Introduction of several modes of LTE

There are two main modes of LTE technology: TDD and FDD.

TD-LTE is a new generation of broadband mobile communication technology, and it is the subsequent evolution technology of TD-SCDMA with independent intellectual property rights in China. While inheriting the advantages of TDD, it also introduces multi-antenna MIMO and frequency division multiplexing OFDM technology. Compared with 3G, TD-LTE greatly improves the system performance and can provide users with more colorful mobile Internet services.

The application of FDD LTE is FDD-LTE. Due to the differences in wireless technologies, frequency bands and the interests of various manufacturers, the standardization and industrial development of FDD-LTE is ahead of TDD-LTE. The characteristic of FDD mode is that the system receives and transmits on two separate symmetrical frequency channels (uplink and downlink frequency interval 190MHz), and the receiving and transmitting channels are separated by guaranteed frequency bands.

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Technical objectives of LTE

1. Capacity improvement: Under the bandwidth of 20MHz, the downlink peak rate reaches 100Mbit/s and the uplink peak rate reaches 50 mbit/s. The spectrum utilization rate reaches 2-4 times of the planned value of 3GPP R6.

2. Coverage enhancement: improve the "cell edge bit rate", the 5km area meets the optimal capacity, and the 30km area decreases slightly, supporting the coverage radius of 100km.

3. All-round diversification of service content: provide high-performance broadcast service MBMS, improve real-time service support capability, and make VoIP reach the performance of UTRAN circuit domain.

4. Reduce operation and maintenance costs: Using flat architecture can reduce CAPEX and 0PEX, and reduce the cost of evolution from R6 UTRA air interface and network architecture.

5. Mobility improvement: 0 ~ 15 km/h has the best performance, and 15 ~ 120 km/h has higher performance, supporting 120 ~ 350 km/h ... even supporting 500km/h in some frequency bands.

Baidu encyclopedia -LTE