K-nested layered look-ahead method and architectures for high throughput Viterbi decoder

A novel K-nested layered look-ahead method and its corresponding architectures, which pack K trellis steps into one step (where K is the encoder constraint length) and combine two look-ahead sub-trellises in a layered manner, are proposed for a high throughput Viterbi decoder. The proposed method guarantees parallel paths between any two-trellis states in the look-ahead trellises and distributes the add-compare-select computations to all trellis layers. It leads to a regular and simple architecture for the Viterbi decoding algorithm. The proposed method can be implemented in a partly or fully parallel manner and can be used for a high throughput Viterbi decoder. The main advantage of the proposed design is that it has the least latency among all look-ahead Viterbi decoders for a given level of parallelism.