Bluetooth signal frame synchronous detection method for wireless general measuring instrument

Abstract

The invention provides a Bluetooth signal frame synchronous detection method for a wireless general measuring instrument. The method comprises the following steps: step S1, inputting a signal; step S2, coarsely synchronizing frame power judgment; step S3, calculating a phase angle; step 4, differentiating; step S5, filtering; step S6, eliminating an initial frequency offset, and obtaining a sequence f (n); step S7, an initial position is n, and the length of each symbol is Ts, and performing a GFSK (Gaussian Frequency Shift Keying) demodulation judgment on every 5 GFSK symbols; step S8, if ''10101'' or ''01010'' is found, then entering the next step; and if ''10101'' or ''01010'' is not found, then n=n+1 and returning to step S7; and step S9, taking points from (n+(1 / 3) *Ts) to (n+(2 / 3) *Ts) as initial points, and orderly performing a sliding judgment on 5 symbols. The Bluetooth signal frame synchronous detection method for the wireless general measuring instrument provided by the invention has the following beneficial effects: Bluetooth signal frame synchronous detection of the wireless general measuring instrument can be realized, an MAC address is not depended, and certain synchronization accuracy can be guaranteed.

Description

technical field [0001] The invention relates to a frame synchronization detection method, in particular to a frame synchronization detection method of a Bluetooth signal of a wireless comprehensive tester. Background technique [0002] Explanation of terms: [0003] DUT: DUT. [0004] BR: Basic rate. [0005] EDR: Enhanced Rate. [0006] BLE: Bluetooth Low Energy. [0007] GFSK: Gaussian Frequency Shift Keying modulation. [0008] DPSK: Differential phase modulation. [0009] GUARD: Guard interval between GFSK and DPSK. [0010] PREAMBLE: leading. [0011] The Bluetooth (Bluetooth) protocol defines three rates in total, one is BR (BasicRate) rate, which supports 1M rate, and the frame header and load part adopt GFSK modulation method; the other is EDR (EnhancedDataRate), which supports 2M and 3M Rate, the frame header part still adopts GFSK modulation mode, the load adopts pi / 4-DQPSK modulation mode at 2M, and the load adopts 8DPSK modulation mode at 3M, both of whic...

AI Technical Summary

Problems solved by technology

This method can only roughly determine the starting position of the frame, and because in practice, the starting part of the signal sent by the DUT sometimes shows a certain stable step signal, resulting in false detection, such as Figure 8 shown

In addition, for the EDR signal, there is a guard interval of about 5us between the GFSK signal and the DPSK signal. After sending the GFSK signal, some DUTs will randomly send some signals without causing a sudden drop in the signal power within the guard interval. Some DUTs Then no signal is sent, causing the signal power in the guard interval to drop; after about 5us, the DPSK signal power starts to rise again. If only relying on the relative power detection method, at this time, it will also cause false detection, such as Figure 9 shown

Using this method, although modifying the relative power value and increasing the identification of the EDR signal guard interval can reduce the false detection probability of the frame start to a certain extent, but due to the diversity of signals sent by the DUT in actual production, it will still occur. False detection

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