# US 12,015,946 B2 · Collision detection method

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- Number: US 12,015,946 B2
- Document ID: US12015946B2
- Status: Granted
- Kind: B2
- Application number: 17/643,966
- Filed: 2021-12-13
- Published: 2022-03-31
- Granted: 2024-06-18
- Earliest claimed: 2018-02-23
- Assignees: Lutron Technology Company LLC
- Applicants: Lutron Technology Company LLC
- Inventors: Ankit Bhutani; Richard S. Camden; Galen E. Knode
- Web page: https://patentgrep.com/patent/US12015946B2

## CPC

- H04W 28/04: Error control
- H04L 1/0083: {Formatting with frames or packets; Protocol or part of protocol for error control}
- H04L 1/206: {for modulated signals}
- H04L 7/042: {Detectors therefor, e.g. correlators, state machines (digital correlators in general G06F17/15)}
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

A wireless device may receive packets according to a protocol, such as Bluetooth, and may rapidly react to receive an interfering RF packet instead of dropping the first RF packet and the interfering RF packet, to decrease message delay due to collisions in high device density environments. When a received signal strength indicator (RSSI) difference between the interfering RF packet and the first RF packet exceeds a threshold, the device may detect the interfering packet and resync a portion of its circuitry to lock on to and receive the interfering packet. The wireless receiver may detect the interfering RF packet by detecting one or more of: a specific resync byte sequence, an increase in RSSI, or a phase shift. Additionally, a wireless device may add the specific resync byte sequence to an RF packet of a standard protocol.

## Claims

### Claim 1

A device configured to:
detect a first radio frequency (RF) packet;
synchronize to and demodulate the first RF packet to create demodulated bits;
store the demodulated bits of the first RF packet in a buffer;
during receipt of the first RF packet, detect a second RF packet, wherein:
the second RF packet comprises a preamble, a resync byte sequence prior to the preamble, and a payload subsequent to the preamble; and
to detect the second RF packet comprises to detect the resync byte sequence;
upon detection of the second RF packet, synchronize to the second RF packet;
demodulate the second RF packet; and
store the demodulated bits from the second RF packet in the buffer.

### Claim 2 (depends on 1)

The device of claim 1, wherein:
the second RF packet further comprises one or more bits of dead time between the resync byte sequence and the preamble; and
the device is configured to clear the demodulated bits from the buffer during the dead time.

### Claim 3 (depends on 1)

The device of claim 1, wherein to detect the second RF packet further comprises to detect an increase in a received signal strength indicator (RSSI) greater than or equal to a threshold during the receipt of the first RF packet.

### Claim 4 (depends on 1)

The device of claim 1, wherein to detect the second RF packet further comprises to detect a phase shift in one or more data symbols during the receipt of the first RF packet.

### Claim 5 (depends on 1)

The device of claim 1, wherein the second RF packet comprises a lighting control command.

### Claim 6

A device configured to:
detect a first RF packet;
synchronize to and demodulate the first RF packet to create demodulated bits;
store the demodulated bits of the first RF packet in a buffer;
detect a second RF packet, wherein to detect the second RF packet comprises to detect an increase in a received signal strength indicator (RSSI) greater than or equal to a threshold during receipt of the first RF packet, wherein the second RF packet comprises a preamble, a resync byte sequence prior to the preamble, a payload subsequent to the preamble, and one or more bits of dead time between the resync byte sequence and the preamble;
upon detection of the second RF packet, synchronize to the second RF packet;
demodulate the second RF packet; and
store the demodulated bits from the second RF packet in the buffer.

### Claim 7 (depends on 6)

The device of claim 6, wherein the device is configured to clear the demodulated bits of the first RF packet from the buffer during the dead time.

### Claim 8 (depends on 6)

The device of claim 6, wherein to detect the second RF packet further comprises to detect a phase shift in one or more data symbols during receipt of the first RF packet.

### Claim 9 (depends on 6)

The device of claim 6, wherein the second RF packet comprises a lighting control command.

### Claim 10

A device configured to:
detect a first RF packet;
synchronize to and demodulate the first RF packet to create demodulated bits;
store the demodulated bits of the first RF packet in a buffer;
detect a second RF packet, wherein the second RF packet comprise a preamble, a resync byte sequence prior to the preamble, a payload subsequent to the preamble, and wherein to detect the second RF packet comprises to detect a rapid change in edges of one or more bits of the first RF packet;
upon detection of the second RF packet, synchronize to the second RF packet;
demodulate the second RF packet; and
store the demodulated bits from the second RF packet in the buffer.

