Bluetooth microphone based on Aptx-LL coding

Abstract

The invention relates to a Bluetooth microphone based on Aptx-LL coding, which is designed for solving the problems that a wireless microphone currently used by a teacher in a class is large in power consumption and distorted in voice and has signal crosstalk. The Bluetooth microphone comprises a shell, and a voice output circuit arranged in the shell. The voice output circuit comprises a pickup used for collecting external voice signals; a power amplification circuit electrically connected with the pickup for amplifying the voice signal; a Bluetooth chip electrically connected with the power amplification circuit, and including an analog-digital conversation (ADC) circuit for performing analog-digital conversion on the voice signals and an Aptx-LL coding output device, wherein the Aptx-LL coding output device performs Aptx-LL coding on the voice signals after ADC, and outputting the coded signals via an antenna based on a Bluetooth protocol; and a power supply module electrically connected with the power amplification circuit and a Bluetooth chip, and used for providing voltage required by the Bluetooth microphone, wherein the power supply module comprises a rechargeable lithium battery.

Description

Technical field [0001] The invention relates to a microphone, in particular to a Bluetooth wireless microphone adopting Aptx-LL coding. Background technique [0002] When two sounds of equal intensity and one delayed sound arrive at the listener's ears at the same time, if the delay is within 30ms, the sound will feel as if the sound comes from the undelayed sound source only, and the delayed sound source will not be felt. When the delay time exceeds 30ms and does not reach 50ms, the sound source that has been delayed can be recognized auditorily, but the sound is still felt from the sound source without delay. Only when the delay time exceeds 50ms, the delayed sound becomes a clear echo. This phenomenon is called the Haas effect, sometimes also called the priority effect. [0003] In daily teaching, teachers use loudspeakers mainly with "little bees" and infrared microphones. Wired microphone: little bee amplifier, wireless microphone: infrared microphone, VHF wireless micropho...

AI Technical Summary

Problems solved by technology

[0004] "Little Bee": It is large in size and inconvenient to carry with cables, making it inconvenient for teachers to attend classes

[0005] Infrared: The effective receiving distance is short, and it cannot support multi-directional transmission; the power consumption is large; the anti-interference is poor; the coverage is small due to the straight-line transmission of infrared; the installation requirements of the receiving antenna (that is, the sensor) are high, and blind spots are prone to appear, etc.

[0006] VHF wireless microphone: It is greatly interfered by VHF TV channels, calling stations, wireless telephones and other industrial interference sources; the radio frequency noise is large; the antenna is long; the audio modulation signal bandwidth is narrow and does not allow expansion; the usable frequency range is not Wide (61MHz), etc.

[0007] UHF wireless microphone: It reflects more on small metal objects, which can cause interference caused by multi-channel propagation; large propagation attenuation; large power consumption, requires large transmission power, short battery life; complex system settings, etc.

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