移动网络4G课程LTE.pdf

Mobile and Wireless Networks 4G LTE 1/27 Requirements of LTE Peak data rate 100 Mbps DL/ 50 Mbps UL within 20 MHz bandwidth Up to 200 active users in a cell (5 MHz) Less than 5 ms user-plane latency Mobility Optimized for 0 – 15 km/h. 15 – 120 km/h supported with high performance. Supported up to 350 km/h or even up to 500 km/h. Spectrum flexibility: 1.25 –20 MHz Enhanced support for end-to-end QoS 2/27 Key Features of LTE Multiple access scheme DL: OFDMA (Orthogonal Frequency Division Multiplexing) UL: Single Carrier FDMA (SC-FDMA) Adaptive modulation and coding DL/UL modulations: QPSK, 16QAM, and 64QAM Advanced MIMO spatial multiplexing techniques Mobility (2 or 4)x(2 or 4) downlink and uplink supported. Multi-user MIMO also supported. Support for both FDD and TDD 3/27 OFDMA SC-FDMA s OFDM s OFDMA r r e e i i r r r r a a C C - - b