Re: [Discuss-gnuradio] How to implement 64QAM?

[alanluo]

Any response?


alanluo wrote:
> 
> Hi, everyone:
> 
> recently I have a project which need to use higher modulation scheme, such
> as 16QAM or 64 QAM. I noticed that in python/gnuradio/blksimpl, there is
> no demodualtion part for higher modulation schemes. Does that mean we need
> to finish it by ourself?
> And i also noticed that from the maillist attached as below, Tom seems
> working on the modualtion models. Did he finish this work, and post at
> some place i just did not find ?
> 
> I really appreciate any help from you guys. Since I am very new to the
> python language and dont have confidence to programme the model in such
> short time.
> 
> ====
> RE: constellation mapping  
> 
> by trondeau Mar 06, 2007; 05:44am :: Rate this Message:    - Use ratings
> to moderate (?) 
> 
> Reply | Reply to Author | Print | View Threaded | Show Only this Message 
>> -----Original Message----- 
>> From: address@hidden [mailto:discuss- 
>> 
>> On Sun, Mar 04, 2007 at 06:20:07PM -0500, address@hidden wrote: 
>> 
>> > I want to do constellation mapping in pyhton.  I have code that does 
>> > a gr.packed_to_unpacked_bb and then gr.chunks_to_symbols_bc using a 
>> > constellation of: 
>> > 
>> > constellation=array((1+1j,1-1j,-1-1j,-1+1j),Complex) 
>> 
>> Use this: 
>> 
>>   constellation=(1+1j,1-1j,-1-1j,-1+1j) 
>> 
>> > My understanding is that this is the constellation mapping for QPSK. 
>> > I want to do constellation mapping for BPSK and 64-QAM.  I don't 
>> > have a lot of GNU radio experience so I'm not really sure how to do 
>> > this.  Is all I do is change the array (all the possibilities from 
>> > 4+4j to -4-4j for 64-QAM and 1+0j to -1+0j for BPSK) and the code 
>> > will do the rest to map the data for the other modulation schemes? 
>> 
>> Have you looked at the mpsk code that's in the tree?  Most of this 
>> stuff is already in place.  I believe that Tom Rondeau is working on 
>> QAM too. 
> ... [show rest of quote]
> 
> Yep, you can already look in python/gnuradio/blksimpl for DBPSK and DQPSK. 
> I'm finishing up the tests on the new stuff now and hopefully will get
> those 
> checked in to the trunk by the end of today. 
> 
> This will include D8PSK and a number of square QAM modulations up to
> M=256. 
> These are currently disabled until the receivers are finished, but the
> code 
> will be there to see how I'm doing it. The modulators have been verified 
> using our signal analyzer. 
> 
> Tom
> ====
> 
> 
> Best wishes,
> 
> Alan
> 

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