Rate matching

Rate matching is a technique used in channel coding to match the channel coded bits to the number of target bits. It serves many purposes few of which are listed below.

  • controls the rate of the channel codes using bit selection.

  • provides robustness against burst/block errors using bit/sub-block interleavers.

  • improves the forward error correction performance for higher modulation orders using channel interleavers.

In 5G, the rate matching is required for all the possible chains/channel codecs. The details of the rate matching for both LDPC codes and Polar codes are discussed in following sections.