Uplink Pilot Structure for IEEE802.16mDocument Number:

IEEE C802.16m-08/293r4

Date Submitted:2008-05-07

Source:Mohammed Nafie, Cairo UniversityMohamed Abdallah, Cairo University

Cairo University, Cairo, Egypt

Re:IEEE 802.16m-08/005: Call for Contributions on Project 802.16m System

Description Document (SDD)Uplink Pilot FormatResource Block Structure

Abstract :This contribution proposes uplink pilot and resource block structures for IEEE802.16m

Purpose:For discussion and approval by TGm

Note: This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups. It represents only the views of the participants listed in the “Source(s)” field above. It is offered as a basis for discussion. It is not binding on the contributor(s), who reserve(s) the right to add, amend or withdraw material contained herein.

Release:The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that

this contribution may be made public by IEEE 802.16.

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Introduction

• We propose two different schemes for the uplink resource block unit with pilot structure– Distributed RBU

• Smaller RBU size and distributed across the frequency spectrum.

• We propose two different examples for distributed RBU.

– Localized RBU• Physically contiguous.

• RBU size similar to that allocated to the download RBU.

Uplink Resource Block Units

• A “localized” resource block unit size is the same as will be agreed upon in the downlink– Example: 18x6.

• A “distributed” resource unit consists of N tiles, such that the size of the distributed resource unit is the same as the localized resource unit.

Uplink Pilot Formats

• Pilot density is higher in distributed resource allocation

• For “localized”, we can use the same pilot format as will be agreed upon in downlink– Speeds up our process

Example 1 (Distributed)

• Tile is 4 subcarriers by 6 symbols, having 4x6-4 = 20 data subcarriers

• Overhead: 25%.

• Can reuse

16e 4x3 tiles

• A “distributed” resource unit consists of 4 tiles. Hence a “Logical Resource Unit” is 16x6.

PP

P P

PP

P P

Pattern 1 Pattern 2

Example 1 (Localized)

• Localized Resource Unit

• If we use 6 pilots, we get 16x6-4 = 92 data subcarriers.

• Figure similar to 1 stream of DL_PHY-08/18

P P

P P

Example 2 (Distributed)

• Tile is 6 subcarriers by 6 symbols, having 6x6-4 = 32 data subcarriers

• Less overhead = 11.11%

• A “distributed” resource unit consists of 3 tiles. Hence a “Logical Resource Unit” is 18x6.

PP

P P

P

P P

P

Pattern 1 Pattern 2

Example 2 (Localized)

• Localized Resource Unit: 18x6

• If we use 6 pilots, we get 18x6-6 = 102 data subcarriers

• We can use the one agreed upon in the downlink

• Figure similar to 1 stream of 139r2

PP

PPP

P P

Conclusion

• Use different pilot formats for “localized” and “distributed” allocations

• Possibly same resource block size as downlink

• Proposed different examples for pilot formats.