Robust Study and Evaluate the BER Performance of Multiuser Massive MIMO Systems

Author Name(s): *Patteti Krishna, B.Balaji, Tipparti Anil Kumar
Author Email: kpatteti@gmail.com

Abstract

The need for higher data rates led researchers to propose another technique called a multiuser massive MIMO system that offers a larger bandwidth compared to the present wireless communication systems. In addition, significant improvement in communications quality of service (QOS), energy and spectral efficiencies and in the reduction of the cost is expected in Massive MIMO. The performance of linear detection schemes used for the uplink and downlink of a single-cell massive multi user MIMO systems in the lower frequency bands. The main objective of this paper is to study and evaluate the minimize bit error rate (BER) performance of a Multiuser massive MIMO system by using linear detection schemes, such as zero forcing precoding (ZF), Maximum-Ratio Transmission (MRT) and Minimum Mean-Square Error (MMSE)

Introduction

In upcoming years, the amount of data traffic in wireless communication will increase considerably; therefore, a new generation network, 5G, has to be developed to increase the data capacity 1000 times compared to current 4G system [3]. Energy efficiency and faster communication response time are also expected in the future network [3]. In order to increase the spectral efficiency, you need to have one of the following options:

  • Very large number of base station antennas [1-2] [5-7].
  • Small cells.
  • In order to support more users, increasing the bandwidth by using the high frequency bands (millimeter Wave) is a very good choice.

In massive MIMO for example, the industry is trying to increase the number ?? of BS antennas to 100 or more in order to simultaneously serve a large number of users ?, say tens, with single or multiple antennas, in the same frequency band [1]. In addition, small cells are also expected in massive MIMO [6]. The channel state information ? is the channel propagation matrix between the ? users and BS antennas array. In general, the channel propagation is modeled as a Rayleigh or Rician fading channel. In practice, the channel matrix has to be estimated by using orthogonal pilot sequences in the uplink transmission [6]. After estimating the channel state information in the uplink transmission, the BS uses the estimated channel in downlink transmission to precode the data streams to all users.

This paper can be organized as follows: Section-I briefly describes introduction of the paper, in Section-II illustrated about the system model, in Section-III and IV explains the massive MIMO uplink and downlink data transmission system, simulation results and conclusion describes in Section-V and VI.

Conclusion

We investigated massive MIMO system and evaluated the performance of uplink and downlink transmission in the lower frequency bands with different number of BS antennas, ?? serving ?=10 users. Although the MRC/MRT requires the lowest complexity among the detectors and precoders such as ZF and MMSE, it performs poorly. However, the BER obtained by MRC/ MRT decreased and might be acceptable by significantly increasing the number of BS antennas ??; therefore, it is better to use MRC/MRT due to its lower complexity compared to the ZF and MMSE detector/precoder when the number of antennas is high.

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