Abstract:
A radio communication system comprises a radio transmitter (2), and a radio receiver (12) configured to receive radio transmissions from the transmitter. The transmitter (2) uses a transmitter clock signal to transmit a succession of connection-event data packets (22a′, 22b′, 22c′) according to a predetermined schedule. The receiver (12) enters a sleep state between receiving successive connection-event data packets from the transmitter (2), in which it does not receive and process radio transmissions from the transmitter. It uses a receiver clock signal to determine when a predetermined number of receiver clock cycles has elapsed after receiving one of the connection-event data packets (22b′), and then enters a ready state. The predetermined number of receiver clock cycles is the number of receiver clock cycles (34a) that elapsed between the respective receipts of two of the connection-event data packets (22a′, 22b′) received by the receiver (12) minus a correction factor (38).
Abstract:
A method of digital radio communication between a first device (2) and a second device (8), where each device comprises a radio transmitter (4, 10) and a radio receiver (6, 12), the method comprising: a) said first and second devices (2, 8) establishing a connection using a predetermined protocol having at least one predefined message format; and b) said first and second devices (2, 8) agreeing that in the event of said connection being broken a re-connection may be established using a coding scheme in which at least some bits specified in said predefined message format are represented by a plurality of bits transmitted.
Abstract:
An interface controller (2) is operated to give one of a plurality of predetermined outputs. An input signal (211) is received and a duration of said input signal is compared with a first and/or second threshold duration. A first output is generated if said input signal duration is shorter than said first threshold duration. A second output is generated if said input signal duration is longer than said first threshold duration but shorter than said second threshold duration. A third output is generated if said input signal duration is longer than said second threshold duration.
Abstract:
A radio transmitter (4) comprises an encoder (5) that receives one or more variable message bits, and encodes each message bit that has a first value as a predetermined first binary chip sequence and encodes each message bit that has the opposite value as a predetermined second binary chip sequence. The radio transmitter (4) transmits data packets, each comprising (i) a predetermined synchronization portion, comprising one or more instances of the first binary chip sequence, and (ii) a variable data portion, comprising one or more encoded message bits output by the encoder. A radio receiver (9) receives such data packets. It uses the synchronization portion of a received data packet to perform a frequency and/or timing synchronization operation, and then decodes message bits from the data portion of the data packet.
Abstract:
A digital radio receiver is adapted to receive radio signals modulated using continuous phase modulation. The receiver includes components for receiving analogue radio signals having various carrier frequencies and a plurality of correlators corresponding to different bit sequences. Each of the plurality of correlators share a common estimator for estimating a frequency offset between the radio signals carrier frequencies and nominal carrier frequencies. The receiver further includes components allowing the estimator to determine which of the correlators produce the most optimal output signal.
Abstract:
A method of digital radio communication between a first device (2) and a second device (8), where each device comprises a radio transmitter (4, 10) and a radio receiver (6, 12), the method comprising: a) said first and second devices (2, 8) establishing a connection using a predetermined protocol having at least one predefined message format; b) if said connection is subsequently broken, said second device (8) transmitting an advertising message at a first data rate indicating a desire to reconnect; and c) if a reconnection is not established, said second device (8) transmitting a further advertising message at a second data rate indicating a desire to reconnect, wherein said second data rate is lower than the first data rate.
Abstract:
An addressable radio is described in which the radio has an address that includes (i) a value derived from a counter and (ii) a hash of a combination of the value and an identity-resolving key for the radio device.
Abstract:
A radio-frequency (RF) amplifier device comprises a signal input for receiving an RF electrical signal, a variable-gain amplifier for amplifying the received signal, and a signal output for outputting the amplified signal. The device has a binary input for switching a gain of the amplifier between a first level and the custom gain level. Configuration logic receives serialised data encoding a custom gain level at a serial input, and stores data representative of the custom gain level in a memory of the device. Gain-control logic reads the data representative of the custom gain level from the memory, and sets the gain of the amplifier to the first level or to the custom gain level in dependence on a state of the binary input.
Abstract:
A radio transmitter (4) comprises an encoder (5) that receives one or more variable message bits, and encodes each message bit that has a first value as a predetermined first binary chip sequence and encodes each message bit that has the opposite value as a predetermined second binary chip sequence. The radio transmitter (4) transmits data packets, each comprising (i) a predetermined synchronisation portion, comprising one or more instances of the first binary chip sequence, and (ii) a variable data portion, comprising one or more encoded message bits output by the encoder. A radio receiver (9) receives such data packets. It uses the synchronisation portion of a received data packet to perform a frequency and/or timing synchronisation operation, and then decodes message bits from the data portion of the data packet.
Abstract:
A digital radio receiver 54 is adapted to receive radio signals which are modulated using continuous phase modulation. The receiver comprises means for receiving an analogue radio signal having a carrier frequency, a plurality of correlators 6, 8 each corresponding to a different bit sequence which share a common estimator 4 for estimating a frequency offset between said carrier frequency and a nominal carrier frequency, and means 12 for determining which of said correlators 6, 8 produces a desired output signal.