Behind Mobile WiMAX Chenxi Zhu, Ph.D. Fujitsu Labs of America - - PowerPoint PPT Presentation

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Behind Mobile WiMAX Chenxi Zhu, Ph.D. Fujitsu Labs of America - - PowerPoint PPT Presentation

May 26, 2023 213 likes •483 views

Behind Mobile WiMAX Chenxi Zhu, Ph.D. Fujitsu Labs of America College Park, MD Email: czhu@ieee.org What is mobile WiMAX? Mobile broadband wireless access Defined by IEEE and WiMAX Forum. IEEE 802.16e_2005: wireless MAN-OFDMA

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Behind Mobile WiMAX

Chenxi Zhu, Ph.D.

Fujitsu Labs of America College Park, MD Email: czhu@ieee.org

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What is mobile WiMAX?

Mobile broadband wireless access

Defined by IEEE and WiMAX Forum.

IEEE 802.16e_2005: wireless MAN-OFDMA

PHY and MAC layer.

WiMAX Forum:

System profiles, testing, networking protocols,

applications, certification, etc.

Marketing and promotion.

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Mobile WiMAX network

TDD or FDD spectrum

802.16e air interface:

  • OFDMA-based PHY,
  • QoS-oriented MAC

Mobile IP-based Networking layer Cellular deployment Core Network Radio Access Network

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OFDMA PHY layer QoS oriented MAC layer Mobile IP-based networking layer Future of WiMAX

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OFDM PHY layer

Frequency domain signaling.

ICI-free: orthogonal between subcarriers. ISI-free: guard interval between symbols. Robust against multiple paths.

No equalization required at receiver.

Time domain Frequency domain

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OFDMA: OFDM for multiple access

User 1 User 2 User 3 User 4

  • Base station assigns the subcarriers to users in DL and UL.
  • Radio resources (subcarriers, transmission powers) are

allocated based on user channel quality and BW requirement (QoS).

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Scalable PHY layer

  • TDD or FDD, variable frame length (2—20 ms).
  • Different FFT sizes (128, 512, 1024, 2048) for variable BW

(1.25MHz--20MHz).

  • Variable CP length (1/32,1/16,1/8,1/4) for different cell size.
  • Same inter-subcarrier spacing (97.2KHz).
  • Multi-modes supported with a single SoC.
  • Adaptive modulation and coding.
  • QPSK, 16QAM, 64QAM.
  • CC, CTC, BTC, LDPC (1/2, 2/3, ¾, 5/6).
  • Beamforming and MIMO.
  • Common or dedicated pilots.
  • HARQ (Chase, IR).
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Different subchannelization for different mobility.

Diversity permutation (PUSC, FUSC) Contiguous permutation (AMC)

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TDD Frame structure

  • Preamble: power boosted for BS identification and

synchronization.

  • Control channel (FCH, DL-MAP, UL-MAP): assign

subchannels to users, power level, modulation/coding.

  • DL/UL Burst: data packets BS MS.
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Multiple antennas (MIMO)

Close loop transmitter beamforming. Space time code (Alamouti scheme). Spatial multiplexing. Up link: virtual MIMO. IFFT IFFT IFFT IFFT FFT FFT FFT FFT MIMO encoder MIMO decoder MIMO SC mapping MIMO SC de-mapping

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OFDMA PHY layer QoS oriented MAC layer Mobile IP-based networking layer Future of WiMAX

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QoS support by connection-

  • riented scheduled MAC

Service Flow over QoS connection

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WiMAX QoS classes

Maximum Rate, Traffic Priority Data Transfer, Web browsing BE (Best Effort Service) Minimum Rate, Maximum Rate, Traffic Priority FTP NRT-VR (Non-Real-Time Variable Rate) Minimum Rate, Maximum Rate, Maximum Delay, Jitter Tolerance, Traffic Priority VoIP with Activity Detection ERT-VR (Extended Real-Time Variable Rate service) Minimum Rate, Maximum Rate, Maximum Delay, Traffic Priority Streaming Audio

  • r Video

RT-VR (Real-Time Variable Rate service) Maximum Rate, Maximum Delay Jitter Tolerance VoIP UGS (CBR) (Unsolicited Grant Service)

QoS Specifications Applications QoS Category

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OFDMA PHY layer QoS oriented MAC layer MIP-based networking layer

defined by WiMAX Forum NWG

Future of WiMAX

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Mobile IP-based network architecture

MIP FA

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OFDMA PHY layer QoS oriented MAC layer Mobile IP-based networking layer Future of WiMAX

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Current development of 802.16

802.16j: multi-hop relay

Enhance coverage and capacity of 802.16e

with relay stations.

802.16m: targeting IMT-Advanced

Support BW ≥ 20MHz. Backward compactable with 802.16e. 100 Mbps at high mobility. 1 Gbps for fixed user.

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Industry synergy

System vendors

Samsung, Motorola, Alcatel-Lucent, Nortel,

Nokia-Siemens, Huawei, ZTE, …

Chip manufactures

Intel, Fujitsu, Runcom, Beecem, …

Device manufactures

Nokia, Samsung, Motorola, Sony-Ericsson,…

Service providers

Sprint, AT&T, Nextwave, SK-Telecom, KDDI, French-

telecom, Telecom-Italia, DirectTV, ….

Content provider

Disney

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Roadmap to market

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Who may deploy WiMAX?

  • Fixed point-to-point (LOS): 802.16d-OFDM
  • Wireless backhaul
  • Fixed point-to-multipoint (NLOS): 802.16d/e-OFDM/OFDMA
  • DSL/cable replacement
  • CCTV
  • Nomadic data application (Laptop, Handhold): OFDM/OFDMA
  • Better coverage than WiFi Hotspot
  • Mobile data, data/voice (OFDMA)
  • 4G?
  • Intelligent transportation system (OFDMA)
  • Transportation infrastructure
  • Vehicle to curb
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World wide WiMAX trials

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Further information

www.wimaxforum.org www.wimaxtrends.com Google!

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Backup slides

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Scalable OFDMA PHY layer

4 FFT sizes (128, 512, 1024, 2048) for variable Bandwidth. Adaptive Modulation and coding for different channel quality

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802.16e Subcarrier allocation

  • Pilot sub-carrier for channel estimation.
  • Data sub-carrier for data transmission.
  • No transmission in Null sub-carriers (DC, guard-band).
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Air Interface Protocol Stack