search

jakapoor / AMRUPT

Animal Movement Research Using Phase-based Trilateration (AMRUPT)
GNU General Public License v3.0
4 stars 7 forks source link

Basic phase difference detection hardware architecture #10

Closed jakapoor closed 6 years ago

jakapoor commented 6 years ago

We have so far considered three possible approached to receiving phase-difference information across multiple antennas:

  1. A multi-channel mixer/demodulator coupled to a multi-channel ADC (see graphic): DF_week_2_02_08_18 15.pdf

  2. A single CC1310 transceiver with RF input multiplexed to multiple antennas via an RF switch, with its ADC doing oversampling (see graphic): DF_week_2_02_08_18 16.pdf

  3. Multiple CC1310s coupled to a linear frequency modulated (LFM) signal and a finite input response (FIR) filter (see graphic below):

Ian’s idea for solving issue of coherent detection.pdf

We need to evaluate which of these solutions, if any, offers the greatest potential to serve as a solution for basic DF.

jakapoor commented 6 years ago

SDRs as a better alternative for radio direction finding?

After doing some reading I'm beginning to realize that restricting ourselves to either the CC1310 or to demodulator boards leaves out an important third option: software defined radios (SDRs). These are extremely flexible, open source, and low cost (some) devices that may greatly simplify the task of synchronization that we've been grappling with.

Please check out the following materials which cover just a few direction finding approaches using SDRs:

Here's a list of SDRs.

A forum for discussing SDRs.

A YouTube video detailing the use of SDRs in direction finding (as well as a detailed description of how they solved the synchronization problem). Their source code is also freely available on GitHub. Here's another link describing their project.

Here's a different SDR-based DF project.

This is a link for an SDR-based TDOA wildlife localization project which has achieved a 3.5 m accuracy from 9 km spacing!!

Also, here's a post about a company that is making hardware to assist in converting individual SDRs into coherent receivers.

Finally, I've attached a PDF of an open-source SDR direction finding project which uses the Raspberry Pi, and achieves an extremely low cost, if coarse, solution to the problem of localization. RasHAWK_AOC_Challenge.pdf

Please check these out, and let me know your thoughts.

-Julian

jakapoor commented 6 years ago

We have collectively decided that an SDR-approach to RDF is superior, and this will be the focus of our future development.