Analysis, computation, and mitigation of radio systems´ mutual interference effects in collocated vehicular transceivers

The recent increase in the use of mobile radios and systems has enhanced the operation probability and harmful mutual interference resulting from the collocation of two transceivers in the same vehicle. Military mobile systems are especially vulnerable to the collocation operation. Civilian systems, however, are now also being affected. This paper provides a better understanding of the effects of mutual interference and the means by which they can be reduced. This is shown by analyzing the conditions which cause mutual interference, developing computational methods to quantize their effects, and applying these computational results to a typical vehicular VHF radio system so as to minimize their effect. Computational methods are developed using both deterministic and novel empirical relationships to quantize the mutual interference effects as a function of antenna spacing and frequency intervals. The shielding and grounding techniques fall outside the scope of this paper, and the mutual interference effects on remote transceivers are treated in a forthcoming paper. The computation results and mitigation techniques presented in this paper can be applied from the initial development phase of transceivers intended for use in collocated operations, thereby significantly improving their system reliability and operational frequency management policy