Low-power radio-frequency receiver
First Claim
1. A load control device for controlling an electrical load receiving power from a power source in response to RF signals transmitted by an RF transmitter, the RF transmitter adapted to transmit a predetermined number of consecutive packets at a predetermined transmission rate during a given transmission event, each of the packets including a same command and characterized by a packet length, the load control device comprising:
- an RF receiver adapted to receive packets from the RF transmitter, the RF receiver operable to be periodically enabled for a sample time period to determine if the RF transmitter is transmitting one of the consecutive packets, the RF receiver operable to enter a sleep mode for a sleep time period between consecutive sample time periods if the RF receiver determines that the RF transmitter is not transmitting one of the consecutive packets during the sample time period; and
a controller operatively coupled to the RF receiver, the controller operable to determine that the RF transmitter is transmitting one of the consecutive packets during the sample time period and to subsequently receive an entire packet of the consecutive packets, the controller operable to control the electrical load in response to the entire packet received from the RF transmitter;
wherein the sleep time period of the RF receiver is longer than the packet length of each of the packets, the sample time period of the RF receiver is less than the packet length, and the sample time period and the sleep time period between sample time periods are sized to ensure that the sample time period coincides with at least one packet of the predetermined number of consecutive packets in the transmission event.
3 Assignments
0 Petitions
Accused Products
Abstract
A low-power RF receiver has a decreased current consumption. The receiver may be used in control devices, such as battery-powered motorized window treatments and two-wire dimmer switches. The receiver uses an RF sub-sampling technique to check for RF signals and then puts the receiver to sleep for a sleep time that is longer than a packet length of a transmitted packet to conserve battery power. The receiver compares detected RF energy to a threshold that may be increased to decrease the sensitivity of the receiver and increase the battery lifetime. After detecting an RF signal, the receiver is put to sleep for a snooze time that is longer than the sleep time and just slightly shorter than the time between two consecutive transmitted packets.
-
Citations
60 Claims
-
1. A load control device for controlling an electrical load receiving power from a power source in response to RF signals transmitted by an RF transmitter, the RF transmitter adapted to transmit a predetermined number of consecutive packets at a predetermined transmission rate during a given transmission event, each of the packets including a same command and characterized by a packet length, the load control device comprising:
-
an RF receiver adapted to receive packets from the RF transmitter, the RF receiver operable to be periodically enabled for a sample time period to determine if the RF transmitter is transmitting one of the consecutive packets, the RF receiver operable to enter a sleep mode for a sleep time period between consecutive sample time periods if the RF receiver determines that the RF transmitter is not transmitting one of the consecutive packets during the sample time period; and a controller operatively coupled to the RF receiver, the controller operable to determine that the RF transmitter is transmitting one of the consecutive packets during the sample time period and to subsequently receive an entire packet of the consecutive packets, the controller operable to control the electrical load in response to the entire packet received from the RF transmitter; wherein the sleep time period of the RF receiver is longer than the packet length of each of the packets, the sample time period of the RF receiver is less than the packet length, and the sample time period and the sleep time period between sample time periods are sized to ensure that the sample time period coincides with at least one packet of the predetermined number of consecutive packets in the transmission event. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
-
-
19. An RF communication system comprising:
-
an RF transmitter adapted to transmit a predetermined number of consecutive packets at a predetermined transmission rate during a given transmission event, each of the packets including a same command and characterized by a packet length; and an RF receiver adapted to receive packets from the RF transmitter, the RF receiver operable to be periodically enabled for a sampling time to determine if the RF transmitter is transmitting one of the consecutive packets, the RF receiver operable to enter a sleep mode for a sleep time period between consecutive sample time periods if the RF receiver determines that the RF transmitter is not transmitting one of the consecutive packets during the sample time period; wherein, if the RF transmitter is transmitting one of the consecutive packets during the sample time period, the RF transmitter is operable to be enabled to subsequently receive an entire packet of the consecutive packets; and wherein the sleep time period of the RF receiver is longer than the packet length of each of the packets, the sampling time of the RF receiver is less than the packet length, and the sampling time and the sleep time period between sampling times are sized to ensure that the sampling time coincides with at least one packet of the predetermined number of consecutive packets in the transmission event. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