### Claim 11 (depends on 10)

The device of claim 10, wherein:
the second RF packet comprises one or more bits of dead time between the resync byte sequence and the preamble;
to detect the second RF packet further comprises to detect the resync byte sequence; and
the device further is configured to clear the demodulated bits of the first RF packet from the buffer during the dead time.

### Claim 12 (depends on 10)

The device of claim 10, wherein the second RF packet comprises a lighting control command.

### Claim 13

A method comprising:
detecting a first radio frequency (RF) packet;
synchronizing to and demodulating the first RF packet to create demodulated bits;
storing the demodulated bits of the first RF packet in a buffer;
while receiving the first RF packet, detecting a second RF packet, wherein:
the second RF packet comprises a preamble, a resync byte sequence prior to the preamble, and a payload subsequent to the preamble, and detecting the second RF packet comprises detecting the resync byte sequence;
upon detecting the second RF packet, synchronizing to the second RF packet;
demodulating the second RF packet; and
storing the demodulated bits from the second RF packet in the buffer.

### Claim 14 (depends on 13)

The method of claim 13, wherein, the second RF packet further comprises one or more bits of dead time between the resync byte sequence and the preamble, the method further comprising clearing the demodulated bits of the first RF packet from the buffer during the dead time.

### Claim 15 (depends on 13)

The method of claim 13, wherein detecting the second RF packet further comprises detecting an increase in a received signal strength indicator (RSSI) greater than or equal to a threshold while receiving the first RF packet.

### Claim 16 (depends on 13)

The method of claim 13, wherein detecting the second RF packet further comprises detecting a phase shift in one or more data symbols while receiving the first RF packet.

### Claim 17 (depends on 13)

The method of claim 13, wherein the second RF packet comprises a lighting control command.

### Claim 18

A method comprising:
detecting a first radio frequency (RF) packet;
synchronizing to and demodulating the first RF packet to create demodulated bits;
storing the demodulated bits of the first RF packet in a buffer;
detecting a second RF packet, wherein detecting the second RF packet comprises detecting an increase in a received signal strength indicator (RSSI) greater than or equal to a threshold during receipt of the first RF packet, wherein the second RF packet comprises a preamble, a resync byte sequence prior to the preamble, a payload subsequent to the preamble, and one or more bits of dead time between the resync byte sequence and the preamble;
upon detecting the second RF packet, synchronizing to the second RF packet;
demodulating the second RF packet; and
storing the demodulated bits from the second RF packet in the buffer.

### Claim 19 (depends on 18)

The method of claim 18, the method further comprising clearing the demodulated bits of the first RF packet from the buffer during the dead time.

### Claim 20 (depends on 18)

The method of claim 18, wherein detecting the second RF packet further comprises detecting a phase shift in one or more data symbols while receiving the first RF packet.

### Claim 21 (depends on 18)

The method of claim 18, wherein the second RF packet comprises a lighting control command.

### Claim 22

A method comprising:
detecting a first radio frequency (RF) packet;
synchronizing to and demodulating the first RF packet to create demodulated bits;
storing the demodulated bits of the first RF packet in a buffer;
detecting a second RF packet, wherein the second RF packet comprise a preamble, a resync byte sequence prior to the preamble, a payload subsequent to the preamble, and wherein detecting the second RF packet comprises detecting a rapid change in edges of one or more bits of the first RF packet;
upon detecting the second RF packet, synchronizing to the second RF packet;
demodulating the second RF packet; and
storing the demodulated bits from the second RF packet in the buffer.

### Claim 23 (depends on 22)

The method of claim 22, wherein the second RF packet comprises one or more bits of dead time between the resync byte sequence and the preamble, the method further comprising:
detecting the second RF packet by detecting the resync byte sequence; and
clearing the demodulated bits of the first RF packet from the buffer during the dead time.

### Claim 24 (depends on 22)

The method of claim 22, wherein the second RF packet comprises a lighting control command.

### Claim 25

At least one non-transitory computer-readable storage medium comprising executable instructions for configuring at least one processor to:
detect a first radio frequency (RF) packet;
synchronize to and demodulate the first RF packet to create demodulated bits;
store the demodulated bits of the first RF packet in a buffer;
while receiving the first RF packet, detect a second RF packet, wherein:
the second RF packet comprises a preamble, a resync byte sequence prior to the preamble, and a payload subsequent to the preamble, and to detect the second RF packet comprises to detect the resync byte sequence;
upon detecting the second RF packet, synchronize to the second RF packet;
demodulate the second RF packet; and
store the demodulated bits from the second RF packet in the buffer.

