摘要(英) |
The primary purpose of this research is to reduce the audio Latency. The headset development board and the Bluetooth receiver (dongle) development board of the same Bluetooth chip manufacturer are used to implement a path that shortens the transmission time, the audio data is sent in the shortest path according to a specific ACL (Asynchronous Connectionless Link) format is transmitted to the Bluetooth low layer and sent out. In the interference environment, the faster the transmission, the more packet loss distortion will be generated. Therefore, a retransmission mechanism is used to process and experimentally analyze the relationship between the distortion caused by signal interference and the latency caused by retransmission in this transmission path.
The experiment will be divided into two parts: objective assessment and subjective evaluation under interference environment. The objective assessment experiment uses APx525b acoustic measuring instrument to measure THD+N (Total Harmonic Distortion + Noise), SNR (Signal-to-noise ratio), which are used to quantify signal performance. Measure indicators to evaluate the linear relationship between distortion and delay caused by signal interference. And then observe the output audio waveform through the recording tool “CoolEdit” and capture its distortion ratio as a reference basis for distortion and latency.
In the subjective assessment experiment, the subject is asked the testers watching and listening to the MV of the audio-visual platform in an interference environment with subtitles/captions to evaluate the feeling of latency and distortion. The result is supplemented by objective experimental data to find out the best retransmission value setting in this interference environment. This value is the best choice for the anti-interference and low latency under this method. |
參考文獻 |
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