Re: [Discuss-gnuradio] Recover the signal

[Marcus Müller]

Hi Maksim,

Could you keep this on the mailing list?

I don't fully understand:

> In fact, the figure shows repeated OFDM signal, each of it in frequency domain.

So you take the OFDM signal, and shift it in frequency domain, and then have N identical OFDM signals transmitted at the same time?
Can you clearly state what your X-Axis and what you Y-Axis are?

For example, I transmitted a zadoff-chu sequence which has a flat characteristic in frequency domain. The environment was a short cable with attenuation. The received signal also showed in frequency domain.
I attached it also "the figure shows the repeated sequences 2Mhz bandwidth in frequency domain". What I am curious about are spikes which appear usually in the center frequency? I thought may it is related some how with dc offset in USRP.

I don't understand this graph:


What is the X-Axis, what is the Y-Axis?

Maybe you meant that you take values from a Zadoff-Chu sequence, IFFT them, thus generating an OFDM signal (which, by the way, is also a ZC sequence), add guard intervals and transmit them?

I attached it also "the figure shows the repeated sequences 2Mhz bandwidth in frequency domain". What I am curious about are spikes which appear usually in the center frequency? I thought may it is related some how with dc offset in USRP.

I'm really getting intrigued by what you observe :) but we'll really have to understand the graphs, which at this point, I'm afraid, I don't.

Best regards,
Marcus