講演抄録/キーワード |
講演名 |
2011-12-15 09:10
Investigation of Dual Threshold Scaling Factors for Bit Flip Decoding ○Julian Webber・Toshihiko Nishimura・Takeo Ohgane・Yasutaka Ogawa(Hokkaido Univ.) RCS2011-232 |
抄録 |
(和) |
Very low error rates can be obtained using low-density parity-check (LDPC) codes and their use is now common in new communications standards such as the Long Term Evolution (LTE) Advanced. The decoders based on belief propagation offer excellent performance but have high complexity. Therefore simpler architectures based on the bit flipping algorithm have been researched. Over the last two years a few adaptive threshold algorithms have been proposed in which a bit is either inverted if it is below a threshold, or the threshold itself is lowered using a scaling factor. This work looks at how the scaling factor influences the iteration count and error performance. We propose an algorithm that switches between two scaling factors based on the syndrome sum on each branch. Using this technique we show that the error performance is comparable with that of a single scaling factor but the iteration count is significantly reduced. Further, if a non-transmitted codeword is detected, which corresponds to a trapped search point, an addition of a small noise perturbation can potentially provide an escape opportunity and this is experimentally investigated. |
(英) |
Very low error rates can be obtained using low-density parity-check (LDPC) codes and their use is now common in new communications standards such as the Long Term Evolution (LTE) Advanced. The decoders based on belief propagation offer excellent performance but have high complexity. Therefore simpler architectures based on the bit flipping algorithm have been researched. Over the last two years a few adaptive threshold algorithms have been proposed in which a bit is either inverted if it is below a threshold, or the threshold itself is lowered using a scaling factor. This work looks at how the scaling factor influences the iteration count and error performance. We propose an algorithm that switches between two scaling factors based on the syndrome sum on each branch. Using this technique we show that the error performance is comparable with that of a single scaling factor but the iteration count is significantly reduced. Further, if a non-transmitted codeword is detected, which corresponds to a trapped search point, an addition of a small noise perturbation can potentially provide an escape opportunity and this is experimentally investigated. |
キーワード |
(和) |
bit-flip decoding / adaptive threshold / LDPC / gradient descent / low-complexity / / / |
(英) |
bit-flip decoding / adaptive threshold / LDPC / gradient descent / low-complexity / / / |
文献情報 |
信学技報, vol. 111, no. 345, RCS2011-232, pp. 1-6, 2011年12月. |
資料番号 |
RCS2011-232 |
発行日 |
2011-12-08 (RCS) |
ISSN |
Print edition: ISSN 0913-5685 Online edition: ISSN 2432-6380 |
著作権に ついて |
技術研究報告に掲載された論文の著作権は電子情報通信学会に帰属します.(許諾番号:10GA0019/12GB0052/13GB0056/17GB0034/18GB0034) |
PDFダウンロード |
RCS2011-232 |
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