4G Wireless Technology

Transcription

1 4G Wireless Technology Airspan Technical Symposium May 3, 2010 By Donn Swedenburg and Mark T. Pflum RVW, Inc. (402)

2 4G Wireless TOPICS 4G Wireless Definition Technologies used in 4G Pre-4G Real World Implications 2009 RVW, Inc. 2

3 4G Wireless: Definition 4G Wireless: Defined by the ITU (International Telecommunication Union). A 4G system targets peak data rates of approximately 100 Mbps for high mobility service. A 4G system targets peak data rates of approximately 1 Gbps for low mobility/ fixed service. Shall support required channel bandwidths from 5 to 20 MHz with an optional 40 MHz channel allowed RVW, Inc. 3

4 4G Wireless: Definition Shall support both TDD and FDD duplexing technologies with UL/DL configurable ratios for both. Network architecture will be all IP based. Must utilize MIMO technology. Latency: Data - 10 ms. In both UL & DL Idle state to active state 100 ms. Site handoff 50 ms. Intrafrequency, 150 ms. Interfrequency RVW, Inc. 4

5 4G Wireless: Technologies used in 4G MIMO - Minimum antenna configurations. For the BS - a minimum of 2 Tx and 2 Rcv antennas For the MS - a minimum of 1 Tx and 2 Rcv antennas MIMO Techniques - Beam forming makes use of multiple antennas to steer or focus signal in a particular direction. Can reduce adjacent site self-interference & add reach. SU-MIMO (Single User MIMO) Transmitting parallel & unique data streams in the same frequency-time resource to a single user. (Spatial Multiplexing) Improves individual users throughput RVW, Inc. 5

6 4G Wireless: Technologies used in 4G MIMO Techniques - continued MU-MIMO (Multiple User MIMO) Transmitting parallel & unique data streams in the same frequency-time to multiple users. (Spatial multiplexing) Improves sector/site capacity throughput. STBC - Space Time Block Coding The simplest of the STBCs transmits multiple copies of a single data stream across a number of antennas which improves the SNR of the received data to improve the reliability of data-transfer RVW, Inc.

7 4G Wireless: Technologies used in 4G OFDMA Orthogonal Frequency Division Multiple Access. (LTE DL only, WiMAX UL and DL). Two types of sub-carrier permutations. Contiguous subcarriers grouped into logical sub-channels (Used in LTE & WiMAX sub channels). Pseudo-random subcarriers grouped into logical sub channels (Used in WiMAX FUSC and PUSC) RVW, Inc. 7

8 4G Wireless: Technologies used in 4G SC-FDMA Single Carrier Frequency Division Multiple Access. (LTE UL only) Low peak-to-average power ratio conserves mobile battery life RVW, Inc. 8

9 4G Wireless: Technologies used in 4G ACM Adaptive Coding and Modulation Changing the coding (1/2, 2/3, 3/4) and modulation schemes (BPSK, QPSK, 16 QAM, 64QAM) based upon current RF conditions. HARQ - Hybrid automatic repeat request The most common version uses transmissions with incrementally more redundant errordetecting codes such as cyclical redundancy checking (CRC) and forward error correction bits (FEC) RVW, Inc. 9

10 4 G Wireless: Pre 4G LTE LTE capable of 100 Mbps in DL and 50 Mbps in UL. This would be for a single user, single site/sector with 20 MHz bandwidth for both uplink and downlink under extremely favorable RF conditions with adequate backhaul capacity. Key Features of LTE Multiple access scheme DL is OFDMA, UL is SC-FDMA. Adaptive modulation. coding, H-ARQ and error correction. Advanced MIMO (2 X 2, 4 X 4) spatial, single or multi-user multiplexing techniques Support for both FDD and TDD 2009 RVW, Inc. 10

11 4 G Wireless: Pre 4G LTE Initial LTE deployment by Verizon will not technically meet the 4G requirement as stated by the ITU Reference: RVW, Inc. 11

12 4G Wireless: Pre 4G - WiMAX (d) is often called Fixed WiMAX Fixed WiMAX does not support Mobility. Does not support 1 cell frequency reuse. Utilizes OFDM-256 FFT (Orthogonal Frequency-Division Multiple) Also supports OFDMA 2048, but only OFDM 256 FFT is specified in WiMAX d profiles. Supports both TDD (Time Division Duplexing) and FDD (Frequency Division Duplexing) services 2009 RVW, Inc. 12

13 4G Wireless: Pre 4G WiMAX d Fixed WiMAX Fixed WiMAX throughputs for OFDM-256 (Unknown SNR) 2009 RVW, Inc. 13

14 4G Wireless: Pre 4G WiMAX e Mobile WiMAX Not backwards compatible with Fixed WiMAX Offers the capability of 1 cell frequency reuse. Supports TDD, FDD, and Half-Duplex FDD operation However the initial release of Mobile WiMAX certification profiles will only include TDD. Sprint/Clearwire are referring to d and e as 4G which is not technically correct RVW, Inc. 14

15 4G Wireless: Pre 4G WiMAX e Theoretical Throughputs The highlighted values indicate data rates for optional 64QAM in the UL. Reference: Mobile WiMAX Part I: A Technical Overview and Performance Evaluation WiMAX Forum 2009 RVW, Inc. 15

16 4G Wireless: Implications So, where are we on the 4G Timeline? February, NTT tests a 4G lab prototype. Achieves 100 Mbps mobile & 1 Gbps fixed with 4 X 4 MIMO. Achieves 5 Gbps DL with a 100 MHz channel and a 12 X 12 MIMO. May, 2007 IEEE proposes m, upgrade to the e standard. April, 2008 LG/Nortel demonstrates the e- UTRA LTE SDR at 50 Mbps mobile at 68 MPH. December, 2009 First commercial LTE deployment in Stockholm, Sweden. Single user tests show 42.8 Mbps down, 5.3 Mbps up RVW, Inc.

17 4G Wireless: Implications While 4G will undoubtedly be a future force, be aware that - Real 4G does not exist today Real 4G will require access to huge amounts of last-mile spectrum that is not available today. Equipment R&D still in progress. Backhaul networks already under stress from 3G networks will need continuing capacity upgrades High capacity ethernet connections over fiber optic networks will probably be the needed at all sites in the near future RVW, Inc. 17

18 Succeeding With Teamwork! 2009 RVW, Inc. 18