载人潜水器“蛟龙”号的水声通信信号处理

蛟龙号的水声通信机实现了世界上首次7000 m深度的潜器与母船间的图像、语音、数据和文字的水声通信传输。研究了适用于载人潜水器的水声通信信号处理。(1)它有4种通信功能:1)相干水声通信,传输速率为5~15 kbps,用于传输图像;2)非相干水声通信,传输速率300 bps,传输文字、指令和数据;3)扩频水声通信,传输速率16 bps,传输指令;4)水声语音通信,采用单边带调制技术传输语音。(2)相干水声通信信号处理方法主要是自适应多普勒补偿的多通道自优化判决反馈自适应均衡器,它与Turbo码级联工作,同时采用定长编码的小波图像压缩方法。(3)声呐线阵吊放至水中一定深度,实现空间分集合并技术。(4)太平洋水域试验表明,水声通信机的作用距离几乎覆盖了所有地球海洋的深度,7s或14s传输一幅光图或声图。      

近红外传感器在汽车改造技术中的应用研究

利用反射式近红外传感器及语音录放组件,研究了汽车倒车防撞语音提示器。当汽车倒车时,只要距车身后尾一定的距离内有人或物体存在,就会有一部分红外光信号经人或物体反射回来,被与发射管同排安装的光敏接收管收到并转换成同频率的电信号后,由模块内部电路进行放大、解调、整形、比较处理后,在输出端输出控制信号,控制语音录放组件工作,告诉司机车后有人、车后有物体。由于近红外线传感器、语音录放组件均为一体化结构,成本低、接线简单、抗震能力强、测量准确、工作稳定可靠,适合在汽车上安装使用。     

叠加态下3色场波形优化增大谐波辐射截止能量及强度

在He~+离子1s态和2s态的叠加态作为初始态时,提出一种优化3束激光场来增大谐波截止能量和强度的方法.结果表明:在叠加初始态下,谐波强度要比基态初始态下增强3个数量级以上.随后,在3色场波形优化下,谐波截止能量又得到增大,进而获得一个高强度、高光子能量的谐波光谱连续区.通过叠加光谱连续区上最后100次的谐波可以获得一个27 as的孤立阿秒脉冲.     

联合精确比值掩蔽与深度神经网络的单通道语音增强方法

针对目前有监督语音增强忽略了纯净语音、噪声与带噪语音之间的幅度谱相似性对增强效果影响等问题,提出了一种联合精确比值掩蔽(ARM)与深度神经网络(DNN)的语音增强方法。该方法利用纯净语音与带噪语音、噪声与带噪语音的幅度谱归一化互相关系数,设计了一种基于时频域理想比值掩蔽的精确比值掩蔽作为目标掩蔽;然后以纯净语音和噪声幅度谱为训练目标的DNN为基线,通过该DNN的输出来估计目标掩蔽,并对基线DNN和目标掩蔽进行联合优化,增强语音由目标掩蔽从带噪语音中估计得到;此外,考虑到纯净语音与噪声的区分性信息,采用一种区分性训练函数代替均方误差(MSE)函数作为基线DNN的目标函数,以使网络输出更加准确。实验表明,区分性训练函数提升了基线DNN以及整个联合优化网络的增强效果;在匹配噪声和不匹配噪声下,相比于其它常见DNN方法,本文方法取得了更高的平均客观语音质量评估(PESQ)和短时客观可懂度(STOI),增强后的语音保留了更多语音成分,同时对噪声的抑制效果更加明显。      

On the pitch of dialogue in Chinese Putonghua

In order to improve the naturalness of TTS speech so as to represent the cadence of natural speech, it is necessary to have a study on the pitch of spontaneous speech. Based on the 973 telephone corpus, the pitch ranges and pitch registers of 1084 intonation phrases are analyzed. It is found that intonation phrases can be classified according to their ranges and registers, and this is related to their positions in dialogue exchange. Compared with read speech, the pitch patterns in dialogue are more variable.     

“神光Ⅱ”装置激光输出波形的数值模拟

推广应用“激光放大一维问题的解”的计算方法,模拟计算了“神光Ⅱ”装置激光束放大链的传输波形,并与实验结果进行比较,符合较好. 为功率平衡的研究提供了有力工具. 关键词： 模拟计算 激光束 波形 功率平衡     

Speech enhancement based on multitaper spectrum and psychoacoustical weighting rule

Multitaper spectrum has lower variance than the traditional periodogram. The noise spectrum and the noise to noisy signal spectrum ratio (NNSR) were estimated from the multitaper spectrum of the noisy signal; the pre-enhanced speech for calculating the noise masking threshold was obtained by the spectral amplitude subtraction method, whose gain is a function of NNSR; the final enhanced speech was obtained by suppressing the Fourier spectrum of the noisy speech with the psychoacoustical weighting rule incorporating the noise masking threshold. Because of the low variance feature of the multitaper spectrum, a modified offset formula was proposed to calculate the noise masking threshold, thus the reconstructed speech with this modification has an improvement in MBSD (Modified Bark Spectral Distortion). When a maximum limitation less than one to the psychoacoustical weighting rule is further proposed, the higher the input SNR (> 0 dB) is, the more improvement the segmental SNR and the overall SNR have. The informal listening tests show that there is little speech distortion for the enhanced speech processed by the proposed method, the background noise is reduced much and free of musical noise.     

一种可调制的连续光谱点光源

短弧氙灯是一种发光强度高,具有从紫外到红外的连续光谱的点光源。本文介绍交流供电的短弧氙灯光源,用两电极短弧氙灯实现三电极短弧氙灯性能的方法。给出了用一个系统满足各种不同发光强度、不同调制波形、不同调制频率的要求,以及在制造和使用过程中应注意的事项。