1. Field of the Invention
The invention relates to a device and a method to reduce the possibility of packet collision, and more particularly to a device and a method to reduce the possibility of packet collision when engaging a wireless power transmitter and a plurality of wireless power receivers.
2. Description of the Related Art
There are several methods of wireless power transmission, of which magnetic induction and magnetic resonance are two of the most common. Magnetic induction basically adopts an induction coil at both the wireless power transmitter and the wireless power receiver. When power is provided to the transmitter coil, the electromagnetic effect is generated since the current generates the magnetism and the magnetism generates the current. When the receiver coil receives the electromagnetic signal, power is generated via the magnetic field change so as to charge the battery. The principle of magnetic resonance is different from magnetic induction that uses mutual induction to exchange electromagnetic power. For magnetic resonance, the charger dock and the object to be charged use the same frequency so that the power can be efficiently transmitted therebetween by resonance. When the wireless power transmitter and the wireless power receiver resonate at the same frequency, the wireless power receiver receives the electromagnetic field generated by the wireless power transmitter, thereby receiving the power from the wireless power transmitter.
To facilitate wireless power transmission, a Bluetooth Low Energy (BLE) technology is further adopts to establish a BLE connection between the transmitter and the receiver for communication. For example, the receiver may inform the transmitter about its power requirement via the BLE connection. However, when collision in the BLE advertising packet occurs, the BLE connection cannot be established successfully. Therefore, a device and a method to avoid BLE advertising packet collision are urgently required.
A wireless power receiver device and a wireless communications device are provided. An exemplary embodiment of a wireless power receiver device capable of performing wireless power reception comprises a processor and a communications module. The processor determines a delay time and generates a delay control signal comprising information regarding the delay time. The communications module is coupled to the processor and capable of providing wireless communications service. The BLE module receives the delay control signal and delays a time to transmit a first packet utilized for establishing communications between the wireless power receiver device and a wireless power transmitter device according to the delay time.
An exemplary embodiment of a wireless power receiver device capable of performing wireless power reception and communicating with a communications device comprises: an analog-to-digital converter (ADC). The ADC generates a digital signal according to an analog voltage. The digital signal or a tick time value generated from a timer is utilized to determine a delay time for the communication device to delay a time to transmit a first packet utilized for establishing communication between the wireless power receiver device and a wireless power transmitter device.
An exemplary embodiment of a wireless communications device capable of providing wireless communications service and coupled to a wireless power receiver device to facilitate the wireless power receiver device to establish a wireless communications with a wireless power transmitter device comprises a processor and a communications module. The processor generates a delay control signal comprising information regarding a delay time. The BLE module is coupled to the processor and capable of providing wireless communications service. The communications module receives the delay control signal and delays a time to transmit a first packet utilized for establishing communications between the wireless power receiver device and the wireless power transmitter device according to the delay time. The first packet is transmitted in response to a beacon frame received from the wireless power transmitter device.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
The advertising packet may comprise information regarding the wireless power receiver device, such as the device name, the manufactory and specification of the wireless power receiver device, and so on. When the wireless power transmitter device receives the advertising packet, the wireless power transmitter device may pair with the wireless power receiver device and establish a wireless connection, such as a Bluetooth Low Energy (BLE) connection, between the wireless power transmitter device and the wireless power receiver device. The wireless power transmitter device and the wireless power receiver device may communicate via the wireless connection to facilitate wireless power transmission. For example, the wireless power receiver device may inform the wireless power transmitter device about its power requirement via the BLE connection.
When there are more than one wireless power receiver device to be charged in the wireless charging system, these wireless power receiver devices may boot concurrently since they receive the same beacon frame from the same wireless power transmitter device. In this manner, collision in the BLE advertising packet may occur. When collision occurs, the BLE connection cannot be established successfully. To solve this problem, several devices and methods to avoid advertising packet collision are provided.
The rectifier 422 may receive the inducing current from the matching circuit 421 and rectify the inducing current to generate a system voltage Vsys and a corresponding current signal as a charging current Ic. The current sensing circuit 423 may receive the charging current Ic and senses an amount of the charging current Ic to generate a corresponding sensed voltage Vc. The DC-DC converter 424 may further converter the system voltage Vsys into an output voltage Vout so as to provide power to a device or a following stage of circuit coupled to the wireless power receiver device 420. The internal thermistor 426 may sense an internal temperature of the wireless power receiver device 420 to generate another sensed voltage Vs. The ADC 425 may receive the voltage signals, such as the system voltage Vsys, the sensed voltage Vc and the sensed voltage Vs, which may be analog voltages, and analog-to-digital convert the voltage signals to generate a corresponding digital signal Sdigital. The timer 428 may provide a timer signal St comprising information regarding a current tick time value to the processor 427. The BLE module 429 may provide BLE communications service. The processor 427 may be coupled to a plurality of elements of the wireless power receiver device 420 and control the operations thereof.
