CP-less OFDM with alignment signals for enhancing spectral efficiency, reducing latency, and improving PHY security of 5G services
Tarih
2018Yazar
Hamamreh, Jehad M.
Ankaralı, Zekeriyya Esat
Arslan, Hüseyin
Üst veri
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Although orthogonal frequency-division multiplexing (OFDM) is a widely accepted waveform
in many standards and is expected to keep its dominance in future 5G systems with various types of
parameterized waveforms, its performance in terms of spectral efficiency as well as transmission latency is
usually degraded due to the excessive usage of cyclic prefix (CP). Particularly, in highly dispersive channels,
CP rate might be very large in order to maintain the low-complex frequency-domain equalization. In this
paper, we propose a novel method that can fit the low latency and high spectral efficiency requirements of
future 5G wireless services by eliminating the need for inserting CP between successive OFDM symbols
while keeping the whole detection process the same at the receiver side. In order to achieve that, we utilize
specially designed alignment signals that can cancel the interference of one symbol on the other and add
an additional signal component that makes the signal circularly convolved with the channel at the receiver
side. Simulation results prove the superiority of the proposed scheme in terms of enhancing spectral and
power efficiency, reducing latency, and improving physical-layer security against eavesdropping while
using a low-complexity one-tap frequency-domain equalizer. These numerous, simultaneous, and desirable
advantages have the potential to make the proposed technique a suitable fit for future 5G wireless services
and applications including Internet of Things-based massive machine-type communication, ultra-reliable
and low-latency communication, and enhanced mobile broadband.