Space-time-frequency coding for OFDM-based WLANs

We study the impact of space-time-frequency processing techniques on the physical layer performance of an orthogonal frequency division multiplexing (OFDM) based wireless LAN (IEEE 802.11a/g). A space frequency code (SFC) with two different soft-input soft-output multiple antenna receivers is compared with an orthogonal space time block code (OSTBC) and a single antenna system. We find that the multiple antenna schemes outperform the single antenna scheme as expected with the OSTBC-OFDM scheme providing a diversity improvement and the SFC-OFDM scheme simultaneously improving the diversity and the achievable rate of the system. Throughput curves are used to benchmark the performance of the schemes for specific packet error rates (PERs) and demonstrate the value of switching between architectures/multi-antenna schemes in practical systems.