A Novel Analysis of Multiple-Input Multiple-Output OFDmwith Polarization Division Multiplexing

Orthogonal frequency division multiplexing withindex modulation (OFDM-PDM) is a novel multicarrier transmissiontechnique which has been proposed as an alternative toclassical OFDM. The main idea of OFDM-IM is the use of the indicesof the active subcarriers in an OFDM system as an additionalsource of information. In this work, we propose multiple-inputmultiple-output OFDM-IM (MIMO-OFDM-IM) scheme bycombining OFDM-IM and MIMO transmission techniques. Thelow complexity transceiver structure of the MIMO-FDM-IMscheme is developed and it is shown via computer simulations thatthe proposed MIMO-OFDMIM scheme achieves significantlybetter error performance than classical MIMO-OFDM for severaldifferent system configurations. This work experimentally demonstrates a 60-GHz direct-detection PDM-OFDM system that does not require polarization tracking. The frequency offset of un-modulated optical carriers and a novel training symbol design enable the estimation of optical polarization mixing and wireless MIMO channels for signal demodulation.