A transmission method of ts0 time slot signal in td-scdma system

Abstract

The invention discloses a transmission method of a TS0 time slot signal, comprising: an RRU in a high-speed rail cell transmits a common channel signal and a preset pilot signal that lasts for the entire TS0 time slot on the TS0 time slot, wherein the common channel signal and The pilot signals are on mutually orthogonal code channels; the high-speed rail repeater located on the high-speed railway train, for any carrier, receives the pilot signal in the TS0 time slot, and estimates the time of TS0 according to the pilot signal saved by itself. The channel characteristic of each chip on the slot; according to the channel characteristic of each chip on the estimated TS0 time slot, carry out MMSE demodulation to the common channel signal on the TS0 time slot, and obtain the chip-level signal of the common channel signal; Carry the obtained chip-level signal on any carrier and send it to the UE on the high-speed railway train. By applying the present invention, Doppler spread can be overcome, and the signal receiving performance of the UE on the TS0 time slot in the high-speed rail cell can be improved.

Description

technical field [0001] The invention relates to the Doppler frequency shift technology of the communication system under the condition of high-speed movement, in particular to a transmission method of the TS0 time slot signal in the TD-SCDMA system. Background technique [0002] In a wireless communication system, when a user equipment (UE) moves at a high speed, Doppler frequency shift occurs. Doppler frequency shift is the biggest problem facing high-speed railway coverage. The current solutions to Doppler frequency shift are as follows: [0003] (1) UE automatic frequency control (AFC): UE performs automatic frequency control in real time to lock the frequency of the base station; [0004] (2) Auxiliary AFC of the base station: the base station can estimate the frequency offset of the UE through the uplink, and compensate it in the downlink, so as to reduce the requirement on the UE's AFC function. [0005] At the same time, handover is also a problem of high-speed cove...

AI Technical Summary

Problems solved by technology

For the above-mentioned Doppler spread, if it is not resolved, the UE cannot receive the TS0 signal correctly

However, since the TS0 time slot is used to carry broadcast signals, there is no corresponding uplink channel, so the base station-assisted AFC cannot be used to solve the Doppler spread problem

At the same time, since the AFC of the UE only locks the center frequency, it can only overcome the Doppler frequency shift, but cannot overcome the Doppler spread

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