Collision detection methods

Abstract

One aspect of this disclosure relates to a collision detection method. A wireless device is disclosed that can receive data packets according to a protocol such as Bluetooth and can react quickly to the reception of interfering RF packets, rather than discarding both the first RF packet and the interfering RF packet, to reduce message delays caused by collisions in high-device-density environments. When the difference in Received Signal Strength Indicator (RSSI) between the interfering RF packet and the first RF packet exceeds a threshold, the device can detect the interfering packet and resynchronize a portion of its circuitry to lock onto and receive the interfering packet. The wireless receiver can detect the interfering RF packet by detecting one or more of a specific resynchronization byte sequence, an increase in RSSI, or a phase shift. Additionally, the wireless device can add the specific resynchronization byte sequence to the RF packets of a standard protocol.

Description

[0001] This application is a divisional application of invention patent application 201980014645.1 entitled "Conflict Detection Method", filed on February 25, 2019.

[0002] Cross-references to related applications

[0003] This application claims priority to U.S. Provisional Patent Application No. 62 / 634,746, filed February 23, 2018, the entire disclosure of which is incorporated herein by reference. Background Technology

[0004] Many wireless communication protocols suffer from wireless congestion, with Bluetooth being particularly vulnerable. In Bluetooth, collisions of radio frequency (RF) packets can cause a wireless receiver to discard both RF packets. As the density of wireless devices in space increases, the number of devices transmitting in the same or overlapping frequency bands also increases, raising the probability of RF packet collisions. Packet collisions can result in both the first RF packet and the incoming colliding RF packet being lost (i.e., discarded), potentially compromising communication reliability.

[0005] This problem is typically mitigated by transmitting multiple redundant RF packets to ensure that at least one of the redundant messages is successfully received by the wireless receiver without being lost due to collisions. However, if the first few RF packets in a set of redundant RF packets are lost due to collisions with one or more RF packets, a time delay may exist between the time the first RF packet is transmitted and the time subsequent redundant RF packets are received. For systems requiring fast response times, such as lighting control systems, this time delay is undesirable and may even be unacceptable. Therefore, it is desirable for the wireless receiver to detect when packet collisions occur and to further recover and receive interfering packets. Summary of the Invention

[0006] This article describes a solution in which a wireless receiver can begin receiving a first RF packet, subsequently detect interfering RF packets (i.e., detect packet collisions), and react quickly to receive the interfering RF packets, rather than discarding both the first and interfering RF packets. This solution can be applied to any protocol, such as Bluetooth. The wireless receiver may be able to detect the presence of interfering packets during the reception of the first RF packet when the difference in Received Signal Strength Indicator (RSSI) between the interfering RF packets and the first RF packets exceeds a threshold.

[0007] Upon detecting interfering RF packets, the wireless receiver can then reset a portion of its circuitry (resynchronize) to quickly lock onto (i.e., synchronize) the interfering packets in order to receive them. This allows the wireless receiver to react quickly to receive the interfering packets, rather than discarding both the initial RF packet and the interfering packet.

[0008] A wireless receiver can detect interfering RF packets based on any one or a combination of three different methods: detecting a specific resynchronization byte sequence (pre-synchronization), detecting an increase in RSSI during the reception of the first RF packet, or detecting a phase shift in one or more data symbols during the reception of the first RF packet. This allows the wireless receiver to prioritize packets from adjacent wireless devices and / or RF packets requiring higher priority, such as lighting control packets.

[0009] Additionally, this document describes a method for a wireless transmitter of a wireless device to add a specific resynchronization byte sequence to RF packets of a standard protocol such as Bluetooth. Although Bluetooth is used as an example throughout this specification, readers will recognize that the examples described herein can also be applied to other standard protocols (e.g., ZigBee, Z-Wave, etc.). Attached Figure Description

[0010] Figure 1 It is an exemplary space with various wireless devices.

[0011] Figure 2 This is an exemplary block diagram of a wireless device.

[0012] Figure 3 yes Figure 2 An exemplary block diagram of a wireless receiver for a wireless device.

[0013] Figure 4A This is a diagram illustrating the components of an exemplary RF data packet.

[0014] Figure 4B This illustrates an exemplary method by which a wireless receiver changes its state in response to the detection of an RF packet.

[0015] Figure 5 This is a diagram of a data packet collision.

[0016] Figure 6 This is a diagram of an exemplary RF packet that has undergone pre-synchronization.

[0017] Figure 7A This is an exemplary method describing how a wireless receiver can detect interfering second RF packets based on RSSI.

[0018] Figure 7BThis is a second exemplary method demonstrating how a wireless receiver can use pre-synchronization and RSSI to lock onto interfering RF packets. Detailed Implementation

[0019] Figure 1 This is an exemplary room 100, which contains multiple wireless devices, i.e., devices that transmit radio frequency waves. The wireless devices may include, for example, one or more wireless audio speakers 103, for playing music received from streaming devices such as tablet computer 115 or voice assistant device 125 (although other wireless devices such as telephones, laptops, PCs, etc., can also be used as streaming devices). For example, tablet computer 115 may stream audio from an internet-based music service and may wirelessly transmit that audio stream to speaker 103 for playback in room 100.

[0020] Room 100 may include a camera 122 and / or a network camera or video intercom 120. The video intercom may include a camera, a microphone, and / or a speaker. The camera 122 and video intercom 120 may communicate wirelessly with a tablet computer 115, wirelessly with each other, or wirelessly with a wireless speaker 103. The video intercom may record images and audio in the user's environment and transmit that image and audio data to a remote device, such as another video intercom, tablet computer, PC, etc.

[0021] Room 100 may also include one or more asset tracking devices, such as one or more beacon devices. For example, room 100 may include a beacon device, such as a key fob 112 shown attached to a set of keys. The key fob 112 may wirelessly communicate with one or more devices, such as a tablet 115 and / or a smartphone, to alert user 105 to the location of the key fob if user 105 misplaces it.

[0022] User 105 may have one or more wearable wireless devices, such as smartwatch 102. One or more wearable wireless devices may periodically communicate with a smartphone (not shown) or other devices. For example, the smartwatch may communicate with a smartphone or tablet 115 to display incoming text messages received by the smartphone or tablet 115 on the surface of the smartwatch screen, making it easier for user 105 to notice that a text message has been received. User 105 may additionally use any number of wearable wireless devices, including but not limited to: health or activity trackers, such as… Smart glasses, wireless headphones, smart shoes, etc. Any or all of these wearable wireless devices can communicate wirelessly with a smartphone or tablet 115.

[0023] Room 100 may also include wireless devices capable of controlling electrical loads, for example, as part of a load control system. For instance, room 100 may have a wireless thermostat 135 for wirelessly controlling an HVAC system. Room 100 may also have a lighting control system with one or more wireless light sources, such as ceiling lights 110A, 110B, and lamp 113. The lighting control system may also include a wireless remote control 104 capable of controlling one or more of the ceiling lights 110A, 110B, and / or lamp 113. The lighting control system may also include one or more wireless occupancy sensors 116. These wireless occupancy sensors may be passive infrared, microwave, ultrasonic, thermopile arrays, or any other type of occupancy sensor or a combination of such sensors listed herein. The wireless occupancy sensors can detect movement in room 100 and can transmit wireless commands to other wireless devices in room 100 based on occupancy detection to control one or more electrical loads, such as lighting loads 110A and 110B.

