Successive Cancellation List Decoder with Adaptive List Length
Jiajie Tang, Ming Chen · 2019
Successive cancellation list decoder, which is generalized from successive cancellation decoder by increasing list size, is an effective decoding algorithm for polar codes. However, the list length is invariant throughout the decoding process which leads to redundant computation. To avoid this redundant computation, we propose an innovative and heuristic method to adjust the list length according to the variance of path metric values during decoding procedure and signal-to-noise ratio. With decision threshold proportional to the best path, the proposed method fully considers the trend of path metric change. Experimental results demonstrate that our proposed algorithm can reduce computational complexity and improve performance compared with successive cancellation list decoder. For (1024, 512) CRC-aided polar codes, the proposed algorithm can achieve ten times better performance at point$\mathrm{SNR}=3\mathrm{dB}$with less computational complexity compared with conventional algorithms.