I am currently interested into the diverse Downlink LTE channels broadcasted over air after some (QPSK, 16QAM...) modulation. More precisely their waveform.

I would like to know if, with a good filtering of the noise, we could characterize the LTE signal in time domain, so we could correlate a waveform with a specific downlink channel.

In another words: is the LTE signal waveform dependant from the data it is carrying or the antenna it comes from? And if yes, which part of the signal in time domain?

I will distinguish two cases here, first the channels carrying information (sequence of bits), and the Reference Signal (RS) which exists only at PHY layer.

  1. We know that transport channel like PBCH are periodic in time (i.e occupying 1st to 4th symbol of the #1 slot in each RF, repeating the same MIB during 4 RF -> %40ms). This is the same thing for the PDCCH controlling channel, with the specificity that the number of allocated symbols can vary from 1 up to 4 symbols (which i guess makes the potential correlation harder).
    I find these channels potentially interesting because of the redundant data they will carry over time (at least i think it's redundant for PBCH - information about the antenna configuration for PBCH, less sure about the PDCCH). Unlikely to the PDSCH channel which carries variable data over time in its payload, and therefore that I'm judging more difficult to characterize (maybe i'm wrong?).

  2. RS is also redundant in time. It's used to help UE figuring out the DL power. Thought, I don't know what we can expect of its waveform.

I don't forget SSCH and PSCH, broadcasted every 5 Sub-Frames. Maybe they are also characterizable?

LTE Radio Frame of 1.4MHZ, cyan stands for PBCH, red for RS, orange for PDCCH

Should it be relevant, I don't have the MathWorks® LTE System Toolbox, even though I'm pretty sure it could be helpful.


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