[0024] It will be understood that the wireless devices shown in room 100 are intended as examples, and different, fewer, or more wireless devices may exist in any given space. Many of the wireless devices shown may transmit RF data packets 108 periodically or non-periodically based on events. For example, a smartwatch 102 may periodically receive updates from a tablet 115 or a smartphone (not shown) to update the current time, or non-periodically receive text messages, etc. In another example, a remote control device 104 may, in response to pressing a button on the remote control device 104, transmit RF data packets 108 containing lighting commands to one or more lighting loads 110A, 110B.

[0025] Wireless devices in room 100 can each wirelessly transmit messages within RF data packets 108 in the same or nearly the same frequency band. For example, the wireless devices can communicate using protocols. For the purposes of this specification, Bluetooth is used as an exemplary protocol (e.g., the Bluetooth protocol specified by Bluetooth 4.2 or later); however, it will be understood that the processes and devices described herein are not limited to any particular protocol but can be applied to any number of different wireless protocols, such as standard protocols defined by ANSI, IEEE, etc., or such as ClearConnect. TM The proprietary agreement.

[0026] As the number of devices transmitting in the same frequency band in room 100 increases, the transmitted messages (i.e., RF packets) may interfere with each other. For example, a wireless receiver, such as one of the speakers 103, may be configured to receive standard protocol RF packets (such as Bluetooth packets). While the tablet 115 may send RF packets to the speaker 103, the speaker 103 may also receive other RF packets transmitted at very close, similar times. For example, the thermostat 135 may transmit RF packets in the same frequency band and / or use the same standard protocol as the RF packets from the tablet 115. Both the RF packets sent by the thermostat 135 and the RF packets sent by the tablet 115 may be received by the speaker 103 at approximately the same time. The two RF packets received simultaneously by the wireless receiver of the speaker 103 may interfere with each other, causing the speaker 103 to discard both packets, so that the message within either RF packet is not processed.

[0027] To complicate matters further, wireless devices located within room 100 may also communicate with (i.e., receive RF data packets from) one or more devices not located within room 100. For example, wireless devices within room 100 may receive RF data packets from other lighting control devices, such as one or more remote controllers, system controller 150, etc., located in one or more adjacent rooms or spaces (not shown). In other words, RF data packets received from outside room 100 may be in the same frequency band as those communicating with wireless devices located within room 100.

[0028] When a wireless device in room 100 is configured to receive external RF packets from other wireless devices outside room 100, the external RF packets may be less relevant compared to RF packets from wireless devices inside room 100. For example, a wireless device inside room 100 may primarily respond to other wireless devices that are very close (i.e., other wireless devices within room 100), while external RF packets received from outside room 100 may generally be irrelevant to wireless devices inside room 100. However, when a wireless device inside room 100 receives an external RF packet, that external RF packet may engage with the wireless transceiver of the wireless device inside room 100, which may increase the probability of interference, i.e., dropping relevant RF packets received from other wireless devices within room 100. One way to reduce the external RF packets received by a wireless device inside room 100 is to limit the wireless range of the wireless device inside room 100 to only receiving RF packets from other wireless devices that are very close (i.e., within room 100). For example, wireless devices within room 100 may reduce or degrade their wireless receivers so that they may not receive RF packets that are not very close to the wireless device (i.e., external RF packets not within room 100). Alternatively or additionally, wireless devices within room 100 (and / or wireless devices outside room 100) may reduce the transmission power of transmitted RF packets to limit the wireless range in which the message can be received.

[0029] However, it may be desirable for one or more wireless devices within room 100 to receive certain external RF packets from outside room 100. For example, system controller 150 may connect to the Internet 152 (e.g., via a router) to receive one or more updates (i.e., software updates). System controller 150 may wirelessly communicate with one or more wireless devices in room 100 to update devices or convey other messages about system functionality, such as instructing one or more lighting control devices 110A, 110B to enter emergency mode. In this case, system controller may coordinate (i.e., generate a schedule) with one or more wireless devices in room 100 such that one or more of the wireless devices in room 100 can maintain a reduced wireless range and selectively increase their respective wireless range at specific times or time intervals to receive RF packets from devices such as system controller 150 outside room 100.

[0030] Optionally or additionally, one or more of the wireless devices in room 100 may maintain an increased wireless range (thus maintaining reception of RF packets from outside room 100, including irrelevant RF packets) while being configured to prioritize relevant RF packets, thereby mitigating RF interference. For example, while one or more of the wireless devices in room 100 receive a first packet, the wireless device(s) may be configured to detect when it is also receiving interfering relevant RF packets, and the wireless device(s) may react quickly to receive the interfering relevant RF packets. That is, the wireless device(s) may resynchronize its wireless receiver to discard the first packet and receive the interfering relevant RF packets. As will be described in more detail herein, relevant RF packets may be identified by a specific resynchronization byte sequence, a higher RSSI, and / or a phase shift.

[0031] Figure 2 This is an exemplary circuit block diagram of wireless device 200, such as those that can represent Figure 1 Any wireless device shown and / or described. Device 200 may be powered by power supply 202. Power supply 202 may be any suitable alternating current (AC) or direct current (DC) power source. For example, power supply 202 may be AC ​​line voltage. Alternatively, power supply 202 may be DC power, such as a 12 or 48-volt power source provided by low-voltage wires, Power over Ethernet (PoE), one or more batteries, solar cells(s), etc. The device may include at least one power supply device 222 that supplies a voltage Vcc for powering the electronic circuitry of the device. Power supply device 222 may be integrated with the device, or the power supply device may be provided as an AC-DC power supply adapter for connecting the device to a wall outlet such as power supply 202.

[0032] Device 200 may have control circuitry 214. This control circuitry may be powered by the voltage Vcc provided by power supply device 222. The control circuitry may include one or more of the following: processor(e.g., multiple microprocessors), multiple microcontrollers, multiple programmable logic devices (PLDs), multiple field-programmable gate arrays (FPGAs), multiple application-specific integrated circuits (ASICs), or any suitable controller or processing device, or a combination thereof.

[0033] Device 200 may include one or more communication circuits 224 operatively connected to control circuit 214. The communication circuit 224 may be a wireless communication circuit and may send or receive wireless commands and / or data to / from external devices or networks. For example, the communication circuit 224 may be a radio transceiver configured to transmit and receive RF protocol messages, such as Bluetooth, via one or more antennas (not shown). Alternatively, device 200 may also have wired communication circuitry, for example, communication circuitry configured to connect to USB-C, Ethernet or Cat5, serial cable, or any other type of communication line.

[0034] The device 200 may have one or more memory modules (“memory”) 220 (including volatile and / or non-volatile memory modules), which may be non-removable and / or removable memory modules. The memory 220 may be communicatively coupled to the control circuitry 414. The non-removable memory 220 may include random access memory (RAM), read-only memory (ROM), hard disk, or any other type of non-removable memory storage device. The removable memory 220 may include a Subscriber Identity Module (SIM) card, memory stick, memory card, or any other type of removable memory. The memory 220 may store one or more software-based control applications that include instructions executed by the control circuitry 214. When such instructions are executed, the control circuitry can provide the functionality described herein. The memory may also store data including operating parameters or received wireless commands.

[0035] The wireless device 200 may include additional circuitry not shown here, including but not limited to: actuators, light-emitting diodes (LEDs), load control circuitry, passive infrared occupancy sensing, microwave occupancy sensing, ambient light sensing, clock or day / night tracking, etc.

