Low-energy-consumption Bluetooth communication system, electronic device and Bluetooth chip thereof

Low-energy Bluetooth communication system, electronic device and Bluetooth chip thereof Technical field

[0001] The present invention relates to a Bluetooth communication, and more particularly to a Bluetooth communication system, an electronic device and a Bluetooth chip thereof, which can confirm whether a retransmitted packet is received after a radio frequency receiver is turned on relative to a receiving time slot to determine whether to turn off the radio frequency receiver early in the receiving time slot to reduce energy consumption.

Background Art

[0002] Please refer to FIG. 1, which is a schematic diagram of message exchange between a master device and a slave device of a Bluetooth communication system. The slave device uses a time interval ts in each receiving time slot RX to receive a packet from the master device, and the master device uses a time interval tm in each receiving time slot RX to receive a packet from the slave device.

[0003] In the current Bluetooth standard protocol, data payload is continuously retransmitted until the source receives a positive acknowledgement or the transmission times out. When the source continuously retransmits the data payload, the destination repeatedly receives the same data payload, wasting unnecessary power.

Summary of the invention

[0004] In view of this, the present invention provides a Bluetooth module or chip configured with a judgment reference, which can determine whether the current packet is a retransmitted packet in each receiving time slot of the destination end, so as to immediately shut down the RF receiver and/or modem of the destination end to reduce unnecessary energy consumption during packet exchange.

[0005] The present invention provides a Bluetooth communication system, an electronic device and a Bluetooth chip thereof, which determine whether a current packet is a retransmitted packet in each receiving time slot to determine whether to continue receiving the data payload of the current packet in each receiving time slot.

[0006] The present invention provides an electronic device comprising an antenna and a Bluetooth chip. The antenna is used to receive packets. The Bluetooth chip is used to determine whether the packet is an asynchronous connection-oriented packet in a receiving time slot, and then determine whether the packet is a retransmitted packet according to the header of the packet, and accordingly decide whether to stop receiving the payload of the packet in the receiving time slot.

[0007] The present invention also provides a Bluetooth chip comprising an antenna, a radio frequency receiver, a modem and a Bluetooth controller. The antenna is used to receive packets and generate a received signal. The radio frequency receiver is used to perform analog processing on the received signal relative to a receiving time slot and generate a digital signal. The modem is used to perform digital processing on the digital signal relative to the receiving time slot and generate a decoded packet. The Bluetooth controller is used to identify whether the decoded packet is a retransmitted packet, and accordingly determine whether to shut down at least one of the radio frequency receiver and the modem in advance in the receiving time slot.

[0008] The present invention also provides a Bluetooth communication system comprising a main device and a first electronic device. The main device is used to send a packet. The first electronic device is used to determine whether the packet is an asynchronous connection-oriented packet in a receiving time slot, and then determine whether the packet is a retransmitted packet according to the header of the packet, and decide whether to stop receiving the payload of the packet in the receiving time slot accordingly.

In order to make the above and other objects, features and advantages of the present invention more obvious, the following will be described in detail with reference to the accompanying drawings.

The detailed description is as follows. In addition, in the description of the present invention, the same components are represented by the same symbols and are described here first.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG1 is a schematic diagram of message exchange in a Bluetooth communication system;

[0011] FIG2 is a block diagram of a Bluetooth chip of an electronic device according to an embodiment of the present invention;

[0012] FIG3 is a schematic diagram of message exchange of a Bluetooth communication system according to an embodiment of the present invention;

[0013] FIG4 is a flow chart of an operation method of a Bluetooth chip of an electronic device according to an embodiment of the present invention;

[0014] FIG5A is a schematic diagram of the operation of a Bluetooth communication system according to an embodiment of the present invention;

[0015] FIG5B is a schematic diagram of the operation of a Bluetooth communication system according to another embodiment of the present invention; and

[0016] FIG. 6 is a schematic diagram of message exchange in the Bluetooth communication system of FIG. 5B.

DESCRIPTION OF NUMBERS

200 Bluetooth chip

[0019] 21 Antenna

22 radio frequency receiver

[0021] 23 Modem

[0022] 24 Bluetooth controller

25 radio frequency transmitter

26 Switcher Specific Implementation Methods

[0025] An object of the present invention is to provide a Bluetooth communication system, an electronic device and a Bluetooth chip thereof that can determine whether to shut down the analog front end and part of the digital back end in advance according to the header of the current packet in each receiving time slot (such as RX shown in Figure 3) to stop continuing to receive the payload (payload) after the header in the current packet in the receiving time slot RX, so as to save energy consumed by repeatedly receiving the same packet.

