[hpsdr] I didn't think it would happen again "PING"

[jeff millar]

Eric Ellison wrote:
> How are our lurkers doing? Anyone have any ideas for me to synergize us
> again?
>   
Here's some ideas:  Extend the SDR concept to multiple antennas with 
digital beamforming.  Some snippets of ideas...

    * Four channel receiver with each channel connected to a vertical in
      a four square.
    * Remote receivers that use 802.11 to link sections of the band back
      to the DSP, such at 3780-3800 KHz
    * Rx with 802.11 has whip, preselector, preamp, A/D, DSP, uproc, USB
      802.11 dongle, battery powered, clocks synchronized by 802.11
      messages.
    * Networked receivers, like IRLP/Echolink on steroids, link 10-20
      kHz of passband in I/Q and let DSP tune with the band, DSP can
      also combine signals from distributed receivers
    * Lay out an array of remote receivers with small whips and beamform
      using all the elements of the random array.
    * Combine beam forming and interference nulling to maximize SNR
    * With an array of whips, null interference in both azimuth and
      elevation
    * For all the signals in the passband, separate them by direction of
      arrival and simultaneously beamform and interference null on _all_
      signals.  Then demodulate all signals.  The output of the receiver
      becomes separate, selectable, audio channels for each signal.

For the mathematically inclined, the paper below suggests some DSP 
approaches to beamforming on all signals simultaneously.

    www.nps.navy.mil/asilomar/asil03/prog03/Asilomar-Keynote.pdf

Look at the slides on "blind signal separation" and "principle component 
analysis".

jeff, wa1hco

 1155953817.0