Performance Analysis of Pilot-based Channel Estimation Techniques in Massive MIMO Systems
No Thumbnail Available
Date
2020-06-15
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
The need for an internet connection is growing globally. So, day-by-day people need
much higher data rate connection to meet their need but every physical resource in communication
like frequency band, transmit signal strength are finite. Within the given
limited resource, higher data speed is accomplished by a new technology called massive
Multiple Input Multiple Output (massive MIMO) system. Massive MIMO fulfills the high
data rate requirement through antenna diversity gain.
Received signal in massive MIMO system is usually distorted by different channel effects
(noise, interference, fading). In order to recover the transmitted signal correctly, channel
effect must be estimated and repaired at the receiver accordingly. This is done by using
different channel estimation techniques. But which one of the channel estimators should
be used for a specific situation is another problem. This thesis will analyze the performance
of different pilot based channel estimation techniques specifically the least square
(LS) and minimum mean square error channel (MMSE) estimation methods for massive
MIMO systems and based on the analysis results different discussions and conclusions
are made. Furthermore, comparison among their characteristics is simulated in MATLAB
and useful conclusions are given. To achieve this goal different scientific articles and
MATLAB simulation results will be used.
When the performance of the channel estimators was tested using the maximum ratio
combining (MRC) detection algorithms, the result showed that the MMSE estimator performed
better. Different comparison techniques were also run and they showed that the
MMSE estimator was affected more than the LS estimator by the increase in the number
of users while the increase in the number of antennas has almost the same effect on both
estimators. The paper also gave possible future works in massive MIMO systems that
continue from this work.
Description
Keywords
pilot-based channel estimation, channel estimation, MIMO, massive MIMO, LS, MMSE, detection algorithms, MRC