nRF9160 power consumption for thermal analysis

[JuhaK]

Hi,

Referring to White Paper nRF9160 Hardware Design Guidelines v1.0, what is the scenario (supply voltage, band, antenna VSWR, TX duty cycle...) behind maximum heat power dissipation value of 1480mW? We are interested in M1 only without GPS. Does this value represent Gen2 HW with reduced power consumption?

Thanks, JuhaK

[Øyvind]

Hello Juha, 

I've forwarded your inquiry to our nRF9160 team. I'll get back to you within today or tomorrow.

Kind regards,
Øyvind

[Øyvind]

Hello again Juha, 

As numbers represent worst case/band numbers they remain pretty same for Gen1 and Gen2 nRF9160.. however on average Gen2 thermal dissipation is on most of bands somewhat better vs. Gen1 as reflected from current consumption figures from PS v2.0.
Maximum heat power dissipation is calculated using supply current of 500mA at 3.7V to antenna load pull of VSWR3:1 with theoretical maximum TX ratio of 86% (LTE-M repetition class A) => (500mA*3.7V) - (250mW/2) * (32ms/37ms) = 1480mW.  For Gen2 supply current of 450mA could be closer, especially if considering on average. Also the theoretical maximum TX ratio of 86% is highly unlikely signaled on real networks, being noticeably lower even in "TX intensive" scenarios, maybe closer to 33% or so.. 

Kind regards,
Øyvind

[JuhaK]

Thank you for good answers! Could you still remind me which 3GPP specs/clauses define the maximum TX ratio of 32ms/37ms for M1 CE mode A, please.

Br, JuhaK

[Øyvind]

Hi Juha, 

Here is what I got from the modem guys, I hope that it answers your question

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3GPP TS 36.213 - chapter 8.0:
A BL/CE UE shall upon detection on a given serving cell of an MPDCCH with DCI format 6-0A/6-0B intended for the UE, perform a corresponding PUSCH transmission in subframe(s) n+ki if a transport block corresponding to the HARQ process of the PUSCH transmission is generated as described in [8] with i = 0, 1, …, N-1 according to the MPDCCH, where... for FDD, x = 4; ...  in case N>1, subframe(s) n+ki with i=0,1,…,N-1 are N consecutive BL/CE UL subframe(s) starting with subframe n+x, and in case N=1, k0=x;
=> TX from n+4 over N (32 max)
 
3GPP TS 36.331 - chapter 6.3.2:
EPDCCH-SetConfig-r11 -> mpdcch-config-r13 ... mpdcch-NumRepetition-r13 ENUMERATED

{r1, r2, r4, r8, r16, r32, r64, r128, r256}

, PUSCH-ConfigCommon-v1310 -> pusch-maxNumRepetitionCEmodeA-r13 ENUMERATED

{r8, r16, r32 }

=> Ctrl ch (RX) min is r1==1ms is continuous except during RX-TX switch and TX 
=> TX duration in CE mode A r32 = 32 max
 
3GPP TS 36.211 - chapter 6.2.5:
For type B half-duplex FDD operation, guard periods, each referred to as a half-duplex guard subframe, are created by the UE by

• not receiving a downlink subframe immediately preceding an uplink subframe from the same UE, and
• not receiving a downlink subframe immediately following an uplink subframe from the same UE.
  => one empty subframe in RX-TX switch point

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Kind regards,
Øyvind

[JuhaK]

Thanks a lot for these references!

JuhaK

[Øyvind]

You're welcome. Closing ticket.
Have a great day!