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1.
INTRODUCTION In order to satisfy the high throughput and lowlatency requirements for next generation mobilecommunication systems, the parallelization of de-coding of Turbo codes (Berrou et al., 1993) has re-ceived remarkable attention. As the interleav-ing/deinterleaving operations may result in memorycontentions, interleaver design (Dinoi and Benedetto,2005; Dobkin et al., 2005; Popovski et al., 2004; Thulet al., 2002) is the bottleneck of the parallel Turbodecoder. For certain inter… 相似文献
2.
Turbo乘积码是一类易于硬件实现高速迭代译码的分组码,本文对单校验码为子码的高维Turbo乘积码的软输入软输出迭代译码算法进行了详细的分析。进而将其与QAM调制结合起来,提出了一种简化的、便于硬件实现的联合解调译码方案,充分利用了高维Turbo乘积码优越的纠错性能。仿真结果表明这种简化方案在高斯和衰落信道下的译码性能很好。 相似文献
3.
介绍了Turbo码的编、译码原理和译码算法,重点对Turbo码在高斯白噪声（AWGN）信道、瑞利衰落信道、莱斯衰落信道下的误码率进行了比较;通过Matlab仿真分析,探讨了Turbo码在不同信道中的优缺点及其适用环境。 相似文献
4.
严添明 《宁波职业技术学院学报》2007,11(5):68-70,80
对向下兼容DAMB系统中的信道编码进行了研究。在DAMB虚拟无线电Matlab仿真平台仿真时采用迭代多级译码方法,分别进行了一次和二次迭代;同时,采用二元Turbo编码,接收端采用串联迭代译码。在Matlab平台上针对DRM标准建议的多级删除卷积码(RCPC)和Turbo码的数字调幅广播系统两种编码方法,分别在AWGN信道和Rice衰落信道中进行了性能仿真。结果表明,Turbo码可获得比两次迭代多级译码更好的性能。在AWGN信道下,Turbo码经过10次迭代译码能获得近3dB增益;在Rice衰落信道下,Turbo码经10次迭代译码可以获得近2dB左右的增益。 相似文献
5.
This paper investigates the interference cancellation (IC) scheme for uplink cognitive radio systems, using the spectrum underlay
strategy where the primary users (PUs) and the secondary users (SUs) coexist and operate in the same spectrum. Joint MMSE-based
parallel interference cancellation (PIC) and Turbo decoding scheme is proposed to reduce the interference to the PUs, as well
as to the SUs, in which the minimum mean square estimation (MMSE) filter is only employed in the first iteration, regarded
as the “weakest link” of the whole detection process, to improve the quality of the preliminary detections results before
they are fed to the Turbo decoder. Simulation results show that the proposed scheme can efficiently eliminate the interference
to the PUs, as well as to the SUs. 相似文献
6.
申时凯 《昭通师范高等专科学校学报》1999,21(2):12-15
分析了ＵＣＤＯＳ汉字系统下Ｔｕｒｂｏ Ｐａｓｃａｌ程序不能正常运行的原因,编写了Ｔｕｒｂｏ Ｐａｓｃａｌ系统的ＣＲＴ单元中的函数与过程,使得在ＵＣＤＯＳ汉字系统下能够正常运行Ｔｕｒｂｏ Ｐａｓｃａｌ程序。 相似文献
7.
Differential frequencyhopping(DFH) as a digital radiotechnology has satisfyingfeatures of multipathfading mitiga-tion,spectral re-use ,non-interferingspreadspectrumoper-ation,andinterferenceresistance[1].Sincetheintroductionof controllable redundancy into… 相似文献
8.
This study explores early stages of reading acquisition, specifically therelation of phoneme blending and letter recoding to individual differencesin word decoding. The hypothesis was that facility in letter recoding andaccuracy of phoneme blending are substantial components of word decodingin beginning readers but not for skilled reading and that reliance onphoneme-sized decoding of words would dissipate as reading proficiencyincreased. In four studies we examined the ability to recode letters, blendphonemes and decode words in four groups of Dutch children (early Grade1, N = 130, older Grade 1, N = 81, Grade 3, N = 54 and a group of children witha reading lag, N = 356). Phoneme blending was only related to the readingability of beginning Grade 1 children. By the end of Grade 1 ability to blendphonemes did not differentiate reading capacity, nor for older children inGrade 3 and reading disabled children. Letter recoding was related to worddecoding in all four studies, although the strength of that relation diddwindle as reading skill level increased. The results of the study appearconsistent with self teaching hypothesis and other theories that imply atransient role of explicit phonological recoding in word identification. 相似文献
9.
就Turbo C2.0环境中存在的一些问题,在Turbo C2.0编译环境下,解决了Turbo C2.0 floating point formats not linked的bug问题. 相似文献
10.
就TurboC2．0环境中存在的一些问题,在TurboC2．0编译环境下,解决了TurboC2．0 floating point for mats not linked的bug问题。 相似文献
11.
本文提出了一种新型交织器,对其完备性从数学上给出了证明,进行了计算机仿真,分析了仿真结果,并与其它交织方案的性能作了比较. 相似文献
12.
软件教学应从视觉上传达人机交互界面的使用操作,Turbo Demo作为专业演示课件制作工具,能够方便、快速的创建出操作演示课件,并输出为多种媒体格式。以《数据库原理》课程中SQL Server软件教学的课件制作为例,Turbo Demo工具通过捕捉、编辑、发布过程创建出演示课件,该方法有利于软件教学内容传达。提高教学质量和促进学生自主学习。 相似文献
13.
