A reader sent me another patent by Bobier “Narrow Band Integer Cycle or Impulse Modulation Spectrum Sharing Method” published 8 September 2006 and asked me to review it, which I did. This patent expands and extends some of the material in earlier patents. It is getting far too tedious and repetitive to try and comment in detail, so I will keep this short.
The patent describes a communication system which employs unconventional waveforms. I see no problem with the system described in the patent – there is an infinite number of ways of choosing the waveforms in a communication system and this is one of them. As in previous patents the inventor makes various false and wrong claims related to the performance of the system, and reveals a surprising lack of knowledge of basic concepts of communication theory including: the Fourier transform, optimal receivers and matched filters, effects of white Gaussian noise on communication receivers, linear filters and filter design, and performance analysis of communication systems. This type of material is typically taught in undergradute courses on “signals and systems” and “introduction to communications” and in graduate courses on “digital communication”. This material is covered in standard textbooks on communications, and if anyone is interested, I can post some specific titles. The communication system described in the patent can be made to work, but its performance would be obviously inferior to that of conventional systems.
Interestingly the patent includes the Shannon capacity equation, indicating that the inventor is aware of it. However, the discussion in the patent shows a fundamental lack of understanding of what this equation actually means. The patent also talks about Eb/N0 as being commonly used in digital communication systems. I note that xG technology did not publish the standard BER vs. Eb/N0 curve for their system. I have commented in some detail about Shannon and Eb/N0 in earlier posts and will not repeat it here.
It is most unfortunate that the inventor did not study the basics of signals and systems and of communication theory. As the patent now stands any competent communication engineer will be able to identify the many inaccurate and wrong statements it contains. As the previous patents, this one too is a curious mixture of fact and nonsense.