1. Jul 12, 2010
07/12/10
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: Adaptive Preamble Length Mode for UWB HRP Ranging
Date Submitted: September 2018
Source: Yi Yang, Jong-Hoon Jang, Moon-Seok Kang, Jonghyo Lee, Aditya V. Padaki, Boon Loong Ng
Company: Samsung
Abstract:[]
Purpose: []
Notice: This document has been prepared to assist the IEEE P 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 P
Slide 1
Slide 1
Page 1

2. Note: Notation/nomenclature based on
Overview
Introduction
Experimental Results to Motivate use of Adaptive Preamble Length
Proposed Frame Format in PHR
Proposed PIB for Adaptive Preamble Length
Conclusions
Note: Notation/nomenclature based on
ppdu-text-contribution.docx
and
enhanced-impulse-radio.pptx

3. Current Preamble Length
SYNC part of SHR is static value set by higher layers
Receiver calculates the first path of Channel Impulse Response(CIR) from Preamble to get the ranging info
Higher layer oblivious to the required Number of symbols (Nsym) in SHR as because environment is always changing
Following issues are observed:
Long preambles may be used even in good LOS scenarios
Wastes power and makes channel busy
Short preambles may be used even in bad NLOS scenarios
Lose the performance ex: ranging accuracy

4. Experimental Test 1: NLOS
True Distance: 3.5m
Nsym=64
Nsym=4096
Nsym=64, results in distance error for NLOS Nsym=4096, gives much better accuracy

5. Experimental Test 2: LOS
Nsym 128 and Nsym achieve almost the same accuracy
Nsym
Tsym(us)
LOS(cm)
128
130.4
340 +/- 3.93
1024
1042.1
340 +/- 4.07

6. Current Developments 802.15.4a 802.15.4z HRP Bits: 0 1-10 11 Reserved
Bits: 0
1-10 11
Reserved
Frame Length
Ranging

7. Proposal
To achieve the best trade off between ranging accuracy and power consumed, dynamically change the preamble duration based on (not exhaustive list)
Setting ranging confidence level(CI)
the S/N of 1st path
Data rate

8. Proposed Workflow

9. Proposed PHR frame structure
Bits:0-1
2-10 11 12
13-18
Data Rate
Frame Length
Ranging
Preamble Mode
SECDED OR
0 Static
1 Dynamic
0~511 byte
Bits:0-1
2-11 11 12
13-18
Data Rate
Frame Length
Ranging
Preamble Mode
SECDED
0 Static
1 Dynamic
0~1023 byte
For the 128 MHz PRF mode, the proposed change in PHR is
Bits: 0
1-10 11 12
Reserved
Frame Length
Ranging
Preamble Mode

10. Proposed PIB for Adaptive Preamble Mode
Attribute
Type
Range
Description
phyHrpUwbAdaptivePreabmleLengthMode
Boolean
FALSE,TRUE
Enable Adaptive Preamble Length modes
phyHrpUwbAdaptivePreabmleLengthConfidenceLevel
3bit
55~99
Confidence Level for the Adaptive Preamble Length modes
Confidence Level
Bit2
Bit1
Bit0
Reserved 1
55%
85%
92%
99%
Low
Medium
High

11. Conclusions
Static SYNC length in the preamble may result in low ranging accuracy or high power consumption
This can be optimized by enabling adaptive preamble mode
Frame structure and PIB for adaptive preamble mode is proposed for performance optimized mode