1. July 2009 doc.: IEEE 802.11-09/0823r0 Submission Progress Report for Corridor Channel Model for TGac Byung-Jae Kwak et al., ETRI Slide 1 NameAffiliationsAddressPhoneE-mail Byung-Jae KwakETRI138 Gajeongno, Yuseong-gu, Daejeon, 305-700, Korea +82-42-860-6618bjkwak@etri.re.kr Myung Don KimETRI138 Gajeongno, Yuseong-gu, Daejeon, 305-700, Korea +82-42-860-6178mdkim@etri.re.kr Jae Joon ParkETRI138 Gajeongno, Yuseong-gu, Daejeon, 305-700, Korea +82-42-860-3958jjpark@etri.re.kr Wonsop KimETRI138 Gajeongno, Yuseong-gu, Daejeon, 305-700, Korea +82-42-860-5302topson@etri.re.kr Minho CheongETRI138 Gajeongno, Yuseong-gu, Daejeon, 305-700, Korea +82-42-860-5635minho@etri.re.kr Hyun Kyu ChungETRI138 Gajeongno, Yuseong-gu, Daejeon, 305-700, Korea +82-42-860-6140hkchung@etri.re.kr

2. July 2009 Submission doc.: IEEE 802.11-09/0823r0 Contents Introduction Channel Measurement Analysis of Channel Measurement –SAGE Algorithm –Clustering Discussion Slide 2 Byung-Jae Kwak et al., ETRI

3. July 2009 Submission doc.: IEEE 802.11-09/0823r0 Introduction During Vancouver Meeting, –it was found out that MIMO performance degrades significantly in environments such as corridor [1]; –TGac agreed further study of corridor channel is needed after discussion. Further study of corridor channel, presented in Montreal Meeting, revealed that the current TGn channel models are inappropriate to model corridor channel [2] In Montreal Meeting, IEEE 802.11-09/0308 was adopted as “TGac Channel Model Addendum” baseline document IEEE 802.11-09/0308r5, “TGac Channel Model Addendum” [3]: “The scope of this document is limited to extensions of the existing TGn channel model definitions (i.e., Models A-F). The introduction of a new model definition covering indoor corridor propagation is TBD.” This contribution is a status report of the work in progress on Corridor Channel Model Slide 3 Byung-Jae Kwak et al., ETRI

4. July 2009 Submission doc.: IEEE 802.11-09/0823r0 Channel Measurement Channel measurement completed with Brand new antenna systems –8x8 uniform linear antenna systems –8x8 uniform circular antenna system (also used for AoD/AoA estimation) 3 measurement sites: –1 st fl., Bldg. 1, ETRI –2 nd fl., Bldg. 11, ETRI –1 st fl., dorm. bldg. Slide 4 Byung-Jae Kwak et al., ETRI

5. July 2009 Submission doc.: IEEE 802.11-09/0823r0 Analysis of Channel Measurement SAGE: Space-Alternating Generalized Expectation-Maximization Algorithm [4] SAGE is widely used for channel estimation [5] ETRI has extensive experience of using SAGE for outdoor measurements ETRI is currently making some improvements to SAGE implementation for indoor environment: larger number of paths, memory efficiency, speed up, etc Slide 5 Byung-Jae Kwak et al., ETRI

6. July 2009 Submission doc.: IEEE 802.11-09/0823r0 Phase Shift by AoD and AoA Slide 6 Byung-Jae Kwak et al., ETRI

7. July 2009 Submission doc.: IEEE 802.11-09/0823r0 Received Signal Matrix Slide 7 Received signal matrix for a single path = Received signal matrix with multi-path Byung-Jae Kwak et al., ETRI

8. July 2009 Submission doc.: IEEE 802.11-09/0823r0 SAGE Algorithm (1/4) EM algorithm: –Stable (eventually approach a stationary point) –Complicated, slow convergence SAGE algorithm: –Extends EM by sequentially updating small groups of elements –Has the same monotonic property as EM  stable –Faster convergence than EM –Significant reduction of complexity Slide 8 Byung-Jae Kwak et al., ETRI

9. July 2009 Submission doc.: IEEE 802.11-09/0823r0 SAGE Algorithm (2/4) The objective function The objective function has peaks when Slide 9 Byung-Jae Kwak et al., ETRI

10. July 2009 Submission doc.: IEEE 802.11-09/0823r0 SAGE Algorithm (3/4) Def: – Iteration: Slide 10 Byung-Jae Kwak et al., ETRI

11. July 2009 Submission doc.: IEEE 802.11-09/0823r0 SAGE Algorithm (4/4) What do we get from SAGE Alg.: –Delay, delay spread –AoD, AoA, and the respective angular spread –Doppler, Doppler spread –K-factor –# clusters, etc Need to do clustering Slide 11 Byung-Jae Kwak et al., ETRI

12. July 2009 Submission doc.: IEEE 802.11-09/0823r0 Clustering Grouping of received rays for interpretation Slide 12 (Source: [6] “TGn Channel Models”) Byung-Jae Kwak et al., ETRI

13. July 2009 Submission doc.: IEEE 802.11-09/0823r0 Discussion Goal: To propose a Corridor Channel Model in Sept. meeting Other parameters can also be obtained from the measurement data Comments and suggestions are welcome Slide 13 Byung-Jae Kwak et al., ETRI

14. July 2009 Submission doc.: IEEE 802.11-09/0823r0 References [1] IEEE 802.11-09/0345r0, “Indoor Channel Measurements for TGac,” IEEE 802.11 #114, March 2009. [2] IEEE 802.11-09/0542r0, “Channel Measurements in Corridors for TGac,” IEEE 802.11 #115, May 2009. [3] IEEE 802.11-09/0308r5, “TGac Channel Model Addendum,” IEEE 802.11 #115, May 2009. [4] J. A. Fessler, A. O. Hero, “Space-Alternating Generalized Expectation- Maximization Algorithm,” IEEE Transactions on Signal Processing, vol. 42, no. 10, pp. 2664-2677, 1994. [5] Bernard H. Fleury, Martin Tschudin, Ralf Heddergott, Dirk Dahlhaus, Klaus Ingeman Pedersen, “Channel Parameter Estimation in Mobile Radio Environments Using the SAGE Algorithm,” IEEE Journal on Selected Areas in Communications, vol. 17, no. 3, March 1999, pp. 434-450. [6] IEEE 802.11-03/940r4, “TGn Channel Models,” May 2004. [7] Adel A. M. Saleh, Reinaldo A. Valenzuela, “A Statistical Model for Indoor Multipath Propagation,” IEEE Journal on Selected Areas in Communications, vol. SAC-5, no. 2, Feb. 1987, pp. 128-137. Slide 14 Byung-Jae Kwak et al., ETRI