A flash card computer program designed to increase decoding speed in reading was evaluated with a sample of 55 eight- to twelve-year-old Dutch poor readers by using a pretest-training-posttest control group design. The reading level of the poor readers was comparable to the reading level of normal readers in grade two. After 8 weeks of practicing (twice a week) for 30 minutes per session, children in the training group showed substantial improvements in decoding speed not only on pseudowords directly practiced during the training, but also in untrained pseudowords and in existing words. The no-training control group did not improve in decoding speed from pre- to posttest. The results, furthermore, indicate that syllable-bound processes play a role in phonological decoding in Dutch, and that the flash card method used in this study stimulates poor readers to decode letter strings into syllabic units, which leads to an increase in decoding speed. The role of the syllable in phonological decoding and the potential of a specific flash card technique as a means to improve decoding skills of poor readers are discussed. 相似文献
14.
LDPC（Lower Density Parity Check）码是一类可以用非常稀疏的校验矩阵定义的线性分组纠错码.由于LDPC码校验矩阵的规律性可以用二分图表现出来,二分图中的环路也会影响到迭代译码的准确性和有效性,尤其是短环.本文给出了一种有效消去周长为4的短环的校验矩阵H的生成算法,并且对该算法构造的校验矩阵进行了仿真分析. 相似文献
15.
A relationship between brain responses at birth and later emerging language and reading skills have been shown, but questions
remain whether changes in brain responses after birth continue to predict the mastery of language-related skills such as reading
development. To determine whether developmental changes in the brain-based perceptual skills are systematically related to
differences in word-level reading proficiency at age 8 years, brain event-related potentials (ERPs) to speech and nonspeech
stimuli were recorded annually at the ages of 1 through 8 years in a sample of 109 typically developing children. Two measures
of word-level reading (one that requires decoding of real words and one of pseudowords) were administered at age 8 years.
Growth curve analysis, using the hierarchical linear models, related reading performance (average versus low) to the longitudinal
maturation in the ERP waveform peak and latencies. Maturational changes (e.g., slope, acceleration, and cubic growth) in N1
amplitude from ages 1 to 4 were related to proficiency in decoding pseudoword stimuli only, with children who were less proficient
in decoding pseudowords evidencing more steeply negative declines in amplitude with age, particularly at the frontal and parietal
recording sites in response to both speech and nonspeech stimuli. In contrast, proficiency in decoding real words was related
to developmental changes in N2 amplitudes from ages 4 to 8 only at the parietal recording site, and only in response to nonspeech
stimuli. The early development of biologically based differences in the perception and processing of auditory information
contributes to later group differences in reading proficiencies at school age. 相似文献
16.
许坤远 《廊坊师范学院学报(自然科学版)》2009,9(4):60-62,67
运用特征矩阵方法研究了一类兼具含缺陷的一维光子晶体特性的“分形”多层结构（准晶）的光学性质。结果表明该结构具有两个明显的特性：一个是由结构的自相似性所导致的光谱的尺度不变性;另一个是在某个宽的频谱范围内出现许多强的局域透射峰。多局域的特性有望运用于设计薄膜“梳状滤波器”。 相似文献
17.
智西湖 《洛阳师范学院学报》1998,(5)
对数字化后的信息进行编码和解码,是计算机对信息进行处理的最基本方式;面对巨大信息量的处理,需要有快速高效的编解码方法,本文给出了一种顺序、累进和无损操作模式的编解码器模型。 相似文献
18.
The translation activity is a process of the interlinguistic transmission of information realized by the information encoding and decoding.Encoding and decoding,cognitive practices operated in objective contexts,are inevitably of selectivity ascribing to the restriction of contextual reasons.The translator as the intermediary agent connects the original author(encoder)and the target readers(decoder),shouldering the dual duties of the decoder and the encoder,for which his subjectivity is irrevocably manipulated by the selectivity of encoding and decoding. 相似文献
19.
This paper presents an efficient VLSI architecture of the contest-based adaptive variable length code (CAVLC) decoder with power optimized for the H.264/advanced video coding (AVC) standard. In the proposed design, according to the regularity of the codewords, the first one detector is used to solve the low efficiency and high power dissipation problem within the traditional method of table-searching. Considering the relevance of the data used in the process of runbefore’s decoding, arithmetic operation is combined with finite state machine (FSM), which achieves higher decoding efficiency. According to the CAVLC decoding flow, clock gating is employed in the module level and the register level respectively, which reduces 43% of the overall dynamic power dissipation. The proposed design can decode every syntax element in one clock cycle. When the proposed design is synthesized at the clock constraint of 100 MHz, the synthesis result shows that the design costs 11 300 gates under a 0.25 μm CMOS technology, which meets the demand of real time decoding in the H.264/AVC standard. 相似文献
20.
Listening is a major challenge for many English as a foreign language (EFL)/English as a second language (ESL) learners. Many learners find it difficult to immediately process and segment an ongoing stream of sounds. Decoding training is one of interventions that have been used to assist EFL/ESL learners. This paper reviewed empirical studies of the effectiveness of decoding training in developing EFL/ESL learners' listening. We examined the following four major factors: (a) the types of instructional activities used; (b) the effects of decoding training on student listening outcomes; (c) the main instructional enablers of decoding training; and (d) the main instructional barriers to decoding training. The two activities most frequently used for decoding training were dictation and pronunciation instruction. A meta-analysis of 13 intervention studies showed an overall significant effect in favor of decoding training over non-decoding instruction for listening education (Hedges's g = 0.553, CI = 0.348–0.759, 95% confidence interval, p = 0.000), with no evidence of publication bias. Two theoretical frameworks, cognitive learning theory and the attention, relevance, confidence, and satisfaction model, were used to synthesize 33 studies to analyze the common elements that promote and hinder the development of learners' decoding skills. We proposed a set of design principles for decoding training that are expected to enhance the effectiveness and efficiency of decoding training in EFL/ESL listening education. 相似文献