Partial MAC and PHY Proposal for 802.11n August 2004 Partial MAC and PHY Proposal for 802.11n Joseph Levy, Fatih M. Ozluturk, Eldad Zeira InterDigital Communications Corporation joseph.levy@interdigital.com This presentations summarizes the Partial Proposal: 11-04-0933-00-000n_Partial_MAC_and_PHY_Proposal.doc J. Levy, et al; InterDigital Communications Corporation

Outline MAC Proposal Highlights PHY Proposal Highlights Conclusions August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Outline MAC Proposal Highlights MAC Characteristics MAC Enhancements Scheduled Resource Allocation Advantages Flexible Resource Management MAC Legacy Support MAC Simulation Results PHY Proposal Highlights PHY Enhancement MIMO System Overview PHY Design SFBC with Eigen-beamforming PHY Simulation Results Summary Conclusions J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

MAC Proposal Highlights August 2004 MAC Proposal Highlights J. Levy, et al; InterDigital Communications Corporation

MAC Features and Advantages August 2004 doc.: IEEE 802.11-04/932r1 August 2004 MAC Features and Advantages Eliminates hidden node problem Reduces STA power consumption Higher performance for non real time services: Better stability under load and better fairness towards AP Higher performance for real time services while guaranteeing QoS: Higher MAC efficiency Enhanced peer to peer direct transfer of data under control of the AP Backward compatibility: With 802.11 MAC - 802.11e - 802.11k Support of efficient PHY operation Allows intelligent scheduling of UL and/or DL users Flexible design efficiently supports: MIMO, AMC and H–ARQ Supports legacy, 20MHz HT STA and 40MHz HT STA in the same superframe J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

Proposed MAC Superframe August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Proposed MAC Superframe new addition Super frame structure with major legacy components: (1) Beacon (2) Contention Free Period (3) Contention Period Introduced Reservation based allocation (scheduling) Scheduled Resource Allocation (SRA) Flexible Management Scheduled Resource Allocation (MSRA) Open Resource Allocation (ORA) J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

Proposed MAC Builds on 802.11 Resource Coordination Function (RCF) August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Proposed MAC Builds on 802.11 Resource Coordination Function (RCF) RCF Management Channel Access (RMCA) for small packet transfers and schedule requests/reservations RCF Scheduled Channel Access (RSCA) for contention free data transfer providing full QoS support J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

MAC Elements Enable Flexibility… August 2004 doc.: IEEE 802.11-04/932r1 August 2004 MAC Elements Enable Flexibility… EB (extended beacon) defines: Higher data rate (than legacy beacon) is possible The scheduled resource allocation for management (MSRA), user data (SRA) and open RA MSRA Slotted Aloha contention for request of BW, association or small data/control packets Collective Response sent at the end of the MSRA period SRA Resource Allocated for RT and NRT services Open RA Resource (e.g. time) not allocated for MSRA and SRA in the extended Beacon Used for quick allocations within the super frame or multicast or broadcast traffic. J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

… and Flexibility Supports Multiple PHYs August 2004 doc.: IEEE 802.11-04/932r1 August 2004 … and Flexibility Supports Multiple PHYs Supports various PHY implementations Resource allocations in Time and Frequency 20 and 40 MHz OFDMA and/or Spatial subchannel allocation J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Extends Peer-to-Peer STA1 STA2 AP 1a 1b 2a 2b 3a 3b Optional messages (3a and 3b) Additional messaging enables RRM support at the AP Enhanced 2b: AP allowed to request teardown of P2P 3a, 3b: Messaging for P2P channel characterization before DLP setup J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

New Mac has Full Legacy Support August 2004 New Mac has Full Legacy Support Legacy station access to the medium is controlled by the MAC The proposed MAC supports all current 802.11/11e MAC processes J. Levy, et al; InterDigital Communications Corporation

Advantages of Scheduling (SRA) August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Advantages of Scheduling (SRA) Significant improvement in battery life Enables new devices Yields receiver (RF and baseband) savings of relative to 802.11e: VoIP: 40-95% HDTV: 25-75% Efficient data management/processing Allows simplified Radio Resource management (RRM) Customization of devices to implement new features High MAC efficiency for stringent latency, low data rate applications (VoIP, new applications) Scheduled resource allocations allows for true QoS management J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

Advantages of Flexible Management August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Advantages of Flexible Management Enables efficient NRT allocations Higher MAC throughput Eliminates hidden nodes Common broadcast packet for all the allocation information within super frame (No 802.11 ACKs) Consistent and predictable MAC operation Removes 802.11 contention overhead No Exponential Back off after every attempt Small Request Packet for Contention in slotted Aloha Flexible, fair and efficient management of resources Driven by application and PHY characteristics J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

MAC NRT Simulation Results Summary August 2004 doc.: IEEE 802.11-04/932r1 August 2004 MAC NRT Simulation Results Summary Higher stability at medium to high loads obtained at a cost of small and controlled delay Increase in uplink throughput relative to 802.11e ~ 15-45 % increase in the number of active users for 0-10% hidden nodes ~ 30-60 % increase in the average user throughput for 10-30% hidden nodes Note: All the comparisons are against the efficient 802.11e MAC (3 packets per transmit opportunity) J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