### Claim 26 (depends on 25)

The at least one non-transitory computer-readable storage medium of claim 25, wherein the second RF packet further comprises one or more bits of dead time between the resync byte sequence and the preamble, the executable instructions further for configuring the at least one processor to clear the demodulated bits of the first RF packet from the buffer during the dead time.

### Claim 27 (depends on 25)

The at least one non-transitory computer-readable storage medium of claim 25, wherein to detect the second RF packet further comprises to detect an increase in a received signal strength indicator (RSSI) greater than or equal to a threshold while receiving the first RF packet.

### Claim 28 (depends on 25)

The at least one non-transitory computer-readable storage medium of claim 25, wherein to detect the second RF packet further comprises to detect a phase shift in one or more data symbols while receiving the first RF packet.

### Claim 29 (depends on 25)

The at least one non-transitory computer-readable storage medium of claim 25, wherein the second RF packet comprises a lighting control command.

### Claim 30

At least one non-transitory computer-readable storage medium comprising executable instructions for configuring at least one processor to:
detect a first radio frequency (RF) packet;
synchronize to and demodulate the first RF packet to create demodulated bits;
store the demodulated bits of the first RF packet in a buffer;
detect a second RF packet, wherein to detect the second RF packet comprises to detect an increase in a received signal strength indicator (RSSI) greater than or equal to a threshold during receipt of or demodulation of the first RF packet, wherein the second RF packet comprises a preamble, a resync byte sequence prior to the preamble, a payload subsequent to the preamble, and one or more bits of dead time between the resync byte sequence and the preamble;
upon detecting the second RF packet, synchronize to the second RF packet;
demodulate the second RF packet; and
store the demodulated bits from the second RF packet in the buffer.

### Claim 31 (depends on 30)

The at least one non-transitory computer-readable storage medium of claim 30, the executable instructions further for configuring the at least one processor to clear the demodulated bits of the first RF packet from the buffer during the dead time.

### Claim 32 (depends on 30)

The at least one non-transitory computer-readable storage medium of claim 30, wherein to detect the second RF packet further comprises to detect a phase shift in one or more data symbols while receiving the first RF packet.

### Claim 33 (depends on 30)

The at least one non-transitory computer-readable storage medium of claim 30, wherein the second RF packet comprises a lighting control command.

### Claim 34

At least one non-transitory computer-readable storage medium comprising executable instructions for configuring at least one processor to:
detect a first radio frequency (RF) packet;
synchronize to and demodulate the first RF packet to create demodulated bits;
store the demodulated bits of the first RF packet in a buffer;
detect a second RF packet, wherein the second RF packet comprise a preamble, a resync byte sequence prior to the preamble, a payload subsequent to the preamble, and wherein to detect the second RF packet comprises to detect a rapid change in edges of one or more bits of the first RF packet;
upon detecting the second RF packet, synchronize to the second RF packet;
demodulate the second RF packet; and
store the demodulated bits from the second RF packet in the buffer.

### Claim 35 (depends on 34)

The at least one non-transitory computer-readable storage medium of claim 34, wherein the second RF packet comprises one or more bits of dead time between the resync byte sequence and the preamble, the executable instructions further for configuring the at least one processor to:
detect the second RF packet by detecting the resync byte sequence; and
clear the demodulated bits of the first RF packet from the buffer during the dead time.

### Claim 36 (depends on 34)

The at least one non-transitory computer-readable storage medium of claim 34, wherein the second RF packet comprises a lighting control command.

### Claim 37

At least one non-transitory computer-readable storage medium comprising executable instructions for configuring at least one processor to:
detect a first radiofrequency (RF) packet;
synchronize to the first RF packet;
demodulate the first RF packet to create first demodulated bits;
store the first demodulated bits of the first RF packet in a buffer;
during receipt of the first RF packet, detect a second RF packet, wherein:
to detect the second RF packet comprises to detect the second RF packet at an increased received signal strength indicator (RSSI) that is greater than or equal to a threshold during a receipt of or the demodulation of the first RF packet; and
the second RF packet comprises a preamble, a resync byte sequence prior to the preamble, and a payload subsequent to the resync byte sequence;
after detection of the second RF packet, synchronize to the second RF packet;
demodulate the second RF packet to create second demodulated bits; and
store the second demodulated bits from the second RF packet in the buffer.