[0036] Figure 3 This is a block diagram of an exemplary wireless receiver 300 capable of receiving and processing (i.e., demodulating) wireless RF packets. For example, the wireless receiver 300 can be coupled with... Figure 2 The wireless receiver is identical to or a component of the communication circuit 224. The wireless receiver may be electrically coupled to the antenna 302. The wireless receiver may comprise a combination of analog components and (multiple) integrated circuits (ICs) (i.e., radio chips), or the antenna may be directly fed to the radio chip (i.e., without intermediate components). The antenna may be a trace on a printed circuit board, such as a planar inverted-F antenna (PIFA); a chip antenna; a wired antenna, etc.

[0037] The antenna can receive wireless RF signals. These RF signals may include RF data packets, which may contain messages or raw signals that the wireless transmitter has modulated using a carrier wave according to a modulation type. Exemplary modulation types include Frequency Shift Keying (FSK), Phase Shift Keying (PSK), Quadrature Phase Shift Keying (QPSK), etc. Other modulation types are known and can be used.

[0038] The wireless receiver 300 may include an RF amplifier and a filter 310. RF signals received by the antenna 302 can pass through the RF amplifier and filter 310. The RF amplifier and filter 310 may include one or more filter stages and / or amplification stages to filter the received RF signals and increase the amplitude of the incoming RF signals. For example, the filter stage may include a wideband bandpass filter stage that rapidly reduces the frequency bandwidth of the incoming signal. For example, a wideband filter for RF packets at a 2.4 GHz carrier frequency may be approximately 100 MHz, or at least the width of the entire frequency band encompassing all communication channels. The RF amplifier and filter 310 may also include automatic gain control (AGC) to automatically scale (i.e., adjust) the magnitude of the signal for better processing, which may, for example, amplify or reduce the signal.

[0039] The filtered and amplified RF signal can then be mixed with mixer 315, in which it is rapidly mixed with another lower-frequency signal provided by a local oscillator (LO) 318. The LO 318 can be located inside the wireless receiver 300 or can be an external crystal oscillator, such as a quartz resonator. Mixer 315 can use the LO 318 to downconvert the frequency, that is, downconvert the frequency of the RF signal to the fundamental frequency or intermediate frequency (IF). For example, the RF signal can be a high-frequency signal such as a 2.4 GHz frequency signal, while the LO signal can be the same frequency or a different frequency, such as a lower frequency.

[0040] Mixer 315 can multiply or heterodyne the RF signal with the LO signal 318 to generate an intermediate frequency (IF) signal. This IF signal may include a beat frequency, which comprises both the sum and difference of the RF and LO signals. The IF signal output of the mixer can be received by one or more IF amplifier and filter stages 320, which can bandwidth-limit the incoming IF signal to remove either the sum or difference signal (unwanted image signal) and amplify the remaining signal. For example, IF amplifier and filter 320 can remove high-frequency components of the IF signal, that is, remove the sum of the original RF and LO signals while amplifying the remaining difference signal. Compared to the first two stages (RF amplifier and filter 310 and mixer 315), the wireless signal throughput through IF amplifier and filter 320 may be relatively low.

[0041] The remaining RF signal at the intermediate frequency (IF) (i.e., the filtered IF signal) can then pass through demodulator 340. Demodulator 340 can receive and lock (i.e., synchronize) to the filtered IF signal and can demodulate or separate the original signal from the carrier. For example, the demodulator can synchronize (synchronize) to the RF signal by aligning each bit's edge / transition. The demodulator can include various sub-components such as analog-to-digital converters (ADCs), (multiple) digital filters, automatic gain control (AGC), etc. The demodulator can have a front end that may include a preselector and a signal sampler. The preselector may include one or more digital filters for further refining the filtered IF signal. The signal sampler can segment the signal into bits of one and zero. The front end segments the symbols by sampling and windowing the IF signal to detect each bit's edge / transition. The back end of the demodulator can receive the segmented sampled symbols and use a correlator or digital signal processor (DSP) to interpret the RF data packets. For example, when the demodulator processes the IF signal by sampling and windowing to resolve the IF signal into bits, the resolved bits can be stored in buffer 350.

[0042] Figure 4A This is an example RF data packet 400. For example, the length of RF data packet 400 may be at least 13 bytes. Each part of data packet 400 is described using an exemplary length of bits in a Bluetooth data packet. However, it will be understood that the length of data packet 400, or a part of data packet 400, or any other data packet described herein, is for illustrative purposes only, and the examples described herein can also be applied to data packets or data packet parts that are shorter or longer than the data packets or data packet parts described herein.

[0043] RF packet 400 may contain a preamble 404. For example, the length of preamble 404 may be approximately one byte. Preamble 404 can warn the wireless receiver that an incoming RF packet is being received. In response to the detection of preamble 404, the wireless receiver can use the bits of preamble 404 to lock (i.e., synchronize) RF packet 400 in order to receive and demodulate RF packet 400.

[0044] The preamble can be followed by address 408. For example, address 408 can be approximately four bytes long. This address indicates to the wireless receiver which wireless device is the intended recipient of the message. The address can also identify the wireless device that sent the message. The address can be any sequence of numbers, characters, or a combination of numbers and characters, such as a hexadecimal address.

[0045] Following address 408, RF packet 400 may include payload 412. For example, payload 412 may be six or more bytes long and may include a message body. The message body of payload 412 may contain instructions that a wireless device can execute when receiving and processing packet 400. For example, a wireless receiver may be part of a wireless lighting load. The wireless receiver may receive RF packet 400 from a load control device such as a wireless dimmer. For example, payload 412 may include lighting control commands from the wireless dimmer instructing the wireless lighting load to increase or decrease its intensity. For example, payload 412 may include a command to set the intensity of the wireless lighting load to 75%.

[0046] Payload 412 may be followed by error check 416. For example, this error check could be a checksum or cyclic redundancy check (CRC). The wireless receiver can use this error check 416 to determine whether data packet 400 has been accurately received. If the wireless receiver determines that the data packet has been accurately received, the wireless device of the wireless receiver can execute the instructions indicated in payload 412. For example, according to the previous example, the wireless lighting load could then change the intensity of the lighting load to seventy-five percent.

[0047] However, if the wireless receiver determines that the data packet has been corrupted—that is, interference RF packets or spurious RF transmissions have corrupted one or more bits of data packet 400—the error check can mark the message 400 as corrupted to the wireless receiver. If the wireless receiver determines that the RF data packet 400 has been corrupted, the wireless receiver can discard the data packet 400.

[0048] Figure 4B It can be made by, for example Figure 3 The wireless receiver 300 performs an exemplary method 450 to receive RF packets. This method 450 may begin at 452. At step 454, the wireless receiver may enter a search state, in which the receiver responds to receiving RF packets. The wireless receiver's bandwidth filter (i.e., set to a wide bandwidth in the search state) may be turned on to receive RF packets. At step 458, the receiver may determine whether an RF packet has been detected. For example, if the preamble of the RF packet has been identified, the receiver may determine that the RF packet has been received. If the preamble is not detected at step 458 (i.e., no RF packet is detected), the wireless receiver may maintain the search state at step 454 to receive RF packets.

