Research Article

A Generalization Belief Propagation Decoding Algorithm for Polar Codes Based on Particle Swarm Optimization

Figure 2

The BP decoding algorithm for polar codes is based on the factor graph representation of the codes [13]. In the algorithm, each node or is associated with two types of probability messages: left-to-right probability messages and right-to-left probability messages. Both of messages are propagated and updated iteratively between adjacent nodes in the procedure of BP. And the messages updated schedule is the same as that of [14]; that is, messages will firstly propagate from the rightmost nodes to the leftmost nodes. After arriving at the leftmost nodes, the course will be reversed, and messages propagation will move toward the rightmost nodes. This procedure makes one round iteration of BP. Diagram of BP-PU.
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