4G Standards International Mobile Telecommunications – Advances (IMT-A) set by the International Telecommunications Union – Radio (ITU-R) All IP packet switch network 1Gbit/s stationary, 100Mbit/s moving Scalable channel bandwidth 5-20 MHz
LTE Technologies / Features E-UTRA – LTE’s air interface Transfer capabilities DL and UL schemes Protocol Architecture Spectrum Flexibility Cell size support Network architecture
Data Rate Peak download rate of 100 Mbit/s Peak upload rate of 50 Mbit/s Low handoff and data transfer latencies (sub 5-ms for small IP packets) How is this achieved?
OFDM OFDM Single Carrier • Serial Symbols S1 • Wide Frequency S2 • Short Symbol Time S1 S2 S3 S5 S4Time S3 Time S4 S5 • Parallel Symbols Frequency • Narrow FrequencyFrequency • Long Symbol Time
Downstream Modulation OFDMA (Orthogonal frequency-division multiple access) Multi-user version of OFDM Achieved by assigning subsets of subcarriers to individual users Allows simultaneous low-data rate transmission High power cost Sub-CarriersSub-Carriers S1 S2 S3 S5 S4 Frequency Time
Upstream Modulation SC-FDMA (Single carrier frequency - division multiple access) Lower peak-to-average-power (PAPR) Acceptable performance loss