[0049] If the receiver detects an RF packet, in step 460, the receiver can change state to enter a processing state. During the processing state, the receiver can lock (i.e., synchronize) to the RF packet being received. For example, the receiver can additionally adjust the bandwidth and / or gain of one or more filters and / or gain stages to receive the RF packet and process the message payload. After the RF packet has been fully received (i.e., CRC or error check is successful), in step 462, the receiver can become idle (i.e., not process the RF packet). (It will be understood that when the error check is unsuccessful, i.e., after the receiver has discarded the packet, the receiver can also or optionally become idle). The receiver can optionally become idle when transitioning to a search state and searching for new RF packets. For example, in step 464, the wireless receiver can transition from an idle state to a search state. To enter the receive search state, the wireless receiver can turn on (i.e., widen) the bandwidth of one or more filters and / or adjust the gain stage to search for new RF packets. The method can then end.

[0050] When the receiver enters the processing state in step 460 to process the currently received RF packet, the wireless receiver may not respond to other RF packets at that time. However, if a second interfering RF packet has been transmitted that overlaps with (i.e., interferes with) the first RF packet that the wireless receiver is currently receiving, the second interfering RF packet may corrupt the message payload of the first RF packet. When the wireless receiver processes and then performs error checking on the first RF packet, the wireless receiver may determine that the first RF packet has been corrupted, and the RF receiver may discard the first RF packet (i.e., the receiver may return to the search state). However, after the wireless receiver has already attempted to process the entire first packet, it may be too late for the wireless receiver to receive the second interfering packet, and both RF packets may be lost.

[0051] Figure 5 It is the wireless receiver of the wireless device (e.g., Figure 3An exemplary diagram of two messages received by a wireless receiver 300, where the two messages overlap in time (i.e., the messages interfere with each other). The wireless receiver (i.e., the radio transceiver) of the wireless device may begin receiving a first data packet, data packet A, at time T1. Data packet A may have a Received Signal Strength Indicator (RSSI) R1, as shown in the diagram. While the wireless receiver is receiving data packet A, a second data packet (data packet B) may begin to overlap with data packet A at time T2. As shown in the diagram, data packet B may have an RSSI of R2, which may be greater than that of data packet A. Therefore, data packet B may be a stronger data packet than data packet A. When a second data packet or interfering data packet with a stronger signal than the first data packet arrives at the receiver, this stronger interfering data packet may overlap and corrupt the data of the first data packet. That is, when data packet B with a stronger signal R2 overlaps with data packet A with a lower R1, the data of data packet A may be corrupted.

[0052] At time T3, at the end of the fully received data packet A (along with the beginning of data packet B), the wireless receiver will perform an error check to determine whether the message content of data packet A has been corrupted. The error check can be any of many known error checking methods, such as Cyclic Redundancy Check (CRC), parity check, checksum, Hamming code, message authentication code, etc. The wireless receiver can use the error check to determine whether data packet A contains errors (e.g., framing errors), which can indicate that data packet A contains a high percentage of erroneous data and therefore cannot be processed. Because data packet B overlaps with data packet A in time and has a stronger signal strength RSSI R2 than data packet A (RSSI R1), data packet A may contain errors, and the message of data packet A may therefore be lost (i.e., discarded).

[0053] For some protocol implementations (e.g., Bluetooth), in addition to losing packet A, the wireless receiver may also discard packet B. The wireless receiver may discard packet B because it cannot detect interfering packets, or, if it does detect interfering packets, it may not respond quickly enough to receive them. When the wireless receiver fails to resynchronize / lock onto packet B, the reception of both RF packet A and RF packet B is delayed until additional redundant first and second RF packets are received.

[0054] This delay in receiver response time can be undesirable, especially for applications such as lighting control, where users expect near-instantaneous response to lighting control commands. For example, if Figure 1When user 105 presses a button on lighting control device 104, the user may expect one or more lighting loads 110A, 110B to turn on with no delay (or minimal delay). In a heavily congested RF environment, delays may occur, which could be unacceptable.

[0055] To minimize latency and prevent both RF packets from being dropped, the wireless receiver can detect at time T2 that it is receiving a second interfering packet (packet B) at the same time it is receiving packet A. Rapid detection of the interference allows the wireless receiver to determine at time T2, rather than time T3, that packet A contains erroneous data, and gives the receiver time to react to the interference and receive packet B.

[0056] When it is determined at time T2 that a second, stronger data packet B is interfering with data packet A, the wireless receiver can attempt to recover the second data packet B. To recover the second data packet B, the wireless receiver can resynchronize (resynchronize) at time T4 by the end of the data packet length to receive data packet B. For this purpose, the signal strength of the second RF data packet (e.g., RSSI, power, or signal-to-noise ratio (SNR)) may need to be much larger than a threshold amount than the signal strength of the first RF data packet. For example, the RSSI difference between data packet B (R2) and data packet A (R1) (i.e., RSSI...) Δ It may require RSSI greater than the threshold. thresh As shown in the following formula:

[0057] |R2-R1|>RSSI thresh

[0058] For example, RSSI thresh It could be 10 or 12 dB, however other examples are possible. If the RSSI of the second RF packet is significantly larger than the RSSI of the first RF packet... thresh Then, the front end of the resynchronization demodulator can allow the receiver to lock onto the second RF packet and receive it correctly. However, if the signal strength of the second RF packet is greater than that of the first RF packet but less than the RSSI... thresh If the signal strength difference is too large, it may be impossible to distinguish the second RF packet from the first RF packet. It will be appreciated that although this paper describes the difference in signal strength using RSSI, other characteristics, such as power or signal-to-noise ratio (SNR), may also be used.

[0059] To resynchronize, the receiver can cause the demodulator to stop demodulating the current first RF packet and can also clear the resolved bits stored in the buffer. The receiver can then resynchronize to the second interfering RF packet. This may also involve adjusting one or more gain stages and / or adjusting the receiver's bandwidth, although it will be recognized that the power level of the second interfering RF packet may be close enough to that of the first RF packet that adjustment of one or more gain stages and / or bandwidth may not be necessary.

[0060] To trigger resynchronization of the demodulator of the wireless receiver so that packet B can be received and demodulated, one or more methods for detecting a second interfering packet (e.g., packet B such as at time T2) can be used, according to the following implementation. For example, according to a first example, the wireless receiver can identify a specific resynchronization byte sequence of the interfering packet. In a second example, the wireless receiver can detect a transition in the RSSI, where the RSSI... Δ Greater than RSSI thresh According to the third example, the wireless receiver can detect an unexpected phase shift while receiving the first message. Each of these methods will be described in more detail in the examples in this article.

[0061] According to one example, a wireless receiver can detect a second, stronger interfering RF packet by identifying a specific resynchronization byte sequence in the interfering packet. The specific resynchronization byte sequence can be any combination of bits that the wireless receiver is configured to identify as a resynchronization trigger. For example, the specific resynchronization byte sequence may include a reserved sequence of bits that would not occur in the RF packet other than the specific resynchronization byte sequence. The specific resynchronization byte sequence allows the wireless receiver to prioritize any RF packet containing that specific resynchronization byte sequence, regardless of the receiver's state, by causing the wireless receiver to resynchronize and receive RF packets. For example, when the specific resynchronization byte sequence is received, the receiver may be in the process of receiving a first RF packet, causing the receiver to change its state from a receive processing state to a receive search state. A state change during resynchronization may cause the wireless receiver to ignore (i.e., discard) the first RF packet. By changing its state again from the receive search state to the receive processing state, the receiver can recover and lock onto receiving the second interfering RF packet.

