Covert wireless (was: A crowdfunding campaign to build a free baseband)

[wirelesswarrior at Safe-mail.net]

-------- Original Message --------
From: coderman <coderman at gmail.com>
To: wirelesswarrior at safe-mail.net
Cc: falcon at ivan.harhan.org, cypherpunks at cpunks.org
Subject: Re: Covert wireless (was: A crowdfunding campaign to build a free baseband)
Date: Fri, 10 Apr 2015 16:11:15 -0700

> On 4/10/15, wirelesswarrior at safe-mail.net <wirelesswarrior at safe-mail.net> wrote:
> > ... I delivered a paper last October regarding the reasons such alternatives are
> > needed, reviewed recent developments and offered some practical directions
> > for future work (some of which I am pursuing):
> >
> > http://www.paralelnipolis.cz/pp-congress-2014/WWPP.pdf
> 
> 
> i didn't see mention of MIMO / beam forming systems for both better
> throughput and greater privacy.

I did not look closely at MIMO due to the lack of inexpensive SDR solutions and their lack of utility at lower bands.

> 
> and as common as HackRF is, there are better kits. why was this unit
> in particular chosen?

Mainly price and frequency coverage. Since my interest is mainly on apps that require transmitting I did not focus on receviers. Starting at twice the HackRF's cost the USRPs are a best buy at the low end.

The HackRF's weakness main weakness is its 8-bit ADC and lack of pre-selector to limit strong out-of-band input signals and reduce out-of-band transmiter spurs. However, it has an internal header to which daughter boards can be added and its CPDL can be reprogrammed for these add-ons and other changes. On the receive side a cheap coax bandstop filter, with acceptable insertion loss, can easily be fabricated to knock down the FM broadcast and pager transmitter signals instead of a pre-selector.

What other kits were you thinking of?

WW

> 
> hard problems ahead!