Wireless audio system and communication method
By using the Bluetooth clock to determine the timing reference in the wireless audio system, the timing alignment of Bluetooth and wireless communication is controlled, solving the timing alignment problem of different communication methods and improving the accuracy and effectiveness of multi-device collaborative work.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HENGXUAN TECH (BEIJING) CO LTD
- Filing Date
- 2026-02-14
- Publication Date
- 2026-04-21
AI Technical Summary
In scenarios where multiple devices work together, it is difficult to achieve precise time alignment when using different types of communication methods, which affects the effectiveness of collaborative work.
By utilizing the Bluetooth clock of Bluetooth communication to determine the timing reference, the sending and receiving of Bluetooth communication frames are controlled, and the sending and receiving timing of wireless communication is aligned based on this reference, thus achieving time alignment for different communication methods.
It improves the collaborative working effect between multiple audio devices in a wireless audio system, reduces the complexity of synchronization protocols or independent clock synchronization mechanisms, and improves time alignment accuracy.
Smart Images
Figure CN121908247A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of wireless communication, and more specifically, provides a wireless audio system and communication method. Background Technology
[0002] In scenarios where multiple devices work collaboratively, the same device may simultaneously use different types of communication methods to communicate with other devices. For example, in an audio playback system, there are two earphones (left and right) and an audio source device. The earphones connect to the audio source device via Bluetooth to receive and play audio playback signals sent by the audio source device. The earphones also connect to each other via Bluetooth to transmit Bluetooth-related information and achieve Bluetooth playback propagation. Each earphone also includes a microphone. The earphones also connect to each other via other wireless communication methods such as Wi-Fi (Wireless Fidelity) and UWB (Ultra Wide Band). Audio data collected by the microphone of one earphone is transmitted to the other earphone via Wi-Fi, UWB, etc., for processing or transmission to the audio source device.
[0003] In scenarios where multiple devices collaborate, different wireless communication methods are used, such as Bluetooth, UWB, and Wi-Fi. Collaboration between these devices may require processing data transmitted via these different methods, necessitating clock and timing alignment. However, because each communication method has its own clock architecture and timing scheduling mechanism, achieving precise time alignment for data transmission across wireless systems is difficult, thus impacting the effectiveness of multi-device collaboration. Summary of the Invention
[0004] Therefore, this application aims to provide a wireless audio system and communication method to improve the time alignment accuracy of different audio devices and different types of communication methods when multiple audio devices in a wireless audio system work together using various types of communication methods, thereby improving the collaborative working effect between multiple audio devices in the wireless audio system.
[0005] In a first aspect, embodiments of this application provide a wireless audio system, comprising: a first audio device and a second audio device; the first audio device and the second audio device are connected via Bluetooth communication, and the first audio device and the second audio device are also connected via wireless communication; the wireless communication includes at least one of ultra-wideband wireless communication (UWB) and wireless local area network communication (Wi-Fi); the first audio device is configured to determine a timing reference based on a Bluetooth clock of the Bluetooth communication; the first audio device is further configured to control the transmission of Bluetooth communication frames based on the timing reference; the first audio device is further configured to determine the transmission timing of the wireless communication based on the timing reference; and the second audio device is further configured to determine the reception timing of the wireless communication based on the reception time of the Bluetooth communication frames.
[0006] Secondly, embodiments of this application provide a communication method for a wireless audio system, comprising: a first audio device determining a timing reference based on a Bluetooth clock for Bluetooth communication; wherein the timing reference is used by the first audio device to control the transmission of Bluetooth communication frames; the first audio device and a second audio device are connected via Bluetooth communication, and the first audio device and the second audio device are also connected via wireless communication; the wireless communication includes at least one of ultra-wideband wireless communication (UWB) and wireless local area network communication (WI-FI); the first audio device determines the transmission timing of the wireless communication based on the timing reference; and the second audio device determines the reception timing of the wireless communication based on the reception time of the Bluetooth communication frames.
[0007] When different audio devices work together, they use different types of communication methods. For example, in this embodiment, the first and second audio devices communicate not only via Bluetooth but also via non-Bluetooth wireless communication methods, including UWB and Wi-Fi. Because different communication methods have their own clock systems and timing mechanisms, when audio devices in a wireless audio system work together, they need to be time-aligned not only by the different audio devices but also by the different types of communication methods. To address this issue, this application uses the Bluetooth clock to determine a timing reference. This timing reference is used not only to control the transmission of Bluetooth communication frames by the first audio device but also to control the reception of Bluetooth communication frames by the second audio device, achieving time alignment on Bluetooth. Furthermore, when the first and second audio devices use wireless communication methods such as UWB and Wi-Fi, this type of wireless communication is also time-aligned based on the timing reference; that is, the first audio device, as the sender, aligns its wireless communication transmission timing, and the second audio device, as the receiver, aligns its wireless communication reception timing. Therefore, Bluetooth, including UWB and Wi-Fi, are all time-aligned based on the same timing reference. This reduces the need for synchronization protocols or independent clock synchronization mechanisms, improves the time alignment accuracy when communicating across wireless communication systems in wireless audio systems, and thus helps improve the working effect of various audio devices when working together. Attached Figure Description
[0008] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0009] Figure 1 This is a schematic diagram of a wireless audio system provided in an embodiment of this application; Figure 2 This is a schematic diagram illustrating the transmission of audio signals acquired by a microphone according to an embodiment of this application; Figure 3 This is a schematic diagram of a communication method for a wireless audio system provided in an embodiment of this application.
