Apparatus and method for producing an SBPSK-type modulated signal using piecewise linear phase transition shaping
AssigneesMnemonics, Inc., Pole/Zero Acquisitions, Inc.
InventorsMadjid A. Belkerdid, Robert G. Schumacher, T J Mears, II
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Abstract
An apparatus and method for generating piecewise linear phase transitions during a phase transition interval of a first signal to control controlling the phase/frequency of a second signal. The initiation point, duration and shaping parameters of the piecewise linear phase transitions are selected to control adjacent channel emissions in the second signal.
Claims25
A method for controlling phase transitions of a modulated signal during a phase transition interval of a modulating signal, the phase transition interval comprising a fractional portion of a bit period, the phase transition interval further comprising a first portion prior to a transition from a first value to a second value in the modulating signal and a second portion after the transition, the method comprising:
- selecting first and second phase trajectories to shape the phase transitions of the modulated signal during the first portion, the first and second phase trajectories operative to successively control the modulated signal during the first portion, the first and second phase trajectories representing different phase shaping parameters;
- selecting third and fourth phase trajectories to shape the phase transition of the modulated signal during the second portion, the third and fourth phase trajectories operative to successively control the modulated signal during the second portion, the third and fourth phase trajectories representing different phase shaping parameters;
- and
- transitioning the phase of the modulated signal during the first and second portions according to the first, second, third and fourth phase shaping parameters.
A method for controlling a frequency of a modulated signal during a phase transition interval of a modulating signal, the phase transition interval comprising a fractional portion of a bit period, wherein the phase transition interval comprises a first portion prior to a transition from a first value to a second value in the modulating signal and a second portion after the transition from the first to the second value in the modulating signal, the method comprising:
- during the first portion of the phase transition interval of the modulating signal, controlling the frequency of the modulated signal according to a phase trajectory represented by two or more successive piecewise linear line segments, each line segment representing a different frequency for the modulated signal;
- and
- during the second portion of the phase transition interval of the modulating signal, controlling the frequency of the modulated signal according to a phase trajectory represented by two or more successive piecewise linear line segments, each line segment representing a different frequency for the modulated signal.
An apparatus for producing a modulated carrier signal responsive to a modulating signal, the modulating signal having a phase transition interval comprising a fractional portion of a bit period of the modulating signal, the phase transition interval comprising a first portion prior to a transition from a first value to a second value in the modulating signal and a second portion after the transition, the apparatus comprising:
- a phase trajectory generator responsive to the modulating signal for producing a first signal represented by two or more successive curve segments each curve segment presenting a different phase shaping parameter for use during the first portion;
- the phase trajectory generator responsive to the modulating signal for producing a second signal represented by two or more successive curve segments each curve segment presenting a different phase shaping parameter for use during the second portion;
- and
- a modulator responsive to the first and second signals and to an oscillating signal, the modulator for operating on the oscillating signal to produce the modulated signal, the modulated signal having a characteristic responsive to the different phase shaping parameters during the first portion of the modulating signal and a characteristic responsive to the different phase shaping parameters during the second portion of the modulating signal.
Dependencies are inferred from the claim text.