Direction Finding DSSS


Sep 30, 2014
I'm curious if anyone here has any knowledge or first-hand experience on direction-finding direct-sequence spread-spectrum radio transmissions. Specifically, whether it's even possible, and if so, any common techniques that are used for it.

Literally any information on this topic would be very helpful for a project I'm experimenting with. Thanks!


Jun 18, 2010
Mojave Desert, California, USA
Think of it this way, the chip width is inversely related to the bandwidth. So a very short chip width results in a wide bandwidth. At this point the signal can appear as noise, possible an increased noise floor.

This means that not all DSSS is as detection proof as others. For example, 802.11b uses DSSS, and is very detectable using even very crude techniques.

If the signal SNR (power spectral density) is great enough to have a noticeably increased noise floor on any specific frequency then most traditional techniques can be used to DF it. If not then you are going to have to get a littel fancier.

However, every emission can be DFed. If you can differentiate it from noise you can DF it. TDOA works particular well against short duration events, as long as you can ID the specific event.



Jul 3, 2023
I bet if you can fingerprint the "chip" via software, then you could narrow in on it with a wide-band SDR and thus DF that...

Another way may be to fingerprint the signal its self belonging to its Xmitter. You can do this and it's done today.

Here's a basic run down. RF Fingerprinting with a SDR

Last I heard, Disney was working on this technology for hands free smart home use. In this context, each person has their own "medium." So for example, your finger and only your finger or hand will be unique to a light switch or whatever and thus made to be more "smart" and tailored to you. You could say to the door, "make a note I need to pick up an item at the store." The next time you pass through the door it'll recognize you and remind you and only you of your note. It's all under the guise of RF fingerprinting.

Last edited: