CN116131867A - Bluetooth audio transmitting equipment, bluetooth audio receiving equipment, related method and system - Google Patents

Bluetooth audio transmitting equipment, bluetooth audio receiving equipment, related method and system Download PDF

Info

Publication number
CN116131867A
CN116131867A CN202211718993.7A CN202211718993A CN116131867A CN 116131867 A CN116131867 A CN 116131867A CN 202211718993 A CN202211718993 A CN 202211718993A CN 116131867 A CN116131867 A CN 116131867A
Authority
CN
China
Prior art keywords
audio
bluetooth audio
receiving
bluetooth
data packet
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202211718993.7A
Other languages
Chinese (zh)
Inventor
徐斌
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zgmicro Nanjing Ltd
Original Assignee
Zgmicro Nanjing Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zgmicro Nanjing Ltd filed Critical Zgmicro Nanjing Ltd
Priority to CN202211718993.7A priority Critical patent/CN116131867A/en
Publication of CN116131867A publication Critical patent/CN116131867A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/02—Transmitters
    • H04B1/04—Circuits
    • H04B1/0483—Transmitters with multiple parallel paths
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/16—Circuits
    • H04B1/18—Input circuits, e.g. for coupling to an antenna or a transmission line
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
    • H04W4/80—Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/10—Connection setup
    • H04W76/15—Setup of multiple wireless link connections
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/02—Transmitters
    • H04B1/04—Circuits
    • H04B2001/0491—Circuits with frequency synthesizers, frequency converters or modulators
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Abstract

The invention discloses Bluetooth audio sending equipment, bluetooth audio receiving equipment, a related method and a related system, which relate to the technical field of wireless communication and are used for solving the problem of low transmission rate of Bluetooth audio data. The Bluetooth audio transmitting apparatus includes: the antenna component comprises a switching unit and an antenna, wherein the antenna is connected with the transmitting unit when in a first state and is used for transmitting a first radio frequency signal in a transmitting time slot of a current isochronous communication interval, so that a corresponding group of audio data packets are respectively transmitted to N Bluetooth audio receiving devices in a frequency division multiplexing mode; the antenna is connected with the receiving unit when in a second state, and is used for receiving second radio frequency signals on the N-item standard links in a time-sharing mode in a receiving time slot in the current isochronous communication interval so as to respectively receive acknowledgement data packets sent by the N Bluetooth audio receiving devices. The embodiment of the invention can improve the transmission rate of the audio data.

Description

Bluetooth audio transmitting equipment, bluetooth audio receiving equipment, related method and system
Technical Field
The present invention relates to the field of wireless communications technologies, and in particular, to a bluetooth audio transmitting device, a bluetooth audio receiving device, and related methods and systems.
Background
With the development of bluetooth communication technology, bluetooth low energy (Bluetooth Low Energy, BLE) Audio (Audio) technology based on a connection isochronous stream (Connected Isochronous Stream, CIS) link and a connection isochronous group (Connected Isochronous Group, CIG) protocol composed of at least one CIS link may provide wireless Multi-channel (Multi-channel) Audio services.
However, since the physical layer of BLE Audio and the CIS link provide a small effective bandwidth, the bluetooth Audio transmitting apparatus generally transmits multi-channel Audio data using a time division multiplexing method when transmitting Audio data through the link.
Devices for bluetooth audio transmission typically include a signal transmit path and a signal receive path. The signal transmission path comprises a processing unit, a modulation unit, a radio frequency transmission unit and an antenna, wherein the processing unit is used for dividing an audio data stream to be transmitted into audio service data units (Service Data Unit, SDUs) with the same size, and packaging each SDU into protocol data units (Protocol Data Unit, PDU) according to a preset Bluetooth communication protocol. The modulation unit processes and modulates the PDUs into digital modulation signals suitable for processing and transmitting by the radio frequency transmission unit, and the radio frequency transmission unit converts the digital modulation signals into analog signals to modulate the analog signals on a radio frequency carrier wave, so that the radio frequency signals are transmitted through an antenna. The signal receiving path comprises a processing unit, a radio frequency receiving unit, a demodulation unit and an antenna, wherein the radio frequency receiving unit receives a radio frequency signal sent by the communication opposite terminal through the antenna, and the demodulation unit demodulates the confirmation information in the radio frequency signal and then analyzes the confirmation information through the processing unit. In order to achieve multi-channel audio data transmission, the device typically needs to transmit audio data of each channel separately in a time division multiplexed manner.
Taking the example of transmitting the bluetooth audio data of the left channel and the right channel in an isochronous communication interval, the bluetooth audio transmitting device transmits a PDU of the left channel in a bluetooth transmitting time slot through a signal transmitting path thereof, and receives acknowledgement information ACK replied by the bluetooth audio receiving device corresponding to the left channel in a bluetooth receiving time slot after the bluetooth transmitting time slot through a signal receiving path thereof, so as to determine whether the transmitted PDU of the left channel is correctly received. Then, a PDU of the right channel is transmitted through the signal transmission path in another Bluetooth transmission time slot of the equal communication interval, and then acknowledgement information ACK replied by the Bluetooth audio receiving device corresponding to the right channel is received through the signal reception path in the following Bluetooth reception time slot, so as to determine whether the transmitted PDU of the right channel is correctly received. When either one of the two PDUs transmitted is not received correctly, then the retransmission is repeated multiple times within the equal communication interval until the upper limit of the number of retransmissions is reached. When the retransmission is not correctly received, the corresponding Bluetooth audio receiving device compensates the missing audio data in a packet loss compensation mode. It is apparent that such bluetooth audio transmission apparatus and method in the prior art have at least a problem that the transmission rate of bluetooth audio data is low. For example, a BLE Audio TWS headset system based on CIG link protocol is limited by the physical layer of BLE Audio up to 2Mbps and the effective bandwidth provided by the CIS link, and only provides two-channel lossy compression coding and packet loss compensated isochronous Audio streaming services with a transmission rate up to 248 kpbs.
Disclosure of Invention
The embodiment of the invention provides Bluetooth audio sending equipment, bluetooth audio receiving equipment, a related method and a related system, which are used for solving the problem of low transmission rate of Bluetooth audio data.
In a first aspect, an embodiment of the present invention provides a bluetooth audio transmission device, where the bluetooth audio transmission device communicates with N bluetooth audio receiving devices based on N target links, where N target links are in one-to-one correspondence with N bluetooth audio receiving devices, and N is a positive integer greater than 1; the Bluetooth audio transmission device includes:
the processing unit is used for processing the digital audio signals to obtain N groups of audio data packets, and each group of audio data packets is used for being sent to a corresponding Bluetooth audio receiving device in the current isochronous communication interval;
the N modulation units are used for respectively modulating the N groups of audio data packets to obtain N paths of first digital modulation signals corresponding to the N groups of audio data packets one by one;
the combining unit is used for respectively modulating N paths of the first digital modulation signals onto different digital carriers and combining the N paths of the first digital modulation signals into one path of multi-carrier digital modulation signals;
the transmitting unit is used for modulating the multi-carrier digital modulation signal onto a radio frequency carrier wave to obtain a first radio frequency signal;
The receiving unit is used for receiving the second radio frequency signals sent by the N Bluetooth audio receiving devices based on the corresponding target links respectively;
an antenna assembly comprising a switching unit and an antenna, the switching unit being adapted to switch the antenna between a first state and a second state;
the antenna is connected with the transmitting unit when in the first state, and is used for transmitting the first radio frequency signal in a transmitting time slot of the current isochronous communication interval, so that a corresponding group of audio data packets are respectively transmitted to N Bluetooth audio receiving devices in a frequency division multiplexing mode; and the antenna is connected with the receiving unit when in the second state, and is used for receiving the second radio frequency signals on N target links in a time-sharing manner in a receiving time slot in the current isochronous communication interval so as to respectively receive acknowledgement data packets sent by N Bluetooth audio receiving devices.
In a second aspect, the embodiment of the present invention further provides a bluetooth audio transmission method, which is applied to a bluetooth audio transmission device, where the bluetooth audio transmission device communicates with N bluetooth audio receiving devices based on N target links, where N target links are in one-to-one correspondence with N bluetooth audio receiving devices, and N is a positive integer greater than 1; the method comprises the following steps:
An audio data processing step, which is used for processing digital audio signals to obtain N groups of audio data packets, wherein each group of audio data packets is used for being sent to a corresponding Bluetooth audio receiving device in the current isochronous communication interval;
a signal modulation step, which is used for modulating N groups of audio data packets respectively to obtain N paths of first digital modulation signals corresponding to the N groups of audio data packets one by one;
a signal combining step, which is used for combining N paths of first digital modulation signals into one path of multi-carrier digital modulation signals after respectively modulating the N paths of first digital modulation signals onto different digital carriers;
a first signal transmitting step, configured to modulate the multi-carrier digital modulation signal onto a radio frequency carrier to obtain a first radio frequency signal, and transmit the first radio frequency signal in a transmission time slot of the current isochronous communication interval, so as to respectively transmit a corresponding group of audio data packets to N bluetooth audio receiving devices in a frequency division multiplexing manner based on the first radio frequency signal;
a first signal receiving step, configured to receive second radio frequency signals on N target links in a time-sharing manner in a receiving time slot in the current isochronous communication interval, so as to respectively receive acknowledgement data packets sent by N bluetooth audio receiving devices;
The Bluetooth audio transmitting device comprises a switching unit and an antenna, wherein the switching unit is used for enabling the antenna to be switched between a first state and a second state, the Bluetooth audio transmitting device executes the first signal transmitting step when the antenna is in the first state, and the Bluetooth audio transmitting device executes the first signal receiving step when the antenna is in the second state.
In a third aspect, an embodiment of the present invention further provides a bluetooth audio receiving method, applied to a bluetooth audio receiving device, where the bluetooth audio receiving device communicates with a bluetooth audio sending device based on a target link, including:
a second target link establishing step, which is used for establishing a target link with the Bluetooth audio transmitting equipment, determining the frequency of a digital carrier wave of which the first radio frequency signal is received and the time for transmitting the confirmation data packet;
a second signal receiving step, configured to receive, in a transmission time slot of a current isochronous communication interval, a first radio frequency signal that is sent by the bluetooth audio transmission device in a frequency division multiplexing manner, so as to obtain a set of audio data packets that are sent by the bluetooth audio transmission device in the current isochronous communication interval based on the target link;
And a second signal transmitting step, configured to transmit an acknowledgement packet on the target link based on the time of transmitting the acknowledgement packet in the receiving slot of the current isochronous communication interval.
In a fourth aspect, an embodiment of the present invention further provides a bluetooth audio transmission system, including the bluetooth audio transmitting device and N bluetooth audio receiving devices according to the first aspect, where the bluetooth audio transmitting device communicates with the N bluetooth audio receiving devices based on N target links, the N target links are in one-to-one correspondence with the N bluetooth audio receiving devices, and N is a positive integer greater than 1.
In the embodiment of the invention, through the arrangement of the processing unit, the N modulation units, the combining unit, the transmitting unit, the receiving unit and the antenna assembly, N groups of audio data packets corresponding to N Bluetooth audio receiving devices can be respectively modulated into digital modulation signals, and then N paths of first digital modulation signals are combined into one path of multi-carrier digital modulation signals for transmission, so that a plurality of groups of audio data packets are transmitted in parallel in a frequency division multiplexing manner based on a single antenna in one transmission time slot, and acknowledgement data packets transmitted by all Bluetooth audio receiving devices are received in a time division manner through the receiving unit and the antenna in a receiving time slot. Therefore, compared with the prior art, the embodiment of the application is simple in structure and can effectively improve the transmission rate of Bluetooth audio data.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort to a person of ordinary skill in the art.
Fig. 1 is a schematic structural diagram of a bluetooth audio transmission device according to an embodiment of the present invention;
fig. 2 is a second schematic structural diagram of a bluetooth audio transmission device according to an embodiment of the present invention;
fig. 3 is one of flowcharts of a bluetooth audio transmission method according to an embodiment of the present invention;
fig. 4 is a flowchart of a bluetooth audio receiving method according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of a bluetooth audio receiving device according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of a bluetooth audio transmission system according to an embodiment of the present invention;
fig. 7 is a schematic diagram of an extended packet header according to an embodiment of the present invention;
fig. 8 is a schematic diagram of a slot structure of an MC-ABAIG link according to an embodiment of the present invention;
fig. 9 is a second flowchart of a bluetooth audio transmission method according to an embodiment of the present invention;
Fig. 10 is a second flowchart of a bluetooth audio receiving method according to an embodiment of the invention.
Detailed Description
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all, of the embodiments of the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application are within the scope of the protection of the present application.
The terms first, second and the like in the description and in the claims, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application are capable of operation in sequences other than those illustrated or otherwise described herein, and that the terms "first" and "second" are generally intended to be used in a generic sense and not to limit the number of objects, for example, the first object may be one or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/" generally means a relationship in which the associated object is an "or" before and after.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a bluetooth audio transmission device according to an embodiment of the present invention. As shown in fig. 1, an embodiment of the present invention provides a bluetooth audio transmission device, where the bluetooth audio transmission device communicates with N bluetooth audio receiving devices based on N target links, where N target links are in one-to-one correspondence with N bluetooth audio receiving devices, and N is a positive integer greater than 1; the Bluetooth audio transmission device includes:
the processing unit is used for processing the digital audio signals to obtain N groups of audio data packets, and each group of audio data packets is used for being sent to a corresponding Bluetooth audio receiving device in the current isochronous communication interval;
the N modulation units are used for respectively modulating the N groups of audio data packets to obtain N paths of first digital modulation signals corresponding to the N groups of audio data packets one by one;
the combining unit is used for respectively modulating N paths of the first digital modulation signals onto different digital carriers and combining the N paths of the first digital modulation signals into one path of multi-carrier digital modulation signals;
the transmitting unit is used for modulating the multi-carrier digital modulation signal onto a radio frequency carrier wave to obtain a first radio frequency signal;
The receiving unit is used for receiving the second radio frequency signals sent by the N Bluetooth audio receiving devices based on the corresponding target links respectively;
an antenna assembly comprising a switching unit and an antenna, the switching unit being adapted to switch the antenna between a first state and a second state;
the antenna is connected with the transmitting unit when in the first state, and is used for transmitting the first radio frequency signal in a transmitting time slot of the current isochronous communication interval, so that a corresponding group of audio data packets are respectively transmitted to N Bluetooth audio receiving devices in a frequency division multiplexing mode; and the antenna is connected with the receiving unit when in the second state, and is used for receiving the second radio frequency signals on N target links in a time-sharing manner in a receiving time slot in the current isochronous communication interval so as to respectively receive acknowledgement data packets sent by N Bluetooth audio receiving devices.
As a specific embodiment, the target link established between the bluetooth audio transmitting device and each bluetooth audio receiving device in the embodiments of the present application may be referred to as an accumulated batch acknowledgment isochronous stream (Accumulated Block Acknowledgement Isochronous Stream, ABAIS) link. The N ABAIS links constitute a Multi-carrier cumulative bulk acknowledgment isochronous group (Multi-Carrier Accumulated Block Acknowledgement Isochronous Group, MC-ABAIG) link between the bluetooth audio transmitting device and the N bluetooth audio receiving devices.
The antenna assembly of the Bluetooth audio transmitting device only comprises one antenna, and the antenna is switched between the first state and the second state through the switching unit, so that the Bluetooth audio transmitting device can be switched between a state of transmitting an audio data packet and a state of receiving a confirmation data packet. The Bluetooth audio transmitting device can realize the parallel transmission of a plurality of groups of audio data packets in a frequency division multiplexing way based on a single antenna in one transmitting time slot, and the receiving unit and the antenna are used for receiving the acknowledgement data packets transmitted by each Bluetooth audio receiving device in a time division way in the receiving time slot. Therefore, compared with the prior art, the embodiment of the application is simple in structure and can effectively improve the transmission rate of Bluetooth audio data.
Optionally, as shown in fig. 2, in some embodiments, the processing unit includes an audio processing unit and a protocol processing unit, the audio processing unit is configured to process the digital audio signal and package the digital audio signal into a service data unit (Service Data Unit, SDU); the protocol processing unit is used for processing the service data unit sent in the current isochronous communication interval to obtain N groups of audio data packets, namely N groups of PDU carrying audio data; the protocol processing unit is also used for analyzing the confirmation data packet.
In other embodiments, the audio processing unit is further configured to store the corresponding codes and data after obtaining the SDU. In this embodiment, the audio processing unit is configured to process the digital audio signal into an audio data stream for transmission and package the audio data stream into SDUs. Illustratively, the processing of the digital audio signal by the audio processing unit comprises at least one of: lossy compression coding, lossless compression coding, non-compression coding, and sound effect processing.
Optionally, in some embodiments, the protocol processing unit is further configured to parse the acknowledgement packet based on a predetermined link protocol, so as to obtain information of each bluetooth audio receiving device that receives an audio data packet, so as to determine an audio data packet that needs to be sent in a next isochronous communication interval. In some embodiments, the audio processing unit processes and buffers a plurality of SDUs. The protocol processing unit processes only SDUs transmitted in the current isochronous communication interval.
The protocol processing unit can acquire the receiving state of a group of audio data packets corresponding to each Bluetooth audio receiving device by processing the received acknowledgement data packets. The reception status of a set of audio data packets corresponding to each bluetooth audio reception device may be used to determine which audio data packets are not received correctly, and thus determine the audio data packets to be transmitted in the next isochronous communication interval.
In some embodiments, the protocol processing unit is configured to encapsulate the SDUs into audio data packets suitable for processing by the modulation unit based on a predetermined link protocol, and to store programs and data for executing the predetermined link protocol. As a specific embodiment, a wireless communication protocol for performing audio transmission by adopting the bluetooth audio transmission method and the bluetooth audio receiving method according to the embodiments of the present application may be referred to as MC-ABAIS link protocol. The predetermined link protocol may be a wireless communication protocol including the MC-ABAIS link protocol.
In some embodiments, as shown in fig. 2, the bluetooth audio transmission apparatus further includes an audio input unit for acquiring a digital audio signal and transmitting to the audio processing unit so that the audio processing unit can process the digital audio signal.
Optionally, as shown in fig. 2, in some embodiments, the bluetooth audio transmission device further includes a demodulation unit, and the receiving unit is further configured to process the received second radio frequency signal into a second digital modulation signal; the demodulation unit is used for demodulating the second digital modulation signal to obtain a confirmation data packet.
Optionally, in some embodiments, the receiving time slots in the current isochronous communication interval include at least N mutually non-overlapping receiving sub-time slots, and each of the target links occupies one of the receiving sub-time slots;
The antenna is connected with the receiving unit in the second state, and is configured to receive, in a time-sharing manner, a second radio frequency signal on each standard link in a receiving slot in the current isochronous communication interval, so as to respectively receive acknowledgement data packets sent by the N bluetooth audio receiving devices, where the antenna includes:
the antenna is connected with the receiving unit in the second state, and is used for respectively receiving second radio frequency signals on the N item standard links in the N receiving sub-time slots in sequence.
When the antenna is in the second state, the antenna is connected with the receiving unit, and the Bluetooth audio transmitting device is in a state of receiving the acknowledgement data packet. Because each target link occupies one receiving sub-time slot, and N receiving sub-time slots are not overlapped with each other, the receiving sub-time slots corresponding to each Bluetooth audio receiving device are not overlapped with each other, and the antenna sequentially receives the second radio frequency signals on the N target links in the N receiving sub-time slots respectively.
Optionally, in some embodiments, each set of the audio data packets includes a number of audio data packets greater than or equal to 2. That is, the bluetooth audio transmitting apparatus may transmit a plurality of audio data packets in batches for each bluetooth audio receiving apparatus in one transmission slot, thereby improving transmission efficiency and transmission bandwidth.
Optionally, in some embodiments, each set of said audio data packets comprises at least one first data packet, and/or at least one second data packet;
the first data packet is an audio data packet which is not sent to the Bluetooth audio receiving device corresponding to the audio data packet before the current isochronous communication interval by the Bluetooth audio sending device;
the second data packet is an audio data packet which is sent by the Bluetooth audio sending device before the current isochronous communication interval but is not confirmed by the Bluetooth audio receiving device corresponding to the audio data packet whether the audio data packet is successfully received or not.
It should be understood that, in this embodiment, only any one of the N sets of audio data packets is taken as an example for illustration, and in a specific implementation, the number of audio data packets included in each of the N sets of audio data packets may be greater than or equal to 2, and each set of audio data packets may include at least one first data packet and/or at least one second data packet.
In some embodiments, each set of audio packets includes only at least two first packets, which may also be referred to as first packets. In other embodiments, each set of audio packets includes only at least two second packets, which may also be referred to as retransmitted packets. The Bluetooth audio transmitting device can transmit the first audio data packet and also can transmit the resent audio data packet in one transmitting time slot, so that the probability that the audio data packet is successfully received by the Bluetooth audio receiving device can be improved, and the reliability of transmitting the audio data packet is improved.
In some embodiments, each set of audio data packets includes at least one first data packet and at least one second data packet. In this embodiment, the number of the first data packet and the second data packet may be adjusted according to actual requirements, so as to implement priority transmission of the first data packet or retransmission of the data packet.
It should be noted that, the first data packet and the second data packet are only bluetooth audio receiving devices corresponding to the audio data packet of the present group, and the transceiving relationship or the corresponding relationship between the audio data packet and other bluetooth audio receiving devices is not limited.
Optionally, in some embodiments, the value of N is 2, the 2 bluetooth audio receiving devices are a left earphone and a right earphone, respectively, the 2 target links are a first target link and a second target link, the left earphone corresponds to the first target link, and the right earphone corresponds to the second target link;
the processing unit is configured to process digital audio data to obtain 2 groups of audio data packets, where the 2 groups of audio data packets are a left channel audio data packet and a right channel audio data packet, the left channel audio data packet is an audio data packet that needs to be received by the left earphone in a current isochronous communication interval, and the right channel audio data packet is an audio data packet that needs to be received by the right earphone in the current isochronous communication interval.
In this embodiment of the present application, the bluetooth audio transmitting device may transmit corresponding audio data packets to the left earpiece and the right earpiece through the first target link and the second target link at the same time, and the left channel audio data packet and the right channel audio data packet may be the same or different. Through the arrangement, the efficiency and the flexibility of sending the audio data to the left earphone and the right earphone are improved.
For ease of understanding, the structure of the bluetooth audio transmission apparatus will be described below by taking a specific embodiment as an example.
Referring to fig. 2, the bluetooth audio transmission apparatus includes an audio input unit, an audio processing unit, a protocol processing unit, N modulation units, a combining unit, a demodulation unit, a transmitting unit, a receiving unit, a switching unit, and an antenna. The audio input unit acquires a digital audio signal and transmits the digital audio signal to the audio processing unit. The audio processing unit is used for processing the digital audio signal into an audio data stream which is convenient for transmission, packaging the audio data stream into SDUs and storing corresponding codes and data. The protocol processing unit is used for executing wireless communication protocols including MC-ABAIG link protocol, encapsulating SDU into audio data packet suitable for processing by the modulating unit, processing received acknowledgement data packet carrying accumulated batch acknowledgement mapping table, and storing program and data for executing communication protocol. The modulation unit is used for processing and modulating the audio data packet into a digital modulation signal which is suitable for being processed and sent by the transmitting unit. The combining unit is used for combining the multi-path digital modulation signals into a multi-carrier digital modulation signal after modulating the multi-path digital modulation signals onto different digital carriers. The multi-carrier digital modulation signal is converted into an analog signal by a transmitting unit, modulated onto a radio frequency carrier and amplified into a first radio frequency signal. The antenna is switched to a first state through the switching unit, the transmitting unit is connected with the antenna and transmits a first radio frequency signal, and a corresponding group of audio data packets are respectively transmitted to N Bluetooth audio receiving devices in a frequency division multiplexing mode. The antenna is also used for receiving a second radio frequency signal sent by the Bluetooth audio receiving device. Specifically, the antenna is switched to the second state by the switching unit, a second radio frequency signal is received on the N-item standard link in a time-sharing manner, the second radio frequency signal is transmitted to the receiving unit, amplified and down-converted to an analog baseband signal, and then converted to a digital modulation signal in a analog-to-digital manner and transmitted to the demodulation unit. The demodulation unit is used for demodulating the accumulated batch acknowledgement mapping table in the acknowledgement data packet, and transmitting the accumulated batch acknowledgement mapping table to the protocol processing unit for analysis.
Referring to fig. 3, as shown in fig. 3, the embodiment of the invention further provides a bluetooth audio transmission method, which is applied to a bluetooth audio transmission device, wherein the bluetooth audio transmission device communicates with N bluetooth audio receiving devices based on N target links, N target links are in one-to-one correspondence with N bluetooth audio receiving devices, and N is a positive integer greater than 1; the method comprises the following steps:
an audio data processing step, which is used for processing digital audio signals to obtain N groups of audio data packets, wherein each group of audio data packets is used for being sent to a corresponding Bluetooth audio receiving device in the current isochronous communication interval;
a signal modulation step, which is used for modulating N groups of audio data packets respectively to obtain N paths of first digital modulation signals corresponding to the N groups of audio data packets one by one;
a signal combining step, which is used for combining N paths of first digital modulation signals into one path of multi-carrier digital modulation signals after respectively modulating the N paths of first digital modulation signals onto different digital carriers;
a first signal transmitting step, configured to modulate the multi-carrier digital modulation signal onto a radio frequency carrier to obtain a first radio frequency signal, and transmit the first radio frequency signal in a transmission time slot of the current isochronous communication interval, so as to respectively transmit a corresponding group of audio data packets to N bluetooth audio receiving devices in a frequency division multiplexing manner based on the first radio frequency signal;
A first signal receiving step, configured to receive second radio frequency signals on N target links in a time-sharing manner in a receiving time slot in the current isochronous communication interval, so as to respectively receive acknowledgement data packets sent by N bluetooth audio receiving devices;
the Bluetooth audio transmitting device comprises a switching unit and an antenna, wherein the switching unit is used for enabling the antenna to be switched between a first state and a second state, the Bluetooth audio transmitting device executes the first signal transmitting step when the antenna is in the first state, and the Bluetooth audio transmitting device executes the first signal receiving step when the antenna is in the second state.
It should be noted that the bluetooth audio transmission method includes a certain step for characterizing that the bluetooth audio transmission device may perform the step, so as to achieve the effect corresponding to the step. The bluetooth audio transmission method includes an audio data processing step for characterization, and the bluetooth audio transmission device performs the audio data processing step, specifically, the bluetooth audio transmission device processes the digital audio signal to obtain N sets of audio data packets.
In the embodiment of the application, the bluetooth audio transmission method includes an audio data processing step, a signal modulating step, a signal combining step, a first signal transmitting step and a first signal receiving step, where when the antennas are in different states, the steps included in the bluetooth audio transmission method are different.
The bluetooth audio transmission method provided in the embodiment of the present application may be applied to the bluetooth audio transmission device shown in fig. 1 and achieve the same beneficial effects, and the specific execution process of each step and the execution sequence between each step in the method may refer to the description in the foregoing embodiment, which is not repeated herein.
Optionally, in some embodiments, the receiving time slots in the current isochronous communication interval include at least N receiving sub-time slots that are not overlapped with each other, N target links are in one-to-one correspondence with N receiving sub-time slots, and each target link occupies a corresponding one of the receiving sub-time slots.
Optionally, in some embodiments, the first signal receiving step is further configured to receive, in each of the receiving sub-slots, a second radio frequency signal on the same target link at least twice in succession, so as to receive the acknowledgement data packet repeatedly sent at least twice in succession by the bluetooth audio receiving device corresponding to the target link.
In some embodiments, the bluetooth audio device corresponding to the target link transmits the acknowledgement data packet at least twice in succession within the current isochronous communication interval, so that the bluetooth audio transmitting device may receive the acknowledgement data packet repeatedly transmitted twice in succession. In the case where the bluetooth audio transmission apparatus successfully receives the repeatedly transmitted acknowledgement packet at least twice, the bluetooth audio transmission apparatus may process only any one of the acknowledgement packets.
In the embodiment of the application, the Bluetooth audio sending device can repeatedly receive the confirmation data packet at least twice continuously, so that the probability of successful reception of the confirmation data packet by the Bluetooth audio sending device can be improved, and the transmission reliability of the confirmation data packet is improved.
Optionally, in some embodiments, the acknowledgement data packet includes a cumulative batch acknowledgement mapping table, where the cumulative batch acknowledgement mapping table is used to characterize a reception status of a corresponding set of audio data packets transmitted by the bluetooth audio transmitting device to the bluetooth audio receiving device during the current isochronous communication interval, and a reception status of a corresponding audio data packet transmitted by the bluetooth audio transmitting device to the bluetooth audio receiving device before the current isochronous communication interval. In some embodiments, the reception status includes reception success and reception failure.
