Investigation of upsampling techniques for TGac Channel Model April 2007 doc.: IEEE 802.11-07/0570r0 May 2009 Investigation of upsampling techniques for TGac Channel Model Date: 2009-05-11 Authors: Eldad Perahia, Intel Corporation Eldad Perahia, Intel Corporation

May 2009 Introduction Approach is to reuse the TGn Channel model with minor modifications [1-4] Allows known channel model to be used Allows a large collection of .l1n results to be compared to TGac techniques Target: When simulating a .11n system, the chosen up-sampling technique should not alter the performance In contiguously 10ns sampled cluster channel taps (channel B), linearly interpolation of the cluster channel tap power was simulated. For channels with sparse sampling (channel D, E were simulated), several interpolation methods of the cluster channel tap power were investigated Eldad Perahia, Intel Corporation

Interpolation Methods May 2009 Interpolation Methods For channel model B a linearly interpolation method was used. Each Cluster channel tap power was linearly interpolated to provide a effective channel tap spacing of 5ns. Channel model D and E were interpolated with several techniques In all cases the first contiguous 10ns sample cluster was linearly interpolated as in the channel B case. The sparse taps were then interpolated with different approaches The target was to find an interpolation method that afforded the best match to a .11n system using the TGn model Eldad Perahia, Intel Corporation

Interpolation Approaches (Channel Model D example) May 2009 Interpolation Approaches (Channel Model D example) Case 1 Initial set of contiguous 10ns cluster channel tap power samples linearly interpolated Remaining sparse taps used as is (assumed to be perfect reflectors) Case 2 Initial set of contiguous 10ns cluster channel tap power samples linearly interpolated Remaining sparse taps linearly interpolated with a new sample place in the middle (in time) of the TGn samples Eldad Perahia, Intel Corporation

Interpolation Approaches (Channel Model D example) Cont. May 2009 Interpolation Approaches (Channel Model D example) Cont. Case 3 Initial set of contiguous 10ns cluster channel tap power samples linearly interpolated Remaining sparse taps linearly interpolated with new samples placed every 5ns between TGn samples Case 4 Initial set of contiguous 10ns cluster channel tap power samples linearly interpolated Remaining sparse taps linearly interpolated with a new sample place 5ns after a TGn sample Eldad Perahia, Intel Corporation

May 2009 802.11n 1x1 1-Spatial Stream, TGn Channel model B (100 MHz), Linearly Interpolated (200MHz), 1000 Byte Packet, CC67, 20MHz, MCS 0 and MCS 7 Eldad Perahia, Intel Corporation

May 2009 802.11n 2x4 2-Spatial Streams, TGn Channel model B (100 MHz), Linearly Interpolated (200MHz), 1000 Byte Packet, CC67, 20MHz, MCS 8 and MCS 15 Eldad Perahia, Intel Corporation

May 2009 802.11n 4x6 4-Spatial Streams, TGn Channel model B (100 MHz), Linearly Interpolated (200MHz), 1000 Byte Packet, CC67, 20MHz, MCS 24 and MCS 31 Eldad Perahia, Intel Corporation

May 2009 802.11n 2x4 2-Spatial Streams, TGn Channel model D (100 MHz), Case 1-4 Interpolated (200MHz), 1000 Byte Packet, CC67, 20MHz, MCS 15 Eldad Perahia, Intel Corporation

May 2009 802.11n 2x4 2-Spatial Streams, TGn Channel model D (100 MHz), Case 1-4 Interpolated (200MHz), 1000 Byte Packet, CC67, 40MHz, MCS 15 Eldad Perahia, Intel Corporation

May 2009 802.11n 4x6 4-Spatial Streams, TGn Channel model D (100 MHz), Case 1-4 Interpolated (200MHz), 1000 Byte Packet, CC67, 20MHz, MCS 31 Eldad Perahia, Intel Corporation

May 2009 802.11n 4x6 4-Spatial Streams, TGn Channel model D (100 MHz), Case 1-4 Interpolated (200MHz), 1000 Byte Packet, CC67, 40MHz, MCS 31 Eldad Perahia, Intel Corporation

May 2009 802.11n 2x4 2-Spatial Streams, TGn Channel model E (100 MHz), Case 1-4 Interpolated (200MHz), 1000 Byte Packet, CC67, 20MHz, MCS 15 Eldad Perahia, Intel Corporation

May 2009 802.11n 2x4 2-Spatial Streams, TGn Channel model E (100 MHz), Case 1-4 Interpolated (200MHz), 1000 Byte Packet, CC67, 40MHz, MCS 15 Eldad Perahia, Intel Corporation

May 2009 802.11n 4x6 4-Spatial Streams, TGn Channel model E (100 MHz), Case 1-4 Interpolated (200MHz), 1000 Byte Packet, CC67, 20MHz, MCS 31 Eldad Perahia, Intel Corporation

May 2009 802.11n 4x6 4-Spatial Streams, TGn Channel model E (100 MHz), Case 1-4 Interpolated (200MHz), 1000 Byte Packet, CC67, 40MHz, MCS 31 Eldad Perahia, Intel Corporation

May 2009 Conclusion Linearly interpolating the cluster channel tap power at 5ns for TGn channel model B provided negligible performance difference for an .11n system Four interpolation techniques were investigated for TGn Channel model D and E Case 2 and Case 4 resulted with a close match to .11n TGn performance It is recommended that the approach of Case 4 be used as the method of interpolation in TGac Provides same performance as the TGn model when simulating a .11n system Felt to be a more intuitive channel for a higher sampling rate Eldad Perahia, Intel Corporation

May 2009 References Breit, G., Sampath, H.,et al., TGac Channel Model Addendum, IEEE 802.11-09/0308r1, Mar 9, 2009 Breit, G., Sampath, H.,et al., Evaluation of AoD for TGac Multi-User MIMO channel Model, IEEE 802.11-09/0307r1, Mar 9, 2009 Kenney, T., Perahia, E., Reuse of TGn Channel Model for SDMA in TGac, IEEE 802.11-09/0179r0, Jan 22, 2009 Breit, G., Sampath, H.,et al., 802.11ac Channel Modeling, IEEE 802.11-09/0088r1, Jan 19, 2009 Eldad Perahia, Intel Corporation