Signal Calculator

Carrier Measurement

Measure the S/N ratio of the steady carrier using the longest possible coherent measurement time (narrowest bandwidth) to obtain an average S/N. Ideally, use a similar time of day and duration to the intended messages.

S/N ratio of carrier:  dB   In bandwidth:  Hz, or measurement period:  seconds

Code Selection

Choose a code, symbol period, message length and decoder list size. Choose the constraint length K according to the capacity of your decoding computer. If you are confident of the clock accuracy of the PCs at both ends, choose a rate 1/16 code, otherwise rate 1/8 is a safer bet.

Select code:
  Rate 1/4 K = 19
  Rate 1/8 K = 19
  Rate 1/16 K = 19
  Rate 1/8 K = 21
  Rate 1/16 K = 21
  Rate 1/16 K = 23
  Rate 1/8 K = 25
  Rate 1/16 K = 25

Symbol period:  seconds     CRC bits:     Number of characters: 

Calculation Results

Eb/N0: 2.09 dB
Signal bits: 4352
Duration: 26112 seconds, 07:15:12.00
Optimum list length: 3475461 (full phase search)
Optimum list length: 10426382 (uniform phase search only)
Percentage of channel capacity: 44.7
Additional info:
Information rate: 31.4 bits per hour
Information bits: 228
Outer code overhead: 24 bits
Inner code block size: 252 bits
Overall code rate: 1/19.09
S/N in 1Hz: -18.5 dB
Signal bandwidth: 0.167 Hz
Es/N0: -10.72 dB
Decoder memory: 4.7 Gbyte
Symbol error rate: 0.34
Shannon capacity: 70.39 bits per hour