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This proposal suggests converging onto a single sounding mechanism, the NDP sounding format, to address compatibility and interoperability issues in TGac. It also defines the P matrices for Nsts<=4 and excludes 5x5 and 7x7 P matrices.
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Sounding and P Matrix Proposal Date: 2010-05-16 Authors: Slide 1 Vinko Erceg et al.
Introduction • Sounding Format • 6x6 and 8x8 P matrices • P matrices for Nsts<=4 • Straw polls Vinko Erceg et al.
Sounding Mechanism (1) • In 11n, there are multiple sounding formats: • Staggered sounding • NDP sounding • It would be desirable in TGac to converge onto a single sounding format • Compatibility and interoperability complications with multiple formats • Our proposal is to converge onto a single sounding mechanism: • NDP sounding frame format Slide 3 Vinko Erceg et al.
Sounding Mechanism (2) • NDP sounding advantages • Defines a cleaner and simpler immediate feedback protocol • ACK is not required • Less latency in providing CSI feedback when to compared to staggered sounding • No Data present • May be important for MU feedback • Channel staleness problem • Only channel estimation for CSI feedback is performed after receiving an NDP packet • Potential parallel processing for data demodulation is avoided • Works well with MU sounding mechanism • Sounding for multiple users Slide 4 Vinko Erceg et al.
P Matrix Definition (1) • In TGac, new P matrices for Nsts > 4 need to be defined • Proposal to define 6x6 DFT matrix P as follows Slide 5 Vinko Erceg et al.
P Matrix Definition (2) • Proposal to define 8x8 matrix P as follows: where P4x4 is the 11n 4x4 P matrix Slide 6 Vinko Erceg et al.
P Matrix Definition (3) • We propose the same P matrix as in 11n, when Nsts<=4 in 11ac packets • We propose not to include 5x5 and 7x7 P matrices in the draft Tgac standard due to implementation complexity reasons Slide 7 Vinko Erceg et al.
Straw Polls Vinko Erceg et al.
Straw Poll #1 • Do you support adding the following item into the specification framework document, 11-09/0992? • R3.2.1.J: All VHT transmissions shall have a preamble which contains a single section of long training fields, with each long training field multiplied by entries belonging to a single P matrix, to enable channel estimation at the receiver. • Yes: • No: • Abs: Vinko Erceg et al.
Straw Poll #2 • Do you support adding the following item into the specification framework document, 11-09/0992? • R3.2.2.C: The draft specification shall include null data packet (NDP) as the only preamble format for sounding PPDUs. • Yes: • No: • Abs: Vinko Erceg et al.
Straw Poll #3 • Do you support adding the following item into the specification framework document, 11-09/0992? • R3.2.1.K: The single section of long training fields consists of one, two, four, six or eight VHT long training fields (VHT-LTFs) that are necessary for demodulation of the VHT-Data portion of the PPDU or for channel estimation during an NDP packet. • Yes: • No: • Abs: Vinko Erceg et al.
Straw Poll #4 • Do you support adding the following item into the specification framework document, 11-09/0992? • R3.2.1.K: The VHT-LTF mapping matrix P for one, two or four VHT-LTFs shall be the same as defined in 802.11n standard specification (Section 20.3.9.4.6, Eq. (20-27)). • Yes: • No: • Abs: Vinko Erceg et al.
Straw Poll #5 • Do you support adding the following item into the specification framework document, 11-09/0992? • R3.2.1.L: The VHT-LTF mapping matrix P for six VHT-LTFs shall be as defined in slide 4 of 11-10/00xxr0. • Yes: • No: • Abs: Vinko Erceg et al.
Straw Poll #6 • Do you support adding the following item into the specification framework document, 11-09/0992? • R3.2.1.L: The VHT-LTF mapping matrix P for eight VHT-LTFs shall be as defined in slide 5 of 11-10/00xxr0. • Yes: • No: • Abs: Vinko Erceg et al.
