Re: [Discuss-gnuradio] Channel model & frequency offset

[Benny Alexandar]

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From: Benny Alexandar
Sent: Friday, October 27, 2017 6:38 AM
To: address@hidden
Subject: RE: [Discuss-gnuradio] Channel model & frequency offset

 

Hi Atif,

For frequency offset , a signal with (cos ((w + delta)t) + j sin((w + delta)t)), where delta is the offset compared to original signal.

This can be achieved by creating a grc as attached. In this grc the signal source (Tx) sample rate is fixed and in the sink (Rx) which is fft, the sample rate is slightly offset to create the frequency offset.

You can add a slider for sample rate offset, and move to see the effect.

 

Similarly If you want to create a time offset, which is (cos (w + delta(t))t) + j sin(w + delta (t))t), where delta (t) is a monotonous function over t: in case delta (t) is positive, the frequency offset will increase over time. 

-ben

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I am trying to analyze channel model effect between am transmitter and receiver but whenever i change frequency offset using slider i can't be able to see the frequency change. In both transmitter and receiver are at the same frequency .

Best,

ATIF JAVED