According to an embodiment of the invention, the processor 427 may determine a delay time Δt and generate a delay control signal Sctrl comprising information regarding the delay time Δt. The BLE module 429 may receive the delay control signal Sctrl from the processor 427 and delay a time to transmit a first advertising packet, such as the advertising packet 301 shown in
In the embodiments of the invention, the processor 427 may determine a delay time Δt randomly, pseudo-randomly, or non-randomly.
According to an embodiment of the invention, the processor 427 may determine the delay time Δt according to the digital signal Sdigital provided by the ADC 425. According to another embodiment of the invention, the processor 427 may also determine the delay time Δt according to the timer signal St provided by the timer 428. For example, the processor 427 may take the value of the digital signal Sdigital or the current tick time value of the timer 428 as a parameter of a predetermined algorithm or equation to calculate a delay time Δt. For another example, the processor 427 may also use the value of the digital signal Sdigital or the current tick time value of the timer 428 as a random seed and generate a random/pseudo-random number as the delay time Δt according to the random seed.
To be more specific, according to an embodiment of the invention, the processor 427 may use the output of the rectifier 422, such as the system voltage Vsys or its ADC result, as a parameter of a predetermined algorithm or equation to calculate a delay time Δt, or as a random seed and generate a random/pseudo-random number as the delay time Δt according to the random seed.
According to another embodiment of the invention, the processor 427 may use the output of the current sensing circuit 423, such as the sensed voltage Vc or its ADC result, as a parameter of a predetermined algorithm or equation to calculate a delay time Δt, or as a random seed and generate a random/pseudo-random number as the delay time Δt according to the random seed.
According to yet another embodiment of the invention, the processor 427 may use the output of the internal thermistor 426, such as the sensed voltage Vs or its ADC result, as a parameter of a predetermined algorithm or equation to calculate a delay time Δt, or as a random seed and generate a random/pseudo-random number as the delay time Δt according to the random seed.
According to yet another embodiment of the invention, the processor 427 may use the output of the internal bandgap voltage reference circuit 430, such as the bandgap voltage Vb or its ADC result, as a parameter of a predetermined algorithm or equation to calculate a delay time Δt, or as a random seed and generate a random/pseudo-random number as the delay time Δt according to the random seed.
According to yet another embodiment of the invention, the processor 427 may use the output of the external voltage reference 431, such as the external voltage Vext or its ADC result, as a parameter of a predetermined algorithm or equation to calculate a delay time Δt, or as a random seed and generate a random/pseudo-random number as the delay time Δt according to the random seed.
According to still another embodiment of the invention, the processor 427 may use the output of the timer 428, such as the current tick time value of the timer 428, as a parameter of a predetermined algorithm or equation to calculate a delay time Δt, or as a random seed and generate a random/pseudo-random number as the delay time Δt according to the random seed.
Note that in some embodiments of the invention, the rectifier 422, the current sensing circuit 423, the DC-DC converter 424, the ADC 425, the internal thermistor 426, the processor 427, the timer 428, the BLE module 429 and the internal bandgap voltage reference circuit 430 may all be integrated in one chip, such as the wireless power receiver chip 40 shown in
In this embodiment, the rectifier 422, the current sensing circuit 423, the DC-DC converter 424, the ADC 425, the internal thermistor 426, the processor 427, the timer 428 and the internal bandgap voltage reference circuit 430 may be integrated in one chip, such as the wireless power receiver chip 50 shown in
In addition, in the embodiment shown in
Although the above descriptions use a BLE module as a communications module or use a BLE communications device or chip as a wireless communications device or chip, it is for illustrative purpose rather than limitation. In other words, the present invention is not limited to using BLE, other communications modules such as WiFi, NFC and Zigbee can also provide the similar function. The processor 427 can control the delay amount of a first packet or a first advertising packet that the communications module or the wireless communications device or chip sends for establishing wireless connection or communications between PTU and PRU. The packet collision possibility can therefore be reduced, and the wireless charging performance can be improved.
While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. Those who are skilled in this technology can still make various alterations and modifications without departing from the scope and spirit of this invention. Therefore, the scope of the present invention shall be defined and protected by the following claims and their equivalents.
This application claims the benefit of U.S. Provisional Application No. 62/082,675 filed on Nov. 21, 2014 and entitled “Method for Preventing A4WP BLE Advertising Packet Collision”, the entire contents of which are hereby incorporated by reference.
Number | Date | Country | |
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62082675 | Nov 2014 | US |