多速率和多级滤波器
多速率滤波器是数字滤波器，它们在更改数字信号的采样率时，不会在速率转换后的信号中引入混叠或成像。这些滤波器分为降低采样率的抽取器、提高采样率的插值器以及兼顾二者的采样率转换器。有关这些采样率转换操作及其在时域和频域中对信号的影响的详细信息，请参阅Overview of Multirate Filters。DSP System Toolbox™ 提供 MATLAB® System object 和 Simulink® 模块，用于实现抽取器、插值器和采样率转换器。通道化器、通道合成器、双通道半带滤波器组和多级滤波器组等高级滤波器技术将这些滤波器用作构建组件。
您可以采用二级或多级（而非单级）方法高效地实现具有大速率转换因子的多速率滤波器。当设计复杂（包含许多系数）且成本较高（每个输入采样需要进行许多乘法和加法运算）时，多级方法的实现效率比单级方法要高。有关详细信息，请参阅Overview of Multistage Filters。
DSP System Toolbox 中的 designMultistageDecimator 和 designMultistageInterpolator 函数自动确定滤波器的最佳配置，包括确定级数和各级的速率转换因子。最佳配置使计算工作量减至最少，您可以使用 cost 函数来衡量这种实现的成本。有关示例，请参阅Multistage Rate Conversion。
对象
函数
模块
主题
多速率模型中的采样率和帧速率
- Inspect Sample and Frame Rates in Simulink
Understand sample time, sample rate, frame period, and frame rate in the context of a Simulink model. Determine the sample and frame rates of signals in your model. - Convert Sample and Frame Rates in Simulink Using Rate Conversion Blocks
Learn how direct-rate conversion blocks impact the sample rate and frame rate of signals in Simulink models. - Convert Sample and Frame Rates in Simulink Using Frame Rebuffering Blocks
Learn how frame rebuffering blocks impact the sample rate and frame rate of signals in Simulink models.
多速率滤波器
- Overview of Multirate Filters
Define multirate filters and understand decimation and interpolation. Understand aliasing and imaging and ways to avoid them. - Design of Decimators and Interpolators
This example shows how to design filters for decimation and interpolation of discrete sequences. - Multirate Filtering in MATLAB and Simulink
Perform multirate filtering using rate conversion objects and blocks. - FIR Nyquist (L-th band) Filter Design
This example shows how to design lowpass FIR Nyquist filters.
多级滤波器
- Overview of Multistage Filters
Different types of multistage filters and their uses. Learn how to implement decimators and interpolators using the multistage approach. - Multistage Rate Conversion
Design multistage rate conversion filters.
滤波器组
- Overview of Filter Banks
Provides an overview of the channelizer, channel synthesizer, and the two-channel filter bank. - Two-Channel Filter Bank Using Halfband Decimators and Halfband Interpolators
Implement a two-channel filter bank using the FIR and IIR halfband filters. Compare the implementation cost and group delay. - Channelize and Synthesize Sine Wave in MATLAB
Channelize and synthesize sinusoidal signal in MATLAB. - Synthesize and Channelize Audio in Simulink
Synthesize and channelize audio signals. - Multilevel Filter Banks
Understand dyadic analysis and dyadic synthesis multilevel filter banks. - Calculate Channel Latencies Required for Wavelet Reconstruction
Learn how to calculate the latencies required for perfect wavelet reconstruction.
数据流
- Model Multirate Signal Processing Systems Using Dataflow
Use a Dataflow Subsystem to automatically calculate frame sizes in multirate systems.
延迟和时滞
- 基于时间的调度和代码生成 (Simulink Coder)
在设计用于代码生成的模型时，要考虑连续和离散模块的使用、采样时间、多速率模型的速率转换、离散化，以及在单任务模式和多任务模式之间进行选择。 - Delay and Latency
Configure the Simulink environment to minimize delay and increase simulation performance.
精选示例
Multistage Rate Conversion
Design multistage rate conversion filters.
Time Delay and Scaling in Multirate DSP Filters
Effect of time delay and scaling in multirate filters. Use
outputDelay function to calculate the time delay and
scaling.
Wavelet Denoising
Use the dsp.DyadicAnalysisFilterBank and dsp.DyadicSynthesisFilterBank System objects to remove noise from a signal.
GSM Digital Down Converter in Simulink
Simulate steady-state behavior of a fixed-point digital down converter for GSM (Global System for Mobile) baseband conversions. The example model uses blocks from Simulink® and the DSP System Toolbox™ to emulate the operation of the TI GC4016 Quad Digital Down Converter (DDC).
Reconstruction Through Two-Channel Filter Banks
Design perfect reconstruction two-channel filter banks, also known as the Quadrature Mirror Filter (QMF) banks. The QMF banks use power complementary filters.
Three-Channel Wavelet Transmultiplexer
Reconstruct three independent combined signals transmitted over a single communications link using a Wavelet Transmultiplexer (WTM). The example illustrates the perfect reconstruction property of the discrete wavelet transform (DWT).
