Proceedings ArticleDOI
Pilot Contamination Reduction in Multi-User TDD Systems
Kumar Appaiah,Alexei Ashikhmin,Thomas L. Marzetta +2 more
- pp 1-5
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TLDR
The effects of shifting the location of pilots in time frames used in neighboring cells are studied, and its effectiveness in obtaining better channel estimates, and, thereby, inter-cell interference reduction is studied.Abstract:
This paper considers the problem of interference mitigation in multi-cell multi-antenna time division duplex (TDD) wireless systems for downlink transmission. An efficient way to obtain channel state information (CSI) at the base station is by using uplink pilots and reciprocity of the downlink channel. At the same time, it has been shown that pilots from different cells contaminate each other, resulting in corruption of precoding matrices used by base stations, and high inter-cell interference. This paper studies the effects of shifting the location of pilots in time frames used in neighboring cells, and its effectiveness in obtaining better channel estimates, and, thereby, inter-cell interference reduction.read more
Citations
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Journal ArticleDOI
An Overview of Massive MIMO: Benefits and Challenges
TL;DR: This paper addresses the potential impact of pilot contamination caused by the use of non-orthogonal pilot sequences by users in adjacent cells, and analyzes the energy efficiency and degrees of freedom provided by massive MIMO systems to enable efficient single-carrier transmission.
Journal ArticleDOI
Inter-Cell Interference in Noncooperative TDD Large Scale Antenna Systems
TL;DR: This paper shows that the contamination of the channel estimates happens whenever a pilot sequence is received at a base station simultaneously with non-orthogonal signals coming from other users, and proposes a method to avoid such simultaneous transmissions from adjacent cells, thus significantly decreasing interference.
Journal ArticleDOI
Millimeter-Wave Massive MIMO Communication for Future Wireless Systems: A Survey
Sherif Adeshina Busari,Kazi Mohammed Saidul Huq,Shahid Mumtaz,Linglong Dai,Jonathan Rodriguez +4 more
TL;DR: The preliminary outcomes of extensive research on mmWave massive MIMO are presented and emerging trends together with their respective benefits, challenges, and proposed solutions are highlighted to point out current trends, evolving research issues and future directions on this technology.
Journal ArticleDOI
A Comprehensive Survey of Pilot Contamination in Massive MIMO—5G System
TL;DR: An extensive survey on pilot contamination in massive MIMO systems is provided, and other possible sources of pilot contamination are identified, which include hardware impairment and non-reciprocal transceivers.
Journal ArticleDOI
Effects of channel aging in massive MIMO systems
Kien T. Truong,Robert W. Heath +1 more
TL;DR: In this article, the impact of channel aging on the performance of massive MIMO systems is considered and the effects of channel variation are characterized as a function of different system parameters assuming a simple model for the channel time variations at the transmitter.
References
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Journal ArticleDOI
Interference cancellation for cellular systems: a contemporary overview
TL;DR: How current and future trends increases the need for and viability of multi-user receivers for both the uplink, where many asynchronous users are simultaneously detected, and the downlink, where users are scheduled and largely orthogonalized is discussed.
Proceedings ArticleDOI
How Much Training is Required for Multiuser Mimo
TL;DR: In this paper, the authors assume that the base station derives its channel estimate from taurp pilot symbols which the terminals transmit on the reverse link, and they determine the optimum number of terminals to serve and the optimum reverse pilot symbols to employ by choosing these parameters to maximize a lower bound on the net sumthroughput.
Journal ArticleDOI
Cochannel interference mitigation and cooperative processing in downlink multicell multiuser MIMO networks
Hongyuan Zhang,Huaiyu Dai +1 more
TL;DR: In this paper, base station cooperative processing is explored to address the CCI mitigation problem in downlink multicell multiuser MIMO networks, and is shown to dramatically increase the capacity with strong CCI.
Journal ArticleDOI
Optimized signaling for MIMO interference systems with feedback
Sigen Ye,Rick S. Blum +1 more
TL;DR: This work model the system as a noncooperative game and perform iterative water-filling to find the Nash equilibrium distributively and proposes several numerical approaches to decide the covariance matrices of the transmitted signals and compare their performance in terms of the system mutual information.
Proceedings ArticleDOI
Pilot contamination problem in multi-cell TDD systems
TL;DR: A multi-cell MMSE-based precoding is proposed that, when combined with frequency/time/pilot reuse techniques, mitigate this problem of pilot contamination.