[0026] In the present invention, the electronic device (including the first electronic device and the second electronic device described later) is selected from, for example, a portable electronic device, a wearable electronic device, a car electronic device, a computer peripheral, a Bluetooth headset, a Bluetooth speaker, or other electronic devices that use Bluetooth communication to send and receive data, without specific limitations.

[0027] The electronic device of the present invention can be a master device or a slave device in Bluetooth communication, and is used to receive a current packet in a receiving time slot RX under a Bluetooth connection state through a Bluetooth chip and determine whether the current packet is a retransmitted packet. When the source retransmits a packet, it can avoid the destination from continuing to turn on the RF receiver and modem to repeatedly receive the same packet and waste unnecessary power.

[0028] Please refer to FIG. 2, which is a block diagram of a Bluetooth chip 200 of an electronic device according to an embodiment of the present invention. The Bluetooth chip 200 includes an antenna 21, a radio frequency receiver 22, a modem 23, a Bluetooth controller 24, and a radio frequency transmitter 25, wherein, in the present invention, the radio frequency receiver 22 is also referred to as an analog front end, and the modem 23 and the Bluetooth controller 24 are also referred to as a digital back end.

[0029] FIG. 2 shows that the Bluetooth chip 200 further includes a switch (shown as T/R) 26 for electrically connecting the antenna 21 to one of the RF receiver 22 and the RF transmitter 25 for signal reception or signal transmission. In other embodiments, the Bluetooth chip 200 includes two antennas connected to the RF receiver 22 and the RF transmitter 25, respectively, so that the switch 26 is not required.

Switches between signal reception and signal transmission.

[0030] The electronic device of the present invention receives the current packet via the antenna 21.

[0031] It should be noted that, although FIG. 2 shows that the antenna 21 is one of the components of the Bluetooth chip 200, the present invention is not limited thereto. In other embodiments, the antenna 21 is a component of the electronic device and is located outside the Bluetooth chip 200, and the RF receiver 22 is electrically coupled to the antenna 21 to receive the current packet.

[0032] The Bluetooth chip 200 receives a current packet in a receiving time slot (e.g., RX shown in FIG. 3 ), wherein the current packet refers to a packet transmitted in the receiving time slot RX. As mentioned above, the Bluetooth chip 200 can be configured in a master device or a slave device, and FIG. 3 is an illustration of the Bluetooth chip 200 being located in a slave device.

[0033] The Bluetooth chip 200 is used to determine whether the current packet is a retransmitted packet according to the header of the current packet after determining that the current packet is an asynchronous connection-oriented (ACL) packet in the receiving time slot RX, and accordingly decide whether to stop continuing to receive the payload of the current packet in the receiving time slot RX.

[0034] In one embodiment, the Bluetooth chip 200 determines whether the current packet is a retransmitted packet according to the SEQN bit of the header of the current packet. For example, when the SEQN bit of the header of the current packet is the same as the SEQN bit of the header of the previous packet (e.g., received in the previous receiving time slot), the current packet is determined to be a retransmitted packet; otherwise, the current packet is not a retransmitted packet and needs to be continuously received.

[0035] In one embodiment, the Bluetooth chip 200 further determines and records whether the cyclic redundancy check code (CRC) check of the previous packet of the current packet has passed. The Bluetooth chip 200, for example, has a register for recording whether the CRC check has passed (for example, stored as a number 1, but not limited to) or failed (for example, stored as a number 0, but not limited to). If the CRC check passes, it means that the previous packet has been completely received.

[0036] In more detail, in an embodiment where the antenna 21 is disposed on the Bluetooth chip 200, the antenna 21 is used to receive packets and generate a receiving signal, such as the signal ACL shown in FIG2. Since the present invention does not receive the payload of the current packet to save energy, it is necessary to terminate the reception of the next data payload in advance only when the current packet is an asynchronous connection-oriented (i.e., ACL) packet.

The RF receiver 22 is used to perform analog processing on the signal ACL in the receiving time slot RX and generate a digital signal Sd/. For example, the RF receiver 22 includes an analog-to-digital converter (not shown) for performing analog-to-digital conversion. The method of analog-to-digital conversion is well known and will not be described in detail here.

In one embodiment, the RF receiver 22 further includes other components for performing analog signal processing on the received signal ACL, such as a low noise amplifier, a mixer, and an amplifier. The other components are known and are not the main purpose of the present invention, so they are not described here. It can be understood that the functions of each component in the RF receiver 22 can be considered to be performed by the RF receiver 22.

