Automatic frequency control system corresponding to multiple base stations in wireless communication system

Abstract

The system includes a parameter database, a control module and an automatic frequency controller. The parameter database stores groups of automatic frequency control parameter corresponding to each adjacent base station. The control module executes a parameter generation program in order to make the automatic frequency controller generate groups of automatic frequency control parameter, and store these groups of automatic frequency control parameter to the parameter database. When mobile communication device is switched from service station to the candidate base station, group of automatic frequency control parameter corresponding to the candidate base station is picked up from the parameter database, receiving group of automatic frequency control parameter corresponding to the candidate base station, the automatic frequency controller updates first sequence signal in order to synchronize second sequence signal.

Description

technical field [0001] The invention relates to an automatic frequency tracking system of a mobile communication device in a wireless communication system, in particular to an automatic frequency tracking system corresponding to multiple base stations. Background technique [0002] "Synchronization" in wireless communication systems is one of the main issues in signal reception technology. Due to the characteristic differences of electronic components, the influence of environmental factors and the Doppler effect, etc., the frequency of the signal received by the mobile communication device often deviates from the frequency value of the standard basic timing sequence, resulting in a frequency error, and the signal does not occur. Synchronization problem. [0003] In order to overcome this problem, known wireless communication systems all have devices or software similar to automatic frequency controllers (automatic frequency controller, AFC), which can adjust the basic timi...

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Problems solved by technology

[0008] In addition, when the mobile communication device 12 periodically detects the signal of the adjacent base station 16, the purpose of this periodic detection of the signal of the adjacent base station 16 is to track the signal strength of the serving base station 14 and the adjacent base station 16 as a It is a reference to decide whether to switch the base station providing communication services from the serving base station 14 to a candidate base station 32 in the neighboring base stations 16, so the mobile communication device 12 will not change its first timing signal 26a during the detection process, so the mobile communication device The first timing signal 26a of 12 is not synchronized with the second timing signal 34 of the candidate base station 32, so its frequency error 28a must be smaller than the range that the receiver / equalizer (equalizer; EQ) can tolerate to avoid being unable to track neighboring base stations 16, which also increases the difficulty of equalizer design

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