From Eugene_Crozier@SRTELECOM.COM Fri Apr 23 09:26:26 2004 Date: Thu, 22 Apr 2004 15:31:17 -0600 From: "Crozier, Eugene" To: l.napoli@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