EM12-G: MIMO vs CA

[kz333]

I have no problem with getting carrier aggregation when downloading large files using EM12-G on firmware EM12GPAR01A21M4G_01.004.01.004.

I don't seem to be able to get MIMO to kick in though. How does that work?

Code: Select all

AT+QCAINFO

+QCAINFO: "pcc",66487,50,"LTE BAND 66",1,253,-97,-12,-67,12
+QCAINFO: "scc",66911,25,"LTE BAND 66",2,415,-100,-9,-74,6
DL

OK

AT+QNWCFG="lte_mimo"

+QNWCFG: "lte_mimo",NO MIMO,RANK 0

OK

[gscheb]

Mimo is working already. If you want to see the difference disconnect your diversity antenna and just run with primary. That will get rid of your mimo ability.

[Didneywhorl]

The lte_mimo commands I don't think are working properly. They are there but not "fleshed out". I could be wrong.

[derekjsmith]

For the EM12

AT+QRSRP
+QRSRP: -105,-107,-140,-140

First number is your primary antenna, the 2nd is your diversity antenna.

[kz333]

That's RSSI, I presume?

Is carrier aggregation distinct from MIMO or is it the same thing?

[mtl26637]

Not RSSI, but RSRP. It shows the power of the reference signals within and across the band it is connected to.

CA is different than MIMO. CA uses different frequency bands (for the most part and for general understanding purposes) such as 700Mhz and 850Mhz connections from the tower and MIMO is just another data connection using the same band such as 2 700Mhz connections from the tower. They both come into play and are based largely on the quality of the signal.

[derekjsmith]

MiMo for LTE is using two or more antennas to analyze the same signal. When a signal is transmitted you end up with what is called multi-pathing in other words the same signal but has been reflected off of objects. So with MiMo it can detect multi-pathing and choose which antenna or both at any given time is giving the best signal. It can also reduce noise by summing out some of the multi-pathing. So MiMo is another method of improving the signal quality. Better quality = more data

CA carriage aggregation is adding LTE channels together to increase overall bandwidth. More channels = more bandwidth

The 4 numbers that matters are:
RSRP dBm - Reference-Signal-Receive-Power (lower is better -80 to -110)
RSRQ dB - Reference-Signal-Receive-Quality (lower is better -10 to -20)
SINR dB - Signal-to-Interference-and-Noise-Ratio (higher is better +6 to +20)
CQI - Channel Quality Indicator (higher is better 1 to 18)

The RRSP and RSRQ will determine the SINR. SINR in turn will determine the CQI.
The CQI indicates the type of signal modulation, from QPSK to 256QAM.
The type of signal modulation is how many bits are encoded into a single packet of data. The higher encoding the higher the effective bandwidth.