The LPC “Linear Predictive Coding” algorithm is a widely used technique for voice coder. In this paper we present different implementations of the LPC algorithm used in the majority of voice decoding standard. The w...The LPC “Linear Predictive Coding” algorithm is a widely used technique for voice coder. In this paper we present different implementations of the LPC algorithm used in the majority of voice decoding standard. The windowing/autocorrelation bloc is implemented by three different versions on an FPGA Spartan 3. Allowing the possibility to integrate a Microblaze processor core a first solution consists of a pure software implementation of the LPC using this core RISC processor. Second solution is a pure hardware architecture implemented using VHDL based methodology starting from description until integration. Finally, the autocorrelation core is then proposed to be implemented using hardware/software (HW/SW) architecture with the existing processor. Each architecture performances are compared for different data lengths.展开更多
This paper presents a real-time implementation of 4.2Kb/s CELP speech coding on single DSP chip. An algorithm reducing search complexity for adaptive codebook is suggested; the solving method that the parameters are c...This paper presents a real-time implementation of 4.2Kb/s CELP speech coding on single DSP chip. An algorithm reducing search complexity for adaptive codebook is suggested; the solving method that the parameters are changed into LSP parameters is discussed. The realtime implementation process of this coding on a commercial development board with a single TMS320C30 is described.展开更多
利用混合激励线性预测(mixed excitation linear prediction,MELP)算法和码激励线性预测(code excitation linear prediction,CELP)算法的优点,提出了一种混合MELP/CELP语音编码模型。编码端对强浊音帧采用MELP编码,对弱浊音帧和清音帧...利用混合激励线性预测(mixed excitation linear prediction,MELP)算法和码激励线性预测(code excitation linear prediction,CELP)算法的优点,提出了一种混合MELP/CELP语音编码模型。编码端对强浊音帧采用MELP编码,对弱浊音帧和清音帧进行CELP编码。MELP编码器采用相位对齐技术提取强浊音帧的相位参数,解决了合成语音与原始语音在时间上不同步的问题。对实现的4 kbit/s混合MELP/CELP声码器进行客观MOS(mean opinion score)值和主观DRT(diagnostic rhythm test)清晰度测试,结果表明,该声码器的合成语音具有较高的可懂度和清晰度。展开更多
文摘The LPC “Linear Predictive Coding” algorithm is a widely used technique for voice coder. In this paper we present different implementations of the LPC algorithm used in the majority of voice decoding standard. The windowing/autocorrelation bloc is implemented by three different versions on an FPGA Spartan 3. Allowing the possibility to integrate a Microblaze processor core a first solution consists of a pure software implementation of the LPC using this core RISC processor. Second solution is a pure hardware architecture implemented using VHDL based methodology starting from description until integration. Finally, the autocorrelation core is then proposed to be implemented using hardware/software (HW/SW) architecture with the existing processor. Each architecture performances are compared for different data lengths.
文摘This paper presents a real-time implementation of 4.2Kb/s CELP speech coding on single DSP chip. An algorithm reducing search complexity for adaptive codebook is suggested; the solving method that the parameters are changed into LSP parameters is discussed. The realtime implementation process of this coding on a commercial development board with a single TMS320C30 is described.
