Signal structures with data encoding/decoding for QCM modulations
AssigneeEse Co., Ltd.
InventorsGordon R. Lang, George D. Forney, Jr., Shahid Qureshi, Fred M. Longstaff, Chi H. Lee
Life of this patent
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Abstract
Locations of a desired number of signal points for a double side band-quadrature carrier modulation system occupy the inner intersections of a multiplicity of concentric rings with a triangular grid. The signal point locations of the desired number on the outer partially occupied ring are provided with additional signal points at positions selected to provide that the centroid of the set of locations is at the center of the rings.
Claims31
Means for providing QCM signals to a transmission link, comprising:
- means for receiving binary signals,
- means for converting groups corresponding to n of such binary signals having 2.sup.n possible group values into signals represent a set of K signal message points each defined by Cartesian coordinate pairs where K>2.sup.n, the signal message points being substantially located at intersections on a regular equilateral triangular grid,
- where each message point corresponds to only one group value of the 2.sup.n possible values, and at least one of the 2.sup.n possible values corresponds to at least two message points,
- said converting means including means responsive to one of said at least one possible values for selecting at different times different ones of said at least two corresponding message points,
- said converting means being designed, responsive to a continuing random sequence of said binary signals, to utilize each of said K message points and to select message points corresponding to the at least one of the values, to substantially reduce the carrier component in said QCM signals,
- means responsive to said message point signals for providing a pair of quadrature carriers respectively modulated in accord with the coordinates of said signal message points.
In a receiver for receiving QCM modulated signals wherein such modulated signals were encoded to represent the rectangular coordinates of signal points arranged at the intersection of lines on a regular equilateral triangular grid,
- means for deriving said rectangular coordinates from the received signal,
- means for converting said derived rectangular coordinates into sets of three signal values, each signal value being characteristic of a zone parallel to a different one of said triangular grid directions.
Means for providing QCM signals to a transmission link, comprising:
- means for receiving binary signals,
- means for converting groups corresponding to n of such binary signals having 2.sup.n possible group values into signals chosen from a set of K signal message points defined by Cartesian coordinate pairs where K>2.sup.n the signal message points being substantially located at intersections or a regular equilateral triangular grid,
- where each message point corresponds to only one group value of the 2.sup.n possible values, and each of the 2.sup.n possible values corresponds to at least one message point,
- means for differentially encoding each of said signals representing message points other than that at the centre of said grid to produce a signal also representing one of said message points,
- said converting means and said differential encoding means being collectively designed, responsive to a continuing random sequence of said binary signals to utilize each of said K signal points, and to select said message points to substantially reduce the carrier component in said QCM signals,
- means responsive to said message point signals for providing a pair of quadrature carriers respectively modulated in accord with the coordinates of said signal message points.
Dependencies are inferred from the claim text.