Daily Archives: November 5, 2021

Convolutional Codes and Viterbi Decoding

In the previous post we discussed block codes and their decoding mechanisms. It was observed that with syndrome-based decoding there is only a minimal advantage over the no coding case. With Maximal Likelihood (ML) decoding there is significant improvement in performance but computational complexity increases exponentially with length of the code and alphabet size. This is where convolutional codes come to the rescue.

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Hamming Codes

We have previously discussed modulation and demodulation in wireless communications, now we turn our attention to channel coding. We know that in a wireless channel the transmitted information gets corrupted due to noise and fading and we get what are called bit errors. One way to overcome this problem is to transmit the same information multiple times. In coding terminology this is called a repetition code. But this is not recommended as it results in reduced data rate and reduced spectral efficiency.

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