共查询到15条相似文献,搜索用时 859 毫秒
1.
2.
3.
为保证遥测系统中的遥测站与中继站之间的无线通信的可靠性,设计基于串行级联编码的无线通信;采用混合纠错的差错控制方式,利用BCH(31,16)纠正三位随机错误、CRC-32检错性能好、交织器能将突发错误变为独立错误的特点,以BCH(31,16)为外码,CRC-32为内码,经交织器变换的串行级联编码;通过研究CRC-32码、BCH(31,16)码、交织器的软件实现方法,实现了遥测系统的数据编、译码及检错、纠错功能;该系统经运行测试,无线通信误码率约为10-5~10-6,稳定可靠,达到了设计要求。 相似文献
4.
无线传感器网络信道编码技术研究 总被引:3,自引:0,他引:3
无线传感器网络信道容易受到干扰, 需要进行误码率比较低的差错控制.在研究了无线传感器网络中差错控制机制与能量消耗的关系的基础上,利用差错控制的能量模型,分析了LDPC码和BCH码的能量效率,最后证明利用LDPC码进行差错控制能有效节省传感器网络的能量消耗. 相似文献
5.
6.
7.
8.
9.
10.
在基于DSP的通信系统中,由于纠错码的复杂性,译码算法要占用DSP大量的时间和资源。针对此问题,该文设计了一种新型的纽带纠错码——Tach码。利用DSP移位指令,通过左右移位进行编解码。介绍了纽带纠错码的编码和译码算法,并与经典的Hamming码、BCH码和RS码进行了纠错性能比较。仿真和分析表明纽带纠错码在与其他码性能相当的情况下,译码简单,不需要占用存储器去存储译码所需的错误图样表,易于DSP实现。采用TMS320vc5410实现了该编解码器。 相似文献
11.
Low density parity check codes (LDPC) exhibit near capacity performance in terms of error correction. Large hardware costs, limited flexibility in terms of code length/code rate and considerable power consumption limit the use of belief-propagation algorithm based LDPC decoders in area and energy sensitive mobile environment. Serial bit flipping algorithms offer a trade-off between resource utilization and error correction performance at the expense of increased number of decoding iterations required for convergence. Parallel weighted bit flipping decoding and its variants aim at reducing the decoding iteration and time by flipping the potential erroneous bits in parallel. However, in most of the existing parallel decoding methods, the flipping threshold requires complex computations.In this paper, Hybrid Weighted Bit Flipping (HWBF) decoding is proposed to allow multiple bit flipping in each decoding iteration. To compute the number of bits that can be flipped in parallel, a criterion for determining the relationship between the erroneous bits in received code word is proposed. Using the proposed relation the proposed scheme can detect and correct a maximum of 3 erreneous hard decision bits in an iteration. The simulation results show that as compared to existing serial bit flipping decoding methods, the number of iterations required for convergence is reduced by 45% and the decoding time is reduced by 40%, by the use of proposed HWBF decoding. As compared to existing parallel bit flipping decoding methods, the proposed HWBF decoding can achieve similar bit error rate (BER) with same number of iterations and lesser computational complexity. Due to reduced number of decoding iterations, less computational complexity and reduced decoding time, the proposed HWBF decoding can be useful in energy sensitive mobile platforms. 相似文献
12.
13.
14.
Chi-Shiang Chan 《Pattern recognition letters》2011,32(14):1679-1690
In 2007, Chan and Chang proposed an image authentication method using the Hamming code technique. The parity check bits were produced from pixels by using the Hamming code technique, and the produced bits were embedded in other pixels. When recovering, the method had to predict the value of the most-significant bit of each tampered pixel first. Then, the tampered pixel was able to be recovered by referring to the predicted bit and its parity check bits. However, using the most-significant bit is unsuitable because of the risk of making an incorrect prediction. In this paper, the parity check bits are produced from pixels whose bits have been rearranged. This way, the value of the most-significant bit of each tampered pixel can be determined according to its parity check bits. The recovery procedure is also modified to accommodate the rearranging procedure. The experimental results show that the proposed method has a better ability to recover the tampered areas, compared with Chan and Chang’s method. Moreover, the quality of the authenticated images of the proposed method is also higher than that of Chan and Chang’s method. 相似文献
15.
针对现有二维码在复杂环境中抗污染能力弱、解码速度慢的问题,提出了一种基于全局距离最优的抗污染极短纠错码。首先,构建了表征污染环境的凹凸多边形数学模型;然后,设计了采用3个编码点表示一个目标数据位的极短纠错码;最后,设计了在有限约束域内全局距离最优的编码点的编排方法,并给出了对应的解码算法。对极短纠错码的抗污染能力和识别速度进行了仿真评估,并与经典的BCH码进行了对比。结果表明,当目标数据长度为18、编码点数为63时,极短纠错码在同等污染环境中识别准确率接近BCH码,而解码速度是BCH码的130倍。所提编码还具有结构简洁明确、编码点数适应能力强、易于标准化推广应用等显著优点。 相似文献