In this embodiment of the present application, in the case where the bluetooth audio transmitting apparatus does not correctly receive the acknowledgement packet transmitted by the bluetooth audio receiving apparatus in any isochronous communication interval, the bluetooth audio transmitting apparatus may still confirm the reception status of the audio packet transmitted in the previous isochronous communication interval through the cumulative batch acknowledgement mapping table in the acknowledgement packet transmitted in the subsequent isochronous communication interval.
Optionally, in some embodiments, each set of the audio data packets includes a number of audio data packets greater than or equal to 2.
Optionally, in some embodiments, each set of said audio data packets comprises at least one first data packet, and/or at least one second data packet;
the first data packet is a data packet which is not sent to the Bluetooth audio receiving device corresponding to the audio data packet before the current isochronous communication interval by the Bluetooth audio sending device;
the second data packet is a data packet which is sent by the Bluetooth audio sending device before the current isochronous communication interval but is not confirmed by the Bluetooth audio receiving device corresponding to the audio data packet whether the data packet is successfully received.
Optionally, in some embodiments, the second data packet is sent earlier than the first data packet, so that the second data packet may be sent with priority. Of course, according to practical requirements, in some embodiments, the sending time of the first data packet may be earlier than the sending time of the second data packet, so that the sending of the first data packet is preferentially guaranteed.
Optionally, in some embodiments, one or more third data packets are further included in the set of audio data packets; the third data packet is at least part of the first data packet and/or the second data packet.
It should be understood that, in this embodiment, only any one of the N sets of audio data packets is taken as an example for illustration, and in a specific implementation, each of the N sets of audio data packets further includes one or more third data packets.
In embodiments of the present application, including one or more third data packets in a set of audio data packets may be referred to as a Pre-Retransmission (PRT) technique. The PRT technique is to repeat transmission of at least part of the first data packet and/or the second data packet in advance, thereby increasing the probability that the first data packet and/or the second data packet is successfully received.
The third data packet is at least part of the first data packets, which is understood as that the effect of repeatedly transmitting at least part of the first data packets is achieved by transmitting the third data packet, so that the probability of successful reception of at least part of the first data packets is improved.
The third data packet is at least part of the second data packets, which is understood as that the effect of repeatedly transmitting at least part of the second data packets is achieved by transmitting the second data packets, so that the probability of successful reception of at least part of the second data packets is improved.
In this embodiment of the present application, the group of audio data packets further includes one or more third data packets, and the number and types of the third data packets are adjusted according to actual needs, so that the number of times of repeatedly sending the first data packet and/or the second data packet can be adjusted, thereby improving the probability that the first data packet and/or the second data packet is successfully received by the bluetooth audio receiving device. When the wireless channel quality is poor, the first data packet and/or the second data packet which need to be sent in the current interval are repeatedly sent in advance by utilizing the redundant time slot in the current isochronous communication interval, so that the reliability of audio data transmission can be improved.
Optionally, in some embodiments, the second data packet is sent earlier than the first data packet, and the third data packet is sent later than the first data packet, so that it may be ensured that after the first data packet and the second data packet have all completed the initial transmission, at least part of the first data packet and/or the second data packet is retransmitted in the case that there is still time in the current isochronous communication interval, so as to avoid missing part of the first data packet and the second data packet.
Optionally, in some embodiments, the audio data processing step is further configured to process the digital audio signal according to a maximum number of receivable audio data packets in a transmission time slot of one isochronous communication interval by each of the bluetooth audio receiving devices and an accumulated batch acknowledgement mapping table of each of the bluetooth audio receiving devices, to obtain N groups of audio data packets.
Optionally, in some embodiments, the method further includes a first target link establishing step, configured to establish N target links with N bluetooth audio receiving devices, respectively, and determine, with the bluetooth audio receiving devices, a time when the bluetooth audio receiving devices transmit the acknowledgement data packet and a frequency of a digital carrier that receives the first radio frequency signal.
After the Bluetooth audio sending device establishes N item mark links with N Bluetooth audio receiving devices respectively, the Bluetooth audio receiving device corresponding to each item mark link determines the time when the Bluetooth audio receiving device sends the confirmation data packet and the frequency of the digital carrier wave of the first radio frequency signal received by the Bluetooth audio receiving device.
The Bluetooth audio receiving device obtains a group of audio data packets sent by the Bluetooth audio sending device in the current isochronous communication interval based on the target link based on the frequency of the digital carrier wave of the first radio frequency signal, and simultaneously sends the confirmation data packets on the target link based on the time of sending the confirmation data packets.
As shown in fig. 4, the embodiment of the present invention further provides a bluetooth audio receiving method, which is applied to a bluetooth audio receiving device, where the bluetooth audio receiving device communicates with a bluetooth audio sending device based on a target link, and includes:
a second target link establishing step, which is used for establishing a target link with the Bluetooth audio transmitting equipment, determining the frequency of a digital carrier wave of which the first radio frequency signal is received and the time for transmitting the confirmation data packet;
a second signal receiving step, configured to receive, in a transmission time slot of a current isochronous communication interval, a first radio frequency signal that is sent by the bluetooth audio transmission device in a frequency division multiplexing manner, so as to obtain a set of audio data packets that are sent by the bluetooth audio transmission device in the current isochronous communication interval based on the target link;
And a second signal transmitting step, configured to transmit an acknowledgement packet on the target link based on the time of transmitting the acknowledgement packet in the receiving slot of the current isochronous communication interval.
It should be understood that this embodiment is an implementation manner of the bluetooth audio receiving device side corresponding to the embodiment shown in fig. 3, and a specific implementation manner of this embodiment may be referred to as related description in the embodiment shown in fig. 3. This embodiment can also be applied to the corresponding example of fig. 3 and achieve the same advantageous effects.
The Bluetooth audio receiving method provided by the embodiment of the invention can be applied to Bluetooth audio receiving equipment, wherein the specific structure of the Bluetooth audio receiving equipment is not limited herein. For example, referring to fig. 5, the bluetooth audio receiving device includes an audio output unit, an audio processing and storing unit, a protocol processing and storing unit, a digital baseband and modulating unit, a digital baseband and demodulating unit, a digital-to-analog conversion and radio frequency transmitting unit, an analog-to-digital conversion and radio frequency receiving unit, an antenna switching unit, and an antenna. The antenna is used for receiving the first radio frequency signal sent by the Bluetooth audio sending device and sending the second radio frequency signal to the Bluetooth audio sending device. The antenna switching unit is used for switching the antenna to be connected with the analog-to-digital conversion and radio frequency receiving unit when receiving the first radio frequency signal and switching the antenna to be connected with the digital-to-analog conversion and radio frequency transmitting unit when transmitting the second radio frequency signal. The analog-to-digital conversion and radio frequency receiving unit is used for amplifying and down-converting the radio frequency signal to an analog baseband and transmitting the analog-to-digital converted digital signal to the baseband and demodulation unit. The baseband and demodulation unit is used for demodulating the audio data packet from the digital modulation signal and transmitting the audio data packet to the protocol processing and storage unit. The baseband and modulation unit is used for generating a confirmation data packet from the accumulated batch confirmation mapping table generated by the protocol processing and storage unit and modulating the confirmation data packet into a digital modulation signal. The digital-to-analog conversion and radio frequency transmitting unit is used for converting the confirmation data packet into an analog signal, modulating the analog signal onto a radio frequency carrier wave, amplifying the analog signal and transmitting the analog signal to the Bluetooth audio transmitting equipment through the antenna. The protocol processing and storing unit executes a wireless communication protocol including the MC-ABAIG link protocol, parses the received audio data packet into audio SDUs, generates an accumulated batch acknowledgement mapping table according to the reception situation, and stores programs and data for executing the communication protocol. The audio processing and storing unit is used for processing the audio SDU into a digital audio signal and storing corresponding codes and data, wherein the audio processing comprises lossy compression decoding, lossless compression decoding, non-compression decoding, sound effect processing and the like. The audio output unit is used for converting the digital audio signal input by the audio processing unit into sound.
Referring to fig. 6, the embodiment of the invention further provides a bluetooth audio transmission system, which includes the bluetooth audio transmitting device and N bluetooth audio receiving devices, where the bluetooth audio transmitting device communicates with the N bluetooth audio receiving devices based on N target links, the N target links are in one-to-one correspondence with the N bluetooth audio receiving devices, and N is a positive integer greater than 1.
Illustratively, the Bluetooth audio transmission system includes one Bluetooth audio transmitting apparatus as shown in FIG. 1 and N Bluetooth audio receiving apparatuses as shown in FIG. 5. Taking a BLE Audio wireless multi-channel Audio transmission system as an example, the Bluetooth Audio transmission system provided by the embodiment of the invention can only increase the number of modulation units and increase and set one merging unit on the basis of the existing BLE Audio transmission equipment without changing a transmitting unit, a receiving unit and a demodulation unit, and meanwhile, the existing BLE Audio receiving equipment is used, so that the effective bandwidth of Audio transmission can be increased by small changes, thereby improving the efficiency of Audio data transmission, and the Bluetooth Audio transmission system has a simple structure and can reduce the cost.
For convenience of understanding, a unidirectional wireless multi-channel audio transmission system will be taken as an example, and the bluetooth audio transmission device and the bluetooth audio transmission method provided by the embodiment of the invention will be respectively described from a protocol level and an application level. In the unidirectional wireless multi-channel audio transmission system, only the Bluetooth audio transmission device transmits audio data, the Bluetooth audio transmission device transmits audio data packets to the corresponding Bluetooth audio receiving device through N ABAIS links, the Bluetooth audio receiving device does not transmit audio data, and each Bluetooth audio receiving device replies acknowledgement data packets to the Bluetooth audio transmission device through the corresponding ABAIS links. It will be appreciated that the apparatus and method provided by embodiments of the present invention may also be used to implement two-way wireless multi-channel audio transmission.
The data packets transmitted over the MC-ABAIG link may be generated based on BLE CIS protocol data units (Protocol Data Unit, PDUs). That is, part of header information in the structure of the BIS CIS PDU is set so as to be a packet suitable for the present application.
For convenience of description, the Data packet of the present application may be referred to as an ABAIS PDU, further, an ABAIS PDU including audio Data may be referred to as an ABAIS Data PDU, and an ABAIS PDU not including audio Data may be referred to as an ABAIS Null PDU. In the embodiment of the present application, the audio Data packet is an ABAIS Data PDU, the acknowledgement Data packet is an ABAIS Null PDU, and the Header of the ABAIS PDU may be referred to as an Extended Header (Extended Header). The header structure in the original BIS CIS PDU is adopted, and the method is continuously applicable to a BLE broadcasting isochronous group (Broadcast Isochronous Group, BIG) system. This allows the method, device and system in this embodiment to be compatible with BLE BIG systems under standard protocols.
The specific method for generating the ABAIS PDU based on the BIS CIS PDU is not limited herein. Please refer to fig. 7. Illustratively, in some embodiments, the ABAIS PDU uses one reserved field (Reserved for Future Use, RFU) bit in the header of the BIS CIS PDU to indicate whether the bulk transmit function (Block Transmission Enable, BTE) of the ABAIS link is enabled, based on the header of the BIS CIS PDU. The second RFU bit is used to indicate whether the cumulative bulk acknowledgment function (Accumulated Block Acknowledgement Enable, ABAE) of the ABAIS link is enabled.
When the BTE value is 1, the ABAIS batch sending function is enabled, and when the BTE value is 0, the ABAIS batch sending function is not enabled. In this embodiment, the ABAIS batch transmission function is enabled, that is, the number of audio data packets included in a group of audio data packets is greater than or equal to 2, and the group of audio data packets each include at least one first data packet and/or at least one second data packet.
When the BTE value is 1, the extension packet header is incremented by a certain number of bytes, including three fields, namely a block transmission number (Block Transmission Number, BTN), a block transmission sequence number (Block Transmission Sequence Number, BTSN) and a PDU sequence number (PDU Sequence Number, PDUSN). Wherein, BTN represents the total number of ABAIS Data PDUs which are transmitted in batches in the current MC-ABAIG interval, and the total number comprises ABAIS Data PDUs which are repeatedly transmitted in advance. The BTSN represents the sequence number of the bulk sent ABAIS Data PDU within the current MC-ABAIG interval. PDUSN represents the sequence number of ABAIS Data PDU sent by bluetooth audio transmission device.
An ABAE value of 1 indicates that the cumulative lot acknowledgment function is enabled, and an ABAE value of 0 indicates that the cumulative lot acknowledgment function is not enabled. In this embodiment, the cumulative batch acknowledgment function is enabled, i.e., the acknowledgment packet includes a cumulative batch acknowledgment mapping table.
When ABAE is assigned 1, the extension header is incremented by a certain number of bytes, including two fields, a start sequence number (START Sequence Number, starsn) and an ABA mapping table (ABA Mapping Table, ABA MT). The ABA MT is used to indicate whether the ABAIS Data PDU, which is sent in the current MC-ABAIG interval and at least one or more previous MC-ABAIG intervals and starts from the PDUSN represented by the stasn, is correctly received, or whether the bluetooth audio transmission device is required to retransmit the information of the corresponding ABAIS Data PDU. In this embodiment, the STARTSN and ABA MT are cumulative batch acknowledgement mapping tables. Each bit of the ABA MT corresponds to the PDUSN of one ABAIS Data PDU, the lowest bit represents the PDUSN of the ABAIS Data PDU indicated by the STARTSP, the bits from low to high which are sequentially arranged represent PDUSNs larger than the STARTSP, and the highest PDUSN which can be indicated is determined by the number of the bits of the STARTSP and the ABA MT. The default value of each bit of the ABA MT is 1, which represents the ABAIS Data PDU represented by its corresponding PDUSN that needs to be transmitted or retransmitted by the bluetooth audio transmitting device. After the ABAIS Data PDU represented by PDUSN from the STARTSN is correctly received by the Bluetooth audio receiving device, setting the corresponding bit of the ABA MT to 0, namely, the Bluetooth audio transmitting device is not required to retransmit the ABAIS Data PDU represented by PDUSN corresponding to the ABAIS Data PDU.
