As a student I'm working on a project where we use 434 MHz RF Transmitter and receiver pairs for distance measurement. I know that this technology is not a good choice for this, but we have to deal with this problem due to external constraints.
Here is the receiver: RF Link Receiver - 4800bps (434MHz).
I did a little bit of research how these receivers works, but I found it a bit overwhelming to understand them bit by bit.
We want to use the signal strength for distance measurement. So we tried sending pulses of signals from one transmitter to a receiver. If the amplitude of the signal received is higher than a certain value (let's say 3V), it sends back a signal (let's call it trigger signal) in the gap between the two pulses.
The problem is that that these signals seems to affect each other even though they are not in the same time (so it's not superposition that we are talking about). When there is a signal sent back, the next pulse will be lower, which results in false distance measurement.
The whole difficulty is (to me it seems) that we are not using these signals to send data, we are using it for distance measurement. My idea is that we are using too long pulses and the AC coupling in the receiver doesn't tolerate it, but again, I don't have enough electrical knowledge to safely say that.
I know this is not descriptive, but I don't know how to make it more descriptive, so I'm happy to answer more questions on demand.