Ant colony‐based strategy to mitigate the pilot contamination problem in multicell massive multiple‐input multiple‐output systems

2021 ◽  
Author(s):  
Abdelfettah Belhabib ◽  
Abdelouhab Zeroual ◽  
Moha M'Rabet Hassani
Keyword(s):  
Multiple Input Multiple Output ◽  
Ant Colony ◽  
Pilot Contamination ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Contamination Problem

scholarly journals An Evaluation of Successive Pilot Decontamination in Massive MIMO

2018 ◽  
Vol 39 (2) ◽  
pp. 107
Author(s):  
Victor Croisfelt Rodrigues ◽  
Taufik Abrão
Keyword(s):  
Spectral Efficiency ◽  
Massive Mimo ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Pilot Training ◽  
Pilot Contamination ◽  
Fundamental Issue ◽  
Data Rates ◽  
Multiple Input ◽  
Input Multiple Output

The demand for higher data rates can be satisfied by the spectral efficiency (SE) improvement offered by Massive multiple-input multiple-output (M-MIMO) systems. However, the pilot contamination remains as a fundamental issue to obtain the paramount SE in such systems. This propitiated the research of several methods to mitigate pilot contamination. One of these procedures is based on the coordination of the cells, culminating in proposals with multiple pilot training phases. This paper aims to expand the results of the original paper, whereby the concepts of large pilot training phases were offered. The evaluation of such method was conducted through more comprehensible numerical results, in which a large number of antennas were assumed and more rigorous SE expressions were used. The channel estimation approaches relying on multiple pilot training phases were considered cumbersome for implementation and an uninteresting solution to overcome pilot contamination; contradicting the results presented in the genuine paper.

scholarly journals Mitigating the Interference Caused by Pilot Contamination in Multi-cell Massive Multiple Input Multiple Output Systems Using Low Density Parity Check Codes in Uplink Scenario

2020 ◽  
Vol 37 (6) ◽  
pp. 1061-1074
Author(s):  
Lokesh Bhardwaj ◽  
Ritesh Kumar Mishra
Keyword(s):  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Base Station ◽  
Low Density ◽  
Pilot Contamination ◽  
Parity Check ◽  
Low Density Parity Check ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Sum Rate

The effects of pilot contamination (PC) on the performance of multi-cell multi-user massive multiple input multiple output (MC-MU-m-MIMO) system in uplink has been analyzed in this article. In a multi-cell scenario, the channel estimation (CE) at the desired cell using pilot reuse to avoid significant overhead results in poor CE due to PC. The improvement in degraded performance due to the effect of PC has been shown using low Density Parity Check (LDPC) codes. The comparative analysis of performance in terms of variation in bit error rate (BER) with the signal to noise ratio (SNR) for LDPC coded and uncoded information blocks of users has been shown when the number of cells sharing the same frequency band is varied. Further, the expression for sum-rate has been derived and its variation with the number of base station (BS) antennas has also been shown. The simulated results have shown that the LDPC coded scheme performs better than the uncoded counterpart and the sum-rate capacity increases when the strength of channel coefficients between the BS antennas of the desired cell and the users of remaining cells is less.

scholarly journals An Efficient Pilot Assignment Scheme for Addressing Pilot Contamination in Multicell Massive MIMO Systems

Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 372 ◽  
Author(s):  
Ahmed Al-hubaishi ◽  
Nor Noordin ◽  
Aduwati Sali ◽  
Shamala Subramaniam ◽  
Ali Mohammed Mansoor
Keyword(s):  
System Performance ◽  
Large Scale ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Cumulative Distribution ◽  
Pilot Contamination ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Scale Characteristics ◽  
Inter Cell Interference

The reuse of the same pilot group across cells to address bandwidth limitations in a network has resulted in pilot contamination. This causes severe inter-cell interference at the targeted cell. Pilot contamination is associated with multicell massive multiple-input multiple-output (MIMO) systems which degrades the system performance even when extra arrays of antennas are added to the network. In this paper, we propose an efficient pilot assignment (EPA) scheme to address this issue by maximizing the minimum uplink rate of the target cell’s users. To achieve this, we exploit the large-scale characteristics of the fading channel to minimize the amount of outgoing inter-cell interference at the target cell. Results from the simulation show that the EPA scheme outperforms both the conventional and the smart pilot assignment (SPA) schemes by reducing the effect of inter-cell interference. These results, show that the EPA scheme has significantly improved the system performance in terms of achievable uplink rate and cumulative distribution function (CDF) for both signal-to-interference-plus-noise ratio (SINR), and uplink rate.

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