Polar Code Rate Matching with Adaptive Extra-Freezing

The patent applies preliminary action by pre-freezing specific bits (extra-freezing) before the puncturing process. This is done by determining a set of extra-frozen bit indices based on the code rate and code length, and freezing these bits to known values (typically zeros) before encoding. This preliminary freezing prevents these bits from becoming incapable bits during puncturing, thereby maintaining bit reliability while still achieving the desired code rate flexibility through controlled puncturing of non-frozen bits.

The patent applies local quality by differentiating the freezing strategy based on the specific code rate and code length conditions. Instead of using a uniform freezing pattern, the patent determines extra-frozen bit indices adaptively based on local conditions (code rate ranges and code lengths). This allows the system to apply enhanced freezing (better reliability) in low-code rate areas where it is most needed, while maintaining standard freezing in other areas, thus optimizing performance without uniformly increasing decoding complexity.

The patent applies dynamics by making the bit allocation and extra-freezing pattern adaptive to the message length. The set of extra-frozen bit indices is determined dynamically based on the relationship between code rate, code length, and message length. This dynamic adaptation ensures that information bits are reliably allocated to positions that maintain their reliability after puncturing, while keeping the allocation process systematic and implementable through predefined rules rather than complex optimization.