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1/18 CJK9 , Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung ([email protected] ) PG707 Chair in TC7, TTA
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1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung ([email protected])[email protected].

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Page 1: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

1/18CJK9 , Zhangjiajie, China

ITU-R Channel ModelImplementation Issues

Document numberZhangjiajia, China

8-10 April 2009

Hyun Kyu(HK) Chung([email protected])

PG707 Chair in TC7, TTA

Page 2: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 2/18

Introduction

Issue

Solution

Action Items

Annex

Page 3: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 3/18

1. Introduction

WINNER Group (Finland & China) released the Matlab source code (in a contribution) claiming implementation of the IMT-Advanced Channel Model.

TTA Eval Group PG707 has been developing C-based implementation of IMT-Advanced channel model for LLS and SLS.

Our works are intended to release C-level source code in the coming WP5D meeting in Geneva

We have some correction issues for Matlab source code, and hope to share with CJK SIG, seeking for comments and possible cooperation.

Page 4: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 4/18

We cannot simply rely on the Matlab Code from the WINNER

Not C/C++

Have we checked they are really correct

We have a C-based channel model butNot sure we implement the channel model correctly

Start thinking about the comparisonUnlike the conventional channel model – described in power delay profile, the comparison is not straightforward

e.g. For a same speed of Mobile Station, Coherence Time can be quite different … Autocorrelation comparison may not work

Conclude that the Random Process Comparison is challenging

2. Issue

Page 5: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 5/18

Start viewing the channel simulator asDeterministic System

Various Independent Random Variables are inputs

Let’s draw a block diagram from the ITU-R Channel Model Document

Use the ASIC-verification conceptReference-model (Vector-based) verification

3. Solution

Page 6: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 6/18

Bubbles are independent Random VariablesG/U are Gaussian N(0,12) and Uniform (0,1) random variables

N is the scenario index LOS indicates LOS or NLOS – binary random variable

3-1. Small-Scale ITU-R Channel Model

Page 7: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 7/18

Compare Matlab & C code results for the same (deterministic) input for all the intermediate points

Also, compare each point’s probability density function

3-2. Large-Scale ITU-R Channel Model

Page 8: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 8/18

If mismatch is foundEither C program’s bug

Or Matlab’s bug

Or Unclear ITU-R description

We found many C program bugs (but now corrected) and have a report for the other two cases

We have about 7-8 issuesRefer the annex

3-3. How did we proceed

Page 9: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 9/18

Already implemented into the SLS

Report to WINNER Group Co-work, maybe?

Contribution (Bug report and C-Source code) to CJK

ITU-R

4. Action Items

Page 10: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 10/18

Bug report about the Matlab code

5. Annex

Page 11: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 11/18

5-1. Issue 1

Where(eq.11) of Step 6

ProblemIn Document M.2135

• Delay distribution for B1 NLOS is exponential distribution

In Matlab code• It is uniform distribution• Line number 310 in generate_bulk_par.m

SolutionCorrect the Matlab code

Page 12: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 12/18

5-2. Issue 2

WhereStep 6

ProblemIn Document M.2135

• There is Zn  ~ N(0, )

In Matlab code• use Zn like Zn  ~ N(0, 2)

• Line number 295 in generate_bulk_par.m

SolutionCorrect the Matlab code

Page 13: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 13/18

5-3. Issue 3

WhereStep 6

ProblemIn Document M.2135

• There is no additional process after (eq.12)

In Matlab code• There is a additional process after (eq.12)• Line number 325 in generate_bulk_par.m

SolutionDelete the Matlab code

Page 14: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 14/18

5-4. Issue 4

WhereTable A1-4 of Step 7

ProblemIn Document M.2135

• As if the scenario is the Indoor Hotspot(InH), there is especial constant C

In Matlab code• We cannot fine the constant C of InH• ConstantCMapping.m

SolutionAdd and Correct the Matlab code

Page 15: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 15/18

5-5. Issue 5

Where(eq.14) of Step 7

ProblemIn Document M.2135

In Matlab code, wrong usage of (eq.14) as follow

• Line number 383 and 409 in generate_bulk_par.m

SolutionCorrect the Matlab code

Page 16: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 16/18

5-6. Issue 6

Where(eq.18) of Step 7

ProblemIn Document M.2135

In Matlab code• Wrong (eq.18) w.r.t X1 and Y1

• Line number 387 in generate_bulk_par.m

SolutionCorrect the Matlab code

• Not random variable, but use X1 and Y1 which is already generated

Page 17: 1/18 CJK9, Zhangjiajie, China ITU-R Channel Model Implementation Issues Document number Zhangjiajia, China 8-10 April 2009 Hyun Kyu(HK) Chung (hkchung@etri.re.kr)hkchung@etri.re.kr.

CJK9 , Zhangjiajie, China 17/18

5-7. Issue 7

Where(eq.18) of Step 7

ProblemIn Document M.2135

• There is Yn ~ N(0, )

In Matlab code• Wrong (eq.18) w.r.t Yn ~ N(0, )

• Line number 387 in generate_bulk_par.m

SolutionCorrect the Matlab code

• In Document M.2135 step 7, there is , Yn ~ N(0, ) but Matlab code Yn use like Yn ~ N(0, ()

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