July. 2005 C. Lee, J. Kim, E. Choi, C. Lee doc.: IEEE 802. 15-05-0426-01-004a Submission Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal.

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 1

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

Submission Title: [Robust Ranging Algorithm for UWB radio]Date Submitted: [19 July, 2005]Source: [Cheolhyo Lee (1), Jae Young Kim (1), Eun Chang Choi (1), Chong Hyun Lee (2)] Company [(1) Electronics and Telecommunications Research Institute (ETRI) (2) Seokyeong University]Address [(1) 161 Gajeong-dong, Yuseong-gu, Daejeon, Republic of Korea (2) 16-1 Jungneung-Dong, Sungbuk-Ku, Seoul, Republic of Korea]Voice:[(1) +82 42 860 5577, (2) +82 2 940 7472], FAX: [(1) +82 42 860 5218 (2) +82 2 919 0345]E-Mail: [(1) [email protected], (2) [email protected]]Abstract: [The robust ranging algorithm is proposed for the alternative PHY for 802.15.4a] Purpose: [This submission is in response to the committee’s request to submit the proposal enabled by an alternate 802.15 TG4a PHY]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.

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 2

Robust Ranging Algorithm for UWB Radio

Electronics and Telecommunications Research Institute (ETRI)

Seokyeong University

Republic of Korea

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 3

• Proposed Algorithm• Proposed algorithm flow & summary• Comparisons of complexities with MERL and

I2R• Simulations for CM1• Simulations for CM8• Conclusions

Outline

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 4

Proposed Algorithm

TOA Estimator

BPF

( )2

LPF / 1-4ns

integrator

ADC

Add few Frames & Compute Energy

FFT

Convert Time to Frequency

High Resolution Algorithm

SNR IncreaseCompute Energy

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 5

Other Architectures for Comparison

TOA Estimator

BPF

( )2

LPF / 2-4ns

integrator

ADC 1D to 2D Conversion

Length-3 Vertical Median or Minimum Filtering

Removes interference

2D to 1D Conversion with Energy Combining

Energy image generation

"Path-arrival dates" table

1D to 2D Conversion

Assumption path synchronization

Matrix

Filtering + Assumption/path

selectionTime base 1-2ns accuracy

Time stamping

Analog comparator

Sliding Correlator

Energy combining across symbols

interference suppression

1D-2D Conversion

2D-1D Conversion

Energy image generation

Bipolar template

MERL

I2R

FT R&D

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 6

Finding the Subspace

Finding Spectrum

Finding TOA

Proposed Algorithm Flow

• Algorithm based High Resolution TOA

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 7

Proposed Algorithm Summary

• Required Operation:– Correlation

– FFT

– Comparison

• Complexity (N: No. of Energy Block)– R: N point Correlation

– FFT: N point FFT

– Noise Subspace: N point scalar and vector multiplication

– Peak Finding: N point comparison

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 8

Complexity of the Proposed Algorithms Algorithm Complexity N = 32

Accumulation of signals

(Preamble symbols-1) x 31 chip sequences adds.

992 op. (= 32 x 31, assuming preamble symbols is 31)

N point FFT

(Two FFTs)

2x(N/2)log2N complex mults.

2xNlog2N complex additions

960 op. (=2x80 complex mults= 2x4x80 real mults. + 2x2x80 real adds.)

640 op. (= 2x160 complex adds. = 2x320 real adds.)

Correlation 3xN*N real multiplication

3xN*(N-1) real addition

3072 op. (=3x1024 real mults.)

2976 op. (= 3x992 real adds.)

Subspace N complex multiplication 192 op.

(=128 real mults. + 64 real adds.)

Finding Peaks N-1 Comparison 31 comparisons

Total Operations 8863 op. ( Complexity O(N2) )

Memory size N 32

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 9

Complexity of Algorithm by MERL

Algorithm Complexity N = 32

N x N image* (N x N) x 3

rearrange operations

3072 op. (= 32 x 32 x 3)

2D to 1D conversion (Preamble symbols-1) x 31 chip sequences adds.

992 op. (= 31 x 32)

Total operation 4064 op. ( Complexity O (N2) )

Memory size N x N = N2 1024

* Sorting (3 point Median Filtering)

= 32 rearrange operations = (Compare & allocation) = 9

- Complexity Ratio = Proposed/MERL = 8863/4064 = 218% -> Two times

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 10

Complexity of Algorithm by I2R Algorithm Complexity N = 32

Sliding Correlation N*N real adds. 1024 real adds.

N/2 x N image sliding correlation x 31 chip sequences

31744 op. (= 1024 x 31)

2D to 1D conversion (Preamble symbols-1) x 31 chip sequences adds.

