October 1981 | Technical Report TR-81-87
Signals and Interference in FM Reception: I. Deterministic Models-The "Instantaneous" Approach, with Undistorted Inputs
Cite This Publication
David Middleton and Arthur D. Spaulding, “Signals and Interference in FM Reception: I. Deterministic Models-The "Instantaneous" Approach, with Undistorted Inputs,” Technical Report TR-81-87, U.S. Department of Commerce, National Telecommunications and Information Administration, Institute for Telecommunication Sciences, October 1981.
David Middleton and Arthur D. Spaulding
Abstract: The purposes of this study (and subsequent efforts) are several: (1), to extend earlier models of the FM reception process, to include as much II "realism" – i.e., non-ideality of both the linear and nonlinear elements of the typical FM receiver – as possible, and still retain analytical and computational feasibility; (2), to examine explicit cases of interference produced by one or more deterministic signals; and (3), with such specific examples, both to provide insights into the distortion effects generated by the nonlinear interactions of the various (desired and undesired) signals in the receiver and to present the analytical framework of the instantaneous outputs required in any (subsequent) fully statistical treatment, where now the interference (e.g., "noise") is noticeably nongaussian. In addition, these deterministic models may also provide useful structures for simulation studies. The instantaneous receiver outputs are obtained for the following receiver models, (A), and interference "scenarios", (B): for (A): (I) "superclippinq: and an ideal discriminator; (II), no limiting and ideal discriminator; III, "superclipping" and a non-ideal IV, no limiting and a non–ideal discriminator. For (B), with each (A), we consider explicitly the cases of: (i), one cochannel interfering signal; (ii), one adjacent channel interferer, and (iii), M symmetrical interferers (M = 1, 5). Also included are the mean and mean-square outputs. All the above are obtained here for idealized (i.e. sufficiently wide-band) RF-IF receiver stages, which are essentially linear under this condition. The results are illustrated with cases for selected, typical parameters of the combination of the interference-receiver structure. For other combinations, the appropriate computer programs are included in the Appendix.
Keywords: interference; FM reception; receiver models; multiple interferers; baseband output waveforms
Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.
For questions or information on this or any other NTIA scientific publication, contact the ITS Publications Office at ITSinfo@ntia.gov or 303-497-3572.