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公开(公告)号：US20080198048A1
公开(公告)日：2008-08-21
申请号：US11901661
申请日：2007-09-18
申请人： Ari Klein , Yannis Tsividis
发明人： Ari Klein , Yannis Tsividis
IPC分类号： H03M1/00
摘要： Systems and methods for resizing a signal for use with a fixed-point DSP are provided. More specifically, a process called companding is used in conjunction with fixed-point devices to resize a signal to make use of the available range of these devices. In some embodiments, companding is used to improve the signal-to-noise and distortion ratio. Also, information loss associated with quantization and rounding errors can be reduced in some embodiments.
摘要翻译： 提供了用于调整用于定点DSP的信号大小的系统和方法。 更具体地，称为压扩的过程与定点设备结合使用，以调整信号的大小以利用这些设备的可用范围。 在一些实施例中，使用压扩来提高信噪比和失真比。 此外，在一些实施例中，可以减少与量化和舍入误差相关联的信息丢失。
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22.发明授权Non-linear data conversion system for dynamic range digital signal processing 失效用于动态范围数字信号处理的非线性数据转换系统
公开(公告)号：US5066952A
公开(公告)日：1991-11-19
申请号：US412248
申请日：1989-09-25
申请人： Steve J. Koerner
发明人： Steve J. Koerner
摘要： The data acquisition portion of a data signal processing system has a nonnear data compression and conversion arrangement and a data decompression and scaling arrangement. The non-linear data compression and conversion arrangement employs graduated reference voltage levels provided by resistors having graduated, unequal values, such as values being related as a geometric progression. The graduated form of the reference voltage levels provide a form of data compression wherein large value and small value measurements will have essentially the same fractional resolution. The data decompression and scaling arrangement can decompress previously compressed digital signals and limit the digital data width of such signals in systems which have input dynamic range requirements greater than their output resolution requirements.
摘要翻译： 数据信号处理系统的数据采集部分具有非线性数据压缩和转换装置以及数据解压和缩放装置。 非线性数据压缩和转换装置采用由具有分级，不等值（例如值作为几何级数）的电阻器提供的分级参考电压电平。 参考电压电平的分级形式提供了一种数据压缩形式，其中大值和小值测量将具有基本上相同的分数分辨率。 数据解压缩和缩放布置可以解压缩先前压缩的数字信号，并且在输入动态范围要求大于其输出分辨率要求的系统中限制这些信号的数字数据宽度。
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公开(公告)号：US5047768A
公开(公告)日：1991-09-10
申请号：US514835
申请日：1990-04-26
申请人： Susumu Yamaguchi , Tetsuo Ishiwata
发明人： Susumu Yamaguchi , Tetsuo Ishiwata
IPC分类号： H03M7/50
CPC分类号： H03M7/50
摘要： A data companding method instantaneously compands the 14-bit digital audio signals to be outputted from a satellite broadcast receiver and so on is realized with the given conversion rule, which has a superior companding characteristics across the whole input range of the 14-bit data with SN being not deteriorated as compared with the 14-10 near-instantaneous companding law at the satellite broadcast transmission. A data compressor and a data expander in accordance with the present invention are realized by the construction of the combination of the coefficient table, a data shifter composed of a pluarlity of 4 to 1 data selectors, and an adder.
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公开(公告)号：US4833718A
公开(公告)日：1989-05-23
申请号：US13966
申请日：1987-02-12
申请人： Richard P. Sprague
发明人： Richard P. Sprague
摘要： In a digital text-to-speech conversion system of the type usually contained in all-software form on a floppy disk, memory requirements for the storage of digitized waveform samples are reduced while speech quality is improved, by providing compression techniques and anti-distortion techniques which interact to provide clear speech at widely varying speeds with a minimum of memory. These techniques include using Huffman coding of first- or second-order differences, encoding only differences between successive waveforms where feasible, using a demi-diphone organization of the speech to allow use of the same instruction lists for several sounds, selectively deleting or repeating waveforms in the concatenation to vary speed without affecting pitch, and encoding waveforms linearly or anti-logarithmically for storage while converting the stored linear or anti-logarithmic codes to logarithmic codes such as .mu.-law codes upon retrieval.
