A method for realizing carrier and sampling clock synchronization, and user site equipment

Abstract

The invention discloses a method for realizing synchronization of a carrier and a sampling clock. The method comprises the steps of: determining a carrier frequency deviation and a sampling clock frequency deviation according to the received downlink signal; carrying out carrier frequency compensation according to uplink to-be-sent data; and carrying out sampling clock frequency compensation according to the uplink to-be-sent data. The invention also provides a user site device, which comprises a carrier frequency deviation measuring unit, a frequency deviation compensating unit, a sampling clock frequency deviation measuring unit and a clock sampling frequency compensating unit. According to the invention, the problem of synchronization of medium-short distance messaging systems based on control is solved, especially, the problem of synchronization when uplink multiple users are accessed in parallel is solved. The synchronization of the time and the frequency is mainly completed by an STA according to a downlink synchronization precursor, the deviation of the frequency and the sampling clock frequency is preprocessed, the synchronization problem is simplified to the signal-user synchronization problem, so that multiple access interference is eliminated without a complicated algorithm when a receiving end separates data of multiple users.

Description

[0001] This application claims that the filing date is 2011.3.25, the application number is 201110074379.7, and the title of the invention is a method, device and wireless communication system for realizing carrier and sampling clock synchronization. reflected in this application. technical field [0002] The present invention relates to the technical field of wireless communication, in particular to a method for realizing synchronization of carrier and sampling clock and user station equipment. Background technique [0003] In communication systems, synchronization is the basis for correct demodulation of information. Generalized synchronization includes time synchronization, frequency synchronization, power adjustment, channel estimation, etc. [0004] In the wireless local area network system based on the IEEE802.11 standard, the communication between the access point AP and the user station STA is a burst mode. ) need to carry synchronization information to assist in c...

AI Technical Summary

Problems solved by technology

The two-way communication of the WLAN system is synchronized through the preamble. Although this synchronization method is simple, it is inefficient and cannot meet the needs of simultaneous communication of multiple users. On the one hand, no matter how long the data packet needs to carry the preamble, it will take up time resources; On the one hand, the CSMA / CA access method itself does not support simultaneous access by multiple users, so it does not meet the synchronization requirements for simultaneous communication of multiple users

The synchronization methods of mobile WiMAX and LTE systems can be used for reference, but the uplink synchronization of the two requires closed-loop control, which has high requirements for synchronization; in addition, mobile terminals and base stations use high-cost carrier crystal oscillators to deal with sampling clock synchronization issues, which are not suitable for low-cost WLAN device

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