[0010] Icons: First audio device 100; First Bluetooth module 110; First wireless communication module 120; First Bluetooth controller 130; Second audio device 200; Second Bluetooth module 210; Second wireless communication module 220; First Bluetooth controller 230. Detailed Implementation
[0011] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.
[0012] First, this application provides a wireless audio system; please refer to [link to relevant documentation]. Figure 1 , Figure 1 This is a schematic diagram of a wireless audio system provided in an embodiment of this application. In this embodiment, the wireless audio system includes: a first audio device 100 and a second audio device 200.
[0013] In embodiments of this application, the wireless audio system can be a pair of true wireless earbuds, including a left earbud and a right earbud. Accordingly, the first audio device 100 is one of the left or right earbuds of the true wireless earbud pair, and the second audio device 200 is the other of the left or right earbuds of the true wireless earbud pair. For example, the first audio device 100 is the left earbud and the second audio device 200 is the right earbud. In other embodiments, the first audio device 100 may be the right earbud and the second audio device 200 may be the left earbud. This is not a limitation; the first and second devices in this application are merely for distinguishing between different audio devices.
[0014] In another embodiment of this application, the wireless audio system can also be smart glasses, which include a left component and a right component. The first audio device 100 can be one of the left or right components of the smart glasses, and the second audio device 200 can be the other of the left or right components of the smart glasses. For example, the first audio device 100 may be the left component and the second audio device 200 may be the right component. In other embodiments, the first audio device 100 may be the right component and the second audio device 200 may be the left component.
[0015] The specific functions and structures of smart glasses and true wireless earbuds can be found in existing technologies and will not be elaborated here.
[0016] In the embodiments of this application, the first audio device 100 and the second audio device 200 each include a Bluetooth module and a wireless communication module. Through the Bluetooth module, the first audio device 100 and the second audio device 200 can communicate with each other or with other devices via Bluetooth. Through the wireless communication module, the first audio device 100 and the second audio device 200 can communicate wirelessly with each other or with other devices. For ease of distinction, the Bluetooth module included in the first audio device 100 can be referred to as the first Bluetooth module 110, and the wireless communication module included in the first audio device 100 can be referred to as the first wireless communication module 120. The Bluetooth module included in the second audio device 200 can be referred to as the second Bluetooth module 210, and the wireless communication module included in the second audio device 200 can be referred to as the second wireless communication module 220. The first Bluetooth module 110 and the second Bluetooth module 210 are modules capable of implementing the same Bluetooth communication; their specific structures can be the same or different, and no limitation is made here. Similarly, the first wireless communication module 120 and the second wireless communication module 220 are modules capable of implementing the same wireless communication.
[0017] In embodiments of this application, the Bluetooth module includes, but is not limited to, a Bluetooth module supporting Bluetooth Classic, Bluetooth Low Energy, and other Bluetooth protocols. In embodiments of this application, the wireless communication module includes any one or both of a UWB module and a Wi-Fi module. The UWB module enables the device to support UWB communication, and the Wi-Fi module enables the device to support Wi-Fi communication.
[0018] In the embodiments of this application, the first audio device 100 and the second audio device 200 can acquire and play the audio signal from the audio source device. The first audio device 100 and the second audio device 200 are connected to the audio source device, including but not limited to, directly or indirectly via Bluetooth.
[0019] For example, in some embodiments, one of the first audio devices 100 and the second audio device 200 establishes a Bluetooth connection with the audio source device, and the other audio device receives audio signals from the audio source device by listening to the Bluetooth connection.
[0020] In other embodiments, the first audio device 100 and the second audio device 200 receive audio signals from the audio source device via BIS (Broadcast Isochronous Stream) / CIS (Connected Isochronous Stream) in LE audio (Low Power Audio or Bluetooth Low Power Audio).
[0021] An additional Bluetooth connection is established between the first audio device 100 and the second audio device 200. For ease of distinction, the Bluetooth connection between the first audio device 100 and the second audio device 200 can be referred to as the second Bluetooth connection, and the Bluetooth connections between each of the first audio device 100 and the audio device 200 and the audio source device can be referred to as the first Bluetooth connection. The second Bluetooth connection is used for information transmission between the first audio device 100 and the second audio device 200, such as simultaneous playback on both devices, synchronized volume adjustment, etc. Another example is that one audio device can send information related to its Bluetooth connection with the audio source device to the other audio device.
[0022] Accordingly, the Bluetooth module controls the Bluetooth communication and connection related operations through the Bluetooth controller. Therefore, in the embodiments of this application, the first audio device 100 and the second audio device 200 each further include a Bluetooth controller. The Bluetooth controller of the first audio device 100 can be referred to as the first Bluetooth controller 130, and the Bluetooth controller of the second audio device 200 can be referred to as the second Bluetooth controller 230.
[0023] The first audio device 100 and the second audio device 200 in this application can be used for keyword detection, speech recognition, and other tasks, and perform corresponding operations, such as playback control according to voice commands. Therefore, the first audio device 100 and the second audio device 200 may each include a microphone for acquiring audio signals. For example, the first audio device 100 may include N microphones for acquiring first audio signals, and the second audio device 200 may include M microphones for acquiring second audio signals.
[0024] In some embodiments of the application, the audio signals collected by the first audio device 100 and the second audio device 200 through the microphone can be processed by the same audio device or transmitted to a control device such as an audio source device. For example, the first audio signal collected by the first audio device 100 may be transmitted to the second audio device 200, which then processes it accordingly and sends data back to the first audio device 100 or the audio source device. Conversely, the second audio device 200 may also send the audio signal collected by the microphone to the first audio device 100. The operation between the first audio device 100 and the second audio device 200 can be mutually converted, and this is not limited here.
