FC300 OFDM IP Core Helps OEM Customers Reduce Development Time

The first release of this COTS product targets the SMT351T FPGA module with an XC5VSX95T Virtex-5 FPGA from Xilinx, but because the design does not require any resources other than those commonly found in FPGAs it can easily be retargeted to any device family, from Spartan to Virtex-7 to Altera Cyclone or Stratix. Retargeting to different RF hardware is also possible as the VHDL of FC300 assumes only an I/Q baseband DAC/ADC interface. FC300 may be used as a reference design to jump start the development of any custom RF application based on 802.11 or other proprietary OFDM data-transmission standard.

When used with the SMT911 RF module data may be transmitted at up to 54Mb/s on any standard 20MHz-wide channel in the 2.4GHz ISM or 5GHz U-NII bands. The core contains both transmit and receive chains and interfaces directly to other DSP or FPGA modules provided by the hardware platform. All 802.11a/g features are supported including data scrambling, forward error-correction via convolutional encoding at rates from ½ to ¾, sub-channel coding of BPSK, QPSK, 16QAM or 64QAM, both short- and long-training sequences, pilot insertion, and the IFFT/FFT required to convert to/from time-domain RF I/Q signals. The receiver logic includes estimators for center-frequency offset and fractional-sample symbol timing as well as independent per-sub-channel gain & phase compensation. The SMT911 supports 1x1 SISO and 2x2 MIMO on a single module.

The FC300 OFDM implementation was originally developed for a customer in China and is now available to all Sundance DSP customers. Mr. Fred Huettig, who headed the design efforts at Sundance DSP, said “this was a challenging and complex core to develop, test and release. We spent a considerable amount of time to implement all the features in a flexible yet efficient manner, so customers can save valuable time and gain an advantage over their competitors. At the end, we are pleased that customers will receive a fully working module with excellent performance, which may be used directly or as the basis of custom wireless solutions.”