Transcript Minimum PRF Requirements

June 19nd, 2005
Doc: IEEE 15-05-0350-004a
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks
(WPANs)
Submission Title: [Simulations on non-coherent ranging]
Date Submitted: [19 June 2005]
Source: [Ismail Guvenc, Zafer Sahinoglu, Mitsubishi Electric]
Contact: Zafer Sahinoglu
Voice:[+1 617 621 7588, E-Mail: [email protected]]
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.
TG4a
Slide 1
I. Guvenc, Z. Sahinoglu, Mitsubishi Electric
June 19nd, 2005
Doc: IEEE 15-05-0350-004a
Outline
• Channel energy characteristics
• Threshold statistics for CM1 and CM2
• TOA estimation
– Mean Absolute Errors
TG4a
Slide 2
I. Guvenc, Z. Sahinoglu, Mitsubishi Electric
June 19nd, 2005
Doc: IEEE 15-05-0350-004a
Channel Energy Characteristics
• Unit energy 1ns raised cosine pulse is
passed through CM1 (LOS) and CM2
(NLOS) channels
• Received signal energy is collected in 4ns
integration intervals
• Statistical delay and amplitude
characteristics are derived after averaging
over 1000 realizations
TG4a
Slide 3
I. Guvenc, Z. Sahinoglu, Mitsubishi Electric
June 19nd, 2005
Doc: IEEE 15-05-0350-004a
CM1
– PDF of the delay between the first energy block and strongest energy
block is exponentially distributed (90% of the time less than 25ns)
– Highest energy can reach 0.9, but at a very small probability
• It is less than 0.6 at 90% confidence level
TG4a
Slide 4
I. Guvenc, Z. Sahinoglu, Mitsubishi Electric
June 19nd, 2005
Doc: IEEE 15-05-0350-004a
CM2
– PDF of the delay between the first energy block and strongest energy
block is exponentially distributed (90% of the time less than 25ns)
– Highest energy can reach 0.45
• It is less than 0.25 at 90% confidence level
TG4a
Slide 5
I. Guvenc, Z. Sahinoglu, Mitsubishi Electric
June 19nd, 2005
Doc: IEEE 15-05-0350-004a
CM4
– PDF of the delay between the first energy block
• 90% of the time less than 22ns
– Highest energy can reach 0.6
• It is less than 0.22 (at 90% confidence level)
TG4a
Slide 6
I. Guvenc, Z. Sahinoglu, Mitsubishi Electric
June 19nd, 2005
Doc: IEEE 15-05-0350-004a
CM8
– PDF of the delay between the first energy block
• 90% of the time less than 115ns
– Highest energy can reach 0.0009
• It is less than 0.0006 at 90% confidence level
TG4a
Slide 7
I. Guvenc, Z. Sahinoglu, Mitsubishi Electric
June 19nd, 2005
Doc: IEEE 15-05-0350-004a
Non-Coherent Receiver
• Signal processing techniques are applied onto the
outputs Z[n] of the ADC to find the first energy arrival
2-4ns
BPF
TG4a
( )2
LPF /
integrator
Slide 8
ADC
Z [n]
I. Guvenc, Z. Sahinoglu, Mitsubishi Electric
June 19nd, 2005
Doc: IEEE 15-05-0350-004a
Optimum Normalized Thresholds
• Normalized optimum threshold selection
for “first threshold crossing based TOA”
TG4a
Slide 9
I. Guvenc, Z. Sahinoglu, Mitsubishi Electric
June 19nd, 2005
Doc: IEEE 15-05-0350-004a
Mean Absolute Error
• Even at optimum threshold settings, when threshold crossing is
applied, the MAE is in the order of nanoseconds
• Complex algorithms are needed to identify the first energy block
– In the case of SOP interference, it becomes more challenging
CM1
TG4a
EBN0: {8, 10, 12, 14, 16, 18, 20, 22, 24, 26}
Slide 10
CM2
I. Guvenc, Z. Sahinoglu, Mitsubishi Electric
June 19nd, 2005
Doc: IEEE 15-05-0350-004a
Mean Absolute Error
• Single 4ns unit energy
pulse in each frame
• No IFI
• Search back with threshold
crossing based TOA
tracking
• The MAE is lower bounded
by 3-4ns
• There are very large
outliers that increase the
MAE
• 90% confidence level for
2ns error at 4ns integration
would not be achievable
even at very high SNRs
TG4a
Slide 11
I. Guvenc, Z. Sahinoglu, Mitsubishi Electric