Experimental performance evaluation of SDM-COFDM prototype using hierarchical ICI canceller for MIMO-based broadband wireless access systems

This paper introduces experimental performance evaluation of SDM-COFDM (space division multiplexed-coded OFDM) prototype employing a hierarchical ICI canceller for MIMO-based broadband wireless access systems. The prototype has two types of ICI cancellers, multiplicative and subtractive, to obtain diversity gain. The multiplicative canceller multiplies the received signals by the estimated inverse propagation coefficient matrix. In addition, the subtractive canceller generates ICI replicas, subtracts the replicas from the received symbols, weights the subtracted signals by the estimated propagation coefficients, and combines them to obtain diversity gain. In this paper, the PER (packet error rate) performance of the prototype is evaluated by experiments in frequency selective fading environments. The experimental results quantitatively indicate the required CNR (carrier to noise power ratio) improvements by the hierarchical canceller from only the multiplicative canceller, on the variable conditions of the fading parameters such as delay spread and maximum Doppler frequency.