A Bio-Inspired Cochlear Heterodyning Architecture for an RF Fovea
A Bio-Inspired Cochlear Heterodyning Architecture for an RF Fovea
复制标题
适用于射频中央凹的仿生耳蜗外差架构
DOI：
--
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
R. Sarpeshkar
中科院分区：
文献类型：
--
作者：
S. Mandal;R. Sarpeshkar
我们讨论了使用耳蜗模型在无线电频率的频谱分析。我们描述这样的模型的性能特点，包括噪声，动态范围和频率分辨率。我们表明，相位信息的增加，提高了频率估计相比，单独使用的幅度信息。特别是，在一个新的非线性生物启发的中心环绕重合检测阶段的振幅和相位信息的使用，同时提高了频率估计，并实现了耳蜗输出的低通到带通变换。为了进一步提高频率估计，我们提出了一种新的无线接收机架构，这是一个宽带推广的窄带外差系统中常用的无线电。我们称这种结构为耳蜗外差。它利用耳蜗频谱分析的效率来执行宽带信号的并行、多尺度分析，并且可以用耳蜗状行波结构来构造。当与我们先前在RF耳蜗上的工作相结合时，这样的架构可能在认知无线电中有用，用于创建选择存在于宽带但频谱稀疏信号内的窄带分量的RF中央凹。RF中央凹的操作类似于眼睛在图像的狭窄但有趣的部分上的中央凹。频谱分析和连续分段模数转换过程之间的类比说明了如何在RF中央凹中实现连续更精细的频率分辨率。最后，我们表明，RF中心凹可以用于反馈回路中执行干扰消除。
We discuss the use of cochlear models for spectrum analysis at radio frequencies. We describe performance characteristics of such models, including noise, dynamic range, and frequency resolution. We show that the addition of phase information improves frequency estimation as compared to the use of amplitude information alone. In particular, the use of both amplitude and phase information in a novel nonlinear bio-inspired center-surround coincidence-detection stage simultaneously improves frequency estimation and implements a lowpass-to-bandpass transformation on cochlear outputs. In order to further improve frequency estimation we propose a novel wireless receiver architecture that is a broadband generalization of narrowband heterodyning systems commonly used in radio. We term this architecture cochlear heterodyning. It exploits the efficiency of cochlear spectrum analysis to perform parallel, multi-scale analysis of wideband signals and can be constructed with cochlea-like traveling-wave structures. When combined with our prior work on an RF cochlea, such architectures may be useful in cognitive radios for creating RF foveas that select narrowband components present within wideband, but spectrally sparse signals. The operation of RF foveas is analogous to how the eye foveates on narrow but interesting portions of an image. Analogies between spectrum analysis and the process of successive-subranging analog-to-digital conversion illustrate how successively finer frequency resolution is achieved in an RF fovea. Finally, we show that RF foveas can be used in feedback loops to perform interference cancellation.