The functions and the use methods of other domains in the ABAIS PDU extension packet header are the same as those of the BIS CIS PDU. Illustratively, the ABAIS PDU extension packet header also includes a logical link identification (Logical Link Identifier, LLID) for indicating the ABAIS PDU payload type, a Sequence Number (SN) occupying 1 bit, a next expected Sequence Number (Next Expected Sequence Number, NESN) occupying 1 bit, a flag bit (Close Isochronous Event, CIE) occupying 1 bit of a shutdown isochronous event, a null packet identification (Null PDU Indicator, NPI) occupying 1 bit, and a Length (Length) occupying 8 bits for indicating the ABAIS PDU payload Length. Wherein SN, NESN are invalidated in ABAIS PDU. NPI is set to 0 when ABAIS Data PDUs are sent and is set to 1 when ABAIS Null PDUs are sent.
Referring to fig. 8, fig. 8 is a slot structure of the MC-ABAIG link. The MC-ABAIG link divides the radio transmission time into identical MC-ABAIG intervals (i.e., isochronous communication intervals). Each MC-ABAIG interval includes a transmit slot, an accumulated bulk acknowledgment (Accumulated Block Acknowledgement, ABA) slot (i.e., a receive slot), and other connection slots. In other connection time slots, the Bluetooth audio sending device and each Bluetooth audio receiving device establish connection and maintain connection in a time division multiplexing mode. The details of other connection slots are not described herein, for example, other connection slots include Transmit (TX) and Receive (RX) slots of a BLE non-synchronized (ACL) link, which are used to assist in establishing an ABAIS link and negotiating ABAIS link parameters.
The interval between ABAIS PDUs is the minimum slot space (Minimum Slot Space, t_mss). The interval between the start of the MC-ABAIG interval (i.e., the start of the first ABAIS Data PDU sent) and the start of the ABAIS Null PDU sent is a preset fixed interval, namely the ABA Delay (ABA Delay), which is less than the MC-ABAIG interval.
The transmission time slots between the Bluetooth audio transmitting apparatus and each Bluetooth audio receiving apparatus are synchronized or overlapped with each other in time, and are frequency division multiplexed in frequency by digital multi-carrier modulation to increase transmission bandwidth and avoid mutual interference at the time of simultaneous transmission. Each bluetooth audio receiving device receives audio data transmitted on only one of the carriers. The transmission time slots on each carrier are classified into two types, one is a transmission time slot for transmitting audio data (i.e., a first data packet) generated at the current interval, and the other is a retransmission time slot for retransmitting audio data (i.e., a second data packet) that the bluetooth audio receiving apparatus has not correctly received, or retransmitting audio data (i.e., a third data packet) that is being transmitted at the current time slot in advance. In an ABA slot, each bluetooth audio receiving device replies to the ABA information (i.e., includes acknowledgement packets of the cumulative bulk acknowledgement mapping table) in a time-multiplexed manner, i.e., the slots determined after the transmit slot reply to the ABA information at least one or more times in sequence.
Example 1
The present embodiment will be described in terms of the protocol layer by taking the MC-ABAIG protocol as an example.
The bluetooth audio transmitting apparatus transmits audio Data using ABAIS Data PDU, wherein BTE is set to 1, abae is set to 0, npi is set to 0. The bluetooth audio receiving device sends an accumulated batch acknowledgment mapping table using ABAIS Null PDUs, with BTE set to 0, abae set to 1, npi set to 1.
It should be noted that, in the two-way wireless multi-channel audio transmission system, both the bluetooth audio transmitting apparatus and the bluetooth audio receiving apparatus may use the extended packet header of the ABAIS Data PDU to carry the cumulative batch acknowledgement mapping table, i.e. both BTE and ABAE are set to 1. Reference may be made specifically to the description in this embodiment, and no further description is given here.
In the slot structure shown in fig. 7, no matter how many ABAIS Data PDUs are transmitted by the bluetooth audio transmitting apparatus, the bluetooth audio receiving apparatus transmits ABAIS Null PDUs carrying the cumulative batch acknowledgement mapping table at a preset determined ABA Delay time, so that the bluetooth audio transmitting apparatus can correctly receive the cumulative batch acknowledgement mapping table. The SUM of the number M of the ABAIS Data PDUs transmitted in batches and the number K of the pre-retransmission ABAIS Data PDUs is recorded as SUM, wherein M is not less than SUM, K is not less than 0 and not more than SUM, and M+K is not less than SUM. By adopting the frequency division multiplexing method, the sending time slots between the Bluetooth audio sending device and each Bluetooth audio receiving device are synchronous or mutually overlapped in time, and in the ABA time slot, each Bluetooth audio receiving device replies ABAIS Null PDU carrying ABA information in a time division multiplexing mode, namely, the time slots determined after the sending time slots reply ABAIS Null PDU in sequence, namely, all the ABAIS Null PDU time slots are not overlapped. Different bluetooth audio receiving devices send ABAIS Null PDU's ABA Delay different, ABA Delay 1, ABA Delay 2 in proper order.
In some embodiments, each bluetooth audio receiving device may send ABAIS Null PDUs more than 1. For example, each bluetooth audio receiving device may repeatedly send ABAIS Null PDUs multiple times in sequence, or may repeatedly send ABAIS Null PDUs multiple times in sequence in an interleaved manner.
The bluetooth audio transmission apparatus divides the audio stream Data of each channel into SDUs of the same size, each SDU corresponding to a payload (payload) of one ABAIS Data PDU. The Bluetooth audio sending equipment stores SDUs in a sending buffer after sequentially numbering PDUSNs, namely each SDU or the encapsulated ABAIS Data PDU corresponds to a different PDUSN, wherein the number of new SDUs generated or input at each MC-ABAIG interval is L (namely the number of the encapsulated ABAIS Data PDU is L, L is less than or equal to M and L is less than SUM).
The flow of bluetooth audio transmitting devices transceiving ABAIS PDUs on each ABAIS link is shown in fig. 9. Firstly, SDUs are taken from a sending buffer according to PDUSN numbers from small to large and are packaged into ABAIS Data PDU as loads, wherein the SDUs taken from the sending buffer can be SDUs which are input in the last MC-ABAIG interval or multiple MC-ABAIG intervals and are not confirmed to be correctly received by Bluetooth audio receiving equipment (namely SDUs corresponding to second Data packets), or can be new SDUs which are input in the current MC-ABAIG interval (namely SDUs corresponding to first Data packets). If the number M of SDUs in the transmission buffer is not less than SUM, the number of the SDUs or ABAIS Data PDUs which are most transmitted in the current MC-ABAIG interval is not less than SUM. When M < SUM, if PRT technique is not used, the number of SDUs or ABAIS Data PDUs transmitted in the current MC-ABAIG interval is equal to M. If PRT technique is enabled, the buffered SDUs are pre-retransmitted within the current MC-ABAIG interval. Enabling the PRT technique corresponds to transmitting a third data packet within the current MC-ABAIG interval.
Under the condition that the PRT technology is enabled, the pre-retransmitted SDUs are circularly read from the transmission buffer according to PDUSN from small to large, the number is K, and M+K is less than or equal to SUM. The PDUSN number carried by the extension packet header of the ABAIS Data PDU corresponding to the pre-retransmitted SDU is the same as that of the original ABAIS Data PDU, but the BTSNs are different. The parameters BTN carried by the extension packet header of the ABAIS Data PDU which is sequentially transmitted in the current MC-ABAIG interval are equal to M+K. After the Bluetooth audio transmitting device transmits the BTN group ABAIS Data PDU within the current MC-ABAIG interval, the Bluetooth audio receiving device with the sequence number m transmits the ABAIS PDU carrying the accumulated batch acknowledgement mapping table at the starting point of the MC-ABAIG interval in a Delay mode. If the Bluetooth audio transmitting device does not correctly receive the first ABAIS PDU transmitted by the Bluetooth audio receiving device with the sequence number m, the Bluetooth audio transmitting device continues to receive the repeated ABAIS PDU so as to improve the reliability of the received accumulated batch acknowledgement mapping table.
The Bluetooth audio transmitting device judges which of the ABAIS Data PDUs transmitted in batches are correctly received by the Bluetooth audio receiving device and which of the ABAIS Data PDUs are not correctly received according to the correctly received ABAIS PDUs carrying the accumulated batch acknowledgement mapping table. The Bluetooth audio transmitting device deletes the correctly received SDU from the transmitting buffer according to the information of the accumulated batch acknowledgement mapping table, and the SDU which is not correctly received is reserved in the transmitting buffer and is retransmitted in the next or subsequent MC-ABAIG interval.
If the bluetooth audio transmitting device does not correctly receive the ABAIS PDU carrying the cumulative batch acknowledgement mapping table, it cannot be determined whether the bluetooth audio receiving device correctly receives the current MC-ABAIG interval, or even the SDUs transmitted in batch at the previous MC-ABAIG interval or intervals. In the next MC-ABAIG interval, the bluetooth audio transmission device preferentially transmits new SDUs in the buffer, i.e. SDUs that have not been transmitted by the current MC-ABAIG interval or by the previous MC-ABAIG interval or intervals. And when the number of the new SDUs is smaller than N, sequentially transmitting the SDUs in the buffer from small to large according to PDUSN in the redundant time slot. And after the next MC-ABAIG interval correctly receives the ABAIS PDU carrying the accumulated batch acknowledgement mapping table, judging whether SDUs transmitted in batches at the last MC-ABAIG interval or not are correctly received or whether retransmission is needed. In this way, the effective times of the Bluetooth audio transmitting equipment for receiving the ABAIS PDU carrying the accumulated batch acknowledgement mapping table is increased, and the reliability of receiving the accumulated batch acknowledgement mapping table is improved, so that the times of repeatedly transmitting SDUs and repeatedly transmitting the accumulated batch acknowledgement mapping table are reduced, and the link efficiency is improved.
However, the number of bluetooth audio transmitting devices transmitting new ABAIS Data PDUs cannot exceed the maximum number that ABA MT can indicate. Specifically, based on the latest received starsn of the ABAIS PDU header carrying the cumulative batch acknowledgement mapping table, the maximum PDUSN of a new SDU that can be sent by the bluetooth audio sending device cannot exceed the sum of the starsn and the ABA MT bit number minus 1 before the new cumulative batch acknowledgement mapping table is received again. After exceeding the threshold, the bluetooth audio transmitting apparatus can only cyclically transmit SDUs that have been transmitted in the buffer memory and have not been acknowledged as correctly received by the bluetooth audio receiving apparatus until ABAIS PDUs carrying the cumulative batch acknowledgement mapping table are received again.
The flow of transmitting and receiving ABAIS PDUs by a bluetooth audio receiving device with sequence number m is shown in fig. 10. And sequentially receiving ABAIS Data PDUs which are transmitted in batches by the Bluetooth audio transmitting equipment on the carrier corresponding to each MC-ABAIG interval, and discarding the repeatedly received ABAIS Data PDUs if the PDUSN in the ABAIS Data PDU extension packet is the same as the PDUSN of the ABAIS Data PDU which is correctly received. Then, ABA MT is generated according to the reception situation, i.e., whether each ABAIS Data PDU is correctly received. The bluetooth audio receiving device replies an ABAIS Null PDU carrying an accumulated batch acknowledgement mapping table (i.e., starsn and abamt) to the bluetooth audio transmitting device at the ABA Delay m point in time. The information of which are correctly received and which are not correctly received is set in the corresponding bit of the extended packet header abamt. ABA MT may contain information whether ABAIS Data PDUs sent at one or more MC-ABAIG intervals need to be retransmitted. In order to improve the reliability of replying to the cumulative batch acknowledgement mapping table, the bluetooth audio receiving device may further select to repeatedly send ABAIS PDUs carrying the cumulative batch acknowledgement mapping table for a number of times, where the number of repetitions is R (R is greater than or equal to 0).
The Bluetooth audio receiving device replies an ABAIS PDU packet header of the cumulative batch acknowledgement mapping table that the ABAE assignment is 1, the lowest bit of the ABA MT corresponds to the ABAIS Data PDU represented by PDUSN indicated by the STARTSP, and the high bit of the ABA MT sequentially corresponds to the ABAIS Data PDU represented by the higher PDUSN. A certain bit of ABA MT is set to 1, indicating that the bluetooth audio transmitting device is required to retransmit or transmit ABAIS Data PDUs represented by its corresponding PDUSN. A certain bit of ABA MT set to 0 indicates that the bluetooth audio transmitting device is not required to retransmit the ABAIS Data PDU represented by its corresponding PDUSN. Typically, the lowest bit of ABA MT is always set to 1, i.e., the minimum PDUSN of an ABAIS Data PDU that a bluetooth audio receiving device needs to send or retransmit by a bluetooth audio transmitting device is starsn. The STARTSN may represent the ABAIS Data PDUs transmitted in batches at the current MC-ABAIG interval, or may be the ABAIS Data PDUs transmitted at the last MC-ABAIG interval or may be the PDUSN of the 0 th ABAIS Data PDU to be transmitted at the next MC-ABAIG interval. If the current MC-ABAIG interval and the ABAIS Data PDU of the last one or more MC-ABAIG intervals are correctly received, STARTSN represents PDUSN corresponding to the 0 th ABAIS Data PDU to be transmitted in batches for the next MC-ABAIG interval.
Example two
Based on the first embodiment, the second embodiment will be exemplified by using the wireless dual-channel high-resolution lossless audio headset system as an application embodiment. A wireless two-channel high-resolution lossless audio headset system, or a high-resolution lossless truly wireless stereo (High Resolution Lossless True Wireless Stereo, HRL-TWS) headset system, includes one HRL-TWS sound source device (i.e., a bluetooth audio transmitting device) and two HRL-TWS headphones (i.e., two bluetooth audio receiving devices). In this embodiment, the HRL-TWS audio source device may be a smart phone, a smart tv or a computer, and the two HRL-TWS headphones are a left channel HRL-TWS headphone and a right channel HRL-TWS headphone, respectively.
The HRL-TWS audio source device divides each channel of a two-channel high-resolution digital audio signal with a sampling rate of 48kHz and quantization bits of 24 into one frame every 2.5ms, corresponding to 120 mono sampling points. A frame of the digital audio signal is encoded into no more than 250 bytes of audio data using a lossless audio encoder and encapsulated in an SDU for transmission over an ABAIS link to a corresponding HRL-TWS headset.
In the ABAIS PDU extension header shown in fig. 7, both BTN and BTSN occupy 4 bits, PDUSN occupies 8 bits, starsn is 8 bits, and abamt is 40 bits. Thus, the BTEs of the ABAIS Data PDUs for bulk transfer are configured to 1, ABAE to 0, NPI to 0, and their extension header to 4 bytes. The BTEs for the ABAIS Null PDU to reply to the cumulative batch acknowledgement mapping table are configured to 0, ABAE is configured to 1, NPI is set to 1, and its extended header is 8 bytes.
In the time slot structure shown in fig. 8, the MC-ABAIG interval is 20ms, the number L of SDUs of each channel input by the hrl-TWS audio source device at each MC-ABAIG interval is equal to 8, and the number L of corresponding encapsulated ABAIS Data PDUs is equal to 8. SDUs of each channel are respectively numbered in sequence and then stored in respective sending caches of each channel, wherein the bit number of the number PDUSN is 8, namely, the number is from 0 to 255, and the number is circularly numbered from 0 after the number is more than 255. After the cycle number, a PDUSN equal to 0 is considered to be greater than the immediately adjacent PDUSN equal to 255.
ABAIS PDUs are transmitted at BLE 2Mbps rate, with a payload size of 250 bytes of ABAIS Data PDU over-the-air packet length 1068us. The tmss in the slot structure as shown in fig. 8 is equal to 160us. The air time for transmitting an ABAIS Data PDU is 1068us plus 160us, 1228us total. In the slot structure shown in fig. 8, the number of ABAIS Data PDUs that can be transmitted in bulk is 14 at most, i.e. sun=14, the total air time is 17.192ms, and the corresponding ABA Delay 1 is equal to 17.192ms. The ABAIS Null PDU packet length carrying the cumulative batch acknowledgement mapping table is 68us, plus t_mss, and the air time taken to send one ABAIS Null PDU is 228us. In the slot structure shown in fig. 8, each HRL-TWS headset transmits ABAIS Null PDU at a maximum number of times of 2, i.e., r=2, accounting for 456us in total. Then the corresponding ABA Delay 2 is equal to 17.648ms. 14 ABAIS Data PDUs are transmitted in batches, and each HRL-TWS headset continuously transmits 2 times of ABAIS Null PDUs, and the total occupied time is 18.104ms. 1.896ms remains for the HRL-TWS source device to maintain two BLE ACL links time division multiplexed with the two HRL-TWS headphones.
