Efficient Soft Cancelation Decoder Architectures for Polar Codes

1. Efficient Soft Cancelation Decoder Architectures for Polar
Codes
ABSTRACT:
The flooding belief propagation (FO-BP) and the soft-cancelation (SCAN)
algorithms are the two most popular soft-output BP algorithms for the decoding of
capacity-achieving polar codes. The FO-BP algorithm has high throughput at the
cost of performance degradation in high signal-to-noise ratio (SNR) region or with
large block length. The SCAN algorithm has much better decoding performance
while suffering from long decoding latency and low throughput. In this paper, an
improved BP algorithm, named reduced complexity softcancelation (RCSC)
algorithm, is proposed. Compared with the SCAN algorithm, the number of
memory entries required by the RCSC algorithm is reduced by more than 50% in
general, while achieving comparable or even better (e.g., when block size N=215)
decoding performance. When block size is large(e.g., N ≥215), the proposed RCSC
algorithm reduces the required memory entries by more than 23% compared with
the state-of-the-art FO-BP algorithm. The numerical results show that the error
performance improvement of the RCSC algorithm is more significant when the
SNR increases. For a different tradeoff, a reduced latency soft-cancelation (RLSC)
algorithm is proposed to reduce the decoding latency and increase the throughput
of the RCSC algorithm while slightly sacrificing decoding performance. Finally,

2. the optimized VLSI architectures are presented for the RCSC and RLSC
algorithms, respectively. The synthesis results demonstrate the efficiency of the
proposed algorithms and architectures. The proposed architecture of this paper
analysis the logic size, area and power consumption using Xilinx 14.2.
SOFTWARE IMPLEMENTATION:
 Modelsim
 Xilinx ISE