[0062] Figure 6 This can be an exemplary structure of an RF data packet 600 that may include a specific resynchronization byte sequence. A portion 602 of this RF data packet 600 can be a regular protocol data packet that does not cause the wireless receiver to resynchronize, such as... Figure 4ARF data packet 400. For example, protocol data packet 602 can be a standard protocol data packet such as a Bluetooth protocol data packet, or any other protocol data packet that includes proprietary protocols. For example, by, Figure 3 Each RF packet processed by the wireless receiver of receiver 300 may conform to a protocol standard (i.e., the Bluetooth standard). That is, each packet demodulated by the wireless receiver may include at least the standard components of standard protocol packet 602. Each portion of packet 600 is illustrated using an exemplary bit length of a Bluetooth packet.

[0063] Part 602 of RF data packet 600 can be with Figure 4A The RF packet 400 shown is the same. For example, RF packet 602 may contain a preamble 604, an address 608, a payload 612, and a CRC or error check 616, which may correspond to... Figure 4A The data packet 400 contains a preamble 404, an address 408, a payload 412, and a CRC or error check 416.

[0064] The wireless transmitter of a wireless device can modify RF packet 602 to generate RF packet 600 via preamble 620. Preamble 620 may include pre-synchronization 624, i.e., pre-synchronization preceding the packet preamble. Pre-synchronization 624 may contain a specific resynchronization byte sequence followed by a idle time 626. The idle time 626 can be any bit sequence that allows the receiver to resynchronize. For example, the specific resynchronization byte sequence can trigger the wireless receiver to resynchronize as described above. The wireless receiver can then resynchronize during the idle time 626 following the specific resynchronization byte sequence of pre-synchronization 624, thereby allowing the wireless receiver to lock (i.e., synchronize) to packet 600 using preamble 604. For example, the idle time 626 following pre-synchronization 624 may contain all zero bits, or alternating ones and zeros; however, other examples are also possible.

[0065] Although portion 620, including pre-synchronization 624, has been described as preceding the preamble 604 of the standard protocol data packet 602, it will be understood that other configurations are possible. For example, pre-synchronization may be part of preamble 604, or it may be included immediately before preamble 604 (i.e., idle time 626 may be removed).

[0066] When the wireless receiver begins receiving the first data packet, receiving a specific resynchronization byte sequence of pre-synchronization 624 during the reception of the first data packet can indicate to the wireless receiver that a second interfering RF data packet is being received. The wireless receiver can resynchronize in response to the specific resynchronization byte sequence of pre-synchronization 624 of the second interfering RF data packet. If the second interfering RF data packet has an RSSI greater than [value missing], [further details about RSSI are needed]. thresh RSSI Δ (or power or SNR greater than the threshold), then the wireless receiver can lock onto and receive the entire second interfering RF packet.

[0067] A specific resynchronization byte sequence can be any number of bits or bytes in length, for example, 4 bytes. For instance, there are protocols with resynchronization codes as short as a single byte. This allows a wireless receiver to identify packets specifically targeted at it, unlike random messages in space. Additionally, other devices that transmit using standard protocols without a specific resynchronization byte sequence can still be received by the receiver.

[0068] A longer, specific resynchronization byte sequence (pre-synchronization) may reduce the likelihood that any other message traffic might inadvertently contain that specific resynchronization byte sequence (pre-synchronization). For example, if a transmitted RF packet (or any interference with the transmitted RF packet) happens to contain a segment in its payload or address that matches a pre-synchronized bit / byte sequence, the receiver might identify the bit / byte sequence in the message and incorrectly interpret it as pre-synchronization. This could result in the message being lost or discarded as the wireless receiver resynchronizes and searches for the preamble.

[0069] The longer a particular resynchronization byte sequence is (i.e., the larger the number of bits), the less likely it is that the payload or message portion of an RF packet might unintentionally contain that particular resynchronization byte sequence. For example, the probability that a bit sequence within a message matches a particular resynchronization byte sequence can be expressed as 2^(-n), where n is the number of bits in the resynchronization code.

[0070] For wireless devices that both transmit and receive RF packets, the radio transceiver can modify the transmitted RF packets so that the RF packets transmitted by the device's wireless transmitter do not reset the transmitting device's wireless receiver. Several options exist for achieving this, including, for example, using a coded physical layer (PHY) as described herein; however, other techniques are also possible.

[0071] In the first example, the wireless device can use an encoded PHY, which ensures that data packets transmitted from the device's wireless transmitter do not reset the device's own wireless receiver. For example, an encoded PHY can use a sequence of "01" to replace all bits "0" in the original bit stream, and a sequence of "10" to replace all bits "1". The wireless transmitter can then use the encoded PHY to transmit messages. The encoded PHY prevents the sequential transmission of more than two "0"s or more than two "1"s, and allows sequences of three or more "1"s or "0"s in a line to be used to force resynchronization without the risk of that sequence appearing in valid data (e.g., allowing pre-synchronization sequences "1111" or "0000"). However, it should be noted that this encoding scheme doubles the number of bits transmitted, similar to the Universal Asynchronous Receiver-Transmitter (UART) encoding scheme which increases the number of bits transmitted by 25% (i.e., 10 bits are transmitted for every 8 bits in the original data). People will realize that a receiver that receives RF packets from a transmitter containing an encoded PHY can also decode the encoded PHY in order to process the message.

[0072] The use of encoded PHYs is similar to byte stuffing. For example, in byte stuffing, if a specific resynchronization byte sequence used to force resynchronization is code 0x5A, this sequence can be excluded from the transmitted data by replacing 0x5A in the transmitted data with multi-byte codes such as 0x00, 0x01. In this scheme, code 0x00 appearing in the original data will be replaced by the sequence 0x00, 0x00. This 0x00 can be called an "escape character," and various sequences can be called "escape sequences" or "escape codes." Given the existence of an escape character, more than one specific byte can be excluded from the data (for example, in the example above, using various escape sequences starting with the 0x00 escape character, up to 255 byte patterns can be excluded from the data stream).

[0073] It should be noted that even in wired protocols, using interrupt characters or framing errors within the payload of RF packets to force the receiver's demodulator to resynchronize is a common technique. However, the technique described herein provides a method by which a wireless receiver can adapt to receiving interfering RF packets from any standard protocol (e.g., Bluetooth, or any other standard or proprietary protocol) that does not provide for receiving stronger interfering RF packets, while simultaneously allowing the wireless receiver to receive standard protocol RF packets. This results in the wireless receiver not only having enhanced packet reception capabilities but also backward compatibility with existing protocol architectures. In other words, this allows the wireless receiver to resynchronize regardless of its state.

[0074] According to the second example, as an alternative to using a specific resynchronization byte sequence, the wireless receiver can detect transitions or step changes in the received signal. For example, one or more filter stages (e.g., Figure 3 The RF amplifier and filter 310 are used to quickly detect RSSI transitions. Alternatively, the demodulator of the wireless receiver (e.g., Figure 3 The demodulator 340 can detect transitions in RSSI. Although the method described herein is for transitions in RSSI, it will be understood that transitions in power or signal-to-noise ratio (SNR) can be used equivalently. A transition in RSSI (or power, or SNR) can be defined as an instantaneous increase from a first value to a second value.

