多采样率信号处理
抽取、插值、下采样、上采样、抗混叠滤波器
将均匀或非均匀数据重采样为新固定速率。执行抽取和线性插值或更高阶插值，而不引入混叠。
APP
| 信号分析器 | 可视化和比较多个信号和频谱 |
|---|
函数
| decimate | Decimation — decrease sample rate by integer factor |
|---|---|
| downsample | Decrease sample rate by integer factor |
| fillgaps | Fill gaps using autoregressive modeling |
| interp | Interpolation — increase sample rate by integer factor |
| interp1 | 一维数据插值（表查找） |
| intfilt | Interpolation FIR filter design |
| pchip | 分段三次 Hermite 插值多项式 (PCHIP) |
| resample | Resample uniform or nonuniform data to new fixed rate |
| spline | 三次样条数据插值 |
| upfirdn | Upsample, apply FIR filter, and downsample |
| upsample | Increase sample rate by integer factor |
主题
下采样 - 混叠
- 混叠是信号的频谱重叠时发生的失真。下采样会引入混叠。
在下采样前进行滤波
- 在下采样前进行滤波可减轻混叠造成的失真。
Upsampling — Imaging Artifacts
- Upsample a signal and see how upsampling can result in images.
Filtering After Upsampling — Interpolation
- Upsample a signal and apply a lowpass interpolation filter to remove imaging artifacts.
Simulate a Sample-and-Hold System
- Simulate the output of a sample-and-hold system by upsampling and filtering a signal.
重采样
- 抽取、插值或更改信号的采样率，可选择是否进行中间滤波。
更改信号采样率
- 更改正弦波和录制的语音样本的采样率。
Multirate Filter Bank Implementation
- Implement filter banks using the upfirdn function.