Interleaved Concatenations of Polar Codes With BCH and Convolutional Codes

Ying Wang, Krishna R. Narayanan, Yu-Chih Huang

Research output: Contribution to journalArticle

31 Scopus citations


We analyze interleaved concatenation schemes of polar codes with outer binary BCH codes and convolutional codes. We show that both BCH-polar and Conv-polar codes can have a frame error rate that decays exponentially with the code length for all rates up to capacity, which is a substantial improvement in the error exponent over stand-alone polar codes. Interleaved concatenation with long constraint length convolutional codes is an effective way to leverage the fact that polarization increases the cutoff rate of the channel. Simulation results show that Conv-polar codes when decoded with the proposed soft-output multistage iterative decoding algorithm can outperform stand-alone polar codes decoded with successive cancellation or belief propagation decoding. It may be comparable to stand-alone polar codes with list decoding in the high SNR regime. In addition to this, we show that the proposed concatenation scheme requires lower memory and decoding complexity in comparison to belief propagation and list decoding of polar codes. Practically, the scheme enables rate compatible outer codes which ease hardware implementation. Our results suggest that the proposed method may strike a better balance between performance and complexity compared to existing methods in the finite-length regime.

Original languageEnglish
Pages (from-to)267-277
Number of pages11
JournalIEEE Journal on Selected Areas in Communications
Issue number2
StatePublished - Feb 2016


  • Polar codes
  • cutoff rate
  • sequential decoding
  • interleaved concatenation
  • multistage decoding

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