I recommend you to read the first chapter of my book “Massive MIMO Networks” which describe these things in detail: https://www.nowpublishers.com/article/DownloadSummary/SIG-093

]]>I wonder how the SNRs in different systems such as SISO, MISO/SIMO, MIMO, … increase with the number of antennas? Let there be M transmit antennas and N receivers are present. Then how can we define SNR at one receiver, the overall received SNR and how does the SNR increase with the number of antennas?

]]>2. It depends on how the correlation between the noise and signal is defined, but this is basically what happens under pilot contamination; the noise will grow at the same speed as the signal term.

]]>When using maximum ratio combining, I know that the signal components add “coherently” whereas the noise components add “incoherently.” Hence, the signal amplitude grows with N whereas the noise increases with sqrt(N), so SNR improves with N. My questions are:

1. What if the variance of the signal components is different? How does SNR increase by increasing N?

2. How does the “correlation” affect this relationship? (I mean the case when the noise components are correlated with signal components.)

Thanks a lot in advance for your kind help with this.

]]>In my paper, if I use a normalized noise power and still use the sum spectral efficiency divided by the transmit power, how can I define or name this expression to make it correct. Whether the expression (9) without unit in paper [1] is worth learning.

[1] Ngo H Q, Matthaiou M, Larsson E G. “Massive MIMO With Optimal Power and Training Duration Allocation.” IEEE Wireless Communications Letters, 2014, 3(6): 605-608.

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