Signal receivers

Claim 5

A method of converting a diphase signal into an isochronous baseband data signal as claimed in claim 2 wherein the step of deriving said isochronous baseband signal from said data signal includes retiming said data signal by a delayed phase adjusted clock signal, said delayed phase adjusted clock signal having been delayed by substantially T/6 with respect to said adjusted clock signal.

Claim 6

A diphase to baseband converter wherein a clock signal is derived from a carrier signal modulated by an isochronous baseband data signal, said carrier signal modulated by an isochronous baseband data signal being herein referred to as a diphase signal, the clock signal and said carrier signal having a common frequency equal to the reciprocal of the duration, T, of one element of the isochronous baseband data signal, said converter comprising: a. receiving means for receiving said diphase signal; b. clock signal means for generating said clock signal connected to said receiving means, said clock signal means including harmonic generator means for generating a pth harmonic, where p 2, of said carrier, and frequency divider means, connected in series; c. a modulo-2 adder having a first input connected to said receiving means, a second input connected to said clock signal means, producing an output data signal; d. an ambiguity detector for comparing transitions in said output data signal with transitions in said clock signals, and producing an actuating signal when said transitions in said data signal and transitions in said clock signal have a temporal separation in excess of a predetermined magnitude, said ambiguity detector connected to a phase adjuster which is connected to the output of said frequency divider means, said phase adjuster operable when actuated to phase adjust said clock signal by 360*/p; and e. means for deriving said isochronous baseband data signal from said output data signal, including timer means for retiming said data signal with reference to said clock signal to produce said isochronous baseband data signal, said timer means connected to said phase adjusted clock signal means via delay means for delaying said clock signal by T/6.

Claim 7

A diphase to baseband converter wherein a clock signal is derived from a carrier signal modulated by an isochronous baseband data signal, said carrier signal modulated by an isochronous baseband data signal being herein referred to as a diphase signal, the clock signal and said carrier signal having a common frequency equal to the reciprocal of the duration, T, of one element of the isochronous baseband data signal, said converter comprising: a. receiving means for receiving said diphase signal; b. clock signal means for generating said clock signal connected to said receiving means, said clock signal means including harmonic generator means for generating a pth harmonic, where p 2, of said carrier, and frequency divider means, connected in series; c. a modulo-2 adder having a first input connected to said receiving means, a second input connected to said clock signal means, producing an output data signal; d. an ambiguity detector for comparing transitions in said output data signal with transitions in said clock signals, and producing an actuating signal when said transitions in said data signal and transitions in said clock signal have a temporal separation in excess of a predetermined magnitude, said ambiguity detector connected to a phase adjuster which is connected to the output of said frequency divider means, said phase adjuster operable when actuated to phase adjust said clock signal by 360*/p; and e. means for deriving said isochronous baseband data signal from said output data signal, including timer means for retiming said data signal with reference to said clock signal to produce said isochronous baseband data signal, said timer means connected to said phase adjusted clock signal means via delay means for delaying said clock signal by T/6.

Claim 8

A diphase to baseband converter wherein a clock signal is derived from a carrier signal modulated by an isochronous baseband data signal, said carrier signal modulated by an isochronous baseband data signal being herein referred to as a diphase signal, the clock signal and said carrier signal having a common frequency equal to the reciprocal of the duration, T, of one element of the isochronous baseband data signal, said converter comprising: a. receiving means for receiving said diphase signal; b. clock signal means, arranged to receive said diphase signal, said clock signal means including harmonic generator means for generating a pth harmonic where p 2, of said carrier, and frequency divider means, connected in series, to produce said clock signal; c. a modulo-2 adder having a first input connected to said receiving means, a second input connected to said clock signal means, producing an output data signal; d. an ambiguity detector including transition comparator means for comparing transitions in said clock sIgnal with transitions in said output data signal at discrete intervals and producing an error pulse when transitions in said data signal and transitions in said clock signal have a temporal separation in excess of a predetermined magnitude, and counter means for counting the error pulses, said counter means arranged to produce an actuating signal when n consecutive error pulses have been counted, said actuating signal actuating a phase adjuster connected to an output of said frequency divider means, said phase adjuster having an output connected to said transition comparator means, said phase adjuster operable to phase adjust said clock signal by 360*/p; e. reset means for resetting said counter means, said reset means actuated by said transition comparator means when said temporal separation lies within said predetermined limits; and f. means for deriving said isochronous baseband data signal from said output data signal.

Claim 9

A diphase to baseband converter wherein a clock signal is derived from a carrier signal modulated by an isochronous baseband data signal, said carrier signal modulated by an isochronous baseband data signal being herein referred to as a diphase signal, the clock signal and said carrier signal having a common frequency equal to the reciprocal of the duration, T, of one element of the isochronous baseband data signal, said converter comprising: a. receiving means for receiving said diphase signal; b. clock signal means, arranged to receive said diphase signal, said clock signal means including harmonic generator means for generating a pth harmonic where p 2, of said carrier, and frequency divider means, connected in series, to produce said clock signal; c. a modulo-2 adder having a first input connected to said receiving means, a second input connected to said clock signal means, producing an output data signal; d. an ambiguity detector including transition comparator means for comparing transitions in said clock sIgnal with transitions in said output data signal at discrete intervals and producing an error pulse when transitions in said data signal and transitions in said clock signal have a temporal separation in excess of a predetermined magnitude, and counter means for counting the error pulses, said counter means arranged to produce an actuating signal when n consecutive error pulses have been counted, said actuating signal actuating a phase adjuster connected to an output of said frequency divider means, said phase adjuster having an output connected to said transition comparator means, said phase adjuster operable to phase adjust said clock signal by 360*/p; e. reset means for resetting said counter means, said reset means actuated by said transition comparator means when said temporal separation lies within said predetermined limits; and f. means for deriving said isochronous baseband data signal from said output data signal.

Claim 10

A diphase to baseband converter as claimed in claim 5 including means responsive to consecutive actuating signals to cause said phase adjuster to produce alternate phase adjustments in opposite senses.

Claim 11

A diphase to baseband converter as claimed in claim 5 wherein said means for deriving said isochronous baseband data signal from said output data signal, includes timer means for retiming said output data signal with reference to said phase adjusted clock signal to produce said isochronous baseband data signal, said timer means being connected to said phase adjusted via a delay means, said delay means arranged to delay said clock signal by T/6.