## Abstract

There has been a plethora of papers dealing with wireless communication that use techniques, which when viewed from the perspective of a Maxwellian framework raise more questions than they answer. By Maxwellian framework we imply not only the relevance of electromagnetics in studying communication systems but also the proper interpretation of an ensemble processing in mathematical physics which was first introduced by Maxwell to study the behavior of an aggregate of molecules rather than the property of individuals. Initially, most of the modern signal processing techniques was developed for scalar acoustic problems. However, with the advent of wireless, these same techniques are being applied to the vector electromagnetics problem, which is fundamentally different in concept with respect to the scalar acoustic problem. The objective is to discuss some of these concerns associated with some of the current modeling methodologies particularly related to propagation modeling and antenna diversity. A goal is to initiate a dialog about the scientific merits of these new applications. One of the points to be made is that an incorrect use of probability theory can often lead to erroneous conclusions that directly contradict the principles of physics. A few examples are presented to initiate this dialog, mainly the applicability of scalar techniques to the vector wireless problem, including a proper interpretation of the Shannon channel capacity theorem. A methodology is also presented to illustrate how a simple multiple-input-multiple-output system can be based on the principles of reciprocity. Integration of the electromagnetic principles in some of the current methodologies of signal processing and communications theory may lead to a better system.

Original language | English (US) |
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Pages (from-to) | 3727-3745 |

Number of pages | 19 |

Journal | IEEE Transactions on Antennas and Propagation |

Volume | 54 |

Issue number | 12 |

DOIs | |

State | Published - Dec 2006 |

## Keywords

- Antenna diversity
- Antenna pattern
- Array theory
- Channel capacity
- Detection
- Direct data domain approaches
- Estimation
- Gabor capacity
- Hartley's law
- Matched filter
- Maxwell's equations
- Maxwell-Szilard capacity
- Multipleinput-multiple- output (MIMO)
- Output energy filter
- Probability theory
- Propagation modeling
- Ray tracing
- Reciprocity
- Shannon capacity
- Smart antennas
- Sommerfeld formulation
- Wiener filter

## ASJC Scopus subject areas

- Electrical and Electronic Engineering