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128/256QAM modulator/demodulator

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goxy

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I'm interested in 128 and 256QAM mod and dem for dataspeed 155Mb/s and above.
Does someone know available parts on net?
 

calvinhorng

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I am also interested in this topic, if anyone can share, please PM me also.

Thanks in advanced
 

flatulent

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specialized

This is such a specialized modulation that such things are custom made and probably used only by cross counry microwave relay systems.
 

dainis

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Re: specialized

Look Intersil ISL87060MIK and ISL87060DIK chips ...
 

Jackal

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Hi!

At this moment, we are work with microwave relay system.
And i tryd to find modulators/demodulators... nothing...
At this moment, we are use Altera's FPGA.
At www.altera.com you find Constallation Mapper/Demapper Megacore.
That help you to create modulator/demodulator.

Regards, Jackal.
 

redsk_y

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The most important part for this kind of modulation is the equalization
structure of the receiver.

Furthermore, must be taken in count the phase noise of the LOs and linearity of PA.

Best regards,
 

Wacko2000

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QAM mod/demod chips for 155 Mb do not exist at this moment as far as I know.
This would in practice require a very high constellation like 1024 QAM, which you do not like to have.. Needs very good transmission medium and low phase noise.
I think you have more luck in the range of WLAN OFDM chipsets although 155 Mb is a lot...
 

Wacko2000

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Btw... you can play with those 'plug and play' IP blocks from Altera but those are not efficient with respect to hardware needs.
Furthermore.. 155Mb QAM ? Well.. good luck with your FPGA's...
 

dainis

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Look Intersil site for Broadband wireless modems, modulation up to 128QAM, speed up to 238 Mbps:
h**p://w*w.intersil.com/data/an/an9969.pdf
h**p://w*w.intersil.com/data/an/an9934.pdf

At this time this is more integrated solution for high speed wireless modems .....
 

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