Talk:Guided Tutorial PSK Demodulation: Difference between revisions
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(Provide non-obvious data needed to duplicate tutorial steps.) |
(Link to RRC info (Analog Devices AN) and suggestion for future edits) |
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* \param ntaps number of taps | * \param ntaps number of taps | ||
*/ | */ | ||
== RRC Filtering Information Link == | |||
This link helped me to understand match filtering using a Raised Cosine (& RRC) filter: https://www.analog.com/media/en/technical-documentation/application-notes/AN-922.pdf | |||
I think it would also be beneficial to spend a few sentences to describe why some of the filter coeficients were chosen and why they change for different flowgraphs throughout this tutorial. | |||
Revision as of 17:26, 2 May 2022
- Implementation Hints
I greatly appreciate this guided tutorial. I had some difficulties following along, so the following might help others using this tutorial.
* Hints for mpsk_rrc_rolloff.grc
1. Constellation Modulator property Constellation = qpsk_const
This setting uses the Constellation Rect. Object id qpsk_const (aka <con...(m=4))
* Hints for mpsk_stage1.grc
1. Constellation Modulator property Constellation = qpsk_const
This setting uses the Constellation Rect. Object id qpsk_const (aka <con...(m=4))
2. Variable id rrc_taps value is firdes.root_raised_cosine(1.0,samp_rate,samp_rate/sps,excess_bw,11*sps).
See GNU Radio Manual and C++ API Reference
/*!
* \brief design a Root Cosine FIR Filter (do we need a window?)
*
* \param gain overall gain of filter (typically 1.0)
* \param sampling_freq sampling freq (Hz)
* \param symbol_rate symbol rate, must be a factor of sample rate
* \param alpha excess bandwidth factor
* \param ntaps number of taps
*/
RRC Filtering Information Link
This link helped me to understand match filtering using a Raised Cosine (& RRC) filter: https://www.analog.com/media/en/technical-documentation/application-notes/AN-922.pdf I think it would also be beneficial to spend a few sentences to describe why some of the filter coeficients were chosen and why they change for different flowgraphs throughout this tutorial.