In the Bluetooth audio transmitting apparatus shown in FIG. 1, the HRL-TWS audio source apparatus converts the ABAIS Data PDU of the left channel HRL-TWS earphone and the right channel HRL-TWS earphone into digital modulation signals by two modulation units, and modulates the digital modulation signals of the left channel HRL-TWS earphone and the digital modulation signals of the right channel HRL-TWS earphone on two digital carriers with an interval of 4MHz or 6MHz respectively by a digital carrier modulation and combination unit. Specifically, the left channel HRL-TWS headset uses a digital carrier of 0MHz and is modulated on a radio frequency channel determined according to the BLE protocol adaptive frequency hopping channel selection algorithm. The radio frequency channel spacing used by the right channel HRL-TWS headphones and the radio frequency channel spacing used by the left channel HRL-TWS headphones are typically 4MHz. If the channel spaced 4MHz from the radio frequency channel used by the left channel HRL-TWS headset is a BLE advertisement channel, then the radio frequency channel spaced 6MHz is selected. The radio frequency channel used by the right channel HRL-TWS headset is typically 4MHz or 6MHz higher than the radio frequency channel used by the left channel HRL-TWS headset. If the radio frequency channel of the right channel HRL-TWS earphone selected by the rule is beyond the BLE channel range, a radio frequency channel which is 4MHz or 6MHz lower than the radio frequency channel used by the left channel HRL-TWS earphone is selected as the radio frequency channel of the right channel HRL-TWS earphone. The digital carrier of the right channel HRL-TWS headset is determined by the radio frequency channel, and may be +4MHz, +6MHz, -4MHz or-6 MHz.
In the first MC-ABAIG interval, the number L of SDUs input by each channel of the HRL-TWS sound source equipment is equal to 8, the number L of the ABAIS Data PDU packaged into the package is equal to 8, and the PDUSN is sequentially numbered 0, 1, 2, … … and 7. The PRT technique is adopted, and the number M of the ABAIS Data PDUs transmitted in the current MC-ABAIG interval is equal to 14. The BTN in the ABAIS Data PDU extension packet header is set to 14, and the btsn is sequentially set to 0, 1, 2, … …, 11, 12, 13, and the corresponding PDUSN is 0, 1, 2, … …, 7, 0, 1, 2, … …, 5, respectively. The HRL-TWS sound source equipment sequentially sends 14 ABAIS Data PDUs to the two HRL-TWS headphones in parallel, and simultaneously, the two HRL-TWS headphones sequentially receives 14 ABAIS Data PDUs. When the time point ABA Delay 1 is equal to 17.192ms, the left channel HRL-TWS earphone continuously transmits the ABA Null PDU carrying the accumulated batch acknowledgement mapping table twice, and the ABA Null PDU is correctly received by the HRL-TWS sound source equipment. When the time point ABA Delay 2 is equal to 17.648ms, the right channel HRL-TWS earphone continuously transmits the ABA Null PDU carrying the accumulated batch acknowledgement mapping table twice, and the ABA Null PDU is correctly received by the HRL-TWS sound source equipment.
For interference reasons, ABAIS Data PDUs with a BTSN equal to 1 and 3 for the left channel are not received correctly, but ABAIS Data PDUs corresponding to other BTSNs are received correctly. Since ABAIS Data PDUs with BTSN equal to 1 and 3 are identical to ABAIS Data PDUs with BTSN equal to 9 and 11, respectively, correspond to the same PDUSN. Thus, the HRL-TWS source device receives all of the 8 SDUs of the left channel that are input at the current MC-ABAIG interval correctly, using PRT techniques, although there is interference resulting in erroneous reception. The STARTSN in the ABAIS Null PDU extension packet sent by the left channel HRL-TWS earphone is set to 8, the value of all bits of the ABA MT is 1, and no SDU with PDUSN less than 8 needs to be retransmitted. And after the HRL-TWS sound source equipment correctly receives the ABAIS Null PDU carrying the accumulated batch acknowledgement mapping table and sent by the left channel HRL-TWS earphone, deleting SDUs with PDUSN smaller than 8 in the left channel sending buffer. It follows that enabling PRT technology improves the reliability of transmission of audio data.
For interference reasons, ABAIS Data PDUs with a BTSN equal to 5 for the right channel are not received correctly, but ABAIS Data PDUs corresponding to other BTSNs are received correctly. Since ABAIS Data PDU with BTSN equal to 5 is identical to ABAIS Data PDU with BTSN equal to 13, the same PDUSN is corresponded. Thus, the HRL-TWS source device receives all of the right channel 8 SDUs entered at the current MC-ABAIG interval correctly, using PRT techniques, although there is interference resulting in erroneous reception. The STARTSN in the ABAIS Null PDU extension packet sent by the right channel HRL-TWS earphone is set to 8, the value of all bits of ABA MT is 1, and no SDU with PDUSN less than 8 needs to be retransmitted. And after the HRL-TWS sound source equipment correctly receives the ABAIS Null PDU carrying the accumulated batch acknowledgement mapping table and sent by the right channel HRL-TWS earphone, deleting SDUs with PDUSN smaller than 8 in the right channel sending buffer. It follows that enabling PRT technology improves the reliability of transmission of audio data.
In the second MC-ABAIG interval, the number L of SDUs input by each channel of the HRL-TWS sound source equipment is equal to 8, the number L of the ABAIS Data PDUs packaged into the ABAIS Data PDUs is equal to 8, and the PDUSNs are numbered 8, 9, 10, … … and 15 in sequence. The PRT technique is adopted, and the number M of the ABAIS Data PDUs transmitted in the current MC-ABAIG interval is equal to 14. The BTN in the ABAIS Data PDU extension packet header is set to 14, and the btsn is sequentially set to 0, 1, 2, … …, 11, 12, 13, and the corresponding PDUSN is 8, 9, 10, … …, 15, 8, 9, … …, 13, respectively. The HRL-TWS sound source equipment sequentially sends 14 ABAIS Data PDUs to the two HRL-TWS headphones in parallel, and simultaneously, the two HRL-TWS headphones sequentially receives 14 ABAIS Data PDUs. When the time point ABA Delay 1 is equal to 17.192ms, the left channel HRL-TWS earphone continuously transmits the ABA Null PDU carrying the accumulated batch acknowledgement mapping table twice, and the ABA Null PDU is correctly received by the HRL-TWS sound source equipment. When the time point ABA Delay 2 is equal to 17.648ms, the right channel HRL-TWS earphone continuously transmits the ABA Null PDU carrying the accumulated batch acknowledgement mapping table twice, and the ABA Null PDU is correctly received by the HRL-TWS sound source equipment.
For interference reasons, ABAIS Data PDUs with a BTSN equal to 2 and 7 for the left channel are not received correctly, but ABAIS Data PDUs corresponding to other BTSNs are received correctly. Since the ABAIS Data PDU with BTSN equal to 2 is identical to the ABAIS Data PDU with BTSN equal to 10, the same PDUSN is corresponded. Therefore, although there is interference causing erroneous reception, 8 SDUs of the left channel input at 8 current MC-ABAIG intervals transmitted by HRL-TWS source equipment are received in error only with ABAIS Data PDU with PDUSN of 15, and all other 7 SDUs are received correctly, using PRT technique. The STARTSN in the ABAIS Null PDU extension packet sent by the left channel HRL-TWS earphone is set to 15, the value of all bits of the ABA MT is 1, and the ABAIS Data PDU representing PDUSN of 8 to 14 does not need to be retransmitted, and only the ABAIS Data PDU with PDUSN of 15 needs to be retransmitted. And after the HRL-TWS sound source equipment correctly receives the ABAIS Null PDU carrying the accumulated batch acknowledgement mapping table and sent by the left channel HRL-TWS earphone, deleting SDUs with PDUSN smaller than 15 in a sending buffer, and reserving the SDUs with PDUSN equal to 15 to resend in the next MC-ABAIG interval.
For interference reasons, ABAIS Data PDUs with a BTSN equal to 5 and 13 for the right channel are not received correctly, but ABAIS Data PDUs corresponding to other BTSNs are received correctly. Since ABAIS Data PDU with BTSN equal to 5 is identical to ABAIS Data PDU with BTSN equal to 13, the same PDUSN is corresponded. The 8 SDUs of the right channel input by 8 current MC-ABAIG intervals transmitted by the HRL-TWS sound source device are only received in error by the ABAIS Data PDU with PDUSN of 13, and the other 7 SDUs are received correctly. The STARTSN in the ABAIS Null PDU extension packet sent by the right channel HRL-TWS headset is set to 13, bits 1 and 2 of the ABA MT are 0, the values of all other bits are 1, and no retransmission is needed for ABAIS Data PDUs representing PDUSNs of 8 to 12, 14 and 15, and only the ABAIS Data PDU with PDUSN of 13 is needed to be retransmitted. And deleting SDUs with PDUSN equal to 8,9,10, … …,12, 14 and 15 in a transmission buffer after the HRL-TWS sound source equipment correctly receives the ABAIS Null PDU carrying the accumulated batch acknowledgement mapping table and transmitted by the right channel HRL-TWS earphone, and reserving the SDUs with PDUSN equal to 13 for retransmission at the next MC-ABAIG interval.
In the third MC-ABAIG interval, the number L of SDUs input by each channel of the HRL-TWS sound source equipment is equal to 8, the number L of the ABAIS Data PDU packaged into the package is equal to 8, and the PDUSNs are numbered 16, 17, 18, … … and 23 in sequence. The PRT technique is adopted, and the number M of the ABAIS Data PDUs transmitted in the current MC-ABAIG interval is equal to 14. The BTN in the ABAIS Data PDU extension packet is set to 14, the btsn is sequentially set to 0, 1, 2, … …, 11, 12, 13, the PDUSN corresponding to the left channel is 15, 16, 17, … …, 23, 15, 16, … …, 20, and the PDUSN corresponding to the right channel is 13, 16, 17, … …, 23, 13, 16, … …, 20. The HRL-TWS sound source equipment sequentially sends 14 ABAIS Data PDUs to the two HRL-TWS headphones in parallel, and simultaneously, the two HRL-TWS headphones sequentially receives 14 ABAIS Data PDUs. When the time point ABA Delay 1 is equal to 17.192ms, the left channel HRL-TWS headset continuously transmits ABA Null PDUs carrying the accumulated batch acknowledgement mapping table twice, but due to interference, both the two transmitted ABA Null PDUs are not correctly received by the HRL-TWS audio source device. When the time point ABA Delay 2 is equal to 17.648ms, the right channel HRL-TWS headset continuously transmits two ABA Null PDUs carrying the accumulated batch acknowledgement mapping table, but due to interference, both the two ABA Null PDUs are not correctly received by the HRL-TWS audio source device.
ABAIS Data PDUs corresponding to the BTSN of the left channel are correctly received. The STARTSN in the ABAIS Null PDU extension packet sent by the left channel HRL-TWS earphone is set to 24, the value of all bits of the ABA MT is 1, and no retransmission is needed for the ABAIS Data PDU with PDUSN smaller than 24. However, the HRL-TWS source device does not correctly receive the ABAIS Null PDU carrying the cumulative batch acknowledgement mapping table sent by the left channel HRL-TWS earpiece, and still keeps SDUs with PDUSN equal to 15, 16, 17, … …, 23 in the buffer, and decides whether retransmission is needed after receiving a new ABAIS Null PDU by the next MC-ABAIG interval.
ABAIS Data PDUs corresponding to the BTSN of the right channel are correctly received. The STARTSN in the ABAIS Null PDU extension packet sent by the right channel HRL-TWS headset is set to 24, the value of all bits of ABA MT is 1, and no retransmission is needed for ABAIS Data PDUs with PDUSN less than 24. However, the HRL-TWS source device does not correctly receive the ABAIS Null PDU carrying the cumulative batch acknowledgement mapping table sent by the right channel HRL-TWS earpiece, and still keeps SDUs with PDUSN equal to 13, 16, 17, … …, 23 in the buffer, and decides whether retransmission is needed after receiving a new ABAIS Null PDU by the next MC-ABAIG interval.
In the fourth MC-ABAIG interval, the number L of SDUs input by each channel of the HRL-TWS sound source equipment is equal to 8, the number L of the ABAIS Data PDU packaged into the package is equal to 8, and the PDUSNs are numbered 24, 25, 26, … … and 31 in sequence. The PRT technique is adopted, and the number M of the ABAIS Data PDUs transmitted in the current MC-ABAIG interval is equal to 14. The BTN in the ABAIS Data PDU extension packet is set to 14, the btsn is set to 0, 1, 2, … …, 11, 12, 13 in sequence, the PDUSN corresponding to the left channel is 24, 25, 26, … …, 31, 15, 16, 17, … …, 20, and the PDUSN corresponding to the right channel is 24, 25, 26, … …, 31, 13, 16, 17, … …, 20. The HRL-TWS sound source equipment sequentially sends 14 ABAIS Data PDUs to the two HRL-TWS headphones in parallel, and simultaneously, the two HRL-TWS headphones sequentially receives 14 ABAIS Data PDUs. When the time point ABA Delay 1 is equal to 17.192ms, the left channel HRL-TWS earphone continuously transmits the ABA Null PDU carrying the accumulated batch acknowledgement mapping table twice, and the ABA Null PDU is correctly received by the HRL-TWS sound source equipment. When the time point ABA Delay 2 is equal to 17.648ms, the right channel HRL-TWS earphone continuously transmits the ABA Null PDU carrying the accumulated batch acknowledgement mapping table twice, and the ABA Null PDU is correctly received by the HRL-TWS sound source equipment.
ABAIS Data PDUs corresponding to the BTSN of the left channel are correctly received. The STARTSN in the ABAIS Null PDU extension packet sent by the left channel HRL-TWS earphone is set to 32, the value of all bits of the ABA MT is 1, and no retransmission is needed for the ABAIS Data PDU with PDUSN smaller than 32. And after the HRL-TWS sound source equipment correctly receives the ABAIS Null PDU carrying the accumulated batch acknowledgement mapping table and sent by the left channel HRL-TWS earphone, deleting SDUs with PDUSN smaller than 32 in the left channel sending buffer. This illustrates the advantage of the cumulative batch acknowledgment method that when the HRL-TWS source device does not properly receive the cumulative batch acknowledgment mapping table, no resources need to be wasted to repeatedly send ABAIS Data PDUs that were properly received by the left channel HRL-TWS headphones for the previous MC-ABAIG interval.
ABAIS Data PDUs corresponding to the BTSN of the right channel are correctly received. The STARTSN in the ABAIS Null PDU extension packet sent by the right channel HRL-TWS headset is set to 32, the value of all bits of ABA MT is 1, and no retransmission is needed for ABAIS Data PDUs with PDUSN smaller than 32. And after the HRL-TWS sound source equipment correctly receives the ABAIS Null PDU carrying the accumulated batch acknowledgement mapping table and sent by the right channel HRL-TWS earphone, deleting SDUs with PDUSN smaller than 32 in the right channel sending buffer. This illustrates the advantage of the cumulative batch acknowledgment method that when the HRL-TWS source device does not properly receive the cumulative batch acknowledgment mapping table, no resources need to be wasted to repeatedly send ABAIS Data PDUs that were properly received by the right channel HRL-TWS headphones for the previous MC-ABAIG interval.
As can be seen from the above description, in the embodiment of the present application, based on a single antenna in one transmission time slot, a plurality of groups of audio data packets are sent in parallel in a frequency division multiplexing manner, and in a receiving time slot, acknowledgement data packets sent by each bluetooth audio receiving device are received in a time-sharing manner through the receiving unit and the antenna. Therefore, compared with the prior art, in the same isochronous communication interval length, the embodiment of the application not only can carry out parallel transmission of the multichannel audio data with high speed, but also reserves sufficient bandwidth resources for batch transmission, accumulated batch acknowledgement and pre-retransmission of the multi-data packets, thereby remarkably improving the transmission bandwidth, transmission efficiency and transmission reliability of the Bluetooth audio transmission system and providing reliable wireless multichannel high-resolution lossless audio streaming service.
In the above embodiment, the HRL-TWS headset system based on the MC-ABAIG link protocol can provide reliable two-channel high-resolution lossless audio streaming service (0.8 Mbps for each of the left and right channels) with a transmission rate of up to 1.6 Mbps. Whereas the BLE Audio TWS headset system based on CIG link protocol only provides a two-channel lossy compression-encoded Audio streaming service (124 kbps for each of the left and right channels) with a transmission rate of up to 248 kbps.
In the several embodiments provided in this application, it should be understood that the disclosed methods and apparatus may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the elements is merely a logical functional division, and there may be additional divisions when embodied, e.g., multiple elements or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.
In addition, each functional unit in the embodiments of the present invention may be integrated in one processing unit, or each unit may be physically included separately, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in hardware plus software functional units.
The integrated units implemented in the form of software functional units described above may be stored in a computer readable storage medium. The software functional unit is stored in a storage medium, and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform part of the steps of the transceiving method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
While the foregoing is directed to the preferred embodiments of the present invention, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the present invention.

