Re: Shifting frequency spectrum

[Cinaed Simson]

On 11/11/19 10:46 AM, Snehasish Kar wrote:
> I tuned the usrp to 947.4MHz with sample rate of 25msps. And then using the 
> example in the link I tried shifting the frequency to the centre, so that I 
> can apply a low pass filter and perform resampling on it.

So you're not using gnuradio to shift the signal?

It's trivial to do in gnuradio - assumiing your capture has a signal to
shift.

If you are using gnuradio, then you should post the GRC file.

-- Cinaed

> 
> BR
> Snehasish
> 
> Sent from my iPad
> 
>> On 11-Nov-2019, at 10:02 PM, Müller, Marcus (CEL) <address@hidden> wrote:
>>
>> Hi Snehashish,
>>
>> it's not really clear what you did exactly. How did you do the
>> shifting? Did you already take the mixing (probably by 947.4 MHz) done
>> by your SDR freontend into account?
>> (Also, frequencies and bandwidths have units!) 
>>
>> Best regards,
>> Marcus
>>
>>> On Mon, 2019-11-11 at 14:55 +0000, Snehasish Kar wrote:
>>> Hello 
>>>
>>> I tried capturing GSM 900 band at a sample rate of 25e6 centered at 947.4e6 
>>> and stored in a file. Then on the captured data I tried shifting 935.2e6 to 
>>> the center and perform a low pass filter samples out followed by a 
>>> re-sampler to get 200e3 samples out. But I think the spectrum shifting is 
>>> not wroking as it should be I am following the following link for spectrum 
>>> shifting https://dsp.stackexchange.com/a/1993. I am using twinrx with 10gig 
>>> sfp, UHD_3.13.1.0-0-unknown, ubuntu 16.04 and liquid dsp for signal 
>>> processing.
>>> fft - How to shift the frequency spectrum? - Signal Processing Stack 
>>> Exchange
>>> Stack Exchange network consists of 175 Q&A communities including Stack 
>>> Overflow, the largest, most trusted online community for developers to 
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>>> dsp.stackexchange.com
>>> Please let me know, where I might be going wrong.
>>>
>>> BR
>>> Snehasish
>>>