Method and system for eliminating carrier frequency offset of reference period signal based on Bluetooth fixed frequency expansion

Abstract

The invention discloses a reference period signal carrier frequency offset elimination method and system based on Bluetooth fixed frequency expansion, which are applied to a Bluetooth wireless communication system. The method comprises the following steps: establishing synchronous connection between a Bluetooth receiving end with a receiving antenna array and a Bluetooth transmitting end, and adding compensation to sampling data by calculating a difference value between a phase difference between fixed-frequency extension reference period signal sampling points in a received Bluetooth signal packet and a theoretical phase difference; and eliminating a phase error caused by carrier frequency deviation due to asynchronous crystal oscillators of the receiver and the transmitter in the synchronization process. Under the working mode of single-data-channel multi-antenna time-sharing sampling, the reduction degree of the transmitted signal is improved, so that the estimation precision of the direction of arrival algorithm based on the fixed-frequency extended signal is further improved. The method is low in calculation and hardware complexity and suitable for low-power-consumption Bluetooth 5.1 and above protocols, multiple time-sharing antennas of a receiver share a single data receiving channel, and a received data packet comprises signal phase correction and restoration of a reference period.

Description

technical field [0001] The invention relates to the field of bluetooth technology, in particular to a method and system for eliminating carrier frequency offset errors of a bluetooth fixed-frequency extended reference period signal. Background technique [0002] In the Bluetooth 5.1 standard protocol, in order to support the signal angle of arrival estimation function, the end of each Bluetooth signal packet contains a constant frequency extension signal (CTE). The Bluetooth signal receiving end switches between different antennas in time division, and performs I / Q data sampling and processing on the fixed-frequency extended signal at a certain sampling rate. According to the geometric arrangement information of the antenna array and the phase information of the sampled signal when different antennas are sampled, combined with the angle-of-arrival algorithm such as multiple signal classification, the receiver can calculate the direction of arrival of the signal in space. In...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a method and system for phase compensation of sampled data based on the Bluetooth fixed extension signal reference period signal to overcome the phase error. The resulting deviation in direction-of-arrival angle estimation

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