TGac Channel Model Update Month Year doc.: IEEE 802.11-yy/xxxxr0 May 2009 doc.:IEEE 802.11-09/0575r1 TGac Channel Model Update Greg Breit, gbreit@qualcomm.com Hemanth Sampath, hsampath@qualcomm.com Sameer Vermani, svverman@qualcomm.com Richard Van Nee, rvannee@qualcomm.com Minho Cheong, minho@etri.re.kr Byung-Jae Kwak, bjkwak@etri.re.kr Myung Don Kim, mdkim@etri.re.kr Jae Joon Park, jjpark@etri.re.kr Naoki Honma, honma.naoki@lab.ntt.co.jp Takatori Yasushi, takatori.yasushi@lab.ntt.co.jp Yongho Seok, yhseok@lge.com Seyeong Choi, seyeong.choi@lge.com Phillipe Chambelin, philippe.chambelin@thomson.net John Benko, john.benko@orange-ftgroup.com Laurent Cariou, laurent.cariou@orange-ftgroup.com VK Jones, vkjones@qualcomm.com Allert Van Zelst, allert@qualcomm.com Lin Yang, linyang@qualcomm.com Thomas Kenney, thomas.j.kenney@intel.com Eldad Perahia, eldad.perahia@intel.com Vinko Erceg, verceg@broadcom.com Note: The author list will grow to reflect those providing explicit contributions and review comments John Doe, Some Company

Month Year doc.: IEEE 802.11-yy/xxxxr0 May 2009 doc.:IEEE 802.11-09/0575r1 Introduction The TGn task group has developed a comprehensive MIMO broadband channel models, with support for 40 MHz channelization and 4 antennas. The TGac task group is targeting > 1 Gbps MAC SAP throughput using one or more of the following technologies: Higher order MIMO (> 4x4) Higher Bandwidth (> 40 MHz) Multi-User MIMO with > 4 AP antennas OFDMA This contribution summarizes followup work since the March 2009 presentation of the draft TGac channel model addendum document (Breit et al., 802.11-09/0308r1), and represented in the latest Rev 4. John Doe, Some Company

General Changes Removal of supporting data and detailed justifications May 2009 doc.:IEEE 802.11-09/0575r1 General Changes Removal of supporting data and detailed justifications Earlier revs of 09/0308 contained large amounts of supporting simulation and measurement data as well as justification text for the various proposed channel model extensions Rev 4 has been pared down to a direct statement of the model extensions Supporting data and detailed justification text for 09/0308 are now contained in new contribution 09/0569r0. 09/0308r4 now references 09/0569r0 and other supporting documents

Modifications FOR Large System Bandwidth May 2009 doc.:IEEE 802.11-09/0575r1 Modifications FOR Large System Bandwidth

Modifications For Large System BW Month Year doc.: IEEE 802.11-yy/xxxxr0 May 2009 doc.:IEEE 802.11-09/0575r1 Modifications For Large System BW TGn channel model addressed up to 40 MHz system bandwidth, assuming tap-spacing of 10 nsec. For TGac systems with larger overall system bandwidth (W), we propose to decrease channel tap spacing by a factor of Tap spacing reduction is accomplished by linear interpolation of the TGn-defined channel tap powers on a cluster-by-cluster basis System Bandwidth W Channel Sampling Rate Expansion Factor Channel Tap Spacing W ≤ 40 MHz 1 10 ns 40 MHz < W ≤ 80 MHz 2 5 ns 80 MHz < W ≤ 160 MHz 4 2.5 ns 160 MHz < W ≤ 320 MHz 8 1.25 ns 320 MHz < W ≤ 640 MHz 16 625 ps 640 MHz < W ≤ 1.28 GHz 32 312.5 ps John Doe, Some Company

Proposed Method for Tap Interpolation May 2009 doc.:IEEE 802.11-09/0575r1 Proposed Method for Tap Interpolation For each cluster in the TGn-defined model, and assuming a channel sampling rate expansion factor k (new sampling rate = k*100MHz), a sequence of k-1 new PDP taps, spaced 10/k ns apart, shall be appended after each TGn-defined PDP tap. The first PDP tap in the sequence shall occur 10/k ns after the TGn-defined PDP tap. The power (in dB) assigned to each new tap shall be determined by linear interpolation of the TGn-defined PDP tap powers (in dB) immediately before and after the new PDP tap, in proportion to its position in time relative to the two TGn PDP taps. No new PDP taps shall be added after the final TGn PDP tap for each cluster. Example for k=4

Performance of Tap Interpolation Scheme May 2009 doc.:IEEE 802.11-09/0575r1 Performance of Tap Interpolation Scheme Delay Spread (ns) for Models B-F B C D E F 11n 15.648 33.433 49.953 98.990 148.92 11ac 15.933 33.278 49.402 97.249 142.14 Ricean K factor (linear) calculated from generated channels using the method of Greenstein et al. B (K=1) C D (K=2) E (K=4) F 11n 0.986 1.031 2.036 4.087 3.980 11ac 1.012 1.048 1.912 3.873 4.060

Performance of Tap Interpolation Scheme May 2009 doc.:IEEE 802.11-09/0575r1 Performance of Tap Interpolation Scheme Link performance comparison: 40 MHz TGn vs. 80 MHz TGac (interpolated) 1x1, 64QAM, 2/3, except last column (Values represent dB difference in required SNR to achieve 1% and 10% PER) B C D E F F (QPSK ¾) PER=10% 0.1 0.0 0.25 PER=1% 0.2 0.05 1.0 0.5 Followup simulations performed for 4x4 MIMO Same parameters as SISO simulations above Models B and D only PER curves agree within 0.1dB at 1% and 10% PER

