Synchronization of wireless headphones
Embodiments of wireless audio systems and methods for synchronizing wireless headphones are disclosed herein. In one example, a wireless audio system includes an audio source, a first wireless headphone, and a second wireless headphone. The audio source is configured to separately transmit a left-channel audio signal and a right-channel audio signal using a short-range wireless communication protocol. The first wireless headphone is configured to receive the left-channel audio signal and synchronize a first clock of the first wireless headphone with the audio source based on the left-channel audio signal. The second wireless headphone is configured to receive the right-channel audio signal and synchronize a second clock of the second wireless headphone with the audio source based on the right-channel audio signal, so that the first clock of the first wireless headphone is synchronized with the second clock of the second wireless headphone.
1. A wireless audio system, comprising:
an audio source configured to separately transmit a left-channel audio signal and a right-channel audio signal using a short-range wireless communication protocol;
a first wireless headphone configured to receive, from the audio source, the left-channel audio signal using the short-range wireless communication protocol and synchronize a first clock of the first wireless headphone with the audio source based on the left-channel audio signal; and
a second wireless headphone configured to receive, from the audio source, the right-channel audio signal using the short-range wireless communication protocol and synchronize a second clock of the second wireless headphone with the audio source based on the right-channel audio signal, so that the first clock of the first wireless headphone is synchronized with the second clock of the second wireless headphone,
wherein the audio source comprises:
a decoder configured to separate stereo audio information into left-channel audio information and right-channel audio information;
an encoder operatively coupled to the decoder and configured to separately encode the left-channel audio information and the right-channel audio information; and
a radio frequency (RF) module operatively coupled to the encoder and configured to separately generate the left-channel audio signal based on the encoded left-channel audio information and generate the right-channel audio signal based on the encoded right-channel audio information.
2. The wireless audio system of claim 1 , wherein each of the first and second wireless headphones comprises:
a decoder configured to decode the respective left-channel audio information or right-channel audio information based on Opus codec.
3. The wireless audio system of claim 1 , wherein the short-range wireless communication protocol comprises BLUETOOTH protocol.
4. The wireless audio system of claim 1 , wherein:
the first wireless headphone is further configured to transmit, to the audio source, a first identifier indicative of a left side; and
the second wireless headphone is further configured to transmit, to the audio source, a second identifier indicative of a right side.
5. The wireless audio system of claim 1 , wherein each of the first and second wireless headphones comprises:
a demodulation module configured to obtain at least one synchronization error based on the respective left-channel audio signal or right-channel audio signal;
a clock frequency module configured to adjust a frequency of the first clock or second clock based on the respective at least one synchronization error; and
a timing module configured to synchronize a timing synchronization signal with the respective left-channel audio signal or right-channel audio signal.
6. The wireless audio system of claim 5 , wherein the at least one synchronization error comprises a timing synchronization error and a carrier synchronization error.
7. The wireless audio system of claim 5 , wherein the timing synchronization signal is aligned with a slot start of the respective left-channel audio signal or right-channel audio signal.
8. The wireless audio system of claim 1 , wherein the audio source is further configured to:
receive, from the first wireless headphone, a first identifier indicative of a left side;
transmit the left-channel audio signal to the first wireless headphone based on the first identifier;
receive, from the second wireless headphone, a second identifier indicative of a right side; and
transmit the right-channel audio signal to the second wireless headphone based on the second identifier.