Re: [STDS-802-16] Clarification regarding SS power level control
The power control method is a closed loop method where the Base station
asks for further power control corrections if required. If the base
station requests the subscriber station in the RNG-RESP to increase the
power level by 30dB the SS should increase it by 30dB with a relative
accuracy of 4dB.
If the Base station is going to increase the power of the SS in 5 steps
and the BS requests the SS to increase the power by 8dB the SS will
increase it by 8dB with a relative accuracy of 4dB. In the subsequent
RNG-RESP message the BS instead of requesting a power increase of 8dB
will request for 8dB+(relative accuracy). Therefore after each increase
requested from the BS the relative accuracy should be 4dB.
This assumes that the BS can make an accurate measurement of the SS's
power increase.
Any comments ?
Regards,
-Raja
-----Original Message-----
From: Crozier, Eugene [mailto:Eugene_Crozier@SRTELECOM.COM]
Sent: Monday, April 19, 2004 6:26 AM
To: STDS-802-16@listserv.ieee.org
Subject: Re: [STDS-802-16] Clarification regarding SS power
level control
My understanding of this is that the step size should be
greater than 1 dB but less than 8 dB (I'd assumed for the
relative accuracy that the 50% of the step size can be no
more than 4 dB), but the number of steps is based on the step
size and the relative accuracy to achieve the minimum control
range, so for 1 dB steps, the number of steps can be between
60 and 20 (30/0.5 and 30/1.5) for a 30 dB range, and for 8 dB
step size the number of steps between 8 and 3 for the 30 dB
range.
Regards
Eugene Crozier
-----Original Message-----
From: Eyal Verbin [mailto:everbin@AIRSPAN.COM]
Sent: Monday, April 19, 2004 8:22 AM
To: STDS-802-16@listserv.ieee.org
Subject: [STDS-802-16] Clarification regarding SS
power level control
Power level control for the OFDM PHY is defined
in section 8.3.9.1:
" For an SS not supporting subchannelization, the
transmitter shall support a monotonic power level
control of 30 dB minimum. For an SS supporting
subchannelization, the transmitter shall support
a monotonic power level control of 50 dB minimum.
The minimum step size shall be no more than 1 dB.
The relative accuracy of the power control
mechanism is +/-50% of the step size in dB, but
no more than 4 dB. As an example, for a step size
of 5 dB the relative accuracy is 2.5 dB. For a
BS, the transmitter shall support a monotonic
power level control of 10 dB minimum."
Looking at the SS (subchannelization) for
example, it is possible to go from Min power to
Max power either in 5 steps of 8 dB or in a
single step of 50dB. In the first option the
accumulated offset can reach 5*4dB (20dB) wheras
in the second option the tolerance is limited to
4dB.
Does anyone have a more clear interpretation of
this text?
Eyal Verbin