Abstract:
Maximum ratio combining (MRC), maximum ratio transmission (MRT) and zero forcing (ZF) are well known precoders which have been researched out in recent
studies. In this thesis, the performances of maximum ratio combining (MRC) and
zero forcing (ZF) at uplink and maximum ratio transmission (MRT) and zero forcing
( ZF) at downlink MU - Massive MIMO system have been analyzed and compared.
This work focuses on a single-cell with multiple base station antenna serving multiple
user equipments. The achievable sumrate and all the required metrics in uplink and
downlink system using low complex linear precoding scheme under different scenario
have been derived .
In this work two regimes are considered for SNR and it has been mathematically
proved and simulated using Matlab2018. These two regimes are high SNR and low
SNR. Also low complex linear precoders have been proposed. The proposed idea is to
predict and use the precoder which results better performance in terms of achievable
rate, spectral efficiency and energy efficiency for a given channel. In the downlink
scenario we applied normalization method for equal allocation of power for both MRT
and ZF precoders.
For low SNR, MRC and MRT perform better than zero forcing. For high SNR, zero
forcing (ZF) performs better than MRC and MRT. From the result executed MRT
have better performance than ZF when the number of user is lesser under vector
normalization. Similarly, under low SNR, ZF precoders have lesser performance than
MRT precoding scheme in matrix normalization.
Generally , the performance of the precoders will begin to grow up as the number
of BS antenna is folded. In uplink case an achievable rate for zero forcing and
MRC grows by 31.12 % and 33.4 % respectively for low power. Similarly, achievable
rate for zero forcing and MRC grows by 11.48 % and 36.4 % respectively for high
uplink power.In downlink case an achievable rate under vector normalization for zero
forcing and MRT grows by 28.8 % and 27.1 % respectively for low BS transmitter
power.Similarly, achievable rate for zero forcing and MRT grows by 11.8 % and 7.32
% respectively for high BS transmitter power
