Analog complex gammatone filter for cochlear implant channels
Analog complex gammatone filter for cochlear implant channels
复制标题
用于人工耳蜗通道的模拟复合伽玛通滤波器
DOI：
10.1109/iscas.2010.5537383
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
W. Serdijn
中科院分区：
文献类型：
--
作者：
W. Ngamkham;C. Sawigun;S. Hiseni;W. Serdijn
根据最近的生理实验，语音信号的包络和相位是提高人工耳蜗机感知能力所必需的。为了同时提取输入语音信号的包络和相位信息，并模拟基底膜的光谱选择性，本文介绍了一种模拟复伽马酮滤波器的设计。首先将伽马酮脉冲响应变换到频域，然后将所得到的8阶传递函数映射到正交梯形滤波器的状态空间描述上。使用这种方法，可以使用两个不同的C矩阵来提取具有相同分母的实数和虚数传递函数。这导致了紧凑的过滤器结构。该滤波器采用GM-C积分器和亚阈值器件，采用AMIS0.35μm工艺设计。基于Cadence RF Spectre的仿真结果验证了设计原理和超低功耗工作原理。
According to recent physiological experiments, the envelope and phase of speech signals are required to enhance the perceptive capability of a cochlear implant processor. In this paper, the design of an analog complex gammatone filter is introduced in order to extract both envelope and phase information of the incoming speech signals as well as to emulate the basilar membrane spectral selectivity. The gammatone impulse response is first transformed into the frequency domain and the resulting 8th-order transfer function is subsequently mapped onto a state-space description of an orthonormal ladder filter. Using this approach, the real and imaginary transfer functions that share the same denominator can be extracted using two different C matrices. This results in a compact filter structure. The proposed filter is designed using Gm-C integrators and sub-threshold CMOS devices in AMIS 0.35μm technology. Simulation results using Cadence RF Spectre confirm the design principle and ultra low power operation.