CN-122027415-A - Amplitude shift keying signal decoding method and device

CN122027415ACN 122027415 ACN122027415 ACN 122027415ACN-122027415-A

Abstract

The invention provides an amplitude shift keying signal decoding method and device, which comprise the steps of deburring an amplitude shift keying signal when a preamble is not detected, detecting the preamble of the amplitude shift keying signal by using a windowing filter, stopping deburring after the preamble is detected, performing windowing filtering to identify the level of each observation window, detecting the first byte of the amplitude shift keying signal, performing windowing filtering to identify the level of each observation window by using the windowing filter after the first byte is detected, correcting the level of each observation window by using a bidirectional differential coding rule, and decoding the corrected amplitude shift keying signal by using a message analyzer to obtain an amplitude shift keying message. The method and the device of the invention eliminate the adverse effect of noise and interference on the decoding effect of the amplitude shift keying signal, which are frequently encountered in the decoding process of the amplitude shift keying signal, and obviously improve the success rate of the decoding of the amplitude shift keying signal.

Inventors

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Assignees

上海灿瑞微电子有限公司

Dates

Publication Date: 20260512
Application Date: 20260108

Claims (10)

1. A method for decoding an amplitude shift keyed signal, comprising: Step S1, when no preamble is detected, enabling a dynamic deburring device to be in an on state so as to deburr an amplitude shift keying signal, and then detecting the preamble of the amplitude shift keying signal by using a windowing filter; Step S2, stopping deburring before detecting the first byte before detecting the preamble, and using a windowing filter to perform windowing filtering instead to identify the level of each observation window, so as to obtain corrected amplitude shift keying signals and detect the first byte of the amplitude shift keying signals; Step S3, after the first byte is detected, utilizing a windowing filter to perform windowing filtering to identify the level of each observation window, and then utilizing a bidirectional differential coding rule to correct the level of each observation window to obtain corrected amplitude shift keying signals; and S4, decoding the corrected amplitude shift keying signal by using a message analyzer to obtain an amplitude shift keying message.
2. The method of claim 1, wherein the windowing filter continuously detects a preamble of the amplitude shift keying signal based on a preamble characteristic of the amplitude shift keying signal; The preamble characteristic of the amplitude shift keying signal comprises the length of a preset bit period, the preamble of the amplitude shift keying signal is continuously detected based on the length of the preset bit period, and the preamble characteristic specifically comprises the steps of detecting the duration of two rising edges or the duration of two falling edges of the signal, taking the duration of the two rising edges or the duration of the two falling edges as the length of an actual bit period, comparing the length of the two rising edges or the duration of the two falling edges with the length of the preset bit period, and detecting the preamble of the amplitude shift keying signal if the difference value of the two rising edges or the duration of the two falling edges is smaller than a threshold value.
3. The method according to claim 1, wherein in the step S2, after the windowing filter detects the preamble, the windowing filter feeds back a control signal to the dynamic deburring device, so that the dynamic deburring device is in a closed state, and in the closed state, the dynamic deburring device stops deburring and delays the signal by the same time as in deburring.
4. The method of decoding an amplitude shift keyed signal of claim 1, wherein the step of identifying the level of each observation window by windowing with a windowing filter includes generating each observation window with an effective pulse width on the amplitude shift keyed signal and identifying the level of each observation window.
5. The method of decoding an amplitude shift keying signal according to claim 4, wherein the effective pulse width is obtained by manual setting, the length of a bit period is obtained while detecting the preamble of the amplitude shift keying signal and half thereof is obtained as the effective pulse width, or the average value of the lengths of the bit periods of a plurality of consecutive preambles is detected and half thereof is obtained as the effective pulse width, and/or Identifying the level of the observation window according to the statistics of the level duration inside the observation window, and/or Generating each observation window with effective pulse width, specifically comprising taking the detected ending point of the leading bit period as the starting point of the first observation window, generating the observation window with effective pulse width based on the starting point, searching the change edge of the level near the end point of each observation window, determining the starting point of a new observation window according to the change edge, generating the observation window with effective pulse width based on the starting point, and/or After windowing filtering to identify the level of each observation window, further comprising utilizing the preamble pattern to determine and correct the level of each observation window.
6. The method of decoding an amplitude shift keying signal according to claim 5, wherein searching for a level change edge near the end of each observation window and determining a new start point of the observation window based on the change edge, specifically comprises searching for a change edge within a predetermined range of a fixed size centered on the end of the observation window, and if found, using the change edge as the start point of the new observation window, otherwise, searching for a change edge nearest to the end of the observation window outside the predetermined range, and using the boundary of the predetermined range in the direction of the change edge as the start point of the new observation window.
7. The method of decoding an amplitude shift keying signal according to claim 1, wherein the level of each bit is corrected by using a bi-directional differential encoding rule, and specifically comprising identifying the level of each observation window by windowing filtering, determining the start of the first byte based on the identification result, determining the boundary of the bit from the boundary of the observation window based on the start of the first byte, observing the levels of two consecutive observation windows separated by the boundary of each bit, determining whether the levels are opposite, and if not, correcting is not required, otherwise, making a decision to modify the level.
8. The method for decoding an amplitude shift keying signal according to claim 7, wherein the decision to modify the level comprises comparing a high level duration of two levels when the two levels are on average, selecting a level longer in the high level duration as the high level and the other level as the low level; otherwise, if the two levels are on average to be low level, comparing the low level duration in the two levels, and selecting the level with longer low level duration as the low level and the other level as the high level; Or making a decision for modifying the level, specifically comprising the steps of comparing the time length occupied by the high level in the two levels when the two levels are high according to the preset level turning threshold time length, taking the level with the high level higher than the level turning threshold time length and the other level as the low level if the high level of one of the two levels is higher than the level turning threshold time length and the high level of the other level is lower than the level turning threshold time length, otherwise comparing the time length occupied by the low level in the two levels if the two levels are low, and taking the level with the low level time length higher than the level turning threshold time length and the low level time length of the other level as the high level if the low level time length of one of the two levels is higher than the level turning threshold time length and the low level time length of the other level is lower than the level turning threshold time length.
9. The method for decoding an amplitude shift keying signal according to claim 1, wherein the corrected amplitude shift keying signal is decoded by a message parser, and specifically comprises the steps of pulse width acquisition, preamble re-detection, re-identification of the start point of the first byte, and then bit decoding, byte decoding and verification, message protocol decoding and verification; And when the message parser finishes unpacking, notifying the windowing filter and the dynamic deburring device to restore the initial state so as to stop windowing filtering.
10. An amplitude shift keying signal decoding apparatus, comprising: the dynamic deburring device is arranged to be in an open state to deburr the amplitude shift keying signal when the preamble is not detected; A windowing filter configured to detect a preamble of the amplitude shift keying signal from the de-burred amplitude shift keying signal when the preamble is not detected, to perform windowing filtering to identify a level of each observation window before detecting the preamble until a first byte is detected, to obtain a corrected amplitude shift keying signal, and to detect a first byte of the amplitude shift keying signal, to identify a level of each observation window after detecting the first byte, and to then correct the level of each observation window using a bi-directional differential encoding rule, to obtain a corrected amplitude shift keying signal, and And the message parser is configured to decode the corrected amplitude shift keying signal to obtain an amplitude shift keying message.

