Contents
What is digital decimation filter?
Digital Filters 4.66, is a high-order decimation filter that allows decimation by factors up to 1024. The maximum input sample frequency is 30 MHz. Input data word length is 16 bits using two’s-complement representation. Figure 4.66. The first stage of the HSP43220 decimation FIR filter.
Why multi rate signal processing is required?
Some applications of multirate signal processing are: Up-sampling, i.e., increasing the sampling frequency, before D/A conversion in order to relax the requirements of the analog lowpass antialiasing filter. This allows for efficient parallel signal processing with pro- cessors operating at lower sampling rates.
Why are polyphase filters used for decimation and interpolation?
Due to the nature of the decimation and interpolation processes, polyphase filter structures can be developed to efficiently implement the decimation and interpolation filters (using fewer number of multiplications and additions).
What is the length of a polyphase filter?
Hence, there are two filter banks, ρ0 ( z) and ρ1 ( z ), each having a length of 2, as illustrated in Fig. 11.18. When k = 0 and n = 1, the upper limit of time index required for h ( k + nL) is k + nL = 0 + 1 × 2 = 2. When k = 1 and n = 1, the upper limit of the time index for h ( k + nL) is 3.
Why are polyphase filters used in image rejection?
A polyphase filter could be comprised of several stages in order to achieve sufficient image rejection. Due to the nature of the decimation and interpolation processes, polyphase filter structures can be developed to efficiently implement the decimation and interpolation filters (using fewer number of multiplications and additions).
Which is a parallel decomposition of a FIR filter?
The polyphase realization is a parallel decomposition of a FIR digital filter based on the decomposition of the filter in multiple powers of z. We will discuss the polyphase FIR realization in this section.