共查询到17条相似文献,搜索用时 93 毫秒
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循环码是实际差错控制系统中常用的编码方案,具有检错纠错能力强、实现方便等特点.本文在理论分析循环码编码和译码基本原理的基础上,提出了基于单片机系统的(7,4)循环码软件实现编码、译码的方案. 相似文献
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分块归零Turbo编码方案通过采用与分块并行译码相适应的帧分裂和归零编码处理,使码字具有适应分块并行译码的结构特性。相应算法仿真和FPGA设计实现表明,该方案首先无需在相邻分块间考虑重叠比特以保证误码性能,有助于提高短码块长时的译码吞吐率;其次,分块归零处理也使得译码单元内部的状态度量初始值为一个确定值,从而使得各个SISO之间的译码更加独立,降低了译码器FPGA实现复杂度;此外,分块归零的编码结构特性在迭代译码时能够更快收敛。 相似文献
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提出了未编码DUSTM系统的网格译码。将DUSTM系统视为具有全状态转移的网格结构,采用维特比软译码算法进行信号解调。仿真结果表明该方案相比传统的基于单符号最大似然解调的DUSTM系统性能有大幅提升,且比编码DUSTM系统具有更高的频谱利用率。 相似文献
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介绍一种由多个音频编码的遥控系统,并按照该系统编码的指令格式,采用了四线-十六线译码器译码和大功率驱动开关集成电路进行指令输出的电路形式,成功地为机载遥控接收机设计了一种新的译码电路。该译码电路不仅具有元件少,功耗低;体积小,重量轻之特点,而且译码准确,抗单音频干扰性能优良,很适合于该设备的小型化。 相似文献
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根据Chase译码算法和分阶统计译码(OSD)算法在纠错能力上的互补性,提出一种新的针对RM码的OSD-Chase并行译码算法,其中,OSD算法对接收序列的高可信相互独立符号集合(MRIPs)进行处理,并产生候选码字,若MRIPs中有超过i个错误,则order-i的OSD算法译码失败。Chase算法对接收序列的低可信度符号集合(LRPs)进行处理,若有过多的错误出现在LRPs中,超过代数译码的纠错能力,则Chase译码失败,同时设计一种并行最大似然译码算法。仿真实验结果表明,该算法能够获得较高的译码性能。 相似文献
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IRA码的译码通常是利用BP译码算法来实现的,但是BP译码算法的硬件电路复杂.为了让译码算法在复杂度和译码性能之间取得较好的折衷,提出一种改进型IRA译码算法,该算法采用偏移量近似的方法来逼近于BP译码算法,能够简化BP译码算法的复杂度.仿真结果表明,与BP译码算法相比,改进型IRA译码算法能够在降低算法复杂度的同时保持良好的译码性能,与最小和译码算法相比,改进型IRA译码算法的复杂度几乎不变,但译码性能得到了明显的提高. 相似文献
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为了弥补UMP BP-Based相对于LLR BP译码算法的性能缺陷,提出一种改进型UMP BP-Based译码算法。通过将Normalized BP-Based和Offset BP-Based译码算法的优点相结合,并利用最小均方误差准则来计算该算法中的参数。仿真结果表明,在相同误码率的情况下,改进型UMP BP-Based译码算法比UMP BP-Based、Normalized BP-Based以及Offset BP-Based具有更好的LDPC译码性能。 相似文献
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WU WeiRen TU Juan TU GuoFang GAO ShaoShuai & ZHANG Can School of Information Science Engineering Graduate University of Chinese Academy of Sciences Beijing China Beijing Institute of Electronic System Engineering China Aerospace Science & Industry Corp. Beijing State Key Laboratory of Information Security Graduate University of Chinese Academy of Science 《中国科学:信息科学(英文版)》2011,(9):1883-1894
This paper presents joint source channel variable length (VL) coding/decoding based on a space trellis.Through constructing a joint decoding plane trellis,better decoding performance can be achieved than by using the bit-level decoding algorithm.However,the plane trellis is complicated,which results in high decoding complexity for decoding VL turbo codes.To solve this problem,we construct a space trellis and design a low-complexity joint decoding algorithm with a variable length symbol-a posteriori probabil... 相似文献
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Sanjay Sharma 《Computers & Mathematics with Applications》2012,63(1):280-287
It has been shown that when perfect or partial channel state information (CSI) is available at the transmitter, the performance and capacity of a space-time coded system can be further improved. Multilevel space-time trellis codes (MLSTTC’s) are capable of simultaneously providing bandwidth efficiency, diversity improvement and coding gain with significantly reduced decoding complexity, especially for larger constellations and higher throughputs. In this paper, we present a design of combined multilevel space-time trellis codes and beam forming based on feedback from receiver, henceforth referred to as weighted multilevel space-time trellis codes (WMLSTTCs). The channel profile is used to provide a beam forming scheme that achieves the better performance by properly weighting transmitted signals. Weights are selected that matches best with a channel profile feedback from the receiver indicative of long-term characteristics of the wireless channel. WMLSTTCs provide improvement in performance of MLSTTCs. 相似文献
