基于奇偶检错-汉明纠错算法的误码率后验分布参数,用仿真数据 直接估计纠错后的误码率及其置信区间。 实验利用了两个伪随机二进制序列替代原始量子密钥,长度为1.4×10－7, 误码呈二项分布,通过 奇偶检错后利用(7,4)汉明码对奇偶性不一致的码字进行纠错。实验结果表明:当初始误码率为3%时, 通过一次检错、纠错,误码率降至2.47×10－3, 置信度为95%的上限值为2.77×10－3; 当初始误码率 为0.1%时,通过一次纠错,误码率降至1.43×10－7, 置信度为95%的上限值为10.54×10－7。该方法有 效地估计了奇偶-汉明纠错码对有限长度原始量子密钥纠错后的误码率,为量子密钥分配后续处理提 供了可靠的数据支持。

Based on the parameters of posterior distribution of bit error rate (BER) regarding parity check-Hamming correction protocol, the BER and its confidence interval of the remaining quantum keys were directly estimated. In experiment, instead of the raw quantum keys, two pseudo-random binary sequences were used which have the length of 1.4×10－7 and the BER follow binomial distribution. The error correction process utilizes the parity code and Hamming code for error detection correction respectively. The experimental results showed that when the initial bit error rate at 3% and 0.1%, by one time error detection and error correction, the BER falls to 2.47×10－3 and 1.43×10－7 respectively, when the confidence at 95%, the corresponding upper limit of BER at 2.77×10－3 and 10.57×10－7 respectively. These experimental results effectively assessed parity-Hamming error correction performance on the finite quantum keys, and provided reliable data for the post-processing in the quantum key distribution.