Ascending data synchronization method for TDD system

Abstract

The invention discloses a method for synchronizing uplink data in a time duplex division (TDD) system. The method comprises the following steps: a base band unit (BBU) in the TDD system transmits a preset delay time quantum to all the radio-frequency remote radio units (RRUs) that share the BBU; all the RRUs determine the data cache time of each RRU according to the uplink transmission delay fromeach RRU to the BBU and the received preset delay time quantum; and all the RRUs cache and transmit the received user data according to the determined data cache time of each RRU. The method achievesthe effect of data synchronization of all the RRUs that share the same BBU in the TDD system and prevents the state interference among the RRUs.

Description

technical field [0001] The invention relates to a data synchronization technology in a communication system, in particular to an uplink data synchronization method in a time division duplex system. Background technique [0002] In the existing TD-SCDMA system, in order to reduce the occupied area of ​​the equipment room, the baseband processing unit and the radio frequency processing unit of the base station are set up in the way of optical fiber remote. Specifically, the baseband processing units are centrally arranged to form a baseband pool (BBU), the radio frequency processing unit is connected to the BBU through an optical fiber, and the remote radio frequency processing unit through the optical fiber is called a remote radio unit (RRU). figure 1 It is a typical connection schematic diagram of the cascaded application of BBU and RRU in the TD-SCDMA system. In the fiber-distance TD-SCDMA system, RRU1, RRU2 and RRU3 share the BBU, the direction in which data is sent from...

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Problems solved by technology

[0007] The problem with this method is that every time data passes through one level of RRU, the delay will increase by 5ms. If there are 6 levels of cascading in the system, the data of the last level of RRU will generate an additional 30ms time delay, so that the last level Due to the long processing delay of the RRU, the mobile phone cannot be connected, which is unacceptable for the TD system

[0009] The problem with this method is that the state of the subsequent level of RRU (for example, RRU2) will affect the normal operation of the previous level of RRU (for example, RRU1). If a new level of RRU is added to the system, the entire data link will be affected. And once there is an unstable level in the entire data chain, the entire link will collapse

Moreover, the above two methods have a common shortcoming at the same time, which can only realize data synchronization between RRUs on the same chain, and cannot realize data synchronization between RRUs between chains

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