FC300 – 802.11a/g/n OFDM physical layer

FC300, is a complete implementation of an OFDM physical layer, based on 802.11a/g/n. The core is intended to be used directly or as a reference design by customers, as the basis for application-specific RF developments which may be 802.11 or may be proprietary.

The first release of this COTS product targets an XC5VSX95T Virtex-5 FPGA from Xilinx but with minor modifications it could be easily retargeted to run on any Virtex-5 with enough resources, a Spartan (maybe restricted to a lower bit rate) to a Virtex-6 or 7. As the core does not make use of any resources outside the FPGA (e.g. SDRAM), it can also support hardware platforms based on an Altera Stratix or Cyclone, as long as they can interface to the SMT911 RF module used in this development. Retargeting to a different RF module is also possible; nearly all the changes would be on the software side an not in the VHDL of FC300. As such FC300 can be viewed as a reference design that can be used to jump start the development of any custom RF application solution based on 802.11 or even proprietary.

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 1×1 SISO and 2×2 MIMO on a single module.