An Improved Unique Word DFT-Spread OFDM Scheme for 5G Systems

Şahin, Alphan; Yang, Rui; Ghosh, Monisha; Olesen, Robert L.

doi:10.1109/glocomw.2015.7414173

Cited by 40 publications

(27 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…UW-DFT-s-OFDM Unique word DFT-spread OFDM (UW-DFT-s-OFDM) [29] is another single-carrier scheme that utilizes flexible internal guard band. The zero tails and heads of the ZT-DFT-s-OFDM are replaced with a fixed sequence that enhances cyclic properties of the signal in this approach.…”

Section: C)mentioning

confidence: 99%

Waveform Design for 5G and Beyond

Demir

Elkourdi

Ibrahim

et al. 2018

5G Networks: Fundamental Requirements, Enabling Technologies, and Operations Management

View full text Add to dashboard Cite

The standardization activities of wireless mobile telecommunications have begun with analog standards that were introduced in the 1980s, and a new generation develops almost every 10 years to meet the exponentially growing market demand. The leap from analog to digital started in second-generation (2G) systems, along with the use of mobile data services. The 3G digital evolution enabled video calls and global positioning system (GPS) services on mobile devices. The 4G systems pushed the limits of data services further by better exploiting the time-frequency resources using orthogonal frequency-division multiple access (OFDMA) as an air interface [1]. Recently, the International Telecommunications Union (ITU) has defined the expectations for 5G [2], and the study of the nextgeneration wireless system is in progress with a harmony between academia, industry, and standardization entities to accomplish its first deployment in 2020.5G is envisioned to improve major key performance indicators (KPIs), such as peak data rate, spectral efficiency, power consumption, complexity, connection density, latency, and mobility, significantly. Furthermore, the new standard should support a diverse range of services all under the same network [3]. The IMT-2020 vision defines the use cases into three main categories as enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC) featuring 20 Gb/s peak data rate, 10 6 /km 2 device density, and less than 1 ms latency, respectively [4]. A flexible air interface is required to meet these different requirements. As a result, the waveform, which is the main component of any air interface, has to be designed precisely to facilitate such flexibility [5].This chapter aims to provide a complete picture of the ongoing 5G waveform discussions and overviews the major candidates. The chapter is organized as follows: Section II provides a brief description of the waveform and reveals the 5G use cases and waveform design requirements. Also, this section presents the main features of CP-OFDM that is currently 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. Section III examines the essential characteristics of the major waveform candidates along with the related advantages and disadvantages. Section IV summarizes and compares the key features of the waveforms. Finally, Section V concludes the chapter. This is the pre-peer reviewed version of the article which has been published in final form at [https://onlinelibrary.wiley.com/doi/abs/10.1002/9781119333142.ch2]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.

show abstract

Section: C)mentioning

confidence: 99%

Waveform Design for 5G and Beyond

Demir

Elkourdi

Ibrahim

et al. 2018

5G Networks: Fundamental Requirements, Enabling Technologies, and Operations Management

View full text Add to dashboard Cite

show abstract

“…They include (i) Single-Carrier Frequency Division Multiplexing, also called differently cyclic prefix (CP) DFT-Spread-OFDM (already used in 4G LTE uplink), G-DFT-s-OFDM [14]; (ii) Zero-Tail (ZT) or Unique-Word (UW) DFT-Spread-OFDM [15,16], UW-OFDM, GFDM [17], CP-OFDM (already used in the 4G LTE downlink); (iii) Resource-Block-Filtered OFDM, Filter-Bank-Multicarrier (FBMC), and Universal Filter Multicarrier (UFMC). As can be seen, the OFDM technique is omnipresent in the 5G waveform proposals.…”

Section: International Journal Of Antennas and Propagationmentioning

confidence: 99%

The Complexα-μFading Channel with OFDM Application

Freitas¹,

Bomfin²,

Souza³

et al. 2017

International Journal of Antennas and Propagation

View full text Add to dashboard Cite

The aims of this paper are threefold: (i) to present a model for the complex -fading channel; (ii) to propose an efficient, simple, and general method to generate complex -samples; (iii) to make use of this channel in order to assess the bit error rate performance of an OFDM system. An analytical framework is then used, whose output is validated through Monte Carlo simulation. Several important conclusions concerning the system performance as a function of the channel parameters, namely, nonlinearity, clustering, and power imbalance of in-phase and quadrature components, are drawn.

show abstract

“…Further enhancements on spectral containment based on the insertion of a redundant vector have been presented in [12]. However, the recent literature tends to disregard the concerns related to practical applicability of these waveforms in a real system.…”

Section: Introductionmentioning

confidence: 99%

“…Our initial work on Zero-Tail DFT-s-OFDM (ZT DFT-s-OFDM) [11] has paved the way to a set of solutions which overcome the limited flexibility of CP-based waveform and have the further potential of reducing the out-of-band emission. To mention a few, Unique Word DFT-s-OFDM (UW DFT-s-OFDM) [12] and Guard Interval DFT-s-OFDM (GI DFT-s-OFDM) [13] have been drawing significant attention in the research community. The main principle of such solutions is to replace the CP with an internal guard period whose length can be tuned accordingly to the estimated delay spread of the channel.…”

Section: Introductionmentioning

confidence: 99%

Generalized DFT-s-OFDM Waveforms Without Cyclic Prefix

Berardinelli

2018

IEEE Access

View full text Add to dashboard Cite

This paper deals with generalized discrete Fourier transform-spread-orthogonal frequency division multiplexing (G-DFT-s-OFDM) waveforms, which replace the cyclic prefix of traditional OFDM/DFT-s-OFDM with an internal guard period. Such waveforms feature significant benefits in terms of flexibility, spectral containment, and low peak-to-average power ratio. Aspects related to reference sequence design and mapping for channel estimation are thoroughly addressed, and a new estimator for the specific zero-tail DFT-s-OFDM case is proposed. Furthermore, we address the opportunity of exploiting the internal guard period at each symbol for frequent channel state information updates, thus enabling the possibility of tracking rapidly varying propagation conditions.

show abstract

An Improved Unique Word DFT-Spread OFDM Scheme for 5G Systems

Cited by 40 publications

References 15 publications

Waveform Design for 5G and Beyond

Waveform Design for 5G and Beyond

The Complexα-μFading Channel with OFDM Application

Generalized DFT-s-OFDM Waveforms Without Cyclic Prefix

Contact Info

Product

Resources

About