A Survey on OFDM-Based Elastic Core Optical Networking <s> C. MIMO O-OFDM <s> Multiple-input-multiple-output (MIMO) wireless systems are those that have multiple antenna elements at both the transmitter and receiver. They were first investigated by computer simulations in the 1980s. Since that time, interest in MIMO systems has exploded. They are now being used for third-generation cellular systems (W-CDMA) and are discussed for future high-performance modes of the highly successful IEEE 802.11 standard for wireless local area networks. MIMO-related topics also occupy a considerable part of today's academic communications research. The multiple antennas in MIMO systems can be exploited in two different ways. One is the creation of a highly effective antenna diversity system; the other is the use of the multiple antennas for the transmission of several parallel data streams to increase the capacity of the system. This article presented an overview of MIMO systems with antenna selection. The transmitter, the receiver, or both use only the signals from a subset of the available antennas. This allows considerable reductions in the hardware expense. <s> BIB001 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> C. MIMO O-OFDM <s> Although polarization-mode dispersion (PMD) greatly impairs conventional high-speed single-carrier systems, it is shown that for multicarrier systems such as coherent optical orthogonal frequency-division-multiplexed systems (CO-OFDM), not only does PMD not cause any impairment, but it also provides a benefit of polarization diversity against polarization-dependent-loss-induced fading and consequently improves the system margin. The PMD benefit to fiber nonlinearity reduction in CO-OFDM systems is also predicted <s> BIB002
In wireless communication systems, the term MIMO (Multiple-Input Multiple-Output) is used to describe a range of systems with multiple transmitting and/or receiving antennas. Depending on the relationship between the signals transmitted from different antennas, MIMO schemes can be used to either increase the overall capacity of the system, or to reduce the MIMO, both with and without OFDM, has been successfully applied in single-mode fiber applications by transmitting and receiving signals on both polarizations. In this context, MIMO is also called polarization-division multiplexing (PDM) or dual polarization (DP), whereby data streams are multiplexed on two orthogonal polarization states, thus doubling the total transmission bit rate without increasing the baud rate of the transmission. It has been experimentally shown that, by using MIMO, high-data-rate transmission can be achieved, both in systems using OFDM  [58] BIB002  , and in systems using single-carrier formats BIB001 [60]  .