Modulation Options for OFDM-Based Waveforms: Classification, Comparison, and Future Directions

Ahmad Jaradat

doi:10.1109/ACCESS.2019.2895958

2019-01-01

Ahmad Jaradat *

Jehad M. Hamamreh

Hüseyin Arslan

DOI：10.1109/ACCESS.2019.2895958

原文链接

查看原文

摘要

En 中文

This paper provides a comparative study on the performance of different modulation options for orthogonal frequency division multiplexing (OFDM) in terms of their spectral efficiency, reliability, peak-to-average power ratio, power efficiency, out-of-band emission, and computational complexity. The modulation candidates are classified into two main categories based on the signal plane dimension they exploit. These categories are: 1) 2-D signal plane category including conventional OFDM with classical fixed or adaptive QAM modulation and OFDM with differential modulation, where information is conveyed in changes between two successive symbols in the same subcarrier or between two consecutive subcarriers in the same OFDM symbol and 2) 3-D signal plane category encompassing: a) index-based OFDM modulation schemes which include: i) spatial modulation OFDM, where information is sent by the indices of antennas along with conventional modulated symbols and ii) OFDM with index modulation, where the subcarriers' indices are used to send additional information; b) number-based OFDM modulation schemes which include OFDM with subcarrier number modulation, in which number of subcarriers is exploited to convey additional information; and c) shape-based OFDM modulation schemes which include OFDM with pulse superposition modulation, where the shape of pulses is introduced as a third new dimension to convey additional information. Based on the provided comparative study, the relationship and interaction between these different modulation options and the requirements of future 5G networks are discussed and explained. This paper is then concluded with some recommendations and future research directions.

Keyword:

OFDM

OFDM-SNM

index-based OFDM family

shape-based OFDM family

3-D signal plane

modulation options

PAPR

OOBE

spatial domain

spectral efficiency

URLLC