[0025] In this process, the audio data to be played sent by the audio source device to the first audio device 100 and the second audio device 200 is transmitted via Bluetooth. The Bluetooth connection information between the first audio device 100 and the second audio device 200 is also transmitted via Bluetooth. To reduce the occupancy of Bluetooth, when the first audio device 100 transmits audio signals to the second audio device 200 (or the second audio device 200 transmits them to the first audio device 100), the audio data collected by the microphone is transmitted via wireless communication methods such as UWB or WI-FI.
[0026] Ultra-wideband (UWB) wireless communication, also known as ultra-wideband, will be briefly introduced here for ease of understanding. UWB covers a frequency band of 7 GHz, from 3 GHz to 5 GHz and from 6 GHz to 10 GHz, with a single-channel bandwidth exceeding 500 MHz. Communication methods include IR-UWB (baseband narrow pulse), DS-UWB (direct sequence code division multiple access), and MB-UWB (multi-band orthogonal frequency division multiplexing). IR-UWB transmits directly through an antenna, without the need for sine wave modulation, and features real-time simplicity, low cost, low power consumption, strong multipath resistance, and good penetration. DS-UWB and MB-UWB use bandpass carrier modulation. The most common data exchange method in UWB is request-response. The sending end sends a Data / Request frame, and the receiving end sends a Response / ACK / Data frame after a fixed delay Δt specified in the protocol, thus achieving data exchange.
[0027] Wi-Fi is a wireless local area network technology based on the IEEE 802.11 standard. Typically, before transmitting data, a Wi-Fi transmitter determines whether the channel is idle using both physical layer and virtual carrier sensing methods. If the channel remains idle for a period equal to or greater than DIFS (Distributed Inter-Frame Space), it is allowed to enter the transmission contention phase; if the channel is busy, it must wait for the channel to become idle again. To avoid collisions caused by multiple stations transmitting simultaneously, each transmitter randomly selects a backoff time within the CW (Content Window); after each SlotTime (idle time slot), the backoff counter is decremented by 1; when the counter reaches 0, it gains the right to transmit.
[0028] The above information on Bluetooth modules and wireless communication modules is only a brief introduction. For specific implementation details, please refer to existing technologies, which will not be elaborated upon here.
[0029] Bluetooth communication and wireless communication are different types of communication methods, each operating according to its own communication protocol. Therefore, different communication methods have various corresponding clock and timing logics. When multiple devices work together, they need to process the same data. For example, the first audio device 100 and the second audio device 200 need to play the audio signal sent by the audio source device synchronously. The second audio signal collected by the microphone of the second audio device 200 needs to be aligned with the audio signal collected by the microphone of the first audio device 100. Various collaborative operations involve the alignment of the same data in time.
[0030] In embodiments of this application, the first audio device 100 is used to determine a timing reference based on the Bluetooth clock of the Bluetooth communication. Simultaneously, the first audio device 100 is also used to determine the transmission timing of the wireless communication based on the timing reference. Furthermore, the second audio device 200 is used to determine the reception timing of the wireless communication based on the reception time of the Bluetooth communication frame.
[0031] In Bluetooth communication, the transmission and reception of Bluetooth communication frames are controlled by the Bluetooth clock. In the embodiments of this application, the Bluetooth clock is the hardware clock of the Bluetooth module, which is used to characterize the local time reference during the Bluetooth communication process.
[0032] In one optional implementation, the Bluetooth clock can be the hardware clock of the analog-to-digital converter in the Bluetooth module, or a frequency-divided clock obtained by dividing the hardware clock of the analog-to-digital converter. The Bluetooth clock is used to drive signal processing and communication operations within the Bluetooth module and can also serve as the counting object for the first local hardware clock counter mentioned later.
[0033] In the embodiments of this application, a timing reference can be determined from the Bluetooth clock. This timing reference can also be called the transmission timing, transmission timing mechanism, transmission time, etc. This timing reference is used by the first audio device to control the transmission time of Bluetooth communication frames in Bluetooth communication, or it can be understood that the first audio device controls the transmission of Bluetooth communication frames based on the timing reference.
[0034] Accordingly, the second audio device 200 also needs to control the reception of Bluetooth communication frames based on this timing reference in order to achieve time alignment of Bluetooth communication.
[0035] The moment when the second audio device 200 receives a Bluetooth communication frame can be referred to as the reception moment, which is based on or associated with a timing reference.
[0036] For example, without considering various delays, the expected reception time of a Bluetooth communication frame is generally the same as the transmission time. Therefore, controlling the reception of Bluetooth communication frames based on a timing reference can make the expected reception time the same as the timing reference.
[0037] Due to various factors such as equipment and transmission paths, there will be a fixed time deviation between the reception and transmission times. Therefore, the reception time can also have a fixed time difference from the timing reference. Accordingly, controlling the reception of Bluetooth communication frames based on the timing reference can mean that the sum of the reception time and the fixed time difference equals or corresponds to the timing reference. This fixed time difference can be pre-measured.
[0038] Therefore, in some embodiments of this application, the moment when the second audio device 200 actually receives the Bluetooth communication frame can be determined as the receiving moment, which corresponds to the time reference.
[0039] Wireless communication and Bluetooth communication are two different communication methods. In the embodiments of this application, wireless communication is also made to control the timing of communication based on the timing reference of Bluetooth communication. That is, the transmission timing of wireless communication is determined based on the timing reference, so that the transmission timing of wireless communication is aligned with the timing reference of Bluetooth communication, thereby realizing the control of the transmission of wireless frames in wireless communication based on the timing reference of Bluetooth communication.
