On 6/24/2010 10:28 PM, Li Mei-Wen wrote:
I used USRP1+BasicTX, USRP1+TVRX and ./benchmark_rx/tx.py to transmit
packets but used different bitrate (35K, 125K, 216K) in FM bands
(88Mhz~108Mhz)
Why the 35K can reached distance longer than 125K and 216K.
In my implementation result, the 35K was 20m, 125 was 18m and 216 was
16m.
Why have this result, the modulation was same, just different bitrate.
This is most likely because the higher bit rates require a higher
signal-to-noise ratio (SNR) for the transmitted bits to be received
effectively.
What you are experiencing can probably be characterized with the
Shannon-Hartley theorem.
http://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theorem
~Jeff
--
~Jeffrey Lambert, K1VZX
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