1. 2015/5/13IEEE S802.16m-1 Cooperative MIMO with Randomized Distributed Spatial Multiplexing IEEE 802.16 Presentation Submission Template (Rev. 8.3) Document Number: IEEE S80216m- Date Submitted: 2008-10-30 Source: Chun Nie, Pei Liu, Shu Luo, Thanasis Korakis, Shivendra Panwar Voice: 718-260-3740 Polytechnic Institute of New York University, Fax: 718-260-3074 (formerly Polytechnic University) Email: cnie01@students.poly.edu; 6 Metrotech, Brooklyn, NY 11201 pliu@poly.edu shuo01@students.poly.edu korakis@poly.edu; panwar@catt.poly.edu Venue: IEEE 802.16 Session #58, Denver, Dallas (relay) Base Document: IEEE C802.16m- Purpose: To incorporate cooperative MIMO with randomized distributed spatial multiplexing proposed herein into IEEE 802.16m system description document (SDD). Notice: This document has been prepared to assist IEEE 802.16. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) 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. IEEE 802.16 Patent Policy: The contributor is familiar with the IEEE 802.16 Patent Policy and Procedures, including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.16 Working Group. The Chair will disclose this notification via the IEEE 802.16 web site.

2. 2015/5/13IEEE S802.16m-2 Cooperative MIMO with Randomized Distributed Spatial Multiplexing Chun Nie, Pei Liu, Shu Luo, Thanasis Korakis, Shivendra Panwar Polytechnic Institute of New York University, Brooklyn, NY, 11201 (formerly Polytechnic University, NY) Authors:

3. Outline  Introduction  Randomized Distributed Spatial Multiplexing (RDSM)  Summary of RDSM Advantages  Performance Evaluation  Conclusions 2015/5/13IEEE S802.16m-3

4. Introduction (1/2)  In this contribution, we propose the use of Randomized Distributed Spatial Multiplexing (RDSM) to boost the uplink capacity in a two- hop virtual MIMO system  RDSM is a SM technique that uses Relay Stations (RSs) and Subscriber Stations (SSs) as “helpers” to deliver higher data rtes. 2015/5/13IEEE S802.16m-4

5. Introduction (2/2) 2015/5/13IEEE S802.16m-5 RDSM is implemented in a 2-hop system for the uplink transmission –First hop: All potential helpers decode the source signal. –Second hop: Helpers cooperatively forward the signal to destination by using RDSM encoded signals.  Spatial multiplexing gain is achieved over the second-hop.  RDSM encoder is embedded in each helper as follows.  RDSM does not limit the number of antenna elements at each helper. MIMO encoder’s output: K parallel streams, where K is no larger than the minimum of (M, L), assuming BS has L antennas and the second hop has M helpers. Each helper transmits a random weighted sum of all K streams.,

6. Summary of RDSM Advantages  Provides spatial multiplexing gain for the second hop of a single-antenna SS in the uplink  When the number of stations is large, the source can recruit enough helpers to transmit at peak rate.  Better than Distributed BLAST –A predetermined number of helpers in the system is NOT needed. –No need to index each helper and assign a specific antenna for each of them. Thus, signaling is reduced. All potential helpers can contribute to cooperation. –SS are allowed to participate in cooperation and transparently cooperate with RS to enhance spatial multiplexing gain. –Detailed channel information over the two hops is NOT necessary. The transmitter only needs a statistical estimation of the channel to estimate the outage performance. Hence, signaling for channel estimation is minimized. –RDSM is easy to implement in each helper station by using embedded software. No substantial increment in hardware complexity Conclusion: RDSM is more robust than Distributed BLAST 2015/5/13IEEE S802.16m-6

7. Performance Evaluation 2015/5/13IEEE S802.16m-7 Setting: V-BLAST is used for comparison. Each helper is single-antenna; BS has 4 antennas Single-hop: Direct transmission Two-Hop Single-Relay: One RS only RDSM

8. Conclusions  RDSM can significantly enhance system performance in terms of throughput.  RDSM significantly increases performance for SS at the cell edge.  RDSM provides BER performance comparable to a centralized spatial multiplexing system (e.g., BLAST)  RDSM is more robust than a general distributed BLAST system.  RDSM can be incorporated in a multi-hop scenario.  We suggest incorporating RDSM into IEEE 802.16m 2015/5/13IEEE S802.16m-8