Claims (14)

1. The Bluetooth audio transmission device is characterized in that the Bluetooth audio transmission device is communicated with N Bluetooth audio receiving devices based on N target links, N target links are in one-to-one correspondence with N Bluetooth audio receiving devices, and N is a positive integer greater than 1; the Bluetooth audio transmission device includes:
the processing unit is used for processing the digital audio signals to obtain N groups of audio data packets, and each group of audio data packets is used for being sent to a corresponding Bluetooth audio receiving device in the current isochronous communication interval;
the N modulation units are used for respectively modulating the N groups of audio data packets to obtain N paths of first digital modulation signals corresponding to the N groups of audio data packets one by one;
the combining unit is used for respectively modulating N paths of the first digital modulation signals onto different digital carriers and combining the N paths of the first digital modulation signals into one path of multi-carrier digital modulation signals;
The transmitting unit is used for modulating the multi-carrier digital modulation signal onto a radio frequency carrier wave to obtain a first radio frequency signal;
the receiving unit is used for receiving the second radio frequency signals sent by the N Bluetooth audio receiving devices based on the corresponding target links respectively;
an antenna assembly comprising a switching unit and an antenna, the switching unit being adapted to switch the antenna between a first state and a second state;
the antenna is connected with the transmitting unit when in the first state, and is used for transmitting the first radio frequency signal in a transmitting time slot of the current isochronous communication interval, so that a corresponding group of audio data packets are respectively transmitted to N Bluetooth audio receiving devices in a frequency division multiplexing mode; and the antenna is connected with the receiving unit when in the second state, and is used for receiving the second radio frequency signals on N target links in a time-sharing manner in a receiving time slot in the current isochronous communication interval so as to respectively receive acknowledgement data packets sent by N Bluetooth audio receiving devices.
2. The bluetooth audio transmission device according to claim 1, wherein the reception slots in the current isochronous communication interval include at least N reception sub-slots that do not overlap each other, one of the reception sub-slots being occupied by each of the target links;
The antenna is connected with the receiving unit in the second state, and is configured to receive, in a time-sharing manner, a second radio frequency signal on each standard link in a receiving slot in the current isochronous communication interval, so as to respectively receive acknowledgement data packets sent by the N bluetooth audio receiving devices, where the antenna includes:
the antenna is connected with the receiving unit in the second state, and is used for respectively receiving second radio frequency signals on the N item standard links in the N receiving sub-time slots in sequence.
3. The bluetooth audio transmission apparatus according to claim 1, wherein each of the sets of audio data packets includes a number of audio data packets greater than or equal to 2;
each set of said audio data packets comprises at least one first data packet and/or at least one second data packet;
the first data packet is an audio data packet which is not sent to the Bluetooth audio receiving device corresponding to the audio data packet before the current isochronous communication interval by the Bluetooth audio sending device;
the second data packet is an audio data packet which is sent by the Bluetooth audio sending device before the current isochronous communication interval but is not confirmed by the Bluetooth audio receiving device corresponding to the audio data packet whether the audio data packet is successfully received or not.
4. The bluetooth audio transmission apparatus according to claim 1, wherein the processing unit includes an audio processing unit and a protocol processing unit, the bluetooth audio transmission apparatus further including a demodulation unit;
the audio processing unit is used for processing the digital audio signals and packaging the digital audio signals into service data units;
the receiving unit is further configured to process the received second radio frequency signal into a second digital modulation signal;
the demodulation unit is used for demodulating the second digital modulation signal to obtain the acknowledgement data packet;
the protocol processing unit is used for processing the service data unit sent in the current isochronous communication interval to obtain N groups of audio data packets;
the protocol processing unit is also used for analyzing the confirmation data packet.
5. The bluetooth audio transmission apparatus according to claim 1, wherein N has a value of 2,2 bluetooth audio reception apparatuses are a left earpiece and a right earpiece, respectively, 2 target links are a first target link and a second target link, the left earpiece corresponds to the first target link, and the right earpiece corresponds to the second target link;
The processing unit is configured to process digital audio data to obtain 2 groups of audio data packets, where the 2 groups of audio data packets are a left channel audio data packet and a right channel audio data packet, the left channel audio data packet is an audio data packet that needs to be received by the left earphone in a current isochronous communication interval, and the right channel audio data packet is an audio data packet that needs to be received by the right earphone in the current isochronous communication interval.
6. The Bluetooth audio transmission method is applied to Bluetooth audio transmission equipment and is characterized in that the Bluetooth audio transmission equipment is communicated with N pieces of Bluetooth audio receiving equipment based on N target links, N pieces of target links are in one-to-one correspondence with N pieces of Bluetooth audio receiving equipment, and N is a positive integer greater than 1; the method comprises the following steps:
an audio data processing step, which is used for processing digital audio signals to obtain N groups of audio data packets, wherein each group of audio data packets is used for being sent to a corresponding Bluetooth audio receiving device in the current isochronous communication interval;
a signal modulation step, which is used for modulating N groups of audio data packets respectively to obtain N paths of first digital modulation signals corresponding to the N groups of audio data packets one by one;
A signal combining step, which is used for combining N paths of first digital modulation signals into one path of multi-carrier digital modulation signals after respectively modulating the N paths of first digital modulation signals onto different digital carriers;
a first signal transmitting step, configured to modulate the multi-carrier digital modulation signal onto a radio frequency carrier to obtain a first radio frequency signal, and transmit the first radio frequency signal in a transmission time slot of the current isochronous communication interval, so as to respectively transmit a corresponding group of audio data packets to N bluetooth audio receiving devices in a frequency division multiplexing manner based on the first radio frequency signal;
a first signal receiving step, configured to receive second radio frequency signals on N target links in a time-sharing manner in a receiving time slot in the current isochronous communication interval, so as to respectively receive acknowledgement data packets sent by N bluetooth audio receiving devices;
the Bluetooth audio transmitting device comprises a switching unit and an antenna, wherein the switching unit is used for enabling the antenna to be switched between a first state and a second state, the Bluetooth audio transmitting device executes the first signal transmitting step when the antenna is in the first state, and the Bluetooth audio transmitting device executes the first signal receiving step when the antenna is in the second state.
7. The method of claim 6, wherein the receive time slots in the current isochronous communication interval include at least N mutually non-overlapping receive sub-slots, the N target links being in one-to-one correspondence with the N receive sub-slots, each of the target links occupying a corresponding one of the receive sub-slots.
8. The method of claim 7, wherein the first signal receiving step is further configured to receive a second radio frequency signal on the same target link at least twice in succession in each of the receiving sub-slots, so as to receive the acknowledgement data packet repeatedly transmitted at least twice in succession by a bluetooth audio receiving device corresponding to the target link.
9. The method of claim 6, wherein the acknowledgement data packets include a cumulative batch acknowledgement mapping table that characterizes a receipt status of a corresponding set of audio data packets sent by the bluetooth audio transmitting device to the bluetooth audio receiving device during the current isochronous communication interval and a receipt status of a corresponding audio data packet sent by the bluetooth audio transmitting device to the bluetooth audio receiving device prior to the current isochronous communication interval;
The audio data processing step is further used for processing digital audio signals according to the maximum number of receivable audio data packets of each Bluetooth audio receiving device in a sending time slot of one isochronous communication interval and an accumulated batch confirmation mapping table fed back by each Bluetooth audio receiving device to obtain the N groups of audio data packets.
10. The method according to any one of claims 6 to 9, wherein each set of said audio data packets comprises a number of audio data packets greater than or equal to 2;
each set of said audio data packets comprises at least one first data packet and/or at least one second data packet;
the first data packet is a data packet which is not sent to the Bluetooth audio receiving device corresponding to the audio data packet before the current isochronous communication interval by the Bluetooth audio sending device;
the second data packet is a data packet which is sent by the Bluetooth audio sending device before the current isochronous communication interval but is not confirmed by the Bluetooth audio receiving device corresponding to the audio data packet whether the data packet is successfully received.
11. The method of claim 10, wherein the set of audio data packets further comprises one or more third data packets;
The third data packet is at least part of the first data packet and/or the second data packet.
12. The method of claim 6, further comprising a first target link establishing step for establishing N target links with N bluetooth audio receiving devices, respectively, determining with the bluetooth audio receiving devices when they transmit acknowledgement data packets and the frequency of the digital carrier that received the first radio frequency signal.
13. A bluetooth audio receiving method applied to a bluetooth audio receiving device, wherein the bluetooth audio receiving device communicates with a bluetooth audio transmitting device based on a target link, and the method comprises the following steps:
a second target link establishing step, which is used for establishing a target link with the Bluetooth audio transmitting equipment, determining the frequency of a digital carrier wave of which the first radio frequency signal is received and the time for transmitting the confirmation data packet;
a second signal receiving step, configured to receive, in a transmission time slot of a current isochronous communication interval, a first radio frequency signal that is sent by the bluetooth audio transmission device in a frequency division multiplexing manner, so as to obtain a set of audio data packets that are sent by the bluetooth audio transmission device in the current isochronous communication interval based on the target link;
And a second signal transmitting step, configured to transmit an acknowledgement packet on the target link based on the time of transmitting the acknowledgement packet in the receiving slot of the current isochronous communication interval.
14. A bluetooth audio transmission system comprising a bluetooth audio transmitting device according to any one of claims 1-5 and N bluetooth audio receiving devices, said bluetooth audio transmitting device communicating with N of said bluetooth audio receiving devices based on N target links, N of said target links being in one-to-one correspondence with N of said bluetooth audio receiving devices, N being a positive integer greater than 1.
CN202211718993.7A 2022-12-30 2022-12-30 Bluetooth audio transmitting equipment, bluetooth audio receiving equipment, related method and system Pending CN116131867A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211718993.7A CN116131867A (en) 2022-12-30 2022-12-30 Bluetooth audio transmitting equipment, bluetooth audio receiving equipment, related method and system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211718993.7A CN116131867A (en) 2022-12-30 2022-12-30 Bluetooth audio transmitting equipment, bluetooth audio receiving equipment, related method and system