Description

Amplitude shift keying signal decoding method and device Technical Field The invention belongs to the field of wireless charging of small-sized equipment, and particularly relates to a method and a device for decoding an amplitude shift keying signal. The amplitude shift keying signal decoding method is used for power transmitting equipment of the wireless charging system, namely, the source of the amplitude shift keying signal is power receiving equipment in the wireless charging system. The amplitude shift keying signal may come from a variety of physical information accompanying the power transfer process, such as coil voltage envelope, coil current envelope, phase relationship between coil voltage and power switch signal, etc. Background Early wireless charging systems, which only had power transmissions, did not involve communication between devices. Power is output from the power transmitter and received at the power receiver. The transmission power is wireless, typically a sinusoidal signal with a certain frequency. Within the power transmitter, regulation of the output power is typically achieved by controlling an analog half-bridge or full-bridge with a digital pulse width modulation (Pulse Width Modulation, PWM) signal. The PWM signal adjusts the power in dimensions of frequency, duty cycle, voltage, phase, etc. However, the power transmitter cannot know how much power is received by the power receiver at all, whether a large amount of power is lost in the wireless transmission process, whether the power loss becomes heat energy to affect the safety of the whole system, and what the power receiver can accept. Therefore, introducing a communication mechanism in a wireless charging device is a necessary need for system efficiency upgrades and security upgrades. To advance standardization and security of wireless charging modes, power supply equipment manufacturers have successively introduced various wireless charging protocols, including the Qi protocol architecture that is currently dominant. The protocol is a protocol proposed by the wireless charging consortium (Wireless Power Consortium, WPC) established in 2008. The protocol has significantly accelerated the iterative evolution speed of the protocol in recent years due to the addition and support of apple companies, and has become one of the most mainstream in wireless charging protocols. The qi2.2 protocol introduced in 2025 has increased the charging power from 15W to 25W and puts more stringent demands on the safety of charging, the accuracy of power regulation. The quality of communication between the power transmitting and receiving devices is the basis for ensuring reliable execution of the above-mentioned protocols. The communication is split into two directions as shown in fig. 1. One of which is transmitted from a power transmitter and received by a power receiver, and the transmission mode is Frequency shift keying (Frequency SHIFT KEYING, FSK). This directional communication is used for complex control handshakes in the protocol. The other direction is from the power receiver, received by the power transmitter, and the transmission is Amplitude shift keying (Amplitude-SHIFT KEYING, ASK). This directional communication is the basic communication link of a wireless charging system, and contains information about the power requirements of the power receiver (increasing or decreasing the power transmission requirements) and the power measurements actually obtained by the power receiver, and if the communication in this direction is not smooth, the charging will stop within a few seconds. ASK communication is critical for wireless charging, and therefore, a transmitting side (a power receiver) of ASK and a receiving side (a power transmitter) of ASK both have multiple circuits for modulating and demodulating ASK, and they operate simultaneously or in a time-sharing manner to cope with complex wireless communication environments, including factors such as a coil used for charging, a battery margin of a charged device, and a state (whether a screen is being opened for operation or standby) at the time of charging, which affect the communication effect of ASK, so that different modes need to be selected for modulation and demodulation. On the transmitting side of ASK, two modes, i.e., resistance modulation and capacitance modulation, are generally used to interfere with the power transmitted by the power transmitter, so as to achieve the effect of modulating ASK waveforms. On the receiving side of ASK, the demodulation methods commonly used are voltage demodulation, current demodulation, phase demodulation, and the like. In order to ensure the communication quality and prevent packet missing and packet error, the demodulation modes are generally started at the same time, and then one path of successfully unpacked packet is selected to be sent to a protocol layer. On the ASK receiving side, i.e., the power transmitter side, various demodulat