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本文介绍了AMBE算法和AMBE-2000编解码芯片以及它在数字语音通信系统中的使用,给出了一个应用AMBE-2000芯片实现无线数字语音通信的设计实例,详细说明了使用AMBE-2000芯片进行数字语音通信系统的软硬件实现方法。 相似文献
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本文介绍能适用现有无线通信网、并满足高保密度要求的9EC755型数字语言保密机。该机的特点是采用了数字信号处理及传输,有识别语音的功能,对语音的特征不敏感,不缩小电台的通信范围,与电台相比,功耗可以忽略,体积小,并采用陆地线路通信中的标准数传机。 相似文献
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设计了一种基于DSP的语音信号采集系统,并根据设计思路分别给出了系统各模块的功能和实现方式。该系统能够完成对音频信号的实时采集和数字处理,还具有存储、与上位机进行串口通信等功能 相似文献
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本系统采用TI公司生产的MSP430F149单片机和凌阳公司的SPCE061A单片机实现。MSP430F149因其功耗低,超小型,低成本,功能完整,在国内越来越受到用户的重视和广泛的运用。该红外测温仪运用单片机与PC机通信技术,通过巧妙的软件设计和硬件电路,及其凌阳单片机强大的语音功能实现了温度的采集、语音播报及其PC机对下位机的监控及其数据的存储。温度信号由ANT-OTP-538U热电堆传感器和电压放大温度补偿电路处理后提供。同时,具有温度数字语音播报和显示。 相似文献
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为了解决在受阻塞干扰的跳频信道上语音质量受影响严重的问题,对以传输语音为主的数字跳频系统采用CVSD(连续可变斜率增量调制)编码时的编码算法进行了优化研究。在传统CVSD编码基本原理的基础上,提出了一种新的CVSD编码优化算法,并给出了数字跳频系统中语音质量衡量准则和基于优化算法的数字跳频系统CVSD基带仿真模型,具体分析了在部分频带噪声干扰下优化算法对系统接收语音信号恶化量的影响。仿真结果表明,优化算法较之传统CVSD编码算法能有效地控制接收语音信号恶化量,即使在受阻塞干扰十分严重的情况下也能获得较好的语音质量。 相似文献
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给出了一种基于DSP技术实现的模数兼容的多通道数字电话的系统设计方案,设计中采用了DSP、低比特率语音压缩编解码、信道复用、快闪存储、串口和调制解调器通信等技术。在通用调制解调器构成的点对点通信平台上实现了两种语音的复用、传输及交换。 相似文献
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A low-complexity pseudo-analog speech transmission scheme is proposed for portable communications. It uses a speech coder based on adaptive differential pulse code modulation (ADPCM) in combination with a multilevel digital modulation technique such as M -ary DPSK or M -ary FSK and features low quantization noise, bandwidth efficiency, and robustness to transmission errors. A nonsymmetric M -ary DPSK scheme called skewed M -ary DPSK is proposed to enhance the noisy channel performance. Comparison to conventional analog FM and a digital speech transmission scheme using adaptive predictive coding and forward error correction (FEC) based on convolutional coding shows that the pseudo-analog system has the best objective signal-to-noise ratio performance under most channel conditions. Informal subjective evaluations rate the digital system superior to the pseudo-analog scheme for bad channels and conversely for good channels. It is concluded that the pseudo-analog system can be designed with low delay and high speech quality for good channels with high spectral efficiency 相似文献
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Wai-Choong Wong Sundberg C.-E.W. Seshadri N. 《Vehicular Technology, IEEE Transactions on》1994,43(4):934-945
Various strategies to provide low-delay high-quality digital speech communications in a high-capacity wireless network are examined. Various multiple access schemes based on time-division and packet reservation are compared in terms of their statistical multiplexing capabilities, sensitivity to speech packet dropping, delay, robustness to lossy packet environments, and overhead efficiency. In particular, a low-delay multiple access scheme, called shared time-division duplexing (STDD) is proposed. This scheme allows both the uplink and downlink traffic to share a common channel, thereby achieving high statistical multiplexing gain even with a low population of simultaneous conversations. The authors also propose a choice of low delay, high quality speech coding and digital modulation systems based on adaptive DPCM, with QDPSK or pseudo-analog transmission (skewed DPSK), for use in conjunction with the STDD multiple access protocol. The choice of the alternative systems depends on required end-to-end delay, recovered speech quality and bandwidth efficiency. Typically, with a total capacity of 1 MBaud, 2 ms frame and 8 kBaud speech coding rate, low delay STDD is able to support 48 pairs of users compared to 38, 35, and 16 for TDMA with speech activity detection, basic TDMA and PRMA respectively. This corresponds to respective gains of 26%, 37% and 200% 相似文献
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提出了一个使用Legendre序列的语音水印隐藏与检测算法。实验结果表明,用这种算法隐藏水印具有很强的隐蔽性,对原始语音的影响基本上察觉不出来,叠加了水印的语音对于多种强干扰及信号处理均具有很好的健壮性。 相似文献
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在车内数字通信系统中,使用基于DSP嵌入式的以太局域网,实现车内语音和数据同传通信。笔者设计该系统时的重点是在语音数字处理,特别提出了一种自行设计的语音起止点判决方法--五点搜索法。 相似文献
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随着音频编辑软件的广泛使用,数字语音材料很容易被重新编辑。如何对数字语音信号原始性进行有效的认证成为一项急需解决的课题。提出了一种置换语音信号的小波包-谱相减(WPT-SS)的被动检测方法,利用语音设备固有噪声特性,对置换语音信号进行有效检测和置换区域定位,通过实验证实了该方法的有效性。 相似文献
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提出了一种结合韵律信息的高性能汉语连续数字语音识别算法,该识别算法基于CHMM(连续隐马尔可夫模型),采用MFCC(MEL频率倒谱系数)为主要语音特征参数,结合韵律信息进行连续数字精确分割,能够有效区分易混数字。算法采用两级识别框架来提高语音识别率,其中,第1级对连续数字分割,在此基础上进行数字语音识别,输出各候选结果,第2级在候选结果中确定易混数字对,并运用韵律信息进一步选择正确结果。实验表明,最终汉语连续数字语音识别率有很大提高。 相似文献
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Robert N. Bostrom John R. Baseheart Charles M. Rossiter 《The Journal of communication》1973,23(4):461-475
The present investigation was concerned with the effect of using profanity in a communication on receiver attitude change and speaker credibility ratings. Results of the investigation found no support for the superiority of a persuasive communication using profanity of a religious, excretory, or sexual nature over the same communication devoid of such profanity. It was found, however, that if one of the above three types of profanity is included in a communication, greater attitude change can be expected to occur if the communicator is a female using any one of the three profanity-types mentioned than if the communicator is a male using the same types of profanity. Finally, it was found that using profanity in a communication generally has a detrimental effect on the perceived credibility of the communicator. 相似文献