摘要翻译： 在通常以软盘形式存在于软盘上的数字文本转语音转换系统中，通过提供压缩技术和抗失真来减少存储数字化波形样本的存储器要求，同时提高语音质量 相互作用的技术以最大限度的记忆在广泛变化的速度下提供清晰的语音。 这些技术包括使用一阶或二阶差分的霍夫曼编码，仅在可行的情况下仅对连续波形之间的差异进行编码，使用语音的二维组合来允许对多个声音使用相同的指令列表，选择性地删除或重复波形 在不影响音调的情况下，连续变化速度，并且线性地或反对数地编码波形以进行存储，同时在存储时将所存储的线性或反对数代码转换成对数代码，例如在检索时的μ-代码。
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公开(公告)号：US4740993A
公开(公告)日：1988-04-26
申请号：US907584
申请日：1986-09-15
申请人： Milan Skubnik
发明人： Milan Skubnik
摘要： A circuit for companding digital signals, incorporating a bidirectional barrel shifter in the form of an array of transmission gate cells for shifting step bits of a compressed PCM signal a predetermined number of locations to the left in response to the magnitude of chord bits thereof. The shifted bits are applied to a linear digital signal bus in the form of an expanded linear representation of the PCM signal. Linear digital signals appearing on the linear bus are compressed via shifting to the right through the barrel shifter and are applied therefrom to a PCM signal bus. The companding circuit is inexpensive, can accommodate both A-law and .mu.-law PCM protocols, is fully static and operates at high speed.
摘要翻译： 一种用于压缩数字信号的电路，包括传输门单元阵列形式的双向桶形移位器，用于响应于其和弦位的大小向左侧的预定数量的位置移位压缩的PCM信号的步进位。 移位的位以PCM信号的扩展线性表示的形式施加到线性数字信号总线。 出现在线性总线上的线性数字信号通过向桶形移位器向右移动而被压缩，并从其上施加到PCM信号总线。 压扩电路价格便宜，可以适应A律和μ-PCM PCM协议，是完全静态的，运行速度很快。
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公开(公告)号：US4669093A
公开(公告)日：1987-05-26
申请号：US782296
申请日：1985-09-30
申请人： Marco Gandini , Alessandro Torielli
发明人： Marco Gandini , Alessandro Torielli
CPC分类号： H03M7/50
摘要： The circuit comprises two registers (SR12, SR8) which temporarily memorize uncompressed and compressed PCM words, respectively. The uncompressed word is sequentially read and a counter (CNT) counts the number of zeroes present in the most significant positions of the absolute value of the word. The compressed word is composed, in the corresponding register, of the sign bit of the uncompressed word, followed by the counting bits of the counter and by the bits of the positions of the uncompressed word following those of the counted zeroes.
摘要翻译： 电路包括分别临时存储未压缩和压缩的PCM字的两个寄存器（SR12，SR8）。 顺序地读取未压缩字，并且计数器（CNT）对存在于字的绝对值的最高有效位置中的零的数目进行计数。 压缩字在相应的寄存器中组成未压缩字的符号位，后跟计数器的计数位和未压缩字的位置与计数零的位的位组成。
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公开(公告)号：US4544916A
公开(公告)日：1985-10-01
申请号：US413470
申请日：1982-08-31
申请人： Craig A. Sharper
发明人： Craig A. Sharper
摘要： The most significant bits of each input word of a linear PCM signal address a read-only memory (ROM). Stored at each ROM address is a table of instruction words, one instruction word for each bit in the output word. The instruction words direct a switch to select each bit for the output word from a choice of 1, 0, or an input bit PCM compression according to a predetermined characteristic is implemented by instruction words which direct selection of the proper chord bits from 1 or 0 and the proper step bits from the input bits. A different compression characteristic may be implemented by a different set of stored instruction words. The instruction words also command selective bit inversion and selective inclusion of the bit in a parity check. Implementation of the translator with commercially available hardware is described.
