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7 - The 5G radio-access technologies
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- By Malte Schellmann, Huawei, Petra Weitkemper, NTT DOCOMO, Eeva Lähetkangas, Nokia, Erik Ström, Chalmers University of Technology, Carsten Bockelmann, University of Bremen, Slimane Ben Slimane, KTH - Royal Institute of Technology
- Edited by Afif Osseiran, Jose F. Monserrat, Patrick Marsch
- Foreword by Mischa Dohler, King's College London, Takehiro Nakamura
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- Book:
- 5G Mobile and Wireless Communications Technology
- Published online:
- 05 June 2016
- Print publication:
- 02 June 2016, pp 158-207
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Summary
The radio access for 5G will have to respond to a number of diverse requirements raised by a large variety of different new services, such as those from the context of massive Machine-Type Communication (mMTC) and ultra-reliable MTC (uMTC), as discussed in Chapter 2. Consequently, a “one-size-fits-all” solution for the air interface as prevalent in today's radio systems may no longer be the adequate choice in the future, as it can merely provide an inadequate compromise. Instead, the system should provide more flexibility and scalability to enable tailoring the system configurations to the service types and their demands. Moreover, as the data rates to be provided by mobile radio systems are ever increasing, technologies need to be devised to squeeze out the last bit from the scarce spectrum resources. This chapter elaborates on novel radio-access technologies addressing the aforementioned issues, which can be considered promising candidates for the 5G system. It is noteworthy that there has been flourishing work on potential radio-access technologies for 5G in recent time; refer to [1][2] for prominent research activities in the field.
The chapter starts with a general introduction to the access design principles for multi-user communications in Section 7.1, which build the fundamentals for the novel access technologies presented in this chapter. Section 7.2 then presents novel multi-carrier waveforms based on filtering, which offer additional degrees of freedom in the system design to enable flexible system configurations. Novel non-orthogonal multiple-access schemes yielding an increased spectral efficiency are presented in Section 7.3. The following three sections then elaborate on radio access technologies and scalable solutions tailored for specific use cases, which are considered key drivers for 5G radio systems. Section 7.4 focuses on Ultra-Dense Networks (UDN), where also higher frequencies beyond 6 GHz are expected to be used. Section 7.5 presents an ad-hoc radio-access solution for the Vehicle-to-Anything (V2X) context, and finally Section 7.6 proposes schemes for the massive access of Machine-Type Communication (MTC) devices, characterized by a low amount of overhead and thus enabling an energy efficient transmission.
Table 7.1 gives a brief overview on the radio-access technologies presented in this chapter, highlighting some of their characteristics and properties. It should be noted that the gathered information is not exhaustive and only the most important aspects are listed.
5 - CoMP Schemes Based on Interf.-Aware Transceivers or Interf. Coord.
- from Part II - Practical CoMP Schemes
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- By Lars Thiele, Institute, Berlin, Thomas Wirth, Institute, Berlin, Malte Schellmann, European Research Center, Thomas Haustein, Institute, Berlin, Volker Jungnickel, Institute, Berlin
- Edited by Patrick Marsch, Gerhard P. Fettweis, Technische Universität, Dresden
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- Book:
- Coordinated Multi-Point in Mobile Communications
- Published online:
- 05 August 2012
- Print publication:
- 21 July 2011, pp 41-80
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Summary
In this chapter, we introduce CoMP schemes where no or little information is exchanged between cooperating base stations. In Section 5.1, we observe an interference-aware downlink transmission scheme where each base station performs individual intra-cell beamforming, while the terminals are able to mitigate inter-cell interference to a certain extent through a particular interference estimation and rejection concept. The level of base station cooperation is then increased in Sections 5.2 and 5.3, where joint multi-cell scheduling and link adaptation, and multi-cell coordinated beamforming are investigated, respectively.
Downlink Multi-User Beamforming with Interference Rejection Combining
In this section, we evaluate a non-cooperative downlink transmission scheme, i.e. where no explicit cooperation takes place between base stations (BSs), but where interference-aware transmission and reception is performed within cells. The BSs perform intra-cell precoding based on limited feedback from the user equipments (UEs), in conjunction with interference-aware scheduling and interference rejection combining (IRC) at the terminal side. This section is based on “Interference-aware scheduling in the synchronous cellular multi-antenna downlink”, by L. Thiele, M. Schellmann, T. Wirth and V. Jungnickel, which appeared in [TSWJ09]. © 2009 IEEE.
Introduction
Transmission with multiple antennas both at the transmitting and receiving ends of a wireless link has become increasingly mature in recent years. From theory, the fundamental capacity gain of the multiple-input multiple-output (MIMO) radio link, being proportional to the minimum of the number of transmit and receive antennas, is well understood for an isolated point-to-point link.