# (no subject)

**URL:** <https://www.ruby-forum.com/t/no-subject/234353>\
**Category:** GNU Radio\
**Created:** [February 26, 2015, 8:29am UTC](https://www.ruby-forum.com/t/no-subject/234353 "2015-02-26T08:29:48Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [February 26, 2015, 8:29am UTC](https://www.ruby-forum.com/t/no-subject/234353/1 "2015-02-26T08:29:48Z")

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sir, what is the importance of the COSTOS loop in the QPSK mod/demod?  
This  
block is working fine for 4-qpsk, 8-qpsk. But it does not works for QAM  
modulation techniques. Is it needs to modify the cc code? if it is,  
where I  
have to modify? plz mail me.