Publications (1)

Publication Number Publication Date
CN116131867A true CN116131867A (en) 2023-05-16

Family

ID=86307380

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211718993.7A Pending CN116131867A (en) 2022-12-30 2022-12-30 Bluetooth audio transmitting equipment, bluetooth audio receiving equipment, related method and system

Country Status (1)

Country Link
CN (1) CN116131867A (en)

Similar Documents

Publication Publication Date Title
CN1973470B (en) Wireless audio transmission system and method
US9338690B2 (en) RLC segmentation for carrier aggregation
KR100889785B1 (en) Retransmission apparatus and method in wireless relay communication system
EP2416518B1 (en) Method for transmission of data in a radio communication system, first network node and second network node thereof
US7782836B2 (en) Method and system for transmission of different types of information in wireless communication
CN110692211B (en) Base station device and terminal device
CN109155704B (en) User equipment, base station and method for uplink data packet transmission
KR20110121551A (en) Apparatus and method for transmitting ack/nack in tdd system
JP2020511895A (en) Construction of a puncture bundle of data for the first service in the transmission of the second service
CN111327405A (en) Method and apparatus in a node used for wireless communication
EP3879780A1 (en) Method and device for identifying security key based on pdcp layer device in next-generation mobile communication system
CN113508546A (en) Wireless communication apparatus and method
US11956089B2 (en) Communication device and communication method
JP2005501479A (en) Data packet transmission in a wireless communication system using a common HARQ (Hybrid Automatic Repeat Request) process
CN101933358B (en) Method and arrangement for transmitting a data unit in a wireless communications system
JP2001197144A (en) Radio equipment
CN111385045B (en) Audio data communication system
WO2010053042A1 (en) Base station apparatus, mobile terminal apparatus, mobile communication system, and information retransmitting method
CN116131867A (en) Bluetooth audio transmitting equipment, bluetooth audio receiving equipment, related method and system
US20220174545A1 (en) Communication control apparatus and method, and wireless communication apparatus and method
KR102561713B1 (en) Method and apparatus for transmission and reception of data in wireless communication system
CN113475027A (en) Base station, terminal, transmission method and reception method
KR20210076488A (en) A method and an apparatus of operating pdcp for udc error in the next wireless communication systems
WO2020179542A1 (en) Wireless communication system and wireless communication method
CN115865280A (en) Data packet loss retransmission method based on MAC layer and transceiving communication device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination