Re: [Discuss-gnuradio] OEM devices with software radio

[Ken Sinclair]

Matthew Tippett wrote:
> Hi
>
> I have just started with a company that is building a product that will
> be using an RF remote.  It will go through a number of revisions, with
> possibly more RF capabilities added in further revisions.
>
> Having being on this list for a couple of months, I put it to this group
> if there are any recommendations for consumer level chips or OEM devices
> that are longer term hackable to be used as generic software radios?
>
> Initially we will be operating in the 900 MHz range.

The key issue will be your power budget.  A software radio is likely
to consume 2X-5X more battery power in operation than a specifically
engineered solution.  If you're trying to build a small remote with
long battery life, this may be your dominant constraint.

If you think you have some power to work with, you could consider
building a "narrowband software radio" which could capture and demodulate
arbitrary signals of 25khz-500khz bandwidth in the 900mhz band, in
addition to your own evolving protocol.  Using an integrated silicon
transceiver such as RFMD RF2915, TI TRF6900, or ChipCon CC1000, you'll
spend about 75mW during receive for hardwired FSK demodulation,
and/or you can digitize the IF signal for software demodulation.
You'll spend another 10-20mW digitizing the signal, plus some amount
of computing cycles for demodulating (50-200 MIPS would be ample,
a 10 MIPS microcontroller might be OK, much less than that and you'd
have to be very careful).

That might provide useful capabilities for your product (e.g. paging or
cellular or cordless voice connectivity), but it's probably not what
people consider a "generic" software radio that can capture broadcast
stations etc.  That would require high-speed wideband capture which
I doubt is compatible with your "RF remote" requirements.

Ken Sinclair
Wavetrain - Wireless computing and embedded system design
address@hidden