Substantially Higher Number of Active Users August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Substantially Higher Number of Active Users NRT Uplink Throughput vs. Number of Active Users J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

Stable Delay for High Number of Users August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Stable Delay for High Number of Users Uplink Delay vs. Number of Active Users for NRT J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

Substantial Improvement in Per-User Throughput August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Substantial Improvement in Per-User Throughput NRT Uplink Throughput vs. Application Data Rate (8 users) J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

Stable Delay as User Throughput Increases August 2004 Stable Delay as User Throughput Increases Uplink Delay vs. Application Data Rate (8 users) for NRT J. Levy, et al; InterDigital Communications Corporation

MAC Conclusions Proposed MAC builds on 802.11 and 802.11e August 2004 doc.: IEEE 802.11-04/932r1 August 2004 MAC Conclusions Proposed MAC builds on 802.11 and 802.11e MAC architecture enables Elimination of hidden nodes Prolonged battery life Higher throughput Radio Resource Management Support of multiple PHYs Performance improvements have been demonstrated J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

PHY Proposal Highlights August 2004 PHY Proposal Highlights J. Levy, et al; InterDigital Communications Corporation

PHY Features and Advantages August 2004 doc.: IEEE 802.11-04/932r1 August 2004 PHY Features and Advantages Robust performance in all channel conditions, with or without channel state information Low complexity at both transmitter and receiver Scalable solution: data rate, throughput Accommodates any antenna configuration Flexible PHY that supports both backward compatibility and enhanced MIMO capability Backward compatible with 802.11a/g High throughput by leveraging OFDM MIMO J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Motivation Maintain backward compatibility while supporting high throughput Find the best compromise between diversity gain and spatial multiplexing gain Simplified operational modes Open loop : Initial acquisition, support of legacy equipment Closed loop : High throughput capability Simple scalable architecture J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Complexity Minimized by Eigen-decomposition Compromise Between Diversity and Multiplexing Space Frequency Block Coding Enhances Diversity Gain Eigen-Beamforming Enhances multiplexing gain Channel decomposition SVD used to diagonalize channel at both Tx and Rcv Channel Coding This proposal is compatible with existing channel coding methods (e.g. FEC, interleaving, etc.) Compatible with other Tx and Rx elements J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

High Throughput Using Closed Loop Eigen Beamforming Mode (CL-EBM) August 2004 doc.: IEEE 802.11-04/932r1 August 2004 High Throughput Using Closed Loop Eigen Beamforming Mode (CL-EBM) Space-frequency coding (SFC) followed by eigen-beamforming Eigen-Beamforming: Based on Singular Value Decomposition (SVD) Provides spatial multiplexing (high throughput) at a reasonable complexity Orthogonalized Eigen-beams assure effective spatial-multiplexing without MMSE/SIC Processing split between the receiver and the transmitter Relaxed latency and feedback rates due to frequency non-selectivity of eigen-values SFC provides diversity gain Channel state information obtained through feedback or exploiting channel reciprocity J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

Eigen-Values are Essentially Non-frequency Selective August 2004 Eigen-Values are Essentially Non-frequency Selective Case B , Case C J. Levy, et al; InterDigital Communications Corporation

Eigen-Values are Essentially Non-frequency Selective August 2004 Eigen-Values are Essentially Non-frequency Selective Case D J. Levy, et al; InterDigital Communications Corporation

Open-Loop Spatial Spreading Mode (OL-SSM) August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Open-Loop Spatial Spreading Mode (OL-SSM) Enables closed loop initiation, transparent support of closed loop operation Provides legacy support Space-frequency block code for diversity with a spatial spreading beam forming network Backward Compatibility OL-SSM can support legacy 802.11a/g STAs or APs OFDM packet structure compatible with legacy 802.11a/g Same spectral mask and allocation of subcarriers as the existing 802.11a/g J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

MIMO Block Diagram Transmitter Receiver Space Frequency Diversity August 2004 doc.: IEEE 802.11-04/932r1 August 2004 MIMO Block Diagram Transmitter Space Frequency Diversity Beamforming Receiver J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

Power and bit loading is incorporated August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Power and bit loading is incorporated Power loading algorithm runs during the CL operation using CSI Eigen-values are ranked, paired, and SFBC (Alamouti) is applied per sub-carrier The average SNR per pair of eigen-modes used to create an index into a CQI table J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

Open Loop Spatial Spreading Mode August 2004 doc.: IEEE 802.11-04/932r1 August 2004 Open Loop Spatial Spreading Mode Spatial spreading supported by reconfiguration of BFN Antenna beams randomly steered to enhance diversity Feedback of CSI not required Legacy support is maintained by removing the SFBC operation J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.

PHY Conclusion Robustness through Space-Frequency Coding August 2004 PHY Conclusion Robustness through Space-Frequency Coding Spatial-multiplexing efficiency through eigen-beamforming Low implementation complexity is distributed between the transmitter and the receiver Backward compatible with 802.11a/g Scalable to various antenna configurations J. Levy, et al; InterDigital Communications Corporation

August 2004 Proposal Conclusions Partial proposals for backward compatible MAC and PHY MAC provides high efficiency and stability, reduces battery consumption and eliminates hidden node problem Scalable PHY provides high throughput and robust performance, with low complexity J. Levy, et al; InterDigital Communications Corporation