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: Maksim 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
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