May 2009 doc.:IEEE 802.11-09/0575r1 Higher Order MIMO

Month Year doc.: IEEE 802.11-yy/xxxxr0 May 2009 doc.:IEEE 802.11-09/0575r1 Higher Order MIMO Retain the TGn Kronecker models for TGac higher order MIMO channel model. Recent measurements and analysis [1] show that TGn channel models, with appropriately chosen cluster AoA and AoDs tightly bound and sweep the range of MIMO performance observed in real environments. John Doe, Some Company

Extensions for Multi-User MIMO May 2009 doc.:IEEE 802.11-09/0575r1 Extensions for Multi-User MIMO

MU-MIMO Channel Model May 2009 doc.:IEEE 802.11-09/0575r1 Assume TGn-defined cluster AoDs and AoAs as baseline. For each client in the DL: Apply single random offset of ±180° to the LOS tap AoD and AoA. Apply single random offset of ±180° to the NLOS cluster AoA Apply single random offset of ±TBD° to the NLOS cluster AoD. For each client in the UL: Apply single random offset of ±180° to the NLOS cluster AoD Apply single random offset of ±TBD° to the NLOS cluster AoA. Notes: The ±TBD° value will be updated upon completion of analysis by ETRI [7]. The random offset can be determined by any well-known algorithm [TBD]. The appendix will specify the exact algorithm and example values.

Advantages of MU-MIMO Model May 2009 doc.:IEEE 802.11-09/0575r1 Advantages of MU-MIMO Model Physically realistic - Introduces statistical AoA/AoD variation across clients Minimal change to TGn channel model Simulation complexity increase is reasonable: TX/RX correlation matrix need to be computed only once per client, for the entire simulation run

Doppler-Related Changes May 2009 doc.:IEEE 802.11-09/0575r1 Doppler-Related Changes

Doppler-Related Changes May 2009 doc.:IEEE 802.11-09/0575r1 Doppler-Related Changes New measurement results by NTT [8] indicate the following: The TGn assumptions for main temporal Doppler component (Section 4.7.1) is too high The fluorescent light effects (mentioned in Section 4.7.3 of TGn channel model document) are absent. New text included in channel addendum document: TGac shall use the Doppler model specified in the TGn channel model document, with the following modifications:  In Section 4.7.1 of TGn channel model document, the environmental speed, vo, shall be reduced to TBD km/h  The effect of fluorescent lighting, as specified in Section 4.7.3 of [(TGn channel model doc)], shall not be included

Model Extensions for DUAL-POLarized ANTENNAS May 2009 doc.:IEEE 802.11-09/0575r1 Model Extensions for DUAL-POLarized ANTENNAS

Incorporating Dual Polarized Antennas May 2009 doc.:IEEE 802.11-09/0575r1 Incorporating Dual Polarized Antennas Dual-polarized antennas are likely to be employed in TGac devices Reduces real-estate in devices. Improves MIMO capacity, especially in LOS channel conditions Retain the TGn Dual-Pol channel model for TGac higher order MIMO channel model, with the following parameters: XPD value of 10 dB for the steering matrix HF, XPD value of 3 dB for the variable matrix Hv. 0.2 correlation for co-located orthogonally-polarized antenna elements Zero correlation for non-co-located orthogonally-polarized antenna elements Recent measurements and analysis [1] show that TGn dual-pol channel models, with appropriately chosen cluster AoA and AoDs tightly bound and sweep the range of MIMO performance observed in real environments.

Normalization of Channel Matrices Incorporating XPD May 2009 doc.:IEEE 802.11-09/0575r1 Normalization of Channel Matrices Incorporating XPD Modeled channels incorporating XPD should be normalized only to the norm of the co-polarized elements of the channel matrix Note: Normalization to the Frobenius norm of the entire channel matrix will fail to account for the additional path loss due to transmitting and receiving on orthogonal polarizations

References May 2009 doc.:IEEE 802.11-09/0575r1 Breit, G. et al. “TGac Channel Model Addendum Supporting Material.” Doc. IEEE802.11-09/0569r0 Erceg, V. et al. “TGn Channel Models.” Doc. IEEE802.11-03/940r4. Schumacher, L.; Pedersen, K.I.; Mogensen, P.E., "From antenna spacings to theoretical capacities - guidelines for simulating MIMO systems," Personal, Indoor and Mobile Radio Communications, 2002. The 13th IEEE International Symposium on , vol.2, no., pp. 587-592 vol.2, 15-18 Sept. 2002. Jian-Guo Wang; Mohan, A.S.; Aubrey, T.A., "Angles-of-arrival of multipath signals in indoor environments,"Vehicular Technology Conference, 1996. 'Mobile Technology for the Human Race,’ IEEE 46th , vol.1, no., pp.155-159 vol.1, 28 Apr-1 May 1996. Kaltenberger, F.; Kountouris, M.; Cardoso, L.; Knopp, R.; Gesbert, D., "Capacity of linear multi-user MIMO precoding schemes with measured channel data," Signal Processing Advances in Wireless Communications, 2008. SPAWC 2008. IEEE 9th Workshop on , vol., no., pp.580-584, 6-9 July 2008 L. J. Greenstein, D. G. Michelson, and V. Erceg, “Moment-method estimation of the Ricean K-factor,” IEEE Commun. Lett., vol. 3, no. 6, pp. 175–176, Jun. 1999. Kwak, B.-J. et al., “Measured Channel Capacity and AoD Estimation for Multi-User MIMO Scenarios.” Doc IEEE802.11-09/543r0 Yasushi, T. et al., “Measured Doppler Frequency in Indoor Office Environment,” Doc. IEEE802.11-09/537r0