摘要翻译： 线性PCM信号的每个输入字的最高有效位寻址只读存储器（ROM）。 存储在每个ROM地址的是一个指令字表，一个指令字用于输出字中的每个位。 指令字指示开关从1，0的选择中选择输出字的每个位，或者根据预定特性的输入位PCM压缩由直接从1或0选择适当的和弦位的指令字实现 和来自输入位的正确的步位。 可以通过不同的存储指令字集来实现不同的压缩特性。 指令字还命令选择性位反转，并在位校验中选择性地包含该位。 描述了具有市售硬件的翻译器的实现。
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公开(公告)号：US4161627A
公开(公告)日：1979-07-17
申请号：US865501
申请日：1977-12-29
申请人： Bertram Amann
发明人： Bertram Amann
CPC分类号： H04B14/04 , G06F1/03 , G06F1/0321 , H03M1/1019 , H03M7/50 , G06F2101/16 , H03M1/04 , H03M1/1071
摘要： To test the performance of a PCM terminal operating in the TDM mode, a simulated message or noise signal is generated by extracting a recurrent sequence of code words from a read-only memory, the stored code words representing a set of values logarithmically related to sucdessive amplitudes of a sine wave or other periodic oscillation to be reproduced. These words are read out at a fixed scanning frequency f.sub.o but with skipping of (p-l) memory stages if a signal frequency pf.sub.o is to be simulated. A volume selector generates supplemental code words which are additively or subtractively combined with the extracted code words to simulate a desired voltage level. The resulting code words are compressed in a code converter in which the quantum steps of the segments of a compander characteristic, conforming to the chosen logarithmic function, are stored in another read-only memory.
摘要翻译： 为了测试在TDM模式下工作的PCM终端的性能，通过从只读存储器提取码字的循环序列来生成模拟消息或噪声信号，存储的代码字表示与成功对数相关的一组值 要再现正弦波或其他周期振荡的振幅。 这些字以固定的扫描频率fo读出，但是如果要模拟信号频率pfo，则跳过（p-1）个存储器级。 音量选择器产生与所提取的码字相加或减去组合的模拟所需电压电平的补码码字。 所得到的代码字在代码转换器中被压缩，其中符合所选择的对数函数的压缩扩展器特征的段的量子步长被存储在另一个只读存储器中。
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29.发明授权Tandem block digital processor for use with nonuniformly encoded digital data 失效用非编码数字数据使用的数字块数字处理器
公开(公告)号：US4040049A
公开(公告)日：1977-08-02
申请号：US621130
申请日：1975-10-09
CPC分类号： H03M7/50 , H03M7/3053 , H04B14/048
摘要： In a PCM system, character compression using nearly instantaneous companding (NIC) is known to obtain a reduction in the number of bits transmitted. Unfortunately, in tandem digital PCM-to-NIC-to-PCM conversions, a signal delay results because a maximum segment value is usually unknown until a block of PCM characters, which are to be converted to make up a block of NIC characters, has been received. Further, if the PCM block is received out-of-phase, a signal degradation may result because the incorrect maximum sgement value may be used during a subsequent conversion. To mitigate delay, the disclosed processor discards certain least significant bits of a PCM character and substitutes therefor a predetermined bit pattern corresponding to the difference between the maximum segment value and the segment value of the first character of the block. To mitigate degradation, the processor adjusts the block phase upon detection of the absence of a predetermined difference between the maximum segment value and the segment value of another character in the block.
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公开(公告)号：US4037226A
公开(公告)日：1977-07-19
申请号：US647298
申请日：1976-01-07
申请人： William L. Betts , Robert T. Greene
发明人： William L. Betts , Robert T. Greene
摘要： A pulse code modulation compressor converts linear pulse code modulation words into companded pulse code modulation words. A read only memory is loaded with a conversion table and used to perform successive approximations for the conversion. The converted output is then passed through a double buffer to allow independent operation of the conversion clock and output clock.
摘要翻译： 脉冲编码调制压缩器将线性脉冲编码调制字转换为压缩脉冲编码调制字。 只读存储器加载了一个转换表，用于对转换执行逐次逼近。 转换的输出然后通过双缓冲器，以允许转换时钟和输出时钟的独立操作。
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