Data transmission method

Abstract

The invention provides a data transmission method used in a time division duplexing system. The method comprises: step 1, a data transmission terminal packages the data in a predetermined frame structure and sends the data to a data reception terminal, in the predetermined frame structure, the random access channel is provided inside the uplink transmission subframe; step 2, the data reception terminal analyzes and processes the data packaged in the predetermined frame structure.

Description

technical field [0001] The invention relates to the field of mobile communication, in particular to a time division duplex system data transmission method. Background technique [0002] The LTE (Long Term Evolution, long-term evolution) system defines two types of frame structures, wherein the second type of frame structure corresponds to the long-term evolution of TD-SCDMA, and adopts a TDD (Time Division Duplex) mode. As shown in Figure 1, in the second type of frame structure, subframe (subframe) 0 is fixed to transmit downlink data; the first n subframes in subframes 1-6 are used to transmit uplink data, and the last 6-n subframes are used to transmit uplink data. Downlink data (1≤n≤6); DwPTS (Downlink Pilot Time Slot, downlink special time slot) in the special time slot is used to transmit downlink synchronization information, GP (Guard Period, protection period) is the guard band, UpPTS (UplinkPilot Time Slot , uplink special time slot) is used to transmit uplink sync...

AI Technical Summary

Problems solved by technology

Note that some symbols of TS1 cannot be reserved as GP, because the uplink control channel is usually on both sides of the system bandwidth, and the duration is one time slot. If some symbols of TS1 are reserved as GP, the reception performance of the uplink control channel will be serious. It is also not possible to reserve some symbols of TS0 as GP. This is because the P / S-SCH signal is sent in the last two symbols of TS0. If some symbols of TS0 are reserved as GP, users may not be able to receive P / S-SCH signals. The SCH signal, and the P / S-SCH signal is the signal that the user needs to receive first when accessing the system. If the user cannot correctly receive the P / S-SCH signal, he cannot access the system.

[0005] 2. The P / S-SCH signal is located at the boundary between the downlink time slot and the uplink time slot switch. As before, the P / S-SCH signal is the first signal that the user needs to receive when accessing the system. Therefore, the P / S-SCH signal The power is usually greater than other signals. In a cellular environment, due to the high power of the P / S-SCH signal, it will seriously affect the receiving performance of the uplink time slot signal.

[0006] 3. The utilization efficiency of the DwPTS time slot is not high. When the system bandwidth is relatively wide, since only the P-SCH signal is sent in the middle bandwidth (1.25MHz) of the system bandwidth, the utilization efficiency of the DwPTS time slot will be very low

[0014] In the "new frame structure", the RACH channel placed in the UpPTS can only use 2 symbols, and the length of its preamble and GT (Guard Time) is relatively short, the preamble length is 133.3us, and the GT length is 9.5us (when the ) or 33.5us (when the CP is long), which cannot meet the requirements of large coverage

If a RACH channel with longer preamble and GT is designed on the basis of the current RACH channel in order to support large coverage, the complexity of the terminal will be greatly increased

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