QoS-aware Antenna Grouping and Cross-layer Scheduling for mmWave - PowerPoint PPT Presentation

QoS-aware Antenna Grouping and Cross-layer Scheduling for mmWave Massive MU-MIMO [1] [1] C. Bocanegra, S. Rodrigo, Z. Li, A. Cabellos, E. Alarcon and K. R. Chowdhury, “Qos-aware Antenna Grouping and Cross-layer Scheduling for mmWave Massive MU-MIMO,” IEEE JSAC , Submitted Jan. 2020 (Under revision) Code.

OBJECTIVES OF THE TALK < > 2 1. Introduce millimeter waves (mmWave) as a key technology Why is mmWave interesting? How is it different from other bands 2. mmWave and MU-MIMO in the 5G and 802.11ad/ay standards How are this standards going to operate in the band? 3. Our cross-layer approach for MU-MIMO in mmWave Leverage upper-layer information to best deal with PHY-layer limitations 4. MATLAB Toolboxes that made it possible Communications, Optimization and WLAN toolboxes 5. Performance evaluation How much better off are we with our approach?

AGENDA < > 3 1. Introduction to mmWaves – key factors 2. Beamforming to overcome losses in mmWaves 3. RF-antenna interconnections in mmWave 4. Beamforming in the 802.11ad standard 5. Our cross-layer approach – an overview 6. Internet traffic – generating realistic flows 7. HELB – heuristically enhanced LCMB beamforming – OPTIMIZATION TOOLBOX 8. The mmWave channel – COMMUNICATIONS TOOLBOX 9. Emulating the mmWave link – WLAN TOOLBOX + PHASED ARRAY TOOLBOX 10.Performance evaluation 11.MATLAB in the project 12.Conclusions

INTRO – MMWAVE APPLICATIONS BEYOND COMMS < > 4 Neuron communication Wider bandwidth allows The higher radar Atacama large mm at 42, 53 and 61 GHz. higher resollution for X- resolution allows for Array (ALMA). A Drug withdrawal, Rays. No ionizing tracking the steam of millimeter wave radio diabetes, cáncer, etc. [1] property [3] the missiles better [3] telescope in Chile [2] [1] M. A. Rojavin and M. C. Ziskin, “Medical application of millimeter waves,” Q J Med 1998, pp. 57-66, vol. 91, 1998 [2] A. Cardama, Ll. Jofre, J. M. Rius, J. Romeu, S. Blanch and M. Fernando, “Antennas,” Edicions UPC, 2002 [3] Y. Niu, Y. Li, D. Jin, L. Su, A. V. Vasilakos, “A Survey of Millimeter Wave (mmWave) Communications for 5G: Opportunities and Challenges”, arXiv:1502.07228, submitted in February 2015

INTRO – WHY MMWAVE? < > 5 Proposed Cellular (5G) Advantage of mmWave • Wider bandwidth. • Low interference, unexploited band. Bad Unlicensed • Channel losses due to a higher carrier (802.11ad/ay) frequency, and molecular absorption (60GHz). Challenges: • Limited coverage: ~200 meters • Beamforming is required to deal with losses. • Higher bandwidth, requires higher sampling rate. Underusage of the • Higher sampling rate requires higher power. wireless spectrum, confined in the sub- 6GHz band

INTRO – BEAMFORMING AS A KEY ENABLER < > 6 Analog beamforming Digital beamforming Hybrid beamforming PRO: Low implementation PRO: Offers the optimum PRO: Reduced power consumption complexity and costs. beamforming. Can create large given with less RF-chains. number of beams. CONS: The resolution of the phase RISK: Its performance depends shifters is limited. Thus, inter-user CONS: Requires a large number of upon the sub-array connectivity. interference is higher. RF-chains, high power consumption.

RF CHAIN TO ANTENA – FLEXIBILITY ON PHY < > 7 Flexible Fully Fully Partially Switching Partially connected connected connected network connected Phase and switch Phase shifters Phase shifters A mmWave arrays is characterized by the phase shifters and/or switches , offering different connectivity levels. The sub-array architecture selection depends upon power consumption, price, and area budget. For example, phase shifters allow for a more flexible design than switches, but their power consumption is higher. [1] Shahar Stein Ioushua, Yonina C. Eldar, “Hybrid Analog-Digital Beamforming for Massive MIMO Systems,” arXiv:1712.03485

INTRO – 802.11ad/ay STANDARDS FOR MMWAVE < > 8 802.11ad MAC structure 802.11ad frame structure A- SP/CBA SP/CBA SP/CBA SP/CBA BTI ATI BFT P P P P SECTOR LEVEL SWEEP (SLS) ATI – POLLING PHASE CDWN=31 CDWN=0 CDWN=31 CDWN=0 CDWN=0 CDWN=31 … … CDWN31 CDWN0 Poll Poll SPR SPR … … … … ID=15 ID=4 ID=3 ID=9 ID=2 ID=13 ID=14 ID=4 ID1 ID4 ID1 ID4 BEST=5 BEST=5 BEST=1 BEST=1 BEST=8 BEST=8 Used to steer the beam towards the receiver BTI A-BFT ATI Very simplistic beamforming procedure that incurs in HIGH PROCESSING time. It does not exploit CSI or mmWave channel statistics. The AP broadcasts beacon frames in a AP polls to make an Device replies back with sectorized/brute force efficient use of the wireless preferred sector. manner. spectrum.

