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Re: [Discuss-gnuradio] 802.11a source codes? or any OFDM implementation
Re: [Discuss-gnuradio] 802.11a source codes? or any OFDM implementation on GNU Radio
Thu, 11 Sep 2008 11:50:35 -0700
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On Sep 11, 2008, at 11:26 AM, Mohsen Baratvand wrote:
Guy, all I need to do is changing some parameters such as preamble,
LTF, STF, modulation and etc of the OFDM transmitter and then send a
predefined pattern to the OFDM receiver, then estimate the channel.
So I'm not gonna pass all the information and data to PC via the USB
link. Just sending some report to my PC.
It's conceivable that by putting the modulation in the FPGA, you could
get 802.11a OFDM modulation to work using the USRP -- just send the
data across the bus. But no one has written such a firmware image yet
- -- feel free! (Disclaimer: I have no idea whether an 802.11a modulator
would fit into the small FPGA on USRP1, and haven't tried).
If you want to do modulation in the host, which doesn't involve FPGA
coding and might allow you to use some of the existing OFDM code,
you're going to be limited by the bandwidth of the USB -- 8 MHz isn't
really enough. If you used 8-bit mode to get 16 MHz of bandwidth AND
used one of the low bitrate encodings, high-SNR packets MIGHT get
received by a good receiver. I don't know enough about 802.11's use of
OFDM to decide. Maybe Kyle or Tom has a comment here.
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