Synchronous device and method in narrowband wireless communication terminal

Abstract

The invention discloses a synchronous detection device applied to a narrowband wireless communication system terminal. The device comprises a down-sampling module, a sliding autocorrelation module and a difference cross-correlation module. A received 1.92 MHz time-domain signal is subjected to down sampling to a 240 kHz signal through the down-sampling module in terms of OFDM symbol time periods and a fixed down-sampling pattern. Through the sliding autocorrelation module, sampling point data in a 10 ms wireless frame processing window is moved bit by bit as an initial position t, date of which the length is eleven OFDM symbol time periods is taken as a sliding window, and the eleven groups of sample points in the sliding window are correlatively accumulated at intervals of two groups. Through the difference cross-correlation module, an obtained primary synchronizing sequence is subjected to differencing to form two approximately equal parts and is correlatively accumulated with a main synchronizing sequence generated locally. According to the invention, by employing the synchronous detection device, main synchronizing signals are detected well in the narrowband-wireless-communication-system application scenario in which the signal-to-noise ratio is low and the frequency deviation is large, and the implementation complexity is low so that the low-cost requirement of the narrowband wireless communication terminal is met.

Description

technical field [0001] The present invention relates to the field of mobile communication, in particular to a synchronization device and method applied to narrowband cellular communication terminals in a future Internet of Things network. Background technique [0002] In the recent communication market, IoT (Internet of Things) has become a bright spot in the industry, and many operators and devices have demonstrated their latest innovations and application cases. Among them, narrowband wireless communication technology (NB-Iot) is the key for operators to enter the Internet of Things market. The narrowband wireless communication system has the advantages of low power consumption, wide coverage, low cost, and large capacity, so it can be widely used in a variety of vertical industries, such as remote meter reading, asset tracking, smart parking, smart agriculture, etc. The first version of the 3GPP standard is expected to be released in June 2016. It is expected that narrow...

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Problems solved by technology

For narrowband wireless communication systems, since the synchronization sequence is short and works in an environment with extremely low signal-to-noise ratio and large initial frequency offset, it is fundamental to apply the synchronization sequence detection method of cross-correlation of frequency domain data used in traditional LTE systems Unable to find relevant peaks for

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