465 op. (= 15 x 31)

Total operation 32209 op. (= 31744+465)

( Complexity O(N3) )

Memory size Preamble symbols x 31 chip sequences

496 (= 16 x 31)

- Complexity Ratio = Proposed/I2R = 8863/32209 = 27.4% -> less than I2R

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 11

Simulation Parameters for CM1

• CM1 Channel considered• Ts = 1ns• SNR 8~22dB• 10 Frames are accumulated.• Three High Resolution Algorithms• Compare with MERL• True TOA = 10

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 12

Simulation Results

• SNR 8dB True TOA

True TOA

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 13

Simulation Results• SNR 8dB

True TOATrue TOA

• High Resolution TOA VS MERL

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 14

• SNR 9dB True TOA

True TOA

Simulation Results

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 15

• SNR 9dB True TOA

True TOA

• High Resolution TOA VS MERL

Simulation Results

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 16

Simulation Results

• SNR 14dB True TOA

True TOA

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 17

Simulation Results• SNR 14dB

True TOATrue TOA

• High Resolution TOA VS MERL

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 18

Simulation Results

• SNR 17dB True TOA

True TOA

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 19

Simulation Results• SNR 17dB

True TOATrue TOA

• High Resolution TOA VS MERL

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 20

Simulation Results• SNR 22dB

True TOA

True TOA

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 21

Simulation Results• SNR 22dB

True TOATrue TOA

• High Resolution TOA VS MERL

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 22

Simulation Parameters for CM8

• CM8 Channel considered

• Window length = 64

• Ts = 1ns

• SNR 10~22dB

• 5 Frames are accumulated.

• High Resolution Algorithms

• Compare with MERL

• True TOA = 10

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 23

Simulation Results• SNR 10dB

0 10 20 30 40 50 60 70-1

-0.5

0

0.5

1

time (ns)

Am

plitu

de

Noisy output

0 10 20 30 40 50 60 70-1

-0.5

0

0.5

1

time (ns)

Am

plitu

de

sum output

0 10 20 30 40 50 60 700

0.1

0.2

0.3

0.4

time (ns)

Am

plitu

de

Energy

0 10 20 30 40 50 60 700

2

4

6

time (ns)

Am

plitu

de

FFT output

True TOA

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 24

Simulation Results• SNR 10 dB

• High Resolution TOA VS MERL

0 10 20 30 40 50 60 70-10

0

10

20

30

40

50

60

70

time (ns)

Mag

nitu

de

Proposed Algorithm

True TOA

True TOA

10 20 30 40 50 601

1.5

2

2.5

3

3.5

4

4.5

5

True TOA

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 25

Simulation Results• SNR 11dB

0 10 20 30 40 50 60 70-1

-0.5

0

0.5

1

time (ns)

Am

plitu

de

Noisy output

0 10 20 30 40 50 60 70-1

-0.5

0

0.5

1

time (ns)

Am

plitu

de

sum output

0 10 20 30 40 50 60 700

0.1

0.2

0.3

0.4

time (ns)

Am

plitu

de

Energy

0 10 20 30 40 50 60 700

2

4

6

time (ns)

Am

plitu

de

FFT output

True TOA

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 26

Simulation Results• SNR 11 dB

• High Resolution TOA VS MERL

0 10 20 30 40 50 60 70-10

0

10

20

30

40

50

60

70

time (ns)

Mag

nitu

de

Proposed Algorithm

True TOA

True TOA

10 20 30 40 50 601

1.5

2

2.5

3

3.5

4

4.5

5

True TOA

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 27

Simulation Results

• SNR 13dB

0 10 20 30 40 50 60 70-0.5

0

0.5

time (ns)

Am

plitu

de

Noisy output

0 10 20 30 40 50 60 70-1

-0.5

0

0.5

1

time (ns)

Am

plitu

de

sum output

0 10 20 30 40 50 60 700

0.2

0.4

0.6

0.8

time (ns)

Am

plitu

de

Energy

0 10 20 30 40 50 60 700

2

4

6

time (ns)

Am

plitu

de

FFT output

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 28

Simulation Results

• SNR 13dB

• High Resolution TOA VS MERL

0 10 20 30 40 50 60 70-10

0

10

20

30

40

50

60

70

time (ns)

Mag

nitu

de

Proposed Algorithm

True TOA

10 20 30 40 50 601

1.5

2

2.5

3

3.5

4

4.5

5

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 29

Simulation Results

• SNR 17dB

0 10 20 30 40 50 60 70-0.5

0

0.5

time (ns)

Am

plitu

de

Noisy output

0 10 20 30 40 50 60 70-1

-0.5

0

0.5

time (ns)

Am

plitu

de

sum output

0 10 20 30 40 50 60 700

0.1

0.2

0.3

0.4

time (ns)

Ampl

itude

Energy

0 10 20 30 40 50 60 700

1

2

3

4

time (ns)

Ampl

itude

FFT output

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 30

Simulation Results

• SNR 17dB

0 10 20 30 40 50 60 70-10

0

10

20

30

40

50

60

70

time (ns)

Mag

nitu

de

Proposed Algorithm

True TOA

10 20 30 40 50 601

1.5

2

2.5

3

3.5

4

4.5

5

• High Resolution TOA VS MERL

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 31

Key Issue• Complexity

– FFT is just the order of O(Nlog2(N))=> O(N)

– What is the complexity of correlator?

-> equal or greater than O(N2)• It depends on how many correlation operation is required

– Order of complexity• Proposed algorithm = MERL < I2R

Proposed algorithm MERL I2R

Complexity O(N2) O(N2) O(N3)

July. 2005

C. Lee, J. Kim, E. Choi, C. Lee

doc.: IEEE 802. 15-05-0426-01-004a

Submission

Slide 32

Conclusions• Advantages

– Low complexity and high performance

– Small memory size

– High performance for low SNR and SINR

– Can be applied to Coherent system

– Small TOA estimation error (by CM8 simulation)

– Independent to signal waveform

• Future works– Need comprehensive simulation

– Consider the SOP environment