Symbol Rate Calculator Tool

Data Rate (DR):
Modulation Factor (m):
Forward Eror Correction (FEC):

Symbol Rate:

Symbol & Baud Rate Information





Symbol Rate or Baudrate is the number of symbol changes per second made to the signal. According to the modulation coding method (MODCOD) used each symbol can represent 1, 2, 3, 4, etc. bits of transmission rate data. So for example, when BPSK modulation is used the symbol rate is the same as the bit rate because 1 bit of data is transmitted per symbol.

The rate at which symbols are transmitted is the baud rate.

SR – Symbol Rate
FECForward Error Correction
DR – Data Rate
m – Modulation Factor
sps – Symbols per second

Bits per Symbol (modulation factor)

  • BPSK = 1
  • QPSK = 2
  • 8PSK = 3
  • 8QAM or 8APSK= 3
  • 16QAM or 16 APSK = 4
  • 32QAM or 32 APSK = 5
  • 64QAM or 64 APSK = 6
  • 128QAM or 128 APSK = 7
  • 256QAM or 256 APSK = 8

Symbol Rate Formula




Symbol Rate = DR / (m x FEC)

 

iNetVu Antenna Symbol Rate Calculation (ksps)

Example of Symbol Rate Calculation

Data Rate is 2048 kbps

FEC ¾

Modulation type 8QAM

Symbol Rate = Data Rate / (m x FEC)

SR = 2048 / (3 x 0.75 ) = 910.2 ksps


Many modern satellite modems will calculate the symbol rate for you in the configuration pages.

 

sym_rate
Comtech CDM-625 Symbol Rate Config