[0075] While receiving a first message, a step change (i.e., a jump) in the RSSI from a first value to a second value can indicate that a second message with a higher RSSI is causing interference. A wireless receiver can detect an RSSI jump by monitoring the RSSI of the sampled signal for the step change or hysteresis. For example, the demodulator's detection of an RSSI jump might trigger an interrupt. It is well known that triggering an interrupt adjusts the automatic gain control (AGC) to allow the wireless receiver to readjust to a new RSSI level. However, since a jump in the RSSI assumes the reception of a second, stronger message, according to this example, an interrupt could also be used to resynchronize the demodulator as previously described.

[0076] It will be recognized that, in addition to RF collisions that interfere with RF packets, RF packets may contain intermediate messages with increasing RSSI. For example, a moving target may cause the RSSI to gradually increase. Alternatively, electrical changes or events on the wireless receiver's printed circuit board (PCB) may affect the antenna and / or the wireless receiver, thus erroneously causing a noticeable RSSI jump. To prevent the wireless receiver from erroneously resynchronizing the demodulator and losing RF packets in these situations, an RSSI jump threshold can be used. That is, the demodulator can only resynchronize if the RSSI jump is greater than the threshold. In this way, erroneous resynchronization can be reduced. For example, the threshold amount can be the RSSI as described above. thresh However, other values ​​can also be used. For example, if an electrical event on the PCB is known to cause an RSSI jump of up to 12 dB, an RSSI threshold of 15 dB can be used.

[0077] According to another example, a wireless receiver can detect a phase shift in one or more data symbols while receiving a first message, and in response to the detected phase shift, determine that a second, stronger message is causing interference. This phase shift can be detected by the wireless receiver. For a sampling rate of 16 samples per bit, a phase shift can be detected when the apparent bit of the message is longer or shorter than expected. This can indicate that a second message with a different phase than the first message is interfering with the first message (i.e., being received simultaneously). A demodulator can detect a phase shift by detecting edges of bits or symbols that appear in unexpected locations. For example, a signal can contain oversampled data, meaning that several samples can include a single bit. As part of a downsampling routine, the demodulator can convert the oversampled data into a bit stream. To downsample an oversampled signal, the demodulator must align the downsampling routine so that the oversampled data will match one or more bits (i.e., discrete "1"s or "0"s) within a window. Therefore, the demodulator can detect a phase shift by detecting edges in the oversampled data to align the downsampling routine. The demodulator's sampler may expect these edges to be separated by a multiple of the oversampling rate. Therefore, a phase shift can be easily detected when the sample count between edges deviates from this multiple by more than a threshold. Similarly, downsampling can be done using a voting scheme (i.e., for 16x oversampling, if more than 8 samples are high, the output will be 1). A phase shift (or noise event) can be detected when the number of high or low samples is in an out-of-range range (e.g., 5-11), thus leading to doubt about the accuracy of the downsampled bit output. For example, when the bits or signs are correctly aligned, the expected count will be sixteen counts for one value ("0" or "1") and zero counts for another value ("1" or "0"). Some discrepancies may be due to sign or bit drift (i.e., jitter) or minor noise. However, even if it is the majority, any number close to fifty percent may indicate a relatively low confidence that the byte has been correctly sampled.

[0078] Optionally, the demodulator front end can detect phase shift by detecting a rapid decrease in symbol edge jitter. For example, the edges of symbols or bits in RF packets with RSSI close to the noise floor may jitter or change over time. However, if the amount of phase jitter decreases rapidly, causing the edges of symbols or bits in the RF packets to suddenly become neat (i.e., the jitter has decreased by more than a threshold amount), this may indicate that a second RF packet with a higher RSSI is being received (i.e., the second interfering RF packet may be corrupting the data in the first RF packet).

[0079] According to Figure 7A The method shown causes the wireless receiver to resynchronize. Figure 7A It can be made by, for example Figure 3The exemplary method 700 performed by the wireless receiver of the wireless device 300 is described below. The method may begin at step 702. At 704, the wireless receiver may begin receiving a first message, such as data packet A of FIG. 4. At step 706, the wireless receiver may detect a stronger interfering message (i.e., a second message with an RSSI greater than the first message, such as data packet B of FIG. 4). The wireless receiver may detect the stronger interfering message in any one or a combination of several ways, which will be described in further detail herein.

[0080] If no stronger interference message is detected in step 706, the wireless receiver may continue receiving data packets in step 732, and the method may exit in step 712. Otherwise, the wireless receiver may resynchronize to the stronger data packet B. To perform resynchronization, the wireless receiver may reset a portion of its internal circuitry. Resynchronization can occur in a very short amount of time, less than the length of the data packet (unlike a reset of the entire radio or wireless receiver, which may take longer than the length of the data packet). This allows the wireless receiver to lock onto the second, more interference-laden RF data packet to receive the second RF data packet, rather than losing / discarding both the first and second interfering RF data packets.

[0081] The implementation of wireless receiver resynchronization can be specific to the wireless receiver used. As a result, in response to the detection of interfering packets, resynchronization causes the wireless receiver to undergo a state change from a processing state to a search state. During the intermediate transition state of receiving the first packet, the first packet is lost (i.e., discarded); however, a second interfering RF packet can be received. In an exemplary implementation, the radio transceiver can resynchronize the front end of the demodulator. Resynchronization can cause the demodulator to stop demodulating the current RF packet, and the receiver can also clear any previously demodulated / parsed bits from the buffer. The demodulator can also resynchronize (i.e., lock) to the edges of the input bits of the second interfering RF packet. A bandwidth cycle may also occur when the demodulator front end, which tracks the transition between signals, is resynchronized. This bandwidth cycle can briefly open (i.e., widen) the frequency bandwidth of the received signal before narrowing the frequency bandwidth and locking onto the second message. This allows the wireless receiver to quickly lock onto the second packet, packet B, instead of undergoing a complete reset of the wireless receiver, which could take much longer. For example, a reset of the wireless receiver or radio transceiver might cause the wireless receiver to undergo a power-on or startup cycle. After the wireless receiver has been resynchronized to packet B, in step 710, the wireless receiver can receive the remainder of the stronger message (packet B). The method can then end in step 712.

[0082] Any of the described methods (pre-synchronization, RSSI detection, phase detection) can be combined to increase the reliability of detecting second interfering RF packets. Using two or more methods requires the wireless receiver to confirm that all conditions have been met before partially resynchronizing the radio. For example, a phase shift detection method can be used in conjunction with an RSSI jump detection method. When the wireless receiver confirms that the first condition (i.e., there exists an RSSI greater than 0.5%) has been met... thresh RSSI Δ In this case, the wireless receiver can wait to confirm the presence of a second condition before resynchronizing part of the wireless receiver. For example, before resynchronizing part of the wireless receiver, the wireless receiver can wait to confirm that a phase shift has also been detected. In this way, the wireless receiver can be more accurately able to detect when interfering RF packets are being received, and can only resynchronize under this condition.

[0083] It will also be recognized that specific resynchronization byte sequences can be used additionally or optionally. For example, a specific resynchronization byte sequence can be used in conjunction with RSSI detection to provide a higher confidence rating for the fact that a second, stronger message is actually being received during the reception of the first message. Alternatively, a specific resynchronization byte sequence can be used in conjunction with phase shift detection. Optionally, all three methods can be used in combination.

