Bit by Bit Signal Processing Tutorials
Bit by Bit Signal Processing Tutorials
Bit by Bit Signal Processing is happy to provide tutorials to help customers understand the intended application of its products.
This presentation derives the math behind the Polyphase Filter Bank channelizer. It assumes a reader is familiar with a number of digital signal processing topics, including theory of mixers, filters, and multirate sampling. From these beginnings, it derives a Polyphase Filter Bank (PFB). It shows the PFB's equivalence to an ideal basebanding filter, which is invaluable in analysis of the PFB. It provides some teasers for more advanced topics, such as performance and applications. These may eventually become additional presentations here at this site.
Bit by Bit Signal Processing now offers a Polyphase Filter Bank channelizer, the BxBChan. You can find more information about the product here.
This example gives a glimpse into why Bit by Bit Signal Processing's BxBFFT and BxBChan products exceed all known competitors in resource efficiency and Fmax.
This example illustrates one piece of the "secret sauce", which is the Verilog coding style used to code the BxBFFT and BxBChan. This coding style originated with Cray Research in their supercomputer design. The coding style makes it easier to understand the levels of logic between registers, making it more suitable for high speed designs. It's less prone to common errors -- errors that were so common that the Verilog language was changed from "always" to add "always_ff" and "always_comb" to help prevent them. It's more compact, to see more code without scrolling, so that complex code is more easily understood to make performance adjustments.
This example comes from a discussion on Reddit of how to code a module that measures the frequency of a clock using a known-frequency reference. It's a small illustration of the coding technique used internally for the BxBFFT and BxBChan.