Joint List Polar Decoder with Successive Cancellation and Sphere Decoding

Abstract

For polar codes, both successive cancellation list (SCL) decoding and list sphere decoding (LSD) aim to balance performance and complexity. The same list structure but different decoding schedules of SCL and LSD can lead to a combination of both schemes. In this paper, an efficient joint list decoder with SCL and LSD (JLSCD) is proposed to reduce time complexity. We apply SCL and LSD schemes simultaneously but independently, then merge them at the middle point of the decoding. Numerical results have demonstrated JLSCD scheme's advantage in complexity. FPGA implementation of JLSCD decoder is also given in this paper.