The duplex mode and frame structure of the difference between Tdd-lte and Fdd-lte

In this section, let's talk about the difference between the two duplex modes of TDD and FDD and their frame structure.

For FDD, it transmits data at two symmetrical frequencies, and there is a protection frequency between the upper and lower rows of data, but in the time dimension, the upper and lower rows of data are consistent and continuous;

In the case of TDD systems, the data on the upper and lower lines of the frequency dimension can be identical, and in the time dimension, the upper and lower rows of data are separated by the protection interval to prevent interference between the upper and lower lines of the same frequency.

From the time dimension, the FDD system can be understood as the car (data) on the highway in two directions, while TDD is only in the same lane, so the FDD mode will be faster.

It is because of the difference in duplex mode that the frame structure is designed differently. FDD mode is TYPE1 frame structure, and TDD mode is TYPE2 frame structure.

Td-lte Wireless Frames Each 10ms, contains two 5ms half frames, each half frame consists of 4 data sub-frames and a special sub-frame.

Special sub-frame contains 3 special time slots, namely: dwpts,gp,uppts, the total length is 1ms, wherein the dwpts and uppts two time slots can be configured, wherein the length of dwpts is 3-12 OFDM symbols, uppts length of 1-2 OFDM symbols, The corresponding GP has a length of 1-10 OFDM symbols.

The Fdd-lte 10ms wireless frame is divided into 10 sub-frames, each sub-frame contains two slots, each with a time slot of 0.5ms.

After the above comparison, I believe that the TDD and FDD two kinds of duplex mode and frame structure has a certain understanding, we have any better understanding of the method, I hope the message to advise.

The next time we continue our analysis of the differences between TDD and FDD.

The duplex mode and frame structure of the difference between Tdd-lte and Fdd-lte