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Partial MAC and PHY Proposal for 802.11n
August 2004 Partial MAC and PHY Proposal for n Joseph Levy, Fatih M. Ozluturk, Eldad Zeira InterDigital Communications Corporation This presentations summarizes the Partial Proposal: n_Partial_MAC_and_PHY_Proposal.doc J. Levy, et al; InterDigital Communications Corporation
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Outline MAC Proposal Highlights PHY Proposal Highlights Conclusions
August 2004 doc.: IEEE /932r0 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.
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MAC Proposal Highlights
August 2004 MAC Proposal Highlights J. Levy, et al; InterDigital Communications Corporation
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MAC Features and Advantages
August 2004 doc.: IEEE /932r0 August 2004 MAC Features and Advantages Eliminates hidden node problem Higher performance for non real time services: Better stability and fairness towards AP Higher performance for real time services while guaranteeing QoS: Reduced STA power consumption and Higher MAC efficiency Enhanced peer to peer direct transfer of data under control of the AP Backward compatibility: With MAC e k STA and AP Support of efficient PHY operation Multiplex of UL and/or DL users Flexible design efficiently supports: MIMO, FEC and H–ARQ OFDMA support Both 20MHz and 40MHz HT STA in the same superframe J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.
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Proposed MAC Superframe
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) Flexible Management Scheduled Resource Allocation (MSRA) Scheduled Resource Allocation (SRA) Open Resource Allocation (ORA) J. Levy, et al; InterDigital Communications Corporation
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Advantages of Scheduling (SRA)
August 2004 doc.: IEEE /932r0 August 2004 Advantages of Scheduling (SRA) Significant improvement in battery life Enables new devices 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.
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Advantages of Flexible Management
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 ACKs) Consistent and predictable MAC operation Removed 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
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Proposed MAC Builds on 802.11 Resource Coordination Function (RCF)
August 2004 Proposed MAC Builds on 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
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MAC Elements Enable Flexibility…
August 2004 MAC Elements Enable Flexibility… EB (extended beacon) defines: Higher data rate (then 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 send after 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
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… and Flexibility Supports Multiple PHYs
August 2004 doc.: IEEE /932r0 August 2004 … and Flexibility Supports Multiple PHYs Supports various PHY implementations Resource allocations in Time, Frequency, and/or Spatial 20 and 40 MHz OFDMA and/or Spatial subchannel allocation J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.
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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 AP allowed to request teardown of P2P Messaging for P2P channel characterization before DLP setup J. Levy, et al; InterDigital Communications Corporation
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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 support all current /11e MAC processes J. Levy, et al; InterDigital Communications Corporation
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MAC NRT Simulation Results Summary
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 e ~ % increase in the number of active users for 0-10% hidden nodes ~ % increase in the average user throughput for 10-30% hidden nodes Note: All the comparisons are against the efficient e MAC (3 packets per transmit opportunity) J. Levy, et al; InterDigital Communications Corporation
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Substantially Higher Number of Active Users
August 2004 Substantially Higher Number of Active Users NRT Uplink Throughput vs. Number of Active Users J. Levy, et al; InterDigital Communications Corporation
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Stable Delay for High Number of Users
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
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Substantial Improvement in Per-User Throughput
August 2004 Substantial Improvement in Per-User Throughput NRT Uplink Throughput vs. Application Data Rate (8 users) J. Levy, et al; InterDigital Communications Corporation
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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
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MAC Conclusions Proposed MAC builds on 802.11 and 802.11e
August 2004 MAC Conclusions Proposed MAC builds on and e 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
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PHY Proposal Highlights
August 2004 PHY Proposal Highlights J. Levy, et al; InterDigital Communications Corporation
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PHY Features and Advantages
August 2004 doc.: IEEE /932r0 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 a/g High throughput by leveraging OFDM MIMO J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.
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August 2004 doc.: IEEE /932r0 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.
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August 2004 doc.: IEEE /932r0 August 2004 Complexity Minimized Through Judicious Use of Diversity and Multiplexing Techniques 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 transmitter or receiver elements J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.
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High Throughput Using Closed Loop Eigen Beamforming Mode (CL-EBM)
August 2004 doc.: IEEE /932r0 August 2004 High Throughput Using Closed Loop Eigen Beamforming Mode (CL-EBM) Space-frequency coding (SFC) followed by eigen-beamforming (EBM) Eigen-beamforming is based on Singular Value Decomposition (SVD) decomposition Eigen-beamforming provides spatial multiplexing (high throughput) at a reasonable complexity SVD splits the processing between the receiver and the transmitter Channel is orthogonalized into eigenbeams that assure effective spatial-multiplexing Does not require complicated receiver processing (no MMSE, SIC, etc) Relaxed latency and feedback rates due to frequency non-selectivity of eigen-values SFC provides diversity gain Robust link maintained with closed loop operation, Channel State Information (CSI) through feedback or reciprocity J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.
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Open-Loop Spatial Spreading Mode (OL-SSM)
August 2004 doc.: IEEE /932r0 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 a/g STAs or APs OFDM packet structure compatible with legacy a/g Same spectral mask and allocation of subcarriers as the existing a/g J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.
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MIMO Block Diagram Transmitter Receiver Space Frequency Diversity
August 2004 doc.: IEEE /932r0 August 2004 MIMO Block Diagram Transmitter Space Frequency Diversity Beamforming Receiver J. Levy, et al; InterDigital Communications Corporation Joseph Levy, InterDigital Communications Corp.
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Power and bit loading is incorporated
August 2004 doc.: IEEE /932r0 August 2004 Power and bit loading is incorporated Power loading algorithm runs during the closed loop operation using CSI Eigen-values are ranked per sub-carrier Eigen-beams are created for each pair of same ranking eigen-values Alamouti space frequency code applied to each pair 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.
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Open Loop Spatial Spreading Mode
August 2004 doc.: IEEE /932r0 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.
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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 a/g Scalable to various antenna configurations J. Levy, et al; InterDigital Communications Corporation
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August 2004 Proposal Conclusions Partial proposals for backward compatible MAC and PHY MAC provides high efficiency and stability, reduces battery consumption and eliminates hidden nodes Scalable PHY provides high throughput and robust performance, with low complexity J. Levy, et al; InterDigital Communications Corporation
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