Overhead optimization in a MIMO-OFDM testbed based on MMSE MIMO decoding

In this paper, the results of overhead optimization in a MIMO-OFDM testbed based on MMSE MIMO decoding are presented. The testbed used for the wireless field measurements is a configurable, non-realtime, 2×2 multi-antenna testbed operating at 5.25 GHz with a bandwidth of 25 MHz. Modulation and demodulation are performed offline. An adaptive, RLS based MMSE solution is used for MIMO decoding. Continuous pilots are used for carrier frequency offset tracking. The performance of the system for different numbers of training symbols and continuous pilots are analyzed for SISO and MIMO 2×2 configurations in the presence of all analog impairments. The results are first presented in CDFs of slicer SNR and then further analyzed for achievable capacity and throughput. The training and pilot overhead optimization analysis have shown an optimum of 10 training symbols and 5 continuous pilots for this RLS based MIMO 2×2 communication system.