Method for transmitting public channel signal in high-speed rail cell

Abstract

The invention discloses a method for transmitting a public channel signal in a high-speed rail cell, which comprises the following steps of: allocating a code channel and midamble code which are adopted by the public channel signal to each launching tower in the high-speed rail cell, wherein code channels and midamble codes which are adopted by the public channel signals of any two adjacent launching towers are different; when a high-speed rail repeater in railway trains is in a public coverage region of any two launching towers, receiving public channel signals transmitted by the any two launching towers, estimating the frequency offset of the public channel signals sent by the two launching towers respectively according to the code channel and midamble code which are adopted by the public channel signals in the two launching towers, and estimating the public channel signal by the high-speed rail repeater; and transmitting the estimated public channel signal to user equipment (UE) inthe railway trains through a main carrier of the high-speed rail cell. By applying the method, the receiving performance of the public channel signal can be improved.

Description

technical field [0001] The invention relates to a signal transmission technology in a communication system, in particular to a transmission method of a common channel signal in a high-speed rail community. Background technique [0002] In a high-speed rail cell, when the UE moves at high speed, it will generate a frequency offset relative to the operating frequency. In the current network processing, after the UE establishes a dedicated link, it can use the frequency offset compensation algorithm to correct the frequency offset relative to the operating frequency. Estimation is performed, so that the frequency offset generated by the dedicated link of the UE in the high-speed rail cell is compensated, and the performance problem of the dedicated service in the high-speed rail cell is solved. [0003] However, in practical applications, it is found that when the UE is running on the high-speed rail, such as in the idle or Cell-FACH / Cell_PCH / Ura_PCH state, there is a problem w...

AI Technical Summary

Problems solved by technology

When the UE moves from the transmission tower 1 to the transmission tower 2, the UE is in the middle area between the transmission tower 1 and the transmission tower 2, such as figure 1 As shown in the middle shaded area, the UE will receive a frequency offset signal of -Δf generated by tower 1, and will receive a frequency offset signal of +Δf generated by tower 2 at the same time, because the two frequency offset signals are on the same main carrier , using the same code channel and midamble code, this will lead to the superposition of the received ±Δf frequency offset signals at the UE. When the signal strengths of the ±Δf frequency offset signals are relatively close, for example, the difference between the two signals is 6dB, which will cause the UE The amplitude of the received signal decays rapidly, the signal cannot be correctly demodulated, and then the system information cannot be read, resulting in the inability to reside in the cell

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