1. Doc: IEEE 15-05-0378-00-004a 5 July 2005 Z. Sahinoglu, Mitsubishi Electric 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Simulations on non-coherent ranging - II] Date Submitted: [5 July 2005] Source: [Zafer Sahinoglu, Ismail Guvenc, Mitsubishi Electric] Contact: Zafer Sahinoglu Voice:[+1 617 621 7588, E-Mail: zafer@merl.com] Abstract: [This document provides statistical analysis of IEEE 802.15.4a channels’ energy distribution] Purpose: [To provide input for optimization of system design parameters] 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.

2. Doc: IEEE 15-05-0xxx-00-004a Saturday, January 23, 2016 T s 3 = 2048ns* T s 1 = T s 4 = 512ns TOA Ambiguity = 256ns Observation window = 512ns Option 3 (16 pulses per 2us) Option 1 ** (32 pulses per 2us) Option 4 (16 pulses per 2us) * Since option-3 uses 31 chip sequences, 1984ns symbol duration is used for option-3 to have multiples of 4ns sampling duration. However, total energy used within 4ms duration are identical for all cases. ** A training sequence of all 1’s are used. Random training sequence will introduce self interference that will degrade the performance. Ranging Simulations

3. Doc: IEEE 15-05-0xxx-00-004a Saturday, January 23, 2016 Normalized threshold = 0.1 (fixed) Search-back window = 32ns (fixed) Both parameters can be further adjusted and optimized based on the SNR Simulation Results 16 pulses per 1 us in option 1, and 8 in others

4. Doc: IEEE 15-05-0xxx-00-004a Saturday, January 23, 2016 T s 3 = 2048ns* T s 1 = T s 4 = 512ns TOA Ambiguity = 256ns Observation window = 512ns Option 3 (16 pulses per 2us) Option 1 ** (16 pulses per 2us) Option 4 (16 pulses per 2us) * Since option-3 uses 31 chip sequences, 1984ns symbol duration is used for option-3 to have multiples of 4ns sampling duration. However, total energy used within 4ms duration are identical for all cases. ** A training sequence of all 1’s are used. Random training sequence will introduce self interference that will degrade the performance. Simulations

5. Doc: IEEE 15-05-0xxx-00-004a Saturday, January 23, 2016 Normalized threshold = 0.1 (fixed) Search-back window = 36ns (fixed) Both parameters can be further adjusted and optimized based on the SNR Simulation Results (8 pulses per 1 us)

6. Doc: IEEE 15-05-0378-00-004a 5 July 2005 Z. Sahinoglu, Mitsubishi Electric 6 Causes of the Differences in the Two Simulation Results Window size: –First set: 32ns –Second set: 36ns Random delay within the TOA ambiguity Number of realizations –First set: 100 –Second set: 1000

7. Doc: IEEE 15-05-0378-00-004a 5 July 2005 Z. Sahinoglu, Mitsubishi Electric 7 Why the Error Floor at 17dB? When a 500MHz signal is passed through a channel sampled at 8GHz, the LOS property is lost Even at a very high SNR, a weak first arriving component is likely to occur First arriving energy block Strongest energy block First arriving and strongest path Channel realization Energy collection at 4ns

8. Doc: IEEE 15-05-0378-00-004a 5 July 2005 Z. Sahinoglu, Mitsubishi Electric 8 Another example Channel realization Energy collection at 4ns With a search back window of 32ns, in this realization the first energy block is missed (the error was 4 energy blocks (2ns +3*4ns = 14ns)

9. Doc: IEEE 15-05-0378-00-004a 5 July 2005 Z. Sahinoglu, Mitsubishi Electric 9 Observations 4ms preamble may be enough to average out noise The main source of error comes from the inefficiency of threshold setting and search back windowing, even with a perfect SNR estimation With a smart search back window adaptation at 4ns sampling, –MEA is likely to be brought down closer to 2ns –Confidence level can be increased, and the SNR for 90% level can be lowered How much? we don’t know yet At what SNR? No answer yet

10. Doc: IEEE 15-05-0378-00-004a 5 July 2005 Z. Sahinoglu, Mitsubishi Electric 10 What Else to Improve the Range Performance Wider signal bandwidth –Better multipath resolution High sampling rate (e.g., 1GHz)