1. C80216m-08_213r1 ProjectIEEE 802.16 Broadband Wireless Access Working Group http://ieee802.org/16 TitleDesign Considerations for Downlink MIMO Pilot Date Submitted 2008-03-10 Source(s)Zhigang Rong, Juejun Liu, Xin Chang, Jianmin Lu Huawei Shanpeng Xiao, Wenqi Liao China Mobile Xiaolu Dong, Ying Du CATR Jiahua Liu Alcatel Shanghai Bell E-mail: zrong@huawei.com xiaoshanpeng@chinamobile.com liaowenqi@chinamobile.com dongxiaolu@mail.ritt.com.cn duying@mail.ritt.com.cn jianhua.liu@alcatel-sbell.com.cn Re:IEEE 802.16m-08/005: Call for Contributions on Project 802.16m System Description Document (SDD). Target topic: “ Pilot Structures as relevant to downlink MIMO ”. AbstractProposal for pilot structures as relevant to downlink MIMO PurposeFor discussion and approval by TGm Notice 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. Patent Policy The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and.http://standards.ieee.org/guides/bylaws/sect6-7.html#6http://standards.ieee.org/guides/opman/sect6.html#6.3 Further information is located at and.http://standards.ieee.org/board/pat/pat-material.htmlhttp://standards.ieee.org/board/pat

2. C80216m-08_213r1 2 Considerations on DL MIMO pilot (I) Antenna configuration: 2/4 transmit antennas Pilot category –Common pilot Channel measurement for CQI report Channel estimation for coherent detection –Dedicated pilot Channel estimation for underserved user –Common pilots cannot serve 100% users within the cell. For those who has low channel quality or high freq./time selectivity, additional allocation of pilot tones within the resource block will enhance channel estimation performance. Channel estimation for dedicated user –For some users, close-loop precoding is preferred to improve performance, Under such case, pilots transmitted in same way as data can reduce complexity and improve channel estimation. –Common pilot is still needed for CQI report Channel estimation for specific scenario, i.e. SFN transmission. Therefore, dedicated pilot should be provided on demand.

3. C80216m-08_213r1 3 Considerations on DL MIMO pilot (II) Common pilots for distributed resource –Inter-cell interference mitigation (i.e. hopping, scramble) shall be considered for pilot of different cells Common pilots for localized resource –In TDM-based mini-frame control channel structure, MS can rely on common pilot only for both channel measurement and data detection –In FDM-based mini-frame control channel structure, common pilots is used for channel measurement only with potentially long interval Dedicated pilots for distributed resource –If resource is distributed sub-carrier by sub-carrier, dedicated pilot is impractical. –If resource is distributed tile by tile (or RB by RB), dedicated pilot could be used for data detection based on user’s need. Dedicated pilots for localized resource –Dedicated pilot is allocated for the purpose of data detection –In TDM-based mini-frame control channel structure, dedicated pilots is not always required and can be assigned based on user’s need.

4. C80216m-08_213r1 4 Proposed Text Insert the following text into Physical Layer sub-clause (IEEE C802.16m-08/003): ------------------------------- Text Start --------------------------------------------------- 11.x Common Pilot for Downlink MIMO 11.y Dedicated Pilot for Downlink MIMO ------------------------------- Text End ---------------------------------------------------