Ignition Noise Measurements in the VHF/UHF Bands

In the operational use of mobile communication terminals, it may often be unavoidable to park them in a location where they would be subject to ignition noise due to local traffic. This type of noise causes errors in digital systems. Since it is impossible to define a general model for impulsive noise, one must measure the necessary statistical paramaters to be used for calculating its effect on a communication link. Although these parameters vary for different types of links, peak amplitude distribution, time distribution, and duration of impulses at various amplitude levels should be known. In this paper noise amplitude distribution (NAD) measurements carried out on the VHF/UHF bands for ignition noise are explained. The information derived from the NAD is the peak amplitude distribution of the impulses; in addition, the average repetition frequency of the impulses is also obtained. An analytical expression is found for the probability density function of the idealized NAD.