GFSK Detector
AssigneeImagination Technologies Limited
InventorsPaul Murrin, Adrian John Anderson
Life of this patent
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Abstract
A Gaussian frequency shift keying (GFSK) detector for decoding a GFSK signal. The detector includes: a multi-symbol detector and a Viterbi decoder. The multi-symbol detector is configured to: receive a series of samples representing a received GFSK modulated signal; and generate, for each set of samples representing an N-symbol sequence of the GFSK modulated signal, a plurality of soft decision values that indicate the probability that the N-symbol sequence is each possible N-symbol pattern, wherein N is an integer greater than or equal to two. The Viterbi decoder is configured to estimate each N-symbol sequence using a Viterbi decoding algorithm wherein the soft decision values for the N-symbol sequence are used as branch metrics in the Viterbi decoding algorithm.
Claims20
A Gaussian frequency shift keying (GFSK) detector comprising:
- a multi-symbol detector configured to:
- receive a series of samples representing a received GFSK modulated signal, and
- generate, for each set of samples representing an N-symbol sequence of the GFSK modulated signal, a plurality of soft decision values that indicate the probability that the N-symbol sequence is each possible N-symbol pattern, wherein N is an integer greater than or equal to two;
- and
- a Viterbi decoder configured to estimate an M-symbol sequence of the GFSK modulated signal using a Viterbi decoding algorithm wherein the soft decision values for the N-symbol sequences of that M-symbol sequence are used as branch metrics in the Viterbi decoding algorithm, wherein M is an integer greater than N.
A method of decoding a received Gaussian frequency shift keying (GFSK) modulated signal at a GFSK receiver, the method comprising:
- receiving a series of samples representing the received GFSK modulated signal;
- generating, each symbol period of the GFSK modulated signal, a plurality of soft decision values that indicate the likelihood that a most recent N-symbol sequence of samples is each possible N-symbol pattern, wherein N is an integer greater than or equal to two;
- and
- estimating an M-symbol sequence of the GFSK modulated signal using a Viterbi decoding algorithm wherein, each symbol period, at least a portion of the plurality of soft decision values are used as branch metrics of the Viterbi decoding algorithm, wherein M is an integer greater than N.
Dependencies are inferred from the claim text.