Power Measurement Method - IEEE Standards Association

September 2009 doc.: IEEE 802.11-09/1053r0 IEEE 802.11 Regulatory AHC Power Measurement Method Date: 2009-09-23 Authors: Name Affiliations Richard Roy SRA Submission Address Slide 1 Phone

email +1-650-861-3351 [email protected] R. Roy, SRA September 2009 doc.: IEEE 802.11-09/1053r0 Abstract This submission presents a general method for measuring/estimating (transmitted or received) timeaveraged power (equivalently total energy) over a specified time interval. Submission Slide 2 September 2009 doc.: IEEE 802.11-09/1053r0

Proposed Power Restriction Approach (from R. Kennedys submission 0997r1) We should offer a variation of the current formula that we believe will suit not only the short range devices, but also protect devices, like 802.11 devices, that have optimized active sharing mechanism Medium Utilization = Energy in millijoules measured over any 1 second of the complete duty cycle; the limit is MU < 4 millijoules Examples 100 mW for 100 milliseconds (out of 1 second) = 10 millijoules 10 mW for 1 second (DC 100%) = 10 millijoules Compared to the current agreement, the 4 Millijoules represents a lower threshold, but on the other hand, apart from the measuring period of 1 second, no further restrictions are applied on modulation e.g. the Tx-on time and Tx-off time Joules preferred over Power x Time to allow non-constant envelope

modulations, or technologies that operate at variable power to benefit from those transmissions where they do not operate at full power. Submission Slide 3 September 2009 doc.: IEEE 802.11-09/1053r0 Time-averaged Power Basic procedure: 1. Obtain a waveform proportional to the square (complex envelope if its a single-sideband waveform) of the voltage (RF electric field into a matched load, suitably bandpass filtered and downconverted to baseband) of the signal of interest as a function of time. 2. Convolve this waveform with a unit-pulse (square-wave) waveform whose width in the time-domain is the time period over which it is desired to calculate the time-averaged power (cf. energy within the specified time interval). 3. Take care to get the normalization factors correct for comparison to an absolute threshold (eg. a threshold in millijoules).

4. Compare the filter output to a threshold if desired. This can be all be done digitally if baseband IQ output sample of the signal of interest are available. Submission Slide 4 September 2009 doc.: IEEE 802.11-09/1053r0 Time-averaged Power For the example in the previous slide: 1. The time interval = 1 sec; so use a 1 second wide unit-pulse as the impulse response of the power measurement filter and process a sufficient amount of the signal of interest so all its transmit modes are captured (this may mean several minutes for very low duty cycle outputs). 2. Set the threshold to 4 millijoules and compare the filter output to this threshold. Submission

Slide 5 September 2009 doc.: IEEE 802.11-09/1053r0 Conclusions The basic idea is to use a sliding window integrator to estimate (calculate) the time-averaged signal power over any time-interval of a specified length. This is a well-known technique an dis easily implemented in a variety of forms. Submission Slide 6

Recently Viewed Presentations

  • PowerPoint Presentation

    PowerPoint Presentation

    Multi-Tiered Systems of Support. 15%. 5%. Community. Community. So, how do we operationalize strategies to support the psychological safety and mental health needs of our students? The answer is not in a single curriculum or single program but requires comprehensive...
  • Chapter 9 Principles of Computer Operations Computer pioneers

    Chapter 9 Principles of Computer Operations Computer pioneers

    Additional information from the computer is needed to make it operate "intelligently" Added processing by software called a device driver gives the peripheral its standard meaning and behavior Every device needs a device driver Machine Instructions Machine instructions are more...
  • The Aftermath of Black Tuesday

    The Aftermath of Black Tuesday

    They could buy now, pay later. The Stock Market in the 1920s. A stock is a percentage - a piece - of a company ... If you don't spend money, businesses lose money, which then made businesses close. What happened...
  • The Challenge: To Create More Value in All Negotiations

    The Challenge: To Create More Value in All Negotiations

    Then it occurred to me that the mid- to long-term "reframing" was more about recasting the nature of work/jobs in, for example, the face of 2020's artificial intelligence than about whether the Spanish bailout is $100 billion or $400 billion—as...
  • Acids, Bases, and Salts

    Acids, Bases, and Salts

    Properties of acids and bases. Acids - Sour taste - Turns blue litmus paper red - Reacts with some metals to produce H. 2 - Dissolves carbonate salts, releasing CO. 2 Bases - Bitter taste - Turns red litmus paper...
  • Powerpoint template for scientific posters (Swarthmore College)

    Powerpoint template for scientific posters (Swarthmore College)

    Suggestions and gripes to: [email protected] Young Stellar Objects in CG4 Chelen Johnson1, Luisa Rebull2, Vivian Hoette3, Kevin McCarron4, Constance Gartner5, Jennifer VanDerMolen5, Lee Gamble6, Carolyn Mallory7, Russ Laher8, Mark Legassie9,
  • SIMATIC S7-200 - automata

    SIMATIC S7-200 - automata

    Analytical model is derived based on governing physical laws for the system such as Newton's law, Ohms law, etc.
  • Slide 1

    Slide 1

    Present the necessary backgroundto connect your hook and your thesis statement. The. Bridge. ties the hook to the . prompt . and . thesis statement . while providing the reader with background information. Introduction: Thesis Statement. Ittakes a stand rather...