802.11ac Channel Modeling Authors: Jan 19, 2009 Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 802.11ac Channel Modeling Authors: Names John Doe, Some Company

Topics Introduction TGn Channel Model Applicability to TGac Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 Topics Introduction TGn Channel Model Applicability to TGac Questions ? Names John Doe, Some Company

Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 Introduction TGn has developed a comprehensive MIMO Broadband Channel Model TGac can re-use the TGn channel models as a baseline with some minor changes to address possible new technology components such as Higher order MIMO (> 4x4) Spatial Division Multiple Access (SDMA) with > 4 AP antennas Distributed MIMO Higher Bandwidth (> 40 MHz) OFDMA - Use multiple 20 MHz channels across multiple users. Names John Doe, Some Company

Topics Introduction TGn Channel Model Applicability to TGac Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 Topics Introduction TGn Channel Model Applicability to TGac Questions ? Names John Doe, Some Company

Measurement Literature Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 Measurement Literature Many published studies of higher order Indoor MIMO measurements in literature. Examples include: E. Bonek Ove, “Experimental validation of analytical MIMO channel models”, Vienna University of Technology, June 2005. Ozcelik, H.; Herdin, M.; Hofstetter, H.; Bonek, E., "A comparison of measured 8 × 8 MIMO systems with a popular stochastic channel model at 5.2 GHz," Telecommunications, 2003. ICT 2003. 10th International Conference on , vol.2, no., pp. 1542-1546 vol.2, 23 Feb.-1 March 2003 Nielsen, J.O.; Anderson, J.B., “Indoor MIMO Channel Measurement and Modeling,” WPMC / IWS Conference, pp. 479-483, September 2005. Qualcomm is also conducting 8x8 and 16x16 indoor channel measurements using a MIMO channel sounding system Names John Doe, Some Company

Jan 19, 2009 Measurement Setup Indoor 8x8 and 16x16 MIMO 20 MHz channel measurements at 5.17 GHz performed at Qualcomm Used a channel sounder built from off the shelf components A mix of LOS and NLOS locations were chosen Two independent channel measurements at each location (STA rotated 90°) Names

Example Antenna Configurations Used Jan 19, 2009 Example Antenna Configurations Used 8 Slot Antenna Array Two V-H and two ±45° pairs λ/2 separation between slot pairs 16 Linear Dipole Antenna Array λ/2 separation between elements Names

Cross-Pol Antenna Array Radiation Pattern Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 Cross-Pol Antenna Array Radiation Pattern Names John Doe, Some Company

Applicability to SDMA, Distributed MIMO & OFDMA Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 Applicability to SDMA, Distributed MIMO & OFDMA Measurements indicate that users separated by a few l experience uncorrelated fading. Spatial correlation coefficients in the 0-0.2 range. We welcome additional measurement results to validate this observation. Recommend using independent TGn NRx x NTx channels for links across multiple users NTx is the number of AP antennas NRx is the number of STA antennas. Names John Doe, Some Company

Changes to Bandwidth, Delay Spread & Doppler Spread Parameters Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 Changes to Bandwidth, Delay Spread & Doppler Spread Parameters TGn channel models are valid up to 100 MHz bandwidth. TGac systems can use TGn models if system bandwidth <= 100 MHz. If TGac systems include non-contiguous channels with total span > 100 MHz, then channel tap spacing needs to be decreased to accommodate the total channel bandwidth span across all the used channels. May need 1ns channel tap spacing to accommodate 1 GHz. Recall that TGn channel tap spacing is 10nsec. Need wider bandwidth channel measurements to derive channel models for such large bandwidths. Measurements in Literature do not invalidate TGn Delay spread model and Doppler spread models. Suggest preserving these parameters, unless new measurements indicate otherwise. Names John Doe, Some Company

TGn Channel Capacity vs. Measured Capacity Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 TGn Channel Capacity vs. Measured Capacity 8x8 channel measurements indicate most locations have capacity CDFs that are bounded between 11n channel models B & D. Assumed uniform linear isotropic antenna array (l/2 spacing) at AP and client. Capacity calculation was performed as follows: Calculate MMSE post-processing SINR at each tone, assuming 24 dB SNR per Rx antenna. Convert SINR at each tone to capacity. Average capacities across all tones across 20 MHz BW Each CDF curve reflects a different test location/orientation Names John Doe, Some Company

TGn Channel Capacity vs. Measured Capacity Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 TGn Channel Capacity vs. Measured Capacity 16x16 channel measurements indicate most locations have capacity CDFs that are bounded between 11n channel models B & D. Assumed uniform linear isotropic antenna array (l/2 spacing) at AP and client. Capacity calculation was performed as follows: Calculate MMSE post-processing SINR at each tone, assuming 24 dB SNR per Rx antenna. Convert SINR at each tone to capacity. Average capacities across all tones across 20 MHz BW Each CDF curve reflects a different test location/orientation Names John Doe, Some Company

Cross-Polarized antennas Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 Cross-Polarized antennas To minimize real estate and to improve LOS MIMO performance, OEMs may also use cross-polarized antennas, as shown in the below figure for 8 antennas TGac may need to specify channel models that include dual-polarized antennas Need to specify XPD, correlations between cross-polarized antennas etc. Recall that TGn provided only a brief description of dual polarized antennas, but didn’t explicitly include dual pol channel models TGac needs to agree on whether we need to include dual-pol antennas for proposal comparison /evaluation Names John Doe, Some Company

TGn Channel Capacity vs. Measured Capacity Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 TGn Channel Capacity vs. Measured Capacity 8x8 cross-pol channel measurements show tightening of capacity CDF bounds across all locations and significant capacity improvement in LOS scenarios, w.r.t the linear dipole array measurements. TGn channel models assume XPD = 3 dB and correlation between cross-pol antennas = 0. Capacity calculation was performed as follows: Calculate MMSE post-processing SINR at each tone, assuming 24 dB SNR per antenna. Convert SINR at each tone to capacity. Average capacities across all tones across 20 MHz BW Each CDF curve reflects a different test location/orientation Names John Doe, Some Company

TGn Channel Capacity vs. Measured Capacity Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 TGn Channel Capacity vs. Measured Capacity 16x16 cross-pol channel measurements show tightening of capacity CDF bounds across all locations and significant capacity improvement in LOS scenarios, w.r.t the linear dipole array measurements. TGn channel models assume XPD = 3 dB and correlation between cross-pol antennas = 0. Capacity calculation was performed as follows: Calculate MMSE post-processing SINR at each tone, assuming 24 dB SNR per antenna. Convert SINR at each tone to capacity. Average capacities across all tones across 20 MHz BW Each CDF curve reflects a different test location/orientation Names John Doe, Some Company

Conclusions TGac can re-use the TGn channel models as a baseline. Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 19, 2009 Conclusions TGac can re-use the TGn channel models as a baseline. TGn channel models seems to accurately bound the 8x8 and 16x16 channel capacities measured in enterprise environment. Use of cross-polarized antennas dramatically improves MIMO system performance for 8x8 and 16x16. TGac channel models may introduce Dual Pol channel models in addition to current models. Need to agree on XPD, antenna correlation etc. Names John Doe, Some Company

Questions ? Jan 19, 2009 Month Year doc.: IEEE 802.11-yy/xxxxr0 Names John Doe, Some Company