How does a CIC filter work?
A CIC filter consists of one or more integrator and comb filter pairs. In the case of a decimating CIC, the input signal is fed through one or more cascaded integrators, then a down-sampler, followed by one or more comb sections (equal in number to the number of integrators).
What is differential delay in CIC filter?
The comb section’s differential delay design parameter N is typically 1 or 2 for high sample rate ratios as is often used in commercial radio frequency up/down-converters. Variable N effectively sets the number of nulls in the frequency response of a decimation filter, as shown in Figure 11(a).
How do you test a CIC filter?
Two Easy Ways To Test Multistage CIC Decimation Filters
- The traditional method for testing such a filter implementation is to apply to the filter a low-frequency sinusoidal xin(n) input sequence of frequency fin Hz, having N samples/cycle, and a peak amplitude of Ain.
- then the filter is operating properly.
How does a polyphase filter work?
A polyphase quadrature filter, or PQF, is a filter bank which splits an input signal into a given number N (mostly a power of 2) of equidistant sub-bands. These sub-bands are subsampled by a factor of N, so they are critically sampled.
What is difference between downsampling and decimation?
Loosely speaking, “decimation” is the process of reducing the sampling rate. In practice, this usually implies lowpass-filtering a signal, then throwing away some of its samples. “Downsampling” is a more specific term which refers to just the process of throwing away samples, without the lowpass filtering operation.
What is CIC decimation?
The CIC Decimation block performs a sample rate decrease (decimation) on an input signal by an integer factor. Cascaded Integrator-Comb (CIC) filters are a class of linear phase FIR filters comprised of a comb part and an integrator part. The block supports real and complex fixed-point inputs.
What is polyphase representation?
The derivation was based on commuting the downsampler with the FIR summer. We now derive the polyphase representation of a filter of any length algebraically by splitting the impulse response into. polyphase components.
Why is downsampling needed?
Downsampling enables you to create even smaller models since the machine learning algorithm doesn’t require as many training data points. For embedded AI, memory usage is vital; creating a smaller but still highly accurate model allows you to save space for other application code and processes on the device.
How do you implement downsampling?
To implement the downsampling part (by a downsampling factor of “M”) simply keep every Mth sample, and throw away the M-1 samples in between. For example, to decimate by 4, keep every fourth sample, and throw three out of every four samples away.
What is the CIC filter design block?
This block brings the filter design capabilities of the filterbuilder function to the Simulink ® environment. See CIC Filter Design — Main Pane for more information about the parameters of this block.
How do I set the differential delay of a CIC filter?
When you design either a decimator or interpolator, the resulting filter is a CIC filter that decimates or interpolates your input signal. Specify the differential delay of your CIC filter as an integer value greater than or equal to 1. The default value is 1.
Are CIC filters more efficient than FIR filters?
CIC filters are often used for the purpose of reducing sampling rate (decimation) and increasing sampling rate (interpolation) . This work is to show the efficiency of CIC filters over FIR filters in fixed point applications.
What is a cascaded integrated C OMB (CIC) filter?
ABSTRACT In this paper a Cascaded Integrated C omb (CIC) filter , an optimized class of linear filters such as FIR is implemented for Digital Down C onversion (DDC) for efficient transmission multi -rate system.