|
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 |
|
|
 |