[0039] The modem 23 is used to digitally process the digital signal Sd in the receiving time slot RX and generate a decoded packet Sdp. For example, the modem 23 includes a decoder (not shown) for decoding the encoded packet sent by the source end (such as the main device shown in FIG. 3) to restore the original packet (i.e., the decoded packet Sdp).

[0040] In one embodiment, the modem 23 also includes other components for digitally processing the digital signal Sd, such as an automatic gain controller (AGC), a down LPF, a DC remover, a rotator, and a low-pass filter (LPF). The down filter is, for example, a sinc filter, which is used to down-convert the digital signal Sd and reduce the effective bits. The DC remover is used to filter out the DC interference of 0MHZ and is coupled to the downstream of the down filter. The rotator is used to perform frequency shifting, converting the data from 1MHZ back to 0MHZ, and is coupled to the downstream of the DC remover. The low-pass filter is used to filter out interference and is coupled to the downstream of the rotator. The AGC is coupled to the downstream of the low-pass filter.

The other components are known and are not the main purpose of the present invention, so they are not described here. It can be understood that the functions of each component in the modem 25 can be considered to be performed by the modem 23.

[0041] The Bluetooth controller (e.g., implemented by hardware) 24 is used to identify whether the decoded packet Sdp is a retransmission packet, and accordingly determine whether to turn off at least one of the RF receiver 22 and the modem 23 in advance in the corresponding receiving time slot RX. For example, when it is determined that the current packet is a retransmission packet (i.e., the SEQN of the header has not changed), the Bluetooth controller 24 sends a control signal rtx_off to the RF receiver 22 and/or the modem 23, and turns off at least one of the RF receiver 22 and the modem 23 after receiving the header to stop continuing to receive the next payload. The Bluetooth controller 27, for example, includes a processor for executing its functions.

[0042] Preferably, the Bluetooth controller 24 also determines and records whether the cyclic redundancy check code check of the previous decoded packet has passed, so as to confirm whether the previous decoded packet has been completely received. If the previous decoding has not been received, the data payload of the current packet must be received regardless of whether it is a resent packet.

[0043] Please refer to FIG. 3 and FIG. 4 simultaneously. FIG. 3 is a schematic diagram of message exchange of a Bluetooth communication system according to an embodiment of the present invention; FIG. 4 is a flow chart of an operation method of a Bluetooth chip 200 of an electronic device according to an embodiment of the present invention, the operation method comprising: confirming whether the current packet is an ACL packet (step S41); when the current packet is an ACL packet, confirming whether the current packet is a retransmitted packet and confirming whether the CRC check passes (step S43); and shutting down at least one of the RF receiver and the modem (step S45). The function of FIG. 4 is mainly performed by the Bluetooth controller 24 of the Bluetooth chip 200.

[0044] Step S41: The Bluetooth controller 24 at the destination end determines whether the current packet (at least a packet that has been processed by analog-to-digital conversion and decoding as described above) belongs to an ACL packet, which includes a CRC data payload. When the current packet belongs to an ACL packet, the process proceeds to step S43. However, if the current packet does not belong to an ACL packet, there is no need to consider whether to continue receiving the CRC data payload.

[0045] Step S43: The Bluetooth controller 24 then determines whether the current packet is a retransmitted packet based on whether the SEQN bit in the header of the current packet changes (from 1 to 0 or from 0 to 1 in the continuous receiving time slot). Preferably, the Bluetooth controller 24 also determines whether the previous packet has been received, i.e., has passed the CRC check.

[0046] The format of the CRC check and header is known, so it will not be described in detail here.

[0047] Step S45: When the current packet is confirmed to be a retransmitted packet and the previous packet has passed the CRC check, it means that there is no need to continue receiving the CRC data payload of the current packet. Therefore, the Bluetooth controller 24 can turn off the RF receiver 22 and/or the modem 23 by issuing a control signal rtx_off to stop continuing to receive the CRC data payload of the current packet in the current receiving time slot RX.

[0048] As shown in FIG. 3, the time of stopping receiving the data payload after the header is represented by a dotted line. It can be clearly seen that the larger the data payload, the more power can be saved.

