Thanks, will read it. From: Marcus D. Leech <[email protected]> Sent: Thursday, August 19, 2021 11:45 AM To: ?? WANG Cui <[email protected]>; [email protected] Subject: Re: [USRP-users] Re: How to prepare I/Q sample for tx_streamer
On 2021-08-18 11:02 p.m., ?? WANG Cui wrote: Hi Marcus, Thanks for the explanation, so I have to prepare the I/Q samples in my program. Furthermore, can I understand the send() function will multiplex/transform the I/Q samples to final REAL baseband waveform samples. Then the USRP hardware simply multiply amplitude of each REAL sample to the carrier frequency and transmit? WANG Cui You might usefully spend some time here: https://kb.ettus.com/Knowledge_Base Also the "tx_samples_from_file" example applicaton shows you how samples are delivered to the send() function. Most applications use floating-point I/Q samples on the host side, and the UHD driver converts them to 16-bit values over the wire. From: Marcus D. Leech <[email protected]><mailto:[email protected]> Sent: Thursday, August 19, 2021 10:43 AM To: [email protected]<mailto:[email protected]> Subject: [USRP-users] Re: How to prepare I/Q sample for tx_streamer On 2021-08-18 10:31 p.m., ?? WANG Cui wrote: Hi, Maybe I am asking a newbie question. When use tx_streamer::send() function to send signal, the required format is I/Q samples (say otw_format = sc16). I understand should provide I/Q samples buffer in arguments. I am wondering for the I/Q samples, should I provide binary values buffer (e.g. I: 1, -1, 1..., Q: -1, 1, -1...), then the USRP firmware will modulate the binary values to specific Cos/Sin waves? Or I should do the Cos/Sin modulation in my program (e.g. I: 0, -.001, 0.002..., Q: -1, 0.999, -0.998...) before pass the buffer send() function? I searched the documents, but can't find answer, thanks in advance for explanation, WANG Cui _______________________________________________ USRP-users mailing list -- [email protected]<mailto:[email protected]> To unsubscribe send an email to [email protected]<mailto:[email protected]> The whole point of an SDR is that it doesn't have any pre-defined notion of what modulation techniques are used, etc. That's entirely up to you. You're sending a complex-baseband representation of *waveforms*. The UHD library is NOT a DSP library. It is a device-interface library. If you need something higher-level, there's Gnu Radio (http://www.gnuradio.org) or even MATLAB. But SDR radios in general don't have any built-in modulation. They want sampled baseband waveforms.
_______________________________________________ USRP-users mailing list -- [email protected] To unsubscribe send an email to [email protected]
