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Perform Fixed-Point Hard Decision Viterbi Decoding

Use the Viterbi Decoder block for fixed-point hard-decision convolutional decoding.

The model uses the PreLoadFcn Callback to specify an ${E_b}/{N_0}$ setting of 4 dB for the AWGN Channel block, and to limit the run duration to 100 errors or 1e6 bits for the Error Rate Calculation block.

The Data Type Conversion (Simulink) block sets the Mode parameter to Fixed point and casts the output data type to fixdt(0,1,0). The signal input to the Viterbi Decoder block is ufix1.

The Viterbi Decoder block has the Decision type parameter set to Hard decision, and on the Data Types tab, the State metric word length is set to 4 and the Output data type is set to boolean. The bit error rate is displayed and captured to the BER workspace variable.

The computed bit error rate is 0.00256.
The total number of errors is 118.
The total number of bits processed is 46144.