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Network coding helps improve communication rate and save bandwidth by performing a special coding at the sending or intermediate nodes. However, encoding/decoding at the nodes creates computation overhead on large input data that causes coding delays. Therefore the progressive method which can hide decoding delay in waiting time is proposed in the previous works. However, the network speed has been greatly accelerated and progressive schemes are no longer the most efficient decoding method. Thus, we present non-progressive decoding algorithm that can be more aggressively parallelized than the progressive network coding, which can diminish the advantages of hidden decoding time of progressive methods by utilizing the multi-core processors. Moreover, the block algorithm implemented by non-progressive decoding helps to reduce cache misses. Through experiments, our scheme which relies on matrix inversion and multiplication shows 46.0% improved execution time and 89.2% last level cache miss reduction compared to the progressive method on multi-core systems. 相似文献
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网络编码的出现为改进网络的传输性能提供了新的方法.J.K.Sundararajan等人将网络编码技术与传输控制协议相结合,提出了基于网络编码的TCP/NC协议,其在改进无线网络中传统TCP的性能方面取得了明显效果.但该协议及其改进协议存在的数据传榆和解码操作同步性问题会严重影响TCP/NC性能.提出的改进协议TCP/NCW根据解码时间调节解码窗口,以确保数据传输和解码操作同步,从而获得更好性能.运用排队论分析了TCP/NCW最优解码窗口的存在性.在NS2中的仿真结果表明,在静态场景和动态场景下TCP/NCW的吞吐率比TCP/Vegas和TCP/NC有显著提高,同时也具有较好的公平性. 相似文献
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结合现代移动通信系统的主要技术,主要针对多输入多输出天线系统(Multiple-Input Multiple-Output,MIMO)、正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术和空时编码技术进行了研究。首先介绍了MIMO技术的发展现状和基本原理;然后介绍了OFDM技术的发展现状和基本原理,并分析该技术的优缺点,分析MIMO-OFDM系统形成的必然性及该系统的关键技术;最后介绍了3种典型空时编码技术,即分层空时码、空时网格码和空时分组码的编译码原理,并利用MATLAB软件对上述内容进行了仿真分析和比较,从而得出MIMO技术、OFDM技术和空时编码技术的结合将是未来移动通信发展的方向。 相似文献
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A wireless sensor network (WSN) usually consists of a large number of battery-powered low-cost sensors with limited data collection and processing capacity. In order to prolong the lifetime of the WSN with a target error performance, a novel clustered distributed coding framework, referred to as distributed multiple-sensor cooperative turbo coding (DMSCTC), is developed for a large-scale WSN with sensor grouped in cooperative cluster. In the proposed DMSCTC scheme, a simple forward error correction is employed at each sensor and a simple multi-sensor joint coding is adopted at the cluster head, while complicated joint iterative decoding is implemented only at the data collector. The proposed DMSCTC scheme achieves extra distributed coding gain and cooperative spatial diversity without introducing extra complexity burden on the sensors by transferring the complicated joint decoding process to the data collector. With the proposed scheme, the WSN can achieve the target error performance with less power consumption, thus prolonging its lifetime. The error performance and energy efficiency of the proposed DMSCTC scheme are analyzed, and followed by Monte Carlo simulations. Both analytical and simulation results show that the DMSCTC can substantially improve the energy efficiency of the clustered WSN. 相似文献