What is TDD configuration?

In TDD, the transmission is divided into time domain, means at one moment of time either downlink subframe is transmitted or uplink. As one can see in above image, one frame is divided into 10 subframes (1ms each), and that subframe can be either downlink, uplink or special subframe.

What is LTE TDD and FDD?

Nevertheless, TDD LTE (also known as TD LTE) stands for Time Division Duplexing-Long Term Evolution. FDD LTE stands for Frequency-Division Duplexing LTE. Both TDD and FDD differ in the way they treat data. TDD means the “receive” and “transmit” channels divide the time between them on the same frequency band.

Where is LTE TDD used?

Time-division duplexing facilitates concurrent send and receive by assigning transmitted signals in the one-time slot and received signals in another time slot. They share the same frequency channel. TDD is used by Wi-Fi Networks and Some 4G/LTE Networks as well.

What is special subframe in TDD?

A Special subframe has three past DwPTS(Downlink Pilot Time Slot),GP (Guard Period) and UpPTS (Uplink Pilot Time Slot) and all of these have configurable lengths while the sum of the lengths has to be 1 ms or 14 symbols.

Which is better TDD or FDD?

In general, FDD is considered better for coverage and TDD better for capacity. While FDD uses separate frequencies for the uplink and the downlink, TDD uses a single frequency for both uplink and downlink, and therefore, they transmit at different times, making it more suitable when paired spectrum is not available.

Which is better TDD or FDD in LTE?

What is the structure of a LTE TDD frame?

As shown in the figure below, an LTE TDD frame is made of total 20 slots, each of 0.5ms. Two consecutive time slots will form one subframe. 10 such subframes form one radio frame. One subframe duration is about 1 ms. Hence LTE radio frame will have duration of about 10ms. Each radio frame will have 307200 Ts.

How is same carrier frequency used in TDD and FDD?

In TDD system, same carrier frequency is used in both transmit and receive path at different time instants say ‘t1’ and ‘t2’. In FDD system, different carrier frequencies such as ‘Fc1’ and ‘Fc2’ are used by transmit and receive paths at same time instant say ‘t1’.

Where is SS in the LTE frame structure?

For the 5ms DL to UL switch point periodicity case, SS (Special subframe ) exists in both the half frames. For the 10ms DL to UL switch point periodicity case, SS exists only in first half frame. The table mentions DL and UL configuration which determines the contents of the subframes in LTE frame structure.

How many subframes of 5ms are there in TDD?

In TDD, there are two periodicity frame one with 5ms periodicity and another with 10 ms periodicity. Special subframe is introduced at subframe #1 and subframe #6 and each half frame of 5ms carries one special subframe in case of 5ms periodicity subframe.