[Note added on 28 July, 2007: The disclaimer discussed in this post seems to have been removed today from the xG Technology web page]
Well, I spoke too soon. I thought that xG Technology has finally decided to come to grips with the fact that xMax has no technical advantages as a physical layer, and move on from there. I was wrong. They have now added the following “disclaimer” to the BER vs. Eb/N0 plot:
“In response to numerous requests, following is a plot showing BER (bit-error-rate) performance against Eb/No (signal-noise ratio). It should be noted that, due to the unconventional nature of xMax technology, traditional BER plots such as these do not convey the true inherent advantages of xMax over existing technologies. These advantages will become evident in the first commercial xMax systems.”
So xMax has some unspecified “true inherent advantages over existing technologies.” These must be different from the advantages mentioned before, which relied on the claim that xMax can operate at vastly lower power levels than existing techniques, a claim clearly falsified by the BER vs. Eb/No plot (as well as by all the other issues discussed in earlier posts). Sounds rather mysterious and intriguing – we will have to wait and see what new advantages arise from the ashes of the old.