On Fri, 27 Jul 2001, Steve Schear wrote:
You could triangulate ultrabroadband with an antenna array, but in real life the reflexion and multipath will make it difficult.
In particular see : http://www.aetherwire.com/Aether_Wire/Integrated_CMOS_Ultra-Wideband_Localiz...
True, but even that application requires cooperation on behalf of the sender -- like most such architectures, it uses sliding correlation and agreed upon pseudorandom sequences to get a considerable process gain in the detection stage. Asynch UWB pulses should be considerably more difficult to deal with, although I don't think that multipath will be the reason: UWB pulses are time-localized enough to make direct separation of the directly propagated one from the echoes feasible. Rather I'd think that the asynchrony and the low power requirements for short-range hops would make remote detection troublesome. Still, I'm more a fan of direct sequence spread-spectrum. How easy is it to detect and/or triangulate that when the spreading sequence is not known, is secure, and we can assume the widest bandwidths to date achieved for DSSS? Sampo Syreeni, aka decoy, mailto:decoy@iki.fi, gsm: +358-50-5756111 student/math+cs/helsinki university, http://www.iki.fi/~decoy/front