How to put errors in the coded sequence:
1. Once that you have coded your message, the channel field will become editable, full with zeros. Replace the 0 with a 1 at every position where you want to put an error.
2. Press the start decoding button.
How to decode the sequence step by step:
1. Once that you have coded your message, and pressed the start decoding button, simply press the next step button as many times you want.
How to insert new bits in the sequence being decoded:
1. Select the advanced user checkbox.
2. Press the next step button util the decoder tells you that " You can now insert bits". This will happen each time that every states of a step have been computed.
3. Press the input zero or input one buttons to input the bits you want. You will see them in the current bits field. You have to enter the right number of bits until the decoder lets you continue the decoding procedure (n bits for a decoder with a 1/n code rate).
4. Press the next step button to go on.
How to finish a decoding procedure:
1. Once that you have started decoding, you can finish the operation at any time (you don't have to wait until the entire sequence is decoded) by pressing the finish button. The whole trellis is then displayed and the optimal path is drawn in red.