[0040] Similarly, the second audio device 200 determines the wireless communication reception timing based on the reception time of the Bluetooth communication frame. This reception time is determined based on the second audio device 200's reception of the Bluetooth communication frame. Since the Bluetooth communication frame is transmitted based on a timing reference, the reception time and the timing reference have a corresponding relationship. Therefore, the wireless communication reception timing of the second audio device 200 has a high correlation with the timing reference and can be calculated using the timing reference. For example, the wireless communication reception timing of the second audio device 200 can be directly obtained from this reception time without needing adjustment by the wireless communication receiving circuit. The reception time and the timing reference are synchronized, and the wireless communication reception timing corresponds to the reception time. Therefore, the wireless communication reception timing is also synchronized with the timing reference. This aligns the wireless communication reception timing with the Bluetooth communication timing reference, enabling control of wireless frame reception in wireless communication based on the Bluetooth communication timing reference.
[0041] By using the above method, the clocks and timing of different types of communication methods are aligned based on the Bluetooth clock and timing standard, thus achieving a unified reference and effectively reducing the complexity of time alignment. At the same time, when different communication methods (or cross-wireless communication systems) control clock and timing alignment based on the same reference, it can help improve alignment accuracy, thereby helping to improve the working effect of various audio devices when working together.
[0042] In the embodiments of this application, the timing reference is selected from a Bluetooth clock at a specific moment. The selection method can be preset, and there are various ways to select the timing reference. For example, in the embodiments of this application, the timing reference is one of the following: the start time of a communication event in the Bluetooth communication protocol timing structure; the start time of a time slot in the Bluetooth communication protocol timing structure; the start boundary of a multi-time slot communication frame in the Bluetooth communication protocol timing structure; or a time identifier corresponding to a Bluetooth communication frame generated by the first audio device 100 based on a first local hardware clock counter. The Bluetooth communication protocol can be referenced from existing technologies and will not be elaborated upon here.
[0043] In embodiments of this application, the first local hardware clock counter is a counter for the first audio device 100. The first audio device 100 may include a first Bluetooth controller 130; the first Bluetooth controller 130 may include a first local hardware clock counter and a transmission scheduling module, the transmission scheduling module being connected to the first local hardware clock counter. The first local hardware clock counter is used to count the first Bluetooth clock of the first audio device to obtain a first count value; when the first count value reaches the count value corresponding to the timing reference, the transmission scheduling module sends a Bluetooth communication frame to the second audio device 200 via Bluetooth connection.
[0044] The first local hardware clock counter is used to record the first Bluetooth clock of the first audio device. Therefore, the change in the count value of the first local hardware clock counter is in a preset ratio relationship with the period of the first Bluetooth clock. For example, in one cycle of the Bluetooth clock, the change in the count value of the first local hardware clock counter is 'a'. 625µs / one cycle of the Bluetooth clock, where 'a' is a positive integer, and 625µs is the classic Bluetooth time slot. For example, in the case where one cycle of the Bluetooth clock is 1µs, the change in the count value is 'a'. 625.
[0045] The timing reference is dynamically updated over a period of time. The ratio of the change in the timing reference over one period to the change in the count value of the first local hardware clock counter is the ratio of one period of the timing reference to the period of the Bluetooth clock.
[0046] In the embodiments of this application, the Bluetooth time slot is 625µs, and the timing reference can adopt a TDD (Time Division Duplex) mechanism based on the 625µs time slot. The first audio device transmits in even-numbered time slots, and the second audio device responds in odd-numbered time slots. The transmission and reception time slots alternate and repeat in a basic transmission and reception cycle of 1250µs. The timing reference is counted using the first Bluetooth clock of the first audio device.
[0047] The first count value corresponding to the start time of the Bluetooth time slot, or the count value plus a fixed deviation, can be the count value corresponding to the timing reference. In this embodiment, the first local hardware clock counter is a hardware circuit. Compared with software programs, hardware circuits are more accurate in counting and less affected by external factors, which helps to further improve the accuracy of time alignment.
[0048] In the foregoing embodiments, the timing reference can be a time identifier corresponding to a Bluetooth communication frame generated by the first audio device 100 based on a first local hardware clock counter. That is, the count value of the first local hardware clock counter related to the Bluetooth communication frame can be used as the timing reference. For example, the count value corresponding to the start time of the Bluetooth communication frame, the boundary value corresponding to the start time of the time slot, the count value corresponding to the boundary of the multi-time slot communication frame, or the count value selected according to other rules, which is not limited here.
[0049] The count value of the first local hardware clock counter can be referred to as the first count value. In the embodiments of this application, when the first count value of the first local hardware clock counter reaches the count value corresponding to the timing reference, the transmission scheduling module controls the Bluetooth module to send a Bluetooth communication frame to the second audio device 200 through the Bluetooth connection. In the embodiments of this application, the transmission scheduling module can be implemented by devices or circuits with processing and control functions. The transmission scheduling module can also implement the software program of the first Bluetooth controller 130, and there is no limitation here.
[0050] Accordingly, the second audio device 200 includes a second Bluetooth controller 230; the second Bluetooth controller 230 may also include a second local hardware clock counter. The second local hardware clock counter is used to count the Bluetooth clock to obtain a second count value; the second audio device 200 is also used to receive Bluetooth communication frames; the second Bluetooth controller 230 is used to record the count value of the second local hardware clock counter at the time of successful reception of the Bluetooth communication frame in response to the successful reception of the Bluetooth communication frame, as the count value corresponding to the reception time. The second local hardware clock counter and the first local hardware clock counter are local hardware clock counters in different audio devices, and their operation is the same. For details, please refer to the aforementioned content on the first local hardware clock counter, which will not be elaborated here. Similarly, the second local hardware clock counter is also a hardware circuit to improve the accuracy of the recorded count value, thereby improving the accuracy of time alignment.
