Radio freq. round trip signal time.
Radio freq. round trip signal time.
(OP)
Hello,
I am trying to develop a circuit that is based on a Radio freq. (RF), a transmitter and a receiver that can tell me
how far is the receiver from the transmitter. I don't have direct line of site so my guess is that i will use multiple antennas since i know the area that i will work with let's say (4 antennas) that's 4 trans. / 4 rec. so that i can pinpoint the receiver withing a few meters. Basically i know the principle but what i need is the schematic for the trnasmitter and the receiver or maybe if somebody can point me to a web page that has some schematics in them for this. The area is 800 squere meters.
Thanks.
I am trying to develop a circuit that is based on a Radio freq. (RF), a transmitter and a receiver that can tell me
how far is the receiver from the transmitter. I don't have direct line of site so my guess is that i will use multiple antennas since i know the area that i will work with let's say (4 antennas) that's 4 trans. / 4 rec. so that i can pinpoint the receiver withing a few meters. Basically i know the principle but what i need is the schematic for the trnasmitter and the receiver or maybe if somebody can point me to a web page that has some schematics in them for this. The area is 800 squere meters.
Thanks.





RE: Radio freq. round trip signal time.
However, new devices based around Zigbee or 802.15.4 can be used to co-locate over short distances. In a mesh-type setup, the approximate location of a single unit can be estimated based on the signal strength at several locations providing a location within a few meters provided the environment is not heavily obstructed. I have seen demos from companies like www.millennialnet.com and www.iwtwireless.com . There are other companies doing this with UWB type radios and proprietary designs. No doubt there are other companies out there doing similar things.
RE: Radio freq. round trip signal time.
If you have many obstructions the only way I can think of, assuming your obstructions are static, is to 'calibrate' your system by taking measurements at fixed locations around the area. For 10 meter accuracy you'd need to take readings every 1-2.5 meters (10:1, or the minimum 4:1 as seen in other posts). Thats about 300-800 calibration points if I have my math correct. If you are dealing with dynamic obstructions you'll need to be smarter than I am because I don't see how you would do it. Unless maybe some UWB (ultra-wide-band) technique (ding!) that I'm not familiar with?
RE: Radio freq. round trip signal time.
Anyway the need is not that much of a problem a GPS company for sure they will jump with a solution to my problem as soon as i ask.
Thanks again for your reply, guys.