>Zeph80 wrote:
>
>> I have a question concering Homeplug and OFDM.What if had to be able
to
>> talk to Homeplug chips, BUT I needed very very low data rates like
nothing
>> more than 800 bps. So since I have such low data rate needs, and would
need
>> to work within the  Homeplug standard  but not use high MIPS and
increase
>> my costs.If the standard allows me to null sub-carriers which it does,
>> would feeding those zeros to the IFFTs mean lower no of butterfly
>> computations.
>> 
>If you null out enough sub-carriers you could avoid doing the FFT 
>altogether, although there probably aren't orders of magnitude MIPs to
save.
>
>-- 
>
>Tim Wescott
>Wescott Design Services
>http://www.wescottdesign.com
>
>Posting from Google?  See http://cfaj.freeshell.org/google/
>
>"Applied Control Theory for Embedded Systems" came out in April.
>See details at http://www.wescottdesign.com/actfes/actfes.html
>

Do you have any suggestions that would allow me to reduce the MIPS, while
working within the standard

Zeph80 wrote:

> I have a question concering Homeplug and OFDM.What if had to be able to
> talk to Homeplug chips, BUT I needed very very low data rates like nothing
> more than 800 bps. So since I have such low data rate needs, and would need
> to work within the  Homeplug standard  but not use high MIPS and increase
> my costs.If the standard allows me to null sub-carriers which it does,
> would feeding those zeros to the IFFTs mean lower no of butterfly
> computations.
> 
If you null out enough sub-carriers you could avoid doing the FFT 
altogether, although there probably aren't orders of magnitude MIPs to save.

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google?  See http://cfaj.freeshell.org/google/

"Applied Control Theory for Embedded Systems" came out in April.
See details at http://www.wescottdesign.com/actfes/actfes.html

I have a question concering Homeplug and OFDM.What if had to be able to
talk to Homeplug chips, BUT I needed very very low data rates like nothing
more than 800 bps. So since I have such low data rate needs, and would need
to work within the  Homeplug standard  but not use high MIPS and increase
my costs.If the standard allows me to null sub-carriers which it does,
would feeding those zeros to the IFFTs mean lower no of butterfly
computations.