[0051] In the embodiments of this application, the second Bluetooth controller 230 is further configured to obtain the time relationship between the first audio device 100 and the second audio device 200 based on the count value corresponding to the receiving time and the count value corresponding to the timing reference.
[0052] In the embodiments of this application, the time relationship between the first audio device 100 and the second audio device 200 represents the delay difference between the first audio device 100 and the second audio device 200. As mentioned above, the reception time is actually recorded by the time of receiving the Bluetooth communication frame. Therefore, it may differ from the timing reference, and the two have a certain time delay. Therefore, if it is necessary to control the two audio devices to work synchronously, the time relationship corresponding to this delay can be determined. Based on this time relationship, the second audio device 200 can perform subsequent work, such as controlling the alignment of Bluetooth communication and transmitted data. The specific use of this time relationship can be configured according to actual needs and is not limited here.
[0053] In Bluetooth communication, successful reception of a Bluetooth communication frame can be attributed to successful frame synchronization. Therefore, in the embodiments of this application, the second Bluetooth controller 230 may determine successful reception of a Bluetooth communication frame only after determining that a preset successful frame synchronization event of the second audio device 200 for the Bluetooth communication frame has occurred.
[0054] There are several events that indicate successful frame synchronization, such as successful detection of the access code for a Bluetooth communication frame, locking of the synchronization word, and confirmation of equivalent physical layer synchronization. In the embodiments of this application, any one of the above situations can be selected and set as a preset successful frame synchronization event, that is, any one of the following situations—successful detection of the access code for a Bluetooth communication frame, locking of the synchronization word, and confirmation of equivalent physical layer synchronization—can be preset as an event representing the occurrence of a successful frame synchronization event.
[0055] In Bluetooth communication, the receiving device receives Bluetooth communication frames at the time corresponding to the receiving window. Accordingly, in the embodiments of this application, the second Bluetooth controller 230 is also used to receive Bluetooth communication frames within a preset receiving window. Determining successful reception of a Bluetooth communication frame requires a period of matching detection, i.e., performing access code detection, synchronization word locking, physical layer synchronization confirmation, etc. Therefore, in the embodiments of this application, the opening time of the preset receiving window needs to match the timing reference, and the opening of the preset receiving window occurs earlier than the successful synchronization event of the pre-approval frame.
[0056] In the embodiments of this application, due to various reasons such as circuit delay, transmission delay, and processing delay, the timing reference is earlier than the receiving time by a certain time deviation. Therefore, the opening time of the preset receiving window is matched with the timing reference, so that the opening time of the preset receiving window is earlier than the preset duration of the timing reference.
[0057] In some other embodiments of this application, the opening time of the preset receiving window is matched with the timing reference. Alternatively, the opening time of the preset receiving window may be earlier than the timing reference by a certain time deviation. For example, the time deviation may be 5us, 10us, 20us, etc. Thus, the opening time of the preset receiving window may be earlier than the preset duration of the timing reference.
[0058] By enabling the second audio device 200 to open its receiving window before receiving the Bluetooth communication frame, and waiting for the Bluetooth communication frame to be received, the relevant synchronization and matching work can be started immediately after the Bluetooth communication frame arrives, without having to wait for the receiving window to open before performing the relevant work. This can effectively reduce the latency of the first audio device 100 and the second audio device 200 working together via Bluetooth communication.
[0059] In the audio acquisition chain, audio data often needs to undergo processing steps such as sampling, buffering, and batch transmission. If the buffer depth and data transmission triggering mechanism are not designed properly, additional waiting latency can be introduced, further amplifying the time deviation between different audio devices and affecting the audio processing effect of multi-microphones. Furthermore, when using wireless communication such as Wi-Fi and UWB, there is usually a significant latency issue.
[0060] For example, the traditional UWB "request-response" mechanism is not conducive to real-time, continuous data transmission and introduces non-negligible round-trip latency. The CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) of the wireless LAN link also significantly increases the transmission latency of the first audio device 100 and the second audio device 200, and this latency has considerable uncertainty.
[0061] In many scenarios, the audio signals captured by the microphone have high real-time requirements, and the latency of UWB and Wi-Fi can affect the collaborative operation of audio devices. To address this issue, embodiments of this application also provide corresponding methods to reduce latency caused by wireless communication.
[0062] In this embodiment, a unified time reference can be established for the UWB or wireless LAN link based on the timing of Bluetooth communication to constrain the transmission and reception of UWB frames or Wi-Fi frames, thereby realizing low-latency audio data transmission between the first audio device 100 and the second audio device 200.
[0063] For example, please see Figure 2 , Figure 2This is a schematic diagram illustrating the transmission of audio signals acquired by a microphone according to an embodiment of this application. In one embodiment, the first audio device 100 may further include a first audio acquisition and processing module, a first buffer module, and a first data transmission module. The first audio acquisition and processing module is used to convert the first audio signal into a first digital audio signal and store it in the first buffer module. The first data transmission module is used to acquire the first digital audio signal from the first buffer module based on the startup timing and transmit it to the wireless transmission storage area for wireless communication; the first wireless communication module 120 is used to acquire the first digital audio signal from the wireless transmission storage area and transmit it to the second audio device 200 via wireless communication.
[0064] In the embodiments of this application, the startup timing refers to the timing of the data transmission module acquiring digital audio signals from the buffer module. After the data transmission module acquires digital audio signals from the buffer module, it stores them in the wireless transmission storage area. Correspondingly, the transmission timing is the timing of the wireless communication module acquiring audio signals from the wireless transmission storage area and transmitting them.
