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What does Viterbi decoder do?
A Viterbi decoder uses the Viterbi algorithm for decoding a bitstream that has been encoded using a convolutional code or trellis code. It is most often used for decoding convolutional codes with constraint lengths k≤3, but values up to k=15 are used in practice. Viterbi decoding was developed by Andrew J.
What is Viterbi score?
The Viterbi algorithm is a dynamic programming algorithm for obtaining the maximum a posteriori probability estimate of the most likely sequence of hidden states—called the Viterbi path—that results in a sequence of observed events, especially in the context of Markov information sources and hidden Markov models (HMM).
What is traceback depth?
The traceback depth influences the decoding delay. The decoding delay is the number of zero symbols that precede the first decoded symbol in the output. For the continuous operating mode, the decoding delay is equal to the number of traceback depth symbols.
How do you decode a convolution code?
Viterbi algorithm is utilized to decode the convolutional codes. Again the decoding can be done in two approaches. One approach is called hard decision decoding which uses Hamming distance as a metric to perform the decoding operation, whereas, the soft decision decoding uses Euclidean distance as a metric.
What is the constraint length for Viterbi decoder?
It is most often used for decoding convolutional codes with constraint lengths k≤3, but values up to k=15 are used in practice. Viterbi decoding was developed by Andrew J. Viterbi and published in the paper Viterbi, A. (April 1967). “Error Bounds for Convolutional Codes and an Asymptotically Optimum Decoding Algorithm”.
What is the optimal quantization zone width for Viterbi?
The optimal quantization zone width is defined by the following formula: is a noise power spectral density, and k is a number of bits for soft decision. ) distance between the received and the actual symbols in the code alphabet may be further simplified into a linear sum/difference form, which makes it less computationally intensive.
What’s the general approach to traceback in Viterbi?
The general approach to traceback is to accumulate path metrics for up to five times the constraint length (5 ( K – 1)), find the node with the largest accumulated cost, and begin traceback from this node.