Mobile radio station and radio communication system

Abstract

During switching among mobile radio stations, one mobile radio station receives information of a target mobile base station and relevant information of sequences used in random access signals supposed to be transmitted to the target mobile base station from a source mobile base station and receives synchronous channel signals transmitted from the target mobile base station. Therefore, the mobile radio station sets time from receiving set time of synchronous channels after a set time shifts and transmits random access signals of frequencies corresponding to the synchronous channels to the target mobile base station. In case of transmitting the random access signals during switching, places utilizing the set time / frequency during transmission are exclusively used by the random access signals transmitted from the mobile radio station or by multiple switching terminals at the same time, interference among random access signals from multiple mobile radio stations can be suppressed to zero or to be lowered, and accordingly, success receiving rate of the random access signals in switching target mobile base stations is increased, probability of retransmitting of the random access signals is reduced and as a result, switching time can be shortened.

Description

[0001] This application is a divisional application, the application number of the original application is 200680055955.0, the international application number is PCT / JP2006 / 319325, the filing date is September 28, 2006, and the title of the invention is "wireless communication device, base station and their control method" . technical field [0002] The present invention relates to a wireless communication device that transmits a random access signal when a mobile terminal is synchronized with a base station. Background technique [0003] In the EUTRAN (Evolved UTRAN), which is the next-generation system of the 3GPP system, which is currently undergoing basic research, the handover between cells covered by different base stations that occurs as the mobile terminal moves is a hard handover. In hard handover, after the mobile terminal is disconnected from the line connection with the base station with which the mobile terminal was communicating before the move, the line betwe...

AI Technical Summary

Problems solved by technology

When amplifying a signal using a CAZAC sequence with a large PAPR as a preamble, since the difference between the average power and peak power of the signal is large, the position of the average power of the input signal is close to the saturation region of the amplification characteristic of the amplifier When the part of the peak power of the signal is not linearly amplified due to the saturation of the amplification characteristic, the signal is deformed

Therefore, in order to eliminate signal distortion and reduce the average power of the signal input to the amplifier, when the signal power reaches a peak value, the power must not reach the region where the amplification characteristics of the amplifier are saturated.

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