[0065] In this embodiment, the startup timing matches a preset time reference, which is determined based on the transmission timing and a preset time deviation. The startup timing matching the preset time reference can be the same as the preset time reference or have a preset difference relationship. The transmission timing can correspond to the start time of the aforementioned transmission scheduling module sending Bluetooth communication frames.
[0066] The preset time reference is determined based on the transmission timing and preset time deviation. This allows the digital audio signal to arrive at the wireless transmission storage area in advance within the preset time deviation range before wireless transmission. As a result, when the digital audio signal is transmitted wirelessly, the digital audio signal is ready to be transmitted in the wireless transmission storage area, reducing the waiting time required for the digital audio signal to be stored in the wireless transmission storage area, thereby reducing the latency before the digital audio signal is transmitted.
[0067] In this embodiment, the startup timing and transmission timing are coordinated to constrain wireless communication. The two work together to ensure that audio data is ready within a short time window before wireless transmission, effectively reducing the waiting latency of audio data within the system.
[0068] Accordingly, the second audio device 200 may further include a second audio acquisition and processing module, which is used to convert the second audio signal into a second digital audio signal. The second audio device 200 is also used to time-align the first digital audio signal and the second digital audio signal based on a preset time reference. Specifically, the second audio device 200 may calculate the time base in reverse based on the receiving time, and then calculate the transmission timing to obtain the preset time reference through the transmission timing calculation; the specific method of obtaining this reference is not limited here.
[0069] In the above embodiments, the second audio acquisition and processing module controls the first and second digital audio signals to perform time alignment based on a preset time reference. This includes, but is not limited to, aligning the two signals in terms of clock and timing based on the preset time reference, so that they can be synchronized in time. In this embodiment, using the same preset time reference as the first audio device 100 achieves timing uniformity, enabling collaborative timing control between different wireless communication systems. This eliminates the need for additional synchronization protocols or independent clock synchronization mechanisms, simplifying the corresponding control logic and thus reducing latency.
[0070] In the above embodiments, the first audio acquisition and processing module may include an ADC (Analog-to-Digital Conversion) module, a filtering and downsampling module, etc. Common ADC sampling frequencies may be 6.144MHz, 3.072MHz, etc., and the digital audio data after passing through the audio acquisition and processing module may be 96kHz, 48kHz, 32kHz, 16kHz, etc. The first buffer module may be a FIFO (First In First Out) buffer, and the first data transmission unit may be a first DMA (Direct Memory Access) module. Similarly, the second audio acquisition and processing module may also include an ADC (Analog-to-Digital Conversion) module, a filtering and downsampling module, etc.
[0071] Data caching and retrieval also cause a certain delay. In the embodiments of this application, the delay caused by caching audio signals can be further reduced.
[0072] In one embodiment of this application, the first audio acquisition and processing module can operate in the first clock domain, sample the first audio signal at a first sampling rate to obtain the first digital audio signal; the first buffer module operates in the first clock domain, and when the first buffer module writes a first preset number of the first digital audio signal, it triggers the first data transmission module so that the first data transmission module writes the first digital audio signal into the wireless transmission storage area.
[0073] On the one hand, in this embodiment, the clock frequency of the first clock domain is greater than the first sampling rate, which means that the operating frequency of the first audio acquisition and processing module is greater than the sampling rate (first sampling rate) required by the first audio signal, thus avoiding the use of the same operating frequency as the first sampling rate. This method can avoid delays caused by some uncertain factors during the sampling process.
[0074] On the other hand, in this embodiment, when the first buffer module writes a first preset number of first digital audio signals, it triggers the first data transmission module to read data. For example, when the first buffer module is written with a predetermined number (e.g., 2, 4, 8, 16 points) of audio signals, it triggers the transmission of that predetermined number of audio signals to the wireless transmission storage area. This method allows digital audio signals to be transmitted in small batches, reducing the amount of data that the buffer module needs to store, thereby reducing the latency caused by buffering audio signals. Simultaneously, this method further reduces the latency caused by wireless communication by not relying on scheduling or control through ultra-wideband wireless links or wireless local area network link protocols.
[0075] Similarly, the second audio device 200 can also be configured accordingly. For example, the second audio device 200 further includes a second buffer module and a second data transmission module; the second audio acquisition and processing module operates in the second clock domain and samples the second audio signal at a second sampling rate to obtain a second digital audio signal; the clock frequency of the second clock domain is greater than the second sampling rate; the second buffer module operates in the second clock domain, and when the second buffer module writes a second preset number of second digital audio signals, it triggers the second data transmission module to read the second digital audio signals from the second buffer module.
[0076] The first sampling rate and the second sampling rate can be the same or different, the second clock domain can be the same or different from the first clock domain, and the first preset quantity and the second preset quantity can also be the same or different. These settings are not limited here, depending on the specific device, scenario, etc.
[0077] The above methods can further reduce latency in wireless communication, helping to further reduce end-to-end transmission latency and improve the time alignment accuracy of multi-microphone audio data. In the embodiments of this application, the Bluetooth communication timing is established as a unified time parameter across wireless standards, thereby coordinating the transmission and sending timing of audio sampling data to achieve low-latency, high-precision time alignment of microphone signals across devices.
[0078] Based on the same inventive concept, embodiments of this application also provide a communication method for a wireless audio system. Please refer to [link to relevant documentation]. Figure 3 , Figure 3 This is a schematic diagram illustrating a communication method for a wireless audio system according to an embodiment of this application. This communication method can be applied to the aforementioned wireless audio system, and includes: S310, the first audio device determines the timing reference based on the Bluetooth clock of Bluetooth communication.