[0084] Figure 7B This is an exemplary method 720, in which a wireless receiver can resynchronize itself using RSSI and a specific resynchronization byte sequence. The method can begin at 722. The wireless receiver can begin receiving a first data packet at step 724 (i.e., the receiver can transition from a search state to a receive / process state). At step 726, the receiver can determine whether a second interfering RF data packet is being received. For example, as previously described, the receiver can quickly detect transitions in the RSSI at one or more locations in the filter amplifier stage. If the second data packet is not received, then at step 732, the receiver can continue receiving and processing the first data packet.

[0085] However, if a transition in the RSSI is detected at 726, then at 738, the receiver can also determine whether a specific resynchronization byte sequence has been received. If the specific resynchronization byte sequence has been received at 738, then at 740, the wireless receiver can resynchronize and lock onto the second interference packet. That is, the wireless receiver can change state when pre-synchronization is detected at 738. For example, the wireless receiver can exit the current receive processing state and enter an idle state. Then, the wireless receiver can transition from the idle state to the receive search state. Then, at 752, the wireless receiver can synchronize to the second interference packet and transition back from the receive search state to the receive processing state to receive the second packet. It will be understood that some wireless receivers may not enter an idle state but may change directly between the receive search state and the receive processing state.

[0086] For example, a wireless receiver can quickly detect a transition in the RSSI; however, it may take longer to detect a specific resynchronization byte sequence because the demodulator may need to process that sequence to identify it as pre-synchronization. In this way, detecting a transition in the RSSI can prepare the receiver to quickly switch states to capture interfering RF packets if pre-synchronization is detected. If pre-synchronization is not detected, as previously described, the wireless receiver can continue receiving the first packet in step 732. The method can then exit.

[0087] Although Bluetooth is used as an example throughout this specification, it will be appreciated that the examples described herein can also be applied to other protocols, namely, any protocol that does not have a built-in method for detecting and recovering from packet collisions. In this way, the implementation of the examples described herein allows a wireless receiver to receive packets according to a protocol that does not provide detection and recovery of conflicting packets, and further detects and recovers packets during RF collision events. Furthermore, adding pre-synchronization to standard protocol packets allows a wireless receiver to receive standard protocol packets, as well as priority packets containing pre-synchronization that can be captured during collision events. It will be understood that this can also be applied to proprietary protocols.

Claims

1. A method for wireless communication, the method comprising: Detect the first RF packet; Synchronize to and demodulate the first RF data packet to generate demodulated bits; The demodulated bits of the first RF data packet are stored in a buffer; While demodulating the first RF data packet, a second RF data packet is detected, wherein the second RF data packet includes a resynchronization byte sequence, and detecting the second RF data packet includes: detecting phase shifts in one or more data symbols while receiving the first RF data packet; Synchronize to the second RF data packet; Demodulate the second RF data packet; and The demodulated bits from the second RF data packet are stored in the buffer.

2. The method of claim 1, wherein detecting the phase shift comprises: It was determined that multiple samples of the received apparent bits were longer or shorter than expected.

3. The method of claim 1, wherein detecting the phase shift comprises: At least one of an unexpected bit edge or an unexpected sign edge was detected in the received sampled data.

4. The method of claim 1, wherein detecting the phase shift comprises: The rapid reduction of edge jitter in the detection symbol is observed.

5. The method of claim 1, wherein the second RF data packet includes a preamble, wherein the resynchronization byte sequence precedes the preamble, and the second RF data packet includes a payload following the preamble.

6. The method of claim 5, wherein the second RF data packet further includes a period of idle time for one or more bits between the resynchronization byte sequence and the preamble, wherein the method further includes clearing the demodulated bits from the buffer during the idle time.

7. The method of claim 1, wherein the first RF data packet and the second RF data packet include Bluetooth data packets.

8. The method of claim 1, wherein the second RF data packet includes a lighting control command.

9. A non-transitory computer-readable storage medium having stored thereon program instructions that, when executed by a control circuit, cause the control circuit to perform the method as described in any one of claims 1-8.

10. An apparatus for wireless communication, comprising components for performing the method as described in any one of claims 1-8.

11. A method performed by a wireless device, comprising: Detect the first RF packet; Synchronize to and demodulate the first RF data packet to generate demodulated bits; The demodulated bits of the first RF data packet are stored in a buffer; During the demodulation of the first RF packet, a second RF packet is detected, wherein the second RF packet includes a resynchronization byte sequence; Synchronize to the second RF data packet; Demodulate the second RF data packet; The demodulated bits from the second RF data packet are stored in the buffer; as well as The physical layer of the transmitted RF data packets is encoded to prevent wireless devices from synchronizing with the transmitted RF data packets.

12. The method of claim 11, wherein the encoded physical layer bitstream comprises no more than a predetermined number of sequential 1s or 0s.

13. The method according to claim 11, wherein: The physical layer encoding includes: replacing the resynchronized byte sequence with the physical layer, and The resynchronization byte sequence is configured to trigger the demodulation of the second RF packet.

14. A non-transitory computer-readable storage medium having stored thereon program instructions that, when executed by a control circuit, cause the control circuit to perform the method as described in any one of claims 11-13.

15. An apparatus for wireless communication, comprising components for performing the method as described in any one of claims 11-13.

16. A method performed by a wireless device, wherein the wireless device is configured to: The first RF data packet is detected via the antenna; Synchronize to and demodulate the first RF data packet to generate demodulated bits; The demodulated bits of the first RF data packet are stored in a buffer; During the demodulation of the first RF packet, a second RF packet is detected, wherein the second RF packet includes a resynchronization byte sequence; Synchronize to the second RF data packet; Demodulate the second RF data packet; as well as The demodulated bits from the second RF data packet are stored in the buffer; The method includes: encoding the physical layer of the transmitted RF data packets to prevent wireless devices from synchronizing to the transmitted RF data packets.

17. The method of claim 16, wherein the encoded physical layer bitstream comprises no more than a predetermined number of sequential 1s or 0s.

18. The method of claim 16, wherein: The physical layer encoding includes: replacing the resynchronized byte sequence with the physical layer, and The resynchronization byte sequence is configured to trigger the demodulation of the second RF packet.

19. A non-transitory computer-readable storage medium having stored thereon program instructions that, when executed by a control circuit, cause the control circuit to perform the method as described in any one of claims 16-18.

20. An apparatus for wireless communication, comprising components for performing the method as described in any one of claims 16-18.

21. A wireless device, comprising: The antenna is configured to transmit wireless signals; A transceiver, operatively connected to an antenna; as well as The processor, wherein the transceiver and the processor are configured to: The first RF data packet is detected via the antenna; Synchronize to and demodulate the first RF data packet to generate demodulated bits; The demodulated bits of the first RF data packet are stored in a buffer; During the demodulation of the first RF packet, a second RF packet is detected, wherein the second RF packet includes a resynchronization byte sequence; Synchronize to the second RF data packet; Demodulate the second RF data packet; The demodulated bits from the second RF data packet are stored in the buffer; as well as The physical layer of the transmitted RF data packets is encoded to prevent wireless devices from synchronizing with the transmitted RF data packets.

22. The wireless device of claim 21, wherein the encoded physical layer bit stream comprises no more than a predetermined number of sequential 1s or 0s.

23. The wireless device according to claim 21, wherein: The physical layer of the encoded RF data packets includes: replacing the resynchronization byte sequence with the physical layer, and The resynchronization byte sequence is configured to trigger the demodulation of the second RF packet.

