existing design and found to offer a significant performance enhancement.