OVERVIEW < > 9 Aim of the project : Explore novel beamforming techniques aiming to accommodate more users in a highly demanding 5G environment. Minimize Inter-User Interference (IUI), maximizing the num. of users scheduled while keeping their PER at a minimum Some numbers for mmWave deployments • 16 antenna arrays for UEs [1]. • 64 [2,3], 128 (and more) antenna arrays for BSs. [1] [2] [3] [1] 10. Hong. W. “Study and prototyping of practically large-scale mmWave antenna systems for 5G cellular devices”. IEEE Commun. 2014 [2] Sadhu B. “A 28-GHz 32-Element TRX Phased-Array IC With Concurrent Dual-Polarized Operation and Orthogonal Phase and Gain Control for 5G Communications”. IEEE J. Solid-State Circuits. 2017 [3] Gu X. “A multilayer organic package with 64 dual-polarized antennas for 28GHz 5G communication”; Proceedings of the IEEE IMS2017. 2017

CROSS-LAYER APPROACH < > 10 INTERNET TRAFFIC MODELING Contribution 1 : (QoS per Application, arrivals, packet length, etc) Cross-layer optimization (Network+Link+PHY) where antennas are allocated to users in time in order to meet their application requirements. SCHEDULING S (Traffic aggregation and user scheduling) Y Central controller - router S INTERNET T User 1 MU-MIMO BEAMFORMING E User 2 Slot 0 (Dynamically formed sub-arrays) M User 1 Beamforming mmWave algorithm MMWAVE ARRAY MMWAVE CHANNEL channel User 2 (RF chain – antenna (LoS vs NLOS, indoors interconnection) vs outdoors)

CROSS-LAYER APPROACH < > 11 INTERNET Contribution 2 : QoS per Application Consider realistic deployment scenarios in a resource constrained system (limited number of antennas and RF). SCHEDULING We explore non-uniform/unconventional antenna S (Traffic aggregation and user scheduling) allocation and beamforming configurations for MU-MIMO Y ([1] only SU-SISO) S T Unconventional Conventional MU-MIMO BEAMFORMING E (Dynamically formed sub-arrays) M User 1 MMWAVE ARRAY MMWAVE CHANNEL User 2 (RF chain – antenna (LoS vs NLOS, indoors User 3 interconnection) vs outdoors) User 4 [1] S. Park, A. Alkhateeb and R. W. Heath, "Dynamic Subarrays for Hybrid Precoding in Wideband mmWave MIMO Systems," TWC , 2017.

CROSS-LAYER APPROACH < > 12 INTERNET Contribution 3 : QoS per Application We group users to be allocated per slot, not only accounting for the spatial diversity (like in [1]), but also considering asymmetric traffic and uneven demands. SCHEDULING S (Traffic aggregation and user scheduling) Slot 0 Slot N Slot 1 Slot 2 Y S … T time MU-MIMO BEAMFORMING E QCI Priority Tol. Delay PER Description (Dynamically formed sub-arrays) M 10 − 2 User 1 1 2 100 Conv. Voice (Live) 10 − 3 2 4 150 Conv. Video (Live) User 2 10 − 3 3 3 50 Real Time Gaming 10 − 6 4 5 300 Non-Conv. Video User 3 65 0.7 75 10 − 2 Mission Critical (Push2Talk) User 4 66 2 100 10 − 2 Non-Mission Critical (Push2Talk) 10 − 6 5 1 100 IMS Signaling MMWAVE ARRAY MMWAVE CHANNEL 10 − 6 6 6 300 Video (Live) 10 − 3 (RF chain – antenna (LoS vs NLOS, indoors 7 7 100 Video (Bu ff ered) 10 − 6 8 8 300 Video (Bu ff ered) interconnection) vs outdoors) 10 − 6 9 9 300 Video (Bu ff ered) 69 0.5 60 10 − 6 Mission Critical Delay Sensitive 70 0.6 200 10 − 6 Mission Critical Data [1] A. Adhikary et al., "Joint Spatial Division and Multiplexing for mm-Wave Channels," in IEEE Journal on Selected Areas in Communications, 2014.