Re: [Discuss-gnuradio] tx_ofdm

[xianda]

Hi:
     Thank you so much.
     1.But from "chunks to symbols"  I see you use the bpsk and qpsk 
both.Right?What is the relationship between 800 bits and 17 symbols?Namely,how 
to calculate the 17 symbols?
17*64=1088.Can you explain?
     2.I have looked at your ppt about the ofdm.You say now have two version 
ofdm.Can you give me some links to them?Or some advices?Thank you.
Best regards
At 2014-05-23 04:33:44,"Martin Braun" <address@hidden> wrote:
>On 05/22/2014 10:12 PM, eontool wrote:
>> IIRC,  the tx and rx files are just a very general implementation of the OFDM
>> model.
>> 
>> Here's my understanding:
>> 
>> - Packet length refers to the data necessary to produce n symbols (48 data
>> carriers, 2 symbols = 96).
>
>Er, no. This is the number of bytes per packet. It's 96 because we add 4
>bytes for CRC, and then the packet number is a round value.
>
>At 100 bytes per packet, the payload is 800 bits. With BPSK, that would
>be 17 OFDM symbols (plus 1 OFDM symbol for header, and 2 for preamble).
>
>You can set whatever here, but remember that the stock equalizers don't
>do a good job on long packets. Also, the length can vary per packet.
>
>> - The number of total carriers in the systems equals the FFT length.
>> In this case, 48 data carriers and 4 pilots, 52 total and the rest are set
>> to 0.
>
>This is correct (compare 802.11a standard).
>
>M
>
>
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