Widely-linear normalised orthogonal gradient adaptive-based algorithm for OFDM systems

In this paper, the modified widely-linear (WL) frequency-domain equalisation based on the normalised version of orthogonal gradient adaptive (NOGA) algorithm is proposed for orthogonal frequency division multiplexing (OFDM) systems. We introduce the extension of NOGA algorithm to widely linear complex-valued approach investigated with mixed-subcarrier cost function. The proposed algorithm can be easily switched between conventional and widely-linear approach. A convergence analysis of proposed algorithm is presented. Simulation results show that the proposed algorithm can achieve the same performance as of standard WL approach compared with the existing algorithm.