具備先期中斷能力的分散式循環冗餘檢驗碼輔助之串行抵消列表解碼器之設計

Design of Distributed CRC-Aided Successive Cancellation List (dCA-SCL) Decoders with Near-Optimal Early Termination Capability

陳怡臻(Yi-Jen Chen)

指導教授 ： 陳伯寧

國立交通大學/電機學院/電信工程系所/碩士(2020年)

摘要

配合使用分散式循環冗餘檢驗碼輔助(distributed CRC-aided)之串行抵消列表解碼器(successive list decoder)的極化碼，已被證實為5G行動通訊的合宜技術選項。此一技術選項不僅能獲得與(非分散式)循環冗餘檢驗碼輔助之串行抵消列表解碼器相類的區塊錯誤率，還能提供先期中斷解碼程序的能力。然而，如何選取適用於此一技術選項的循環冗餘檢驗碼，尚未被深入研究。在此一背景下，我們提出一項簡易準則以快速挑選近於最佳的循環冗餘檢驗多項式，其中最佳代表的是最大化接收雜訊時的先期中斷解碼程序能力。所提的準則僅為訊息符元數與循環冗餘檢驗碼數的函數。模擬結果顯示，符合所提準則的循環冗餘檢驗多項式多能最小化誤認雜訊為合法字碼的機率，即誤報率。基於我們所提準則，能節省進行模擬來尋找適合的循環冗餘檢驗多項式的時間損耗。

關鍵字

極化碼 ； 分散式循環冗餘檢驗碼 ； 先期中斷能力 ； 串行抵消列表解碼器

並列摘要

Polar codes with distributed cyclic-redundancy-check-aided successive cancellation list (dCA-SCL) decoder have been shown to be a good technology option in the 5G eMBB application. This technology option can provide not only a similar block error rate (BLER) performance to CRC-aided SCL decoder (CA-SCL) but also an early termination capability. How to select a good CRC polynomial for dCA-SCL, however, has not yet been studied. At this background, we propose a simple rule to find a near-optimal CRC polynomial in the sense of maximizing the early termination capability against the reception
of a sequence of noises. The proposed rule is only a function of the number of information bits and the number of the CRC bits. Simulation results show that the CRC polynomials identified by the proposed rule can mostly achieve the minimum false alarm rate, defined as the probability of mistreating a sequence of random noises as a legitimate codeword. With the rule we propose, exhaustive simulations to find a proper CRC polynomial among all choices can be saved.

並列關鍵字

Polar code ； Distributed CRC-Aided Successive Cancellation List ； Early Termination Capability ； Distributed CRC

參考文獻

[1] Erdal Arıkan, “Channel polarization: A method for constructing capacity-achieving codes for symmetric binary-input memoryless channels,” IEEE Trans. Inf. Theory, vol. 55, no. 7, pp. 3051–3073, July 2009.

[2] Ido Tal and Alexander Vardy, “List decoding of polar codes,” IEEE Trans. Inf. Theory, vol. 61, no. 5, pp. 2213-2226, May 2015.

[3] Kai Niu and Kai Chen, “CRC-aided decoding of polar codes,” IEEE Comm. Letters, vol. 16, no. 10, pp. 1668-1671, October 2012.

[4] Jie Chen, Yu Cheny, Keeth Jayasinghe, Dongyang Du, and Jun Tan, “Distributing CRC bits to aid polar decoding,” 2017 IEEE Globecom Workshops, Singapore, 4-8

December 2017.