Baud rate and data rate of UHF transmiter

since you posted this in the RFID Forum, i am assuming (hopefully correctly) that your question is related to EPCGen2. 

as in all RFID readers, there is a downlink and an uplink...the downlink with this RFID technology is done with ASK at a data rate between ~27k baud to 128k baud on analog side which is then processed as Pulse Interval Encoding digitally, inside the tag. So they call is ASK modulation with Pulse Interval encoding.

the uplink (this is backscatter from tag back to reader) happens with either ASK or PSK and the encoding is FM0 Baseband encoding (from 40kbps to 640kbps) or Miller subcarrier encoding (@ 5 to 320kbps)

hope that helps you out. 

Hi Chanh,

As you well understand, the bit rate and baud rate can be the same in the case that one symbol equals one bit.  Many chips will allow for different modulation types to be used.  For example, look at the CC1101 datasheet in section 16.1.  This allows for 2-FSK or 4-FSK modulation to be used.  You will see the symbol definition in table 29, which shows 1 bit per symbol with 2-FSK and 2 bits per symbol with 4-FSK.  You will also notice that in the general characteristics of the chip(section 3, page 8), the min and max data rates are shown for each modulation type.  The note for 4-FSK confirms what we now know (the data rate in kbps will be twice the baud rate). 

I hope that helps!     

if you are indeed talking about EPC Gen2, then understand its PIE, which means that a 0 is indicated but 1 times the 1etu and a 1 is indicated by 2 times 1etu...like this: 

and further, also graphically: 

That is correct.  In ASK, 1 symbol equals 1 bit.  I found a write up on this subject that you may also find interesting.  See below.

http://electronicdesign.com/communications/modulation-symbols-and-bits-building-your-wireless-vocabulary