The Polyphase DFT, sometimes referred to as the WOLA (Weighted OverLap and Add) is an efficient method used to implement a uniformly distributed multi-channel filter bank.
The architecture consists of a polyphase front-end that performs the weighting, overlapping and addition followed by a DFT that is usually implemented using an FFT. The Polyphase DFT is generally used in applications that demand high quality filters in terms of stop band rejection and filter shape.
The RF Engines Polyphase DFT solution is built from a highly optimised pipelined polyphase front-end core tightly integrated with a high performance Pipeline FFT core. Both of these cores are highly parameterisable to allow the designer to obtain the optimal solution for the application.
The core has been proven in RF Engine’s Virtex E development system, but is particularly suited to the latest Xilinx Virtex II and Altera Stratix ranges of FPGAs by making efficient use of the embedded multipliers and internal memory hierarchies available in these devices.
Frequency Response of Polyphase DFT versus Blackman-Harris windowed FFT
Features
- Proven in Xilinx Virtex E, place and routed in Xilinx Virtex II and Altera Stratix
- Filter banks up to 16K-bins in a single FPGA (Xilinx XC2V3000)
- Real-time throughput of 800Msps complex
- Filters to over 100dB stop band rejection available
- Fully synchronous design
- Flexible HDL design methodology
Applications
- Digital Down Converter replacement
- Multi-channel communications filtering
- Electronic warfare ( radar,sonar,surveillance)
- Real time spectrum analysis
- High specification filter bank
- OFDM systems
Models
The Polyphase DFT's are available as Modelsim compiled VHDL and more details can be obtained from our sales team who will be happy to process your enquiry. Contact details can be found on the
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