DL MIMO in RC76xx

IoT Modules RC76
1

Hi, is it possible to turn OFF DL MIMO in RC76xx? I found this AT command in the manual and I am trying to understand it better.

AT$LGTRBANDST

I have tried to set mode to SISO, but after power cycle it seems to have been reset. I would like to know if this is the right command to switch from SISO ↔ MIMO?

Info about my modem:
ati
Manufacturer: Sierra Wireless, Incorporated
Model: RC7620
Revision: SWI9X07H_00.08.24.02 f90cbd jenkins 2022/03/21 03:47:54
IMEI: 353634110271292
IMEI SV: 19
FSN: 7Q1524308804B0
+GCAP: +CGSM

OK

Regards,
Sai.

2

have you checked if there is any change in AT!GSTATUS? after switching SISO ↔ MIMO?
e.g. did it still show diversity antenna RSRP?

3

The at!gstatus? shows ‘0’ on the DIV. So looks like it is correct?

AT$LGTRBAND?
AT$LGTRBAND?
$LGTRBAND: 2100,1

OK
at!gstatus?
at!gstatus?
!GSTATUS:
Current Time: 17364 Temperature: 47
Modem Mitigate Level: 0 ModemProc Mitigate Level: 0
Reset Counter: 1 Mode: ONLINE
System mode: LTE PS state: Attached
IMS reg state: NOT REGISTERED IMS mode: Normal
IMS Srv State: NO SMS,NO VoIP
LTE band: B1 LTE bw: 15 MHz
LTE Rx chan: 326 LTE Tx chan: 18326
LTE CA state: INACTIVE
EMM state: Registered Normal Service
RRC state: RRC Connected

PCC RxM RSSI: -81 RSRP (dBm): -108
PCC RxD RSSI: -78 RSRP (dBm): -105
Tx Power: – TAC: 0BCD (3021)
RSRQ (dB): -9 Cell ID: 091C6620 (152856096)
SINR (dB): 9.4

OK
AT$LGTRBANDST=2100,2
AT$LGTRBANDST=2100,2
$LGTRBANDST: 1

OK
at!gstatus?
at!gstatus?
!GSTATUS:
Current Time: 17400 Temperature: 47
Modem Mitigate Level: 0 ModemProc Mitigate Level: 0
Reset Counter: 1 Mode: ONLINE
System mode: LTE PS state: Attached
IMS reg state: NOT REGISTERED IMS mode: Normal
IMS Srv State: NO SMS,NO VoIP
LTE band: B1 LTE bw: 15 MHz
LTE Rx chan: 326 LTE Tx chan: 18326
LTE CA state: INACTIVE
EMM state: Registered Normal Service
RRC state: RRC Connected

PCC RxM RSSI: -83 RSRP (dBm): -109
PCC RxD RSSI: 0 RSRP (dBm): 0
Tx Power: – TAC: 0BCD (3021)
RSRQ (dB): -10 Cell ID: 091C6620 (152856096)
SINR (dB): 6.0

OK
AT$LGTRBAND?
AT$LGTRBAND?
$LGTRBAND: 2100,2

OK
AT!RESET
AT!RESET

OK
AT$LGTRBAND?
AT$LGTRBAND?
$LGTRBAND: 2600,1

OK
at!gstatus?
at!gstatus?
!GSTATUS:
Current Time: 50 Temperature: 46
Modem Mitigate Level: 0 ModemProc Mitigate Level: 0
Reset Counter: 1 Mode: ONLINE
System mode: LTE PS state: Attached
IMS reg state: NOT REGISTERED IMS mode: Normal
IMS Srv State: NO SMS,NO VoIP
LTE band: B7 LTE bw: 10 MHz
LTE Rx chan: 3000 LTE Tx chan: 21000
LTE CA state: INACTIVE
EMM state: Registered Normal Service
RRC state: RRC Idle

PCC RxM RSSI: -74 RSRP (dBm): -106
PCC RxD RSSI: -80 RSRP (dBm): -111
Tx Power: – TAC: 0BCD (3021)
RSRQ (dB): -13 Cell ID: 091C6602 (152856066)
SINR (dB): 10.0

OK
AT$LGTRBANDST=2600,2
AT$LGTRBANDST=2600,2
$LGTRBANDST: 1

OK
at!gstatus?
at!gstatus?
!GSTATUS:
Current Time: 87 Temperature: 46
Modem Mitigate Level: 0 ModemProc Mitigate Level: 0
Reset Counter: 1 Mode: ONLINE
System mode: LTE PS state: Attached
IMS reg state: NOT REGISTERED IMS mode: Normal
IMS Srv State: NO SMS,NO VoIP
LTE band: B7 LTE bw: 10 MHz
LTE Rx chan: 3000 LTE Tx chan: 21000
LTE CA state: INACTIVE
EMM state: Registered Normal Service
RRC state: RRC Connected

PCC RxM RSSI: -83 RSRP (dBm): -106
PCC RxD RSSI: 0 RSRP (dBm): 0
Tx Power: – TAC: 0BCD (3021)
RSRQ (dB): -11 Cell ID: 091C6602 (152856066)
SINR (dB): 8.4

OK

As you can see in the AT commands above, after reset, it seems to default to MIMO, but may be there is some !custom command to make it a persistent change?

Regards,
Sai

4

Why did you need to turn it off?

5

To see if this has any impact on power consumption.

6

then you don’t need to make it off everytime power on
normal usage should enable it be default to have better performance