24. A non-transitory computer-readable storage medium having stored program instructions thereon, the program instructions causing the control circuit, when executed by a control circuit, to: Detect the first RF packet; Synchronize to and demodulate the first RF data packet to generate demodulated bits; The demodulated bits of the first RF data packet are stored in a buffer; While demodulating the first RF data packet, a second RF data packet is detected, wherein the second RF data packet includes a preamble, a resynchronization byte sequence preceding the preamble, and a payload following the preamble, wherein detecting the second RF data packet includes detecting the resynchronization byte sequence; Synchronize to the second RF data packet; Demodulate the second RF data packet; and The demodulated bits from the second RF data packet are stored in the buffer.

25. The non-transitory computer-readable storage medium of claim 24, wherein the first RF data packet and the second RF data packet comprise Bluetooth data packets.

26. The non-transitory computer-readable storage medium of claim 24, wherein the second RF data packet further includes a period of inactivity for one or more bits between the resynchronization byte sequence and the preamble, wherein the program instructions are further configured to cause the control circuitry to clear the demodulated bits from the buffer during the period of inactivity.

27. The non-transitory computer-readable storage medium of claim 24, wherein detecting the second RF data packet further includes detecting an increase in RSSI greater than or equal to a threshold during the reception of the first RF data packet.

28. The non-transitory computer-readable storage medium of claim 27, wherein the threshold is 10 dB.

29. The non-transitory computer-readable storage medium of claim 24, wherein detecting the second RF data packet further includes detecting an increase in RSSI greater than or equal to a threshold during the demodulation of the first RF data packet.

30. The non-transitory computer-readable storage medium of claim 24, wherein detecting the second RF data packet further includes detecting the phase shift of one or more data symbols during the reception of the first RF data packet.

31. The non-transitory computer-readable storage medium of claim 24, wherein the second RF data packet includes lighting control commands.

32. A non-transitory computer-readable storage medium having stored program instructions thereon, the program instructions causing the control circuit, when executed by a control circuit, to: Detect the first RF packet; Synchronize to and demodulate the first RF data packet to generate demodulated bits; The demodulated bits of the first RF data packet are stored in a buffer; While demodulating the first RF data packet, a second RF data packet is detected, wherein the second RF data packet includes a preamble, a resynchronization byte sequence preceding the preamble, a payload following the preamble, and idle time of one or more bits between the resynchronization byte sequence and the preamble, wherein detecting the second RF data packet includes detecting the resynchronization byte sequence; Synchronize to the second RF data packet; Demodulate the second RF data packet; and The demodulated bits from the second RF data packet are stored in the buffer.

33. The non-transitory computer-readable storage medium of claim 32, wherein the first RF data packet and the second RF data packet include Bluetooth data packets.

34. The non-transitory computer-readable storage medium of claim 32, wherein detecting the second RF data packet further includes detecting an increase in RSSI greater than or equal to a threshold during the reception of the first RF data packet.

35. The non-transitory computer-readable storage medium of claim 34, wherein the threshold is 10 dB.

36. The non-transitory computer-readable storage medium of claim 32, wherein detecting the second RF data packet further includes detecting an increase in RSSI greater than or equal to a threshold during the demodulation of the first RF data packet.

37. The non-transitory computer-readable storage medium of claim 32, wherein detecting the second RF data packet further includes detecting the phase shift of one or more data symbols during the reception of the first RF data packet.

38. The non-transitory computer-readable storage medium of claim 32, wherein the second RF data packet includes lighting control commands.

39. A non-transitory computer-readable storage medium having stored program instructions thereon, the program instructions causing the control circuit, when executed by a control circuit, to: The first RF data packet is detected via the antenna; Synchronize to the first RF data packet; Demodulate the first RF data packet to generate the first demodulated bit; Store the first demodulated bit of the first RF data packet in the buffer; During the demodulation of the first RF data packet, a second RF data packet is detected, wherein detecting the second RF data packet includes detecting an increase in Received Signal Strength Indicator (RSSI) greater than or equal to a threshold. Synchronize to the second RF data packet; Demodulate the second RF data packet to generate a second demodulated bit; as well as The second demodulated bit from the second RF data packet is stored in the buffer.

40. The non-transitory computer-readable storage medium of claim 39, wherein the program instructions are further configured to cause the control circuitry to: After detecting the second RF packet, the first demodulated bit is cleared from the buffer before the second demodulated bit from the second RF packet is stored in the buffer.

41. The non-transitory computer-readable storage medium of claim 39, wherein the first RF data packet and the second RF data packet respectively comprise Bluetooth data packets.

42. The non-transitory computer-readable storage medium of claim 39, wherein the threshold is 10 dB.

43. The non-transitory computer-readable storage medium of claim 39, wherein the second RF data packet includes lighting control commands.

44. The non-transitory computer-readable storage medium of claim 39, wherein the program instructions are further configured to cause the control circuitry to stop processing the first RF data packet after detecting the second RF data packet and before demodulating the second RF data packet.

45. The non-transitory computer-readable storage medium of claim 39, wherein the program instructions are further configured to cause the control circuitry to receive a first RF data packet on a first wireless protocol and to receive a second RF data packet on a second wireless protocol.

46. ​​A wireless device, comprising: transceiver; as well as The processor is configured as follows: The first RF data packet is detected via the transceiver; Synchronize to and demodulate the first RF data packet to generate demodulated bits; The demodulated bits of the first RF data packet are stored in a buffer; During the demodulation of the first RF data packet, a second RF data packet is detected, wherein the second RF data packet includes a resynchronization byte sequence, and detecting the second RF data packet includes detecting phase shifts in one or more data symbols while receiving the first RF data packet; Synchronize to the second RF data packet; Demodulate the second RF data packet; as well as The demodulated bits from the second RF data packet are stored in the buffer.

47. The wireless device of claim 46, wherein detecting phase shift includes determining that a certain number of samples of received apparent bits are longer or shorter than expected.

48. The wireless device of claim 46, wherein detecting phase shift includes detecting at least one of unexpected bit edges or unexpected symbol edges in the sampled received data.

49. The wireless device of claim 46, wherein detecting phase shift includes detecting a rapid decrease in symbol edge jitter.

50. The wireless device of claim 46, wherein the second RF data packet includes a preamble, wherein a resynchronization byte sequence precedes the preamble, and wherein the second RF data packet includes a payload following the preamble.

51. The wireless device of claim 50, wherein the second RF data packet further includes a period of inactivity for one or more bits between the resynchronization byte sequence and the preamble, wherein the processor is further configured to clear the demodulated bits from the buffer during the period of inactivity.

52. The wireless device of claim 46, wherein the first RF data packet and the second RF data packet include Bluetooth data packets.

53. The wireless device of claim 46, wherein the second RF data packet includes a lighting control command.

54. A wireless device, comprising: transceiver; as well as The processor is configured as follows: The first RF data packet is detected via the transceiver; Synchronize to the first RF data packet; Demodulate the first RF data packet to generate the first demodulated bit; Store the first demodulated bit of the first RF data packet in the buffer; During the demodulation of the first RF data packet, a second RF data packet is detected, wherein the second RF data packet includes a resynchronization byte sequence, and the detection of the second RF data packet includes detecting an increase in Received Signal Strength Indicator (RSSI) greater than or equal to a threshold. Synchronize to the second RF data packet; Demodulate the second RF data packet to generate a second demodulated bit; as well as The second demodulated bit from the second RF data packet is stored in the buffer.

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