[0079] The timing reference is used by the first audio device to control the transmission of Bluetooth communication frames.
[0080] S320, the first audio device determines the transmission timing of wireless communication based on a timing reference.
[0081] S330, the second audio device determines the wireless communication reception timing based on the reception time of the Bluetooth communication frame.
[0082] In one embodiment, the first audio device includes a first Bluetooth controller; the first Bluetooth controller includes a first local hardware clock counter and a transmission scheduling module, the transmission scheduling module being connected to the first local hardware clock counter. S310, the first audio device determines a timing reference based on the Bluetooth clock of Bluetooth communication, including: counting the first Bluetooth clock of the first audio device using the first local hardware clock counter to obtain a first count value. After S310, the method further includes: when the first count value reaches the count value corresponding to the timing reference, the transmission scheduling module sends the Bluetooth communication frame to the second audio device via Bluetooth connection.
[0083] In one embodiment, the timing reference is one of the following: the start time of a communication event in the Bluetooth communication protocol timing structure; the start time of a time slot in the Bluetooth communication protocol timing structure; the start boundary of a multi-time slot communication frame in the Bluetooth communication protocol timing structure; or a time identifier corresponding to a Bluetooth communication frame generated by the first audio device based on a first local hardware clock counter.
[0084] In one embodiment, the second audio device includes a second Bluetooth controller; the second Bluetooth controller includes a second local hardware clock counter. S330, before the second audio device determines the reception timing of wireless communication based on the reception time of the Bluetooth communication frame, the method further includes: counting a second Bluetooth clock of the second audio device using the second local hardware clock counter to obtain a second count value; receiving the Bluetooth communication frame through the second audio device; and, in response to the successful reception of the Bluetooth communication frame, recording the count value of the second local hardware clock counter at the time of successful reception of the Bluetooth communication frame as the count value corresponding to the reception time.
[0085] After recording the count value of the second local hardware clock counter when the Bluetooth communication frame is successfully received, the method further includes: obtaining the time relationship between the first audio device and the second audio device by the second Bluetooth controller based on the count value corresponding to the reception time and the count value corresponding to the timing reference.
[0086] In one embodiment, receiving the Bluetooth communication frame via a second audio device includes: determining that the Bluetooth communication frame has been successfully received by a second Bluetooth controller when a preset frame synchronization success event for the second audio device occurs. One of the following conditions is preset to indicate that the frame synchronization success event has occurred: successful access code detection of the Bluetooth communication frame, synchronization word locking, or completion of an equivalent physical layer synchronization confirmation event.
[0087] In one embodiment, receiving the Bluetooth communication frame via a second audio device includes: receiving the Bluetooth communication frame via a second Bluetooth controller within a preset receiving window; the opening time of the preset receiving window matches the timing reference, and the opening of the preset receiving window occurs earlier than the successful synchronization event of the pre-approval frame.
[0088] In one embodiment, the first audio device includes: N microphones, a first audio acquisition and processing module, a first buffer module, a first data transmission module, and a first wireless communication module. In S320, after the first audio device determines the transmission timing of the wireless communication based on a timing reference, the method further includes: converting the first audio signal into a first digital audio signal through the first audio acquisition and processing module and storing it in the first buffer module; obtaining the first digital audio signal from the first buffer module based on a startup timing sequence through the first data transmission module and transmitting it to the wireless transmission storage area of the wireless communication; obtaining the first digital audio signal from the wireless transmission storage area through the first wireless communication module and transmitting it to the second audio device via the wireless communication. The startup timing sequence matches a preset time reference, and the preset time reference is determined based on the transmission timing sequence and a preset time deviation.
[0089] In one embodiment, the second audio device includes M microphones, a second audio acquisition and processing module, and a second wireless communication module. In S320, after the first audio device determines the transmission timing of wireless communication based on a timing reference, the method further includes: acquiring a second audio signal through the M microphones of the second audio device, converting the second audio signal into a second digital audio signal through the second audio acquisition and processing module; and aligning the first digital audio signal and the second digital audio signal in time based on a preset time reference.
[0090] In one embodiment, the method further includes: controlling a first audio acquisition and processing module to operate in a first clock domain, sampling the first audio signal at a first sampling rate to obtain the first digital audio signal; the clock frequency of the first clock domain is greater than the first sampling rate; controlling the first buffer module to operate in the first clock domain, and triggering the first data transmission module when the first buffer module writes a first preset number of first digital audio signals, so that the first data transmission module writes the first digital audio signal into the wireless transmission storage area.
[0091] In one embodiment, the second audio device further includes a second buffer module, and the method further includes: controlling the second audio acquisition and processing module to operate in a second clock domain, sampling the second audio signal at a second sampling rate to obtain the second digital audio signal; the clock frequency of the second clock domain is greater than the second sampling rate; the second buffer module operates in the second clock domain, and when the second buffer module writes a second preset number of second digital audio signals, it triggers the second data transmission module to read the second digital audio signals from the second buffer module.
[0092] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
[0093] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
Claims
1. A wireless audio system, characterized in that, include: First audio device and second audio device; The first audio device and the second audio device are connected via Bluetooth, and the first audio device and the second audio device are also connected via wireless communication; the wireless communication includes at least one of ultra-wideband wireless communication (UWB) and wireless local area network communication (Wi-Fi); The first audio device is used to determine a timing reference based on the Bluetooth clock of the Bluetooth communication; The first audio device is also used to control the transmission of Bluetooth communication frames based on the timing reference; The first audio device is further configured to determine the transmission timing of the wireless communication based on the timing reference; Furthermore, the second audio device is also configured to determine the reception timing of the wireless communication based on the reception time of the Bluetooth communication frame.
