May 5, 2005 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: TG4a PRF (Pulse Repetition Frequency) Selection Guidelines Date Submitted: May 2005 Source: Gian Mario Maggio (STMicroelectronics), Philippe Rouzet (STMicroelectronics) Contact: Gian Mario Maggio Voice: +41 22 929 6917, E-Mail: maggio@ieee.org Abstract: PRF value(s) selection guidelines for TG4a PHY standard (UWB-IR part) Purpose: To provide information for further investigation and selection of the PRF value(s) for UWB Impulse Radio (low bit-rate plus ranging) Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. Gian Mario Maggio & Philippe Rouzet (STM)

PRF (Pulse Repetition Frequency) Selection Guidelines May 5, 2005 PRF (Pulse Repetition Frequency) Selection Guidelines Gian Mario Maggio & Philippe Rouzet (STMicroelectronics) Gian Mario Maggio & Philippe Rouzet (STM)

PRF Selection Strategy May 5, 2005 PRF Selection Strategy For each sub-band (mandatory + optionals), based on physical parameters, derive PRF range: Min PRF (technology, regulation, ranging, etc.) Max PRF (channel delay spread, etc.) Optimize PRF value(s) based upon design parameters: Modulation/demodulation Acquisition Implementation … Gian Mario Maggio & Philippe Rouzet (STM)

PRF: Physical Parameters (1/2) May 5, 2005 PRF: Physical Parameters (1/2) UWB Radio PRF  PRF  Comments Bandwidth B   The higher the bandwidth, B, the higher minimum required PRF @Vpp constant  Scalable PRF (mandatory + optional) Technology Peak-to-Peak Voltage Vpp  Baseline: CMOS 90nm, max Vpp = 1 V (conservative) Channel Delay Spread  Typical (indoor) channel delay spread in the range ~50-120 ns Regulations Peak-to-Average Power Ratio  Any “hidden” regulation limit? Ranging Ranging Accuracy  Higher PRF  Better ranging accuracy Gian Mario Maggio & Philippe Rouzet (STM)

PRF: Design Parameters (2/2) May 5, 2005 PRF: Design Parameters (2/2) UWB Radio PRF  PRF  Comments Mod/Demod BPPM + BPSK Energy/Pulse   Low PRF  high energy/pulse: challenging to generate, easier to detect (non-coherent) Coherent Integration Higher SNR  Relax minimum energy/pulse Acquisition Acquisition Time  For higher PRF, in general, it takes less time to acquire code synchronization Complexity  For lower PRF, the synch matched filter is smaller than for higher PRF Implementation Cost  Generally speaking, low PRF may result in lower cost (lower frequency) components RX Dynamic Range  Ex: 12 MHz PRF reduces the RX dynamic range by 7 dB, compared to 60 MHz PRF ADC frequency  Note: ADC frequency may be dictated by ranging requirements Gian Mario Maggio & Philippe Rouzet (STM)

May 5, 2005 Supporting Material I2R - Francois Chin (15-05-0231-00-004a): PRF definition, Minimum PRF Wideband Access - Ismail Lakkis/Saeid Safavi (15-05-0226-01-004a): Minimum PRF Wisair - Gadi Shor (15-05-0213-00-004a): PRF proposals CEA-LETI/STM: PRP vs. pulse amplitude and peak power Gian Mario Maggio & Philippe Rouzet (STM)

May 5, 2005 (a) PRF: Definition Pulse repetition frequency (PRF): Number of pulses occurring in 1 s. Pulse repetition interval (PRI): Time from the beginning of one pulse to the beginning of the next. VPeak TC PRI Gian Mario Maggio & Philippe Rouzet (STM)

(a) PRF Definition: Example May 5, 2005 (a) PRF Definition: Example Pulse Repetition Interval 1 2 3 4 5 6 7 8 N-1 N ………………………… Non-inverted pulses are blue, Inverted pulses are green. …………………………................. Active time Quiet time Symbol Interval Gian Mario Maggio & Philippe Rouzet (STM)

(a) Minimum PRF Requirements May 5, 2005 (a) Minimum PRF Requirements BW = 528 MHz Technology CMOS 90nm 0.7 Vpp TChip (nsec) 1.9 Sequence Bipolar Ternary (equal ±1 & 0) VPeak (v) 0.35 PAve (dBm) -14 PPeak (dBm) 1 -2 PRF (MHz) @ VPeak 16.5 33 BW = 1584 MHz Technology CMOS 90nm 0.7 Vpp TChip (nsec) 0.54 BW (MHz) Bipolar Ternary (equal ±1 & 0) VPeak (v) 0.35 PAve (dBm) -9.3 PPeak (dBm) 1.5 -1.5 PRF (MHz) @ VPeak 132 264 Gian Mario Maggio & Philippe Rouzet (STM)

(b) Minimum PRF Requirements May 5, 2005 (b) Minimum PRF Requirements BW = 520 MHz Technology CMOS 90nm 2.5 Vpp CMOS 90nm 1.0 Vpp TChip (nsec) 1.9 BW (MHz) 520 VPeak (v) 1.25 0.5 PAve (dBm) -14 -9.4 PPeak (dBm) 12 4 PRF (MHz) @ VPeak 1.3 8 BW = 1560 Technology CMOS 90nm 2.5 Vpp CMOS 90nm 1.0 Vpp TChip (nsec) 1.9 BW (MHz) 1560 VPeak (v) 1.25 0.5 PAve (dBm) -14 -9.4 PPeak (dBm) 12 4 PRF (MHz) @ VPeak 11.5 72 Gian Mario Maggio & Philippe Rouzet (STM)

May 5, 2005 (c) PRF Proposals The PRF represents the rate of transmission of the basic pattern. The PRF is an integer division of all center frequencies. The basic PRF is 66 MHz. A PRF of 33 MHz is also supported for environments with long delay spread. Justification: PRF can be generated from a PLL by dividing the center frequency down to the PRF. The first divisions can be based on the divisions implemented as part of the PLL. The center frequencies and PRF are selected such that the first two divisions for off the shelf XOs are divisions by 2. This simplifies the implementation of the high frequency division elements. Gian Mario Maggio & Philippe Rouzet (STM)

(d) PRP vs. Pulse Amplitude and Peak Power May 5, 2005 (d) PRP vs. Pulse Amplitude and Peak Power Fcc limit : 0 dBm (upper band only) Gian Mario Maggio & Philippe Rouzet (STM)

Conclusions (Preliminary) May 5, 2005 Conclusions (Preliminary) Scalable PRF: Bands supported: 500MHz (mandatory), 1.5 GHz No. of supported PRF values: 2 (or more) For CMOS 90nm, PRF lower bound @500 MHz seems to be ~10 MHz Proposed PRF values (so far): Basic: 13/33 MHz Optional: 26/66 MHz PRI value to be dictated by sequence design Note: PRF requirements may be mitigated by the adoption of multi-pulse chips Gian Mario Maggio & Philippe Rouzet (STM)