Orthogonal Frequency Division Multiplexing - Assignment Solution

• Introduction to Orthogonal Frequency Division Multiplexing (OFDM) and Index modulation (IM)

One of the leading multicarrier modulation method is known as OFDM, stands for Orthogonal frequency division multiplexing. For a number of existing and potential broadband communication systems, this method has been selected as the modulation plan (Pérez-Neira & Campalans, 2009). Specifically, in broadband wireless communication systems, OFDM is prevalent because of its refusal to go along with multipath fading, in addition to this, to give elevated data rates with rational computational intricacy, OFDM possesses great ability. Further, a broadband channel is split by OFDM into manifold parallel narrowband sub-channels. And in every single sub-channel, a low data rate stream is incorporated that sums up to an elevated data rate diffusion. 

In the domain of wireless networks, Index modulation (IM) is a prominent term. It is a newly-evolving notion that alludes to a class of modulation approaches that depend on the index or indexes of certain medium to curb information bits; as far as the mode is concerned, it can be either concrete (for instance, frequency carrier, antenna, etc.), or imaginary (for example, antenna activation order, space-time matrix and so forth) (Basar, Wen, Mesleh, Renzo, Xiao & Haas, 2017). For the 5th generation (5G) wireless networks, IM methods are considered as extremely competitive contenders seeing that information bits took by the indexes usually use slight or even no power; plus, both energy effectiveness as well as high spectral efficiency are targeted by 5G wireless networks (Wen, Cheng & Yang, 2017).

Basar, Wen, Mesleh, Renzo, Xiao and Haas (2017) carried out a research study in which they scrutinized three kinds of IM, namely:

• Orthogonal frequency division multiplexing with index modulation
• Spatial modulation
• Channel modulation

For IM based plans concerning low-intricacy, spectrum and energy-efficient 5G wireless networks, Basar, Wen, Mesleh, Di Renzo, Xiao and Haas (2017) portrayed the latest developments in the aforementioned three leading edge modulations that show potential and also examined potential future research trends in this area.

• Introduction to ‘Enhanced Orthogonal Frequency Division Multiplexing with Index Modulation’ and ‘Space-Time Multiple-Mode Orthogonal Frequency Division Multiplexing with Index Modulation’

Wen, Ye, Basar, Li, and Ji (2017) put forward two improved Orthogonal Frequency Division Multiplexing with Index Modulation (OFDM-IM) schemes. The researchers referred the first one as orthogonal frequency division multiplexing with hybrid in-phase/quadrature IM where they focused on attaining great spectral efficiency. In the initial scheme, they investigated the dimensions for IM, permitting broadcast of more IM bits in every single sub-carrier set. The researchers referred the second scheme as linear constellation pre-coded OFDM-IQ-IM (LP-OFDMIQ-IM) where they focused on diversity gain. In this scheme, by means of linear group pre-coding to gather supplementary diversity gain, information symbols were disseminated across two nearby sub-carriers that were active. Two diverse insights of LP-OFDM-IQIM were aroused by means of raising the least squared Euclidean distance. This brought about a revolved and a diamond designed constellation, correspondingly.