1. TDD Frame Structures for Legacy Support in 16m IEEE 802.16 Presentation Submission Template (Rev. 9) Document Number: IEEE S802.16m-07/242r1, TDD Frame Structures for Legacy Support in 16m Date Submitted: 2007-11-7 Source: Dong Li, Liyu Cai, Hongwei Yang, Jimin LiuVoice: +86 21 58541240 Ext 9292 E-mail: {dong.li, liyu.cai, hongwei.yang, jimin.liu}@alcatel-sbell.com.cn Joerg Schaepperle Voice: +49 711 821 32266 E-mail: Joerg.Schaepperle@alcatel-lucent.de Krishna Balachandran Voice: +1 908 582 2691 E-mail: krishnab@alcatel-lucent.com * http://standards.ieee.org/faqs/affiliationFAQ.html Venue: Call for 802.16m contributions on SDD Base Contribution: C80216m-07+242r1 Purpose: For 802.16m discussion and eventual adoption for standardization 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. Outline Frame structures with legacy support shall be designed for both cases of equal bandwidths and different bandwidths between legacy system and 16m system –In case of equal bandwidths between 16m and legacy systems, two solutions may be considered Solution 1 with reuse of 16e preamble Solution 2 with staggered frame structure using new 16m preamble –In case of different bandwidths for 16m and legacy systems Sub-case 1: 16m system with the same frame duration as legacy system –Solution 1 in support of one legacy system with preamble sequence extended on the legacy preamble –Solution 2 in support of multiple parallel legacy systems with staggered frame structure using new 16m preamble Sub-case 2: 16m frame with shorter frame duration than a legacy system –Solution with introduction of mini-frames to reduce the latency

3. Same bandwidth for 16m system and legacy system (1/2) – Option 1 16e preamble is re-used Frame control information (e.g., FCH, DL/UL-MAP etc) can be extended to support the new zones for 16m transmission New zones are defined for the 16m DL/UL traffic –Advanced transmission techniques can be exploited in the new 16m zones to improve the system performance

4. Same bandwidth for 16m system and legacy system (2/2) – Option 2 Staggered frame structure where the start of the 16m frame is staggered in time with respect to the legacy frame New 16m preamble sequence and frame control information which provides greater flexibility for 16m system design no mutual interference will result between 16m allocations and 16e allocations

5. Wider bandwidth for 16m system (1/4) - Unchanged frame duration Support of one legacy system –Legacy frame are embedded within the 16m frame through FDM or combined FDM&TDM –The legacy frame can be located on the edge of the spectrum or in the middle of it to simplify the 16m system definition –Specification shall be defined for both the partial-spectrum zones (e.g., 10MHz out of 20MHz) and full-spectrum zones in 16m specification (e.g., permutation mapping of subcarriers to logical subchannels) –It is preferred that the 16m preamble and legacy preamble co-exist in the same OFDM symbol in order to ensure the frames of 16m BS and legacy BS are synchronous in views of both legacy MSs and 16m MSs. The joint design of the 16m preamble and legacy preamble should guarantee low PAPR and good auto/cross-correlation properties. –Some guard tones may be reserved between legacy system spectrum and the remaining spectrum to facilitate the filtering at MS

6. Wider bandwidth for 16m system (2/4) - Unchanged frame duration Option 1: Legacy frame located on the edge of spectrum Option 2: Legacy frame located in the middle of spectrum Support for one legacy system

7. Wider bandwidth for 16m system (3/4) - Unchanged frame duration Support for multiple parallel legacy systems –Staggered frame for 16m with the start of the frame preceded by allocations for multiple parallel and synchronous legacy systems –New 16m preamble sequence and frame control information which provide larger flexibility for 16m system design –Specification shall be defined for only the full-spectrum zones, which reduces the system complexity

8. Wider bandwidth for 16m system (4/4) - Reduced frame duration Reduced frame duration –The reduced mini-frame duration is beneficial for reducing the latency –The last DL-to-UL transition position of 16m frame can be switched between the transition point of legacy system and the transition point of the last mini-frame through resource scheduling –Other features are the same as those shown in page 5

9. Recommendation It is suggested to discuss and include the proposed TDD frame structures with legacy support into the 16m SDD