[0049] Referring to FIG. 5A and FIG. 5B, when the electronic device of the embodiment of the present invention is implemented as a true wireless Bluetooth headset (TWS) set, it includes a first electronic device (for example, suitable for the left ear, but not limited to) 531 and a second electronic device 532 (for example, suitable for the right ear, but not limited to). The first electronic device 531 and the second electronic device 532, for example, respectively include the Bluetooth chip 200 shown in FIG. 2.

[0050] In one embodiment, the first electronic device 531 and the second electronic device 533 are both used as slave devices of the Bluetooth communication system, and are used to respectively receive packets sent by the master device (such as a mobile phone, a car central control, but not limited to) 51. After the first electronic device 531 and the second electronic device 533 determine that the packet is an asynchronous connection-oriented packet (ACL) in the receiving time slot RX, they determine whether the packet is a retransmitted packet based on the header of the packet, and decide whether to stop receiving the payload of the packet in the receiving time slot RX, that is, turn off the RF receiver and/or modem therein.

[0051] As shown in FIG. 5A, after receiving each packet (e.g., completing the CRC check), the first electronic device 531 and the second electronic device 533 each send an affirmative response (shown as ACK1 and ACK2) to the main device 51 in the transmission time slot TX. When the main device 51 does not receive the affirmative response ACK from at least one of the first electronic device 531 and the second electronic device 533 (i.e., does not receive ACK1 and/or ACK2), the main device 51 sends the same packet, i.e., resends the packet.

[0052] When the first electronic device 531 determines that a certain packet is a retransmitted packet, it stops receiving the payload of the certain packet in the corresponding receiving time slot RX, and sends an affirmative acknowledgement ACK1 in the next sending time slot TX of the receiving time slot RX. When the second electronic device 533 determines that a certain packet is a retransmitted packet, it stops receiving the payload of the certain packet in the corresponding receiving time slot RX, and sends an affirmative acknowledgement ACK2 in the next sending time slot TX of the receiving time slot RX.

[0053] Referring to FIG. 5B and FIG. 6, the first electronic device 531 is, for example, a primary slave of the Bluetooth communication system and the second electronic device 533 is, for example, a secondary slave of the Bluetooth communication system. After the second electronic device 533 receives each packet from the master device 51 (for example, after the CRC check is completed), it sends a secondary ACKs to the first electronic device 531. The first electronic device 531 sends an ACKp to the master device 51 only after it receives each packet from the master device 51 (for example, after the CRC check is completed) and receives the secondary ACKs from the second electronic device 533.

[0054] When the host device 51 does not receive the positive response ACKp (ACKs is not related to the host device 51) from the first electronic device 531, the host device 51 sends the same packet, ie, resends the packet.

[0055] However, the first electronic device 531 and the second electronic device 533 are not limited to receiving packets from the main device 51 in the same receiving time slot. As shown in FIG6, the first electronic device 531 and the second electronic device 533 can receive packets from the main device 51 in different receiving time slots, such as receiving time slots S3 and S5 or S7 and S9. The symbol "X" shown in FIG6 indicates that the packet of the main device 51 is not received.

[0056] When the first electronic device 531 determines (for example, using its Bluetooth controller) that the packet is a retransmitted packet and does not receive a secondary positive acknowledgement ACKs from the second electronic device 533 (for example, in the receiving time slot S7), in addition to stopping (for example, turning off its RF receiver and/or modem) continuing to receive the payload of the packet in the receiving time slot S7, and not sending a positive acknowledgement ACKp or sending a negative acknowledgement NACK in the next sending time slot S8 of the receiving time slot S7, so that the main device 51 retransmits the packet again.

[0057] In this embodiment, the first electronic device 531 will send an ACKp in the next sending time slot TX only when it receives a packet from the main device 51 and a secondary ACKs from the second electronic device 533 in consecutive receiving time slots (which may be the same or different receiving time slots as shown in FIG. 6).

[0058] In summary, since the Bluetooth module of the conventional electronic device does not have the function of determining whether to continue to receive the remaining packets according to the RSSI, the RF receiver will still be turned on in the receiving time slot for receiving the retransmitted packets to receive the payload of all the retransmitted packets, thereby wasting energy. Therefore, the present invention further provides a Bluetooth communication system (refer to FIGS. 5A to 5B ), an electronic device and a Bluetooth chip thereof (refer to FIG. 2 ), which can determine whether the current packet is a retransmitted packet according to the packet header in each receiving time slot, so as to determine whether to shut down at least one of the RF receiver and the modem in advance to save energy.

Although the present invention is disclosed by the aforementioned examples, it is not intended to limit the present invention, and any person skilled in the art to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope defined by the appended claims.