Office of Telecommunications OT Report 75-67

Optimum Reception in an Impulsive Interference Environment

June 1975

A.D. Spaulding and David Middleton

Abstract: Since communications systems are seldom interfered with by classical white Gaussian noise, Middleton’s recently developed physical-statistical model of impulsive interference is applied to real world communications channels.

The main impulsive interference models that have been proposed to date are summarized, and Middleton’s model is specified in some detail, giving the statistics required for the solution of signal detection problems. Excellent agreement of these statistics with corresponding measured statistics is shown.

Middleton’s model for narrow-band impulsive interference (a subset of the overall model) is applied to a class of optimal signal detection problems. Optimum detection algorithms are given for coherent and incoherent binary detection. The three basic digital signaling waveforms are considered; i.e., antipodal, orthogonal, and ON-OFF keying. Performance bounds are obtained for these signaling situations. Since it is known that in order to gain significant improvement over current receivers, the number of independent samples of the received interference waveform must be large, the performance results are given parametrically in the number of samples, or equivalently, the time-bandwidth product. Performance of the current suboptimum receivers is obtained and compared to the optimum performance. It is shown that substantial savings in signal power and/or spectrum space can be achieved.

Since physical realization of the completely optimum detection algorithms cannot, in general, be economically obtained, the corresponding locally optimum or threshold receivers are derived and their performance given. These threshold receiver structures are canonical in nature in that their structure is independent of the form of the interference. They are also adaptive in that they must be able to adjust to the changing interference environment. Locally optimum structures are given here for coherent and incoherent detection with constant signal levels and various kinds of fading. The case in which phase estimation is used (partially coherent reception) is also onsidered.

Keywords: impulsive interference; impulsive noise; interference models; man-made noise; optimum detection; threshold receivers

• Title Page; Statement of Mission; Preface; Table of Contents; List of Tables; List of Figures; Glossary of Principal Symbols

• Chapter 1: Introduction

• Chapter 2: Models of Impulsive Interference (6.3 MB)
• Chapter 2: Figures
  
  
• Chapter 3: Background Theory and Results; Section 3.1: Elements of Statistical-Decision Theory (7.9 MB)
• Section 3.2: The Assumption of Independent Sampling
  
  
• Chapter 4: Optimum Coherent Reception; Section 4.1: The Optimum Coherent Receiver
• Chapter 4; Section 4.2: Performance Calculations for Optimum Coherent Receivers
• Chapter 4; Section 4.2: Tables (6.8 MB)
• Chapter 4; Section 4.2: Figures
• Chapter 4; Section 4.3: Performance of Sub-optimum Receivers
• Chapter 4; Section 4.4: Coherent Threshold Detection (6.1 MB)
  
  
• Chapter 5: Optimum Incoherent Reception, pp. 139-152
• Chapter 5: pp. 153-164
• Chapter 5: pp. 165-179
  
  
• Chapter 6: Summary and Conclusions; Chapter 7: Acknowledgments

• Chapter 8: References

• Appendix: An Approximation to the Noise Probability Density Function; Bibliographic Data Sheet

Disclaimer: Certain commercial equipment, components, and software are 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.

To request a reprint of this report, contact:
Margaret Luebs, Publications Officer
Institute for Telecommunication Sciences
Voice: (303) 497-3572
info@its.bldrdoc.gov

For technical information concerning this report, contact:
Robert Achatz, Electronics Engineer
Institute for Telecommunication Sciences
Voice: (303) 497-3498
rachatz@its.bldrdoc.gov