Radio communication
First Claim
1. A radio transmitter comprising an encoder configured to receive one or more variable message bits and to encode each message bit that has a first value as a predetermined first binary chip sequence and to encode each message bit that has the opposite value as a predetermined second binary chip sequence,wherein the radio transmitter is configured to transmit 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;
- wherein the radio transmitter is configured to transmit the data packets modulated on a radio carrier signal using Gaussian frequency-shift-keying (GFSK), andwherein the modulation of the first and second binary chip sequences is such that, for each binary chip sequence of the first and second binary chip sequences, the respective phase of the radio carrier signal at the end of the binary chip sequence is the same as the respective phase of the radio carrier signal at the start of the binary chip sequence.
1 Assignment
0 Petitions
Accused Products
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.
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Citations
32 Claims
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1. A radio transmitter comprising an encoder configured to receive one or more variable message bits and to encode each message bit that has a first value as a predetermined first binary chip sequence and to encode each message bit that has the opposite value as a predetermined second binary chip sequence,
wherein the radio transmitter is configured to transmit 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; -
wherein the radio transmitter is configured to transmit the data packets modulated on a radio carrier signal using Gaussian frequency-shift-keying (GFSK), and wherein the modulation of the first and second binary chip sequences is such that, for each binary chip sequence of the first and second binary chip sequences, the respective phase of the radio carrier signal at the end of the binary chip sequence is the same as the respective phase of the radio carrier signal at the start of the binary chip sequence. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A radio receiver configured to:
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receive data packets, each comprising a predetermined synchronisation portion, comprising one or more instances of a predetermined first binary chip sequence, and a variable data portion, comprising one or more encoded message bits, wherein each message bit that has a first value is encoded as the first binary chip sequence and each message bit that has the opposite value is encoded as a predetermined second binary chip sequence, wherein the data packets are modulated on a radio carrier signal using Gaussian frequency-shift-keying (GFSK), and wherein the modulation of the first and second binary chip sequences is such that, for each binary chip sequence of the first and second binary chip sequences, the respective phase of the radio carrier signal at the end of the binary chip sequence is the same as the respective phase of the radio carrier signal at the start of the binary chip sequence; use the synchronisation portion of a received data packet to perform a frequency or timing synchronisation operation, before decoding the variable data portion of the received data packet; and decode message bits from the variable data portion of the received data packet. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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- 23. A radio receiver comprising a fixed-coefficient correlator that is switchable between a first mode in which the correlator is configured to correlate a received signal against a binary chip sequence, and a second mode in which the correlator is configured to correlate a received signal against a sub-sequence from the binary chip sequence, shorter than the binary chip sequence, wherein the correlator is configured, when in the second mode, to output a signal representative of a phase shift between two successive occurrences of the sub-sequence in a received signal.
Specification