Mobile communication system, base station, and communication control method

Abstract

A wireless communication system comprising a transmitting station and a receiving station, and a control method therefore. A mobile station (101) as the transmitting station has a facility for transmitting a preamble signal to a base station (102) as the receiving station before transmission of information data from the mobile station (101) to the base station (102). On the other hand, the base station (102) has a facility for performing path detection by using a signal threshold for the preamble signal received from the mobile station (101), a facility for performing further path detection by using another threshold for the received preamble signal if paths are detected in the path detection, and a facility for setting path information of the paths detected by using the plurality of thresholds for a receiver (206) installed in the base station (102) so as to perform a path diversity reception. In the wireless communication system and the control method therefore, the receiver (206) of the base station (102) receives information data transmitted from the mobile station (101).

Description

technical field [0001] The present invention relates to a mobile communication system and a communication method, and more particularly to a CDMA (Code Division Multiple Access: Code Division Multiple Access) method suitable for random access using a single prefix signal in an uplink channel from a mobile station to a base station A suitable method, system and base station structure for wireless communication. Background technique [0002] In a mobile communication system using CDMA, there is a technique of applying random access to one of uplink channels from a mobile station to a base station. This channel is called "RACH" (Random Access Channel: Random Access Channel). [0003] RACH as figure 1 As shown in A, it consists of prefix signals 601, 602 and message signal 603. Prefix signals 601 and 602 are used as signals for transmitting a request for permission to transmit a message signal from a mobile station to a base station, and a message signal 603 is used for actua...

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Problems solved by technology

[0010] Therefore, when the prefix signal is detected, it is judged that the number of detected paths is often less, even if these paths are set as they are in the RAKE receiver (for example, when the number of paths is far less than the rake index ), cannot obtain sufficient gain, and cannot achieve a large characteristic improvement

[0011] In addition, if there is a large time difference between the transmission of the prefix signal and the transmission of the message signal, the propagation environment will change, and there is a high possibility that the path detected in the reception of the prefix signal at the base station has changed when the message signal is received. situation

[0012] Therefore, if the route is set without considering the above fluctuations, and the RAKE reception of the message signal is started, sufficient gain cannot be obtained, and errors frequently occur in the received data.

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