-
-
35. A wireless signal receiver comprising:
-
a wireless receiver circuit for detecting transmitted signals transmitted in a predetermined number of consecutive packets during a given transmission event, where each packet comprises a same data, there being a packet time and a time between packets longer than the packet time; and a control circuit operable to turn on the wireless receiver circuit for an on-time, the on-time being less than an off-time of the wireless receiver circuit, the on-time of the wireless receiver circuit being less than the packet time, the off-time between on-times being less than the time between packets and the off-time being longer than the packet time, the control circuit operable to determine that the wireless receiver circuit is receiving one of the consecutive packets during the on-time and to subsequently receive an entire packet of the consecutive packets; wherein the off-time and the on-time are selected so that within the plurality of packets, the on-time will coincide with the packet time to ensure that the wireless receiver circuit detects at least one packet during the transmission of the predetermined number of packets if packets are being transmitted. - View Dependent Claims (36, 37, 38, 39, 40, 41)
-
-
42. A method of communicating in a load control system, the method comprising:
-
transmitting by an RF transmitter during a given transmission event a predetermined number of consecutive packets at a predetermined transmission rate, each of the packets including a same command and characterized by a packet length; periodically enabling an RF receiver for a sample time period to determine if the RF transmitter is transmitting one of the packets; if the RF transmitter is not transmitting one of the consecutive packets during the sample time period, putting the RF receiver in a sleep mode for a sleep time period between consecutive sample time periods; and if the RF transmitter is transmitting one of the consecutive packets during the sample time period, enabling the RF receiver to subsequently receive an entire packet of the consecutive packets; wherein the sleep time period of the RF receiver is longer than the packet length of each of the packets, the sample time period of the RF receiver is less than the packet length, and the sample time period and the sleep time period between sample time periods are sized to ensure that the sample time period coincides with at least one packet of the predetermined number of consecutive packets in the transmission event. - View Dependent Claims (43, 44, 45, 46, 47)
-
-
48. A wireless signal receiver circuit for detecting wireless control signals and having an on/off operation to conserve power comprising:
-
a control circuit; a wireless receiver having an on state when it consumes power and an off state when it consumes less power than consumed in the on state, the on state having a duration substantially shorter than the off state, whereby the wireless receiver receives wireless control signals during the on state to be processed by the control circuit, the wireless control signals being sent in packets with a packet time such that there is a predefined time between packets; and wherein the wireless receiver is operable to periodically be in the on state for a sample time substantially less than the packet time to detect a wireless control signal, whereby upon detecting a first packet during the sample time, the wireless receiver is operable to enter the off state to conserve power for an amount of time slightly less than the predefined time between packets, to subsequently turn on and remain on until a succeeding packet starts to be received, and to turn off after the succeeding packet is fully received. - View Dependent Claims (49, 50, 51, 52, 53, 54)
-
-
55. A system for conserving battery power of a battery powered wireless signal receiver comprising:
-
a wireless signal receiver that periodically turns on to determine if a wireless signal is being transmitted, the wireless signal receiver being capable of receiving on any of multiple channels, the wireless signal receiver including a control circuit that determines if the wireless signal is intended for the wireless signal receiver; and a transceiver circuit for retransmitting said wireless signals, the transceiver circuit determining a number of transmitted wireless signals, and if the number exceeds a threshold amount, said transceiver circuit communicating with the wireless signal receiver to change the channel of communication to an alternate channel and retransmitting wireless signals intended for the wireless signal receiver on the alternate channel, whereby the wireless signal receiver will receive fewer wireless signals on the alternate channel, thereby remaining on for less time and reducing battery power consumption. - View Dependent Claims (56, 57, 58, 59, 60)
-
Specification