2. The wireless audio system according to claim 1, characterized in that, The first audio device includes a first Bluetooth controller; The first Bluetooth controller includes: a first local hardware clock counter and a transmission scheduling module, wherein the transmission scheduling module is connected to the first local hardware clock counter; The first local hardware clock counter is used to count the first Bluetooth clock of the first audio device to obtain a first count value; When the first count value reaches the count value corresponding to the timing reference, the sending scheduling module sends the Bluetooth communication frame to the second audio device through the Bluetooth connection.
3. The wireless audio system according to claim 2, characterized in that, The timing reference is one of the following: The start time of communication events in the Bluetooth communication protocol timing structure; The start time of a time slot in the timing structure of the Bluetooth communication protocol; The starting boundary of a multi-slot communication frame in the Bluetooth communication protocol timing structure; The first audio device generates a time stamp corresponding to the Bluetooth communication frame based on the first local hardware clock counter.
4. The wireless audio system according to claim 2, characterized in that, The second audio device includes a second Bluetooth controller; The second Bluetooth controller includes a second local hardware clock counter; The second local hardware clock counter is used to count the second Bluetooth clock of the second audio device to obtain a second count value; The second audio device is also used to receive the Bluetooth communication frame; The second Bluetooth controller is used to record the count value of the second local hardware clock counter when the Bluetooth communication frame is successfully received, in response to the successful reception of the Bluetooth communication frame, as the count value corresponding to the reception time.
5. The wireless audio system according to claim 4, characterized in that, The second Bluetooth controller is further configured to obtain the time relationship between the first audio device and the second audio device based on the count value corresponding to the receiving time and the count value corresponding to the timing reference.
6. The wireless audio system according to claim 4, characterized in that, The second Bluetooth controller is used to determine that the Bluetooth communication frame has been successfully received when a preset frame synchronization success event for the Bluetooth communication frame by the second audio device occurs. One of the following conditions is preset to indicate that the frame synchronization success event has occurred: the access code of the Bluetooth communication frame is successfully detected, the synchronization word is locked, or the equivalent physical layer synchronization confirmation event is completed.
7. The wireless audio system according to claim 6, characterized in that, The second Bluetooth controller is also configured to receive the Bluetooth communication frame within a preset receiving window; The opening time of the preset receiving window matches the timing reference, and the opening of the preset receiving window occurs earlier than the preset frame synchronization success event.
8. The wireless audio system according to any one of claims 1-7, characterized in that, The first audio device includes: N microphones, a first audio acquisition and processing module, a first buffer module, a first data transmission module, and a first wireless communication module; The N microphones are used to collect the first audio signal; The first audio acquisition and processing module is used to convert the first audio signal into a first digital audio signal and store it in the first buffer module; The first data transmission module is used to obtain the first digital audio signal from the first buffer module based on the startup timing and transmit it to the wireless transmission storage area of the wireless communication. The first wireless communication module is used to acquire the first digital audio signal from the wireless transmission storage area and transmit it to the second audio device via the wireless communication. The startup timing is matched with a preset time reference, which is determined based on the transmission timing and the preset time deviation.
9. The wireless audio system according to claim 8, characterized in that, The second audio device includes M microphones, a second audio acquisition and processing module, and a second wireless communication module; The M microphones are used to collect the second audio signal; The second audio acquisition and processing module is used to convert the second audio signal into a second digital audio signal; The second audio device is also used to time-align the first digital audio signal and the second digital audio signal based on the preset time reference.
10. The wireless audio system according to claim 8, characterized in that, The first audio acquisition and processing module operates in the first clock domain and samples the first audio signal at a first sampling rate to obtain the first digital audio signal; the clock frequency of the first clock domain is greater than the first sampling rate. The first buffer module operates in the first clock domain, and when the first buffer module writes a first preset number of first digital audio signals, it triggers the first data transmission module so that the first data transmission module writes the first digital audio signals into the wireless transmission storage area.
11. The wireless audio system according to claim 9, characterized in that, The second audio device also includes a second buffer module and a second data transmission module; The second audio acquisition and processing module operates in the second clock domain and samples the second audio signal at the second sampling rate to obtain the second digital audio signal; the clock frequency of the second clock domain is greater than the second sampling rate. The second buffer module operates in the second clock domain, and when the second buffer module writes a second preset number of second digital audio signals, it triggers the second data transmission module to read the second digital audio signals from the second buffer module.
12. The wireless audio system according to claim 1, characterized in that, The first audio device is one of the left or right earbuds of the true wireless earbud pair, and the second audio device is the other of the left or right earbuds of the true wireless earbud pair. Alternatively, the first audio device may be one of the left or right components of the smart glasses, and the second audio device may be the other of the left or right components of the smart glasses.
13. A communication method for a wireless audio system, characterized in that, The wireless audio system includes a first audio device and a second audio device, and the communication method includes: The first audio device determines a timing reference based on the Bluetooth clock of Bluetooth communication; wherein, the timing reference is used by the first audio device to control the transmission of Bluetooth communication frames; the first audio device and the second audio device are connected via Bluetooth communication, and the first audio device and the second audio device are also connected via wireless communication; the wireless communication includes at least one of ultra-wideband wireless communication (UWB) and wireless local area network communication (Wi-Fi); The first audio device determines the transmission timing of the wireless communication based on the timing reference; The second audio device determines the reception timing of the wireless communication based on the reception time of the Bluetooth communication frame.