6,696 research outputs found
ML CFO and PO Estimation in DCT OFDM Systems under Non-Circular Transmissions
Frequency synchronization is one of the most important
components in orthogonal frequency-division multiplexing
(OFDM) systems. Recently, the discrete cosine transform (DCT)
based OFDM system has received wide attentions due to several
advantages. Hence, the study of frequency synchronization issue
for this newly raised system is well on its time. To provide
a thorough study, we consider the non-circular transmissions,
and the results can be easily generated to circular transmissions
if the elliptic variance is set to zero. We present three joint
maximum likelihood (ML) carrier frequency offset (CFO) and
phase offset (PO) estimators. From both the theoretical analysis
and the numerical comparisons, we found new advantages of
the DCT-OFDM over the traditional discrete Fourier transform
(DFT) based OFDM. These advantages, as well as those already
studied in the early works on DCT-OFDM, support the belief that
the DCT-OFDM is a new promising multi-carrier modulation
(MCM) scheme
Waveform Design for 5G and Beyond
5G is envisioned to improve major key performance indicators (KPIs), such as
peak data rate, spectral efficiency, power consumption, complexity, connection
density, latency, and mobility. This chapter aims to provide a complete picture
of the ongoing 5G waveform discussions and overviews the major candidates. It
provides a brief description of the waveform and reveals the 5G use cases and
waveform design requirements. The chapter presents the main features of cyclic
prefix-orthogonal frequency-division multiplexing (CP-OFDM) that is deployed in
4G LTE systems. CP-OFDM is the baseline of the 5G waveform discussions since
the performance of a new waveform is usually compared with it. The chapter
examines the essential characteristics of the major waveform candidates along
with the related advantages and disadvantages. It summarizes and compares the
key features of different waveforms.Comment: 22 pages, 21 figures, 2 tables; accepted version (The URL for the
final version:
https://onlinelibrary.wiley.com/doi/abs/10.1002/9781119333142.ch2
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