Claims
- 1. A method of adding a secondary channel to a QAM signal mapped in the complex plane with data points assuming normal positions on concentric rings comprising the steps of:
- (a) locating a pair of positions in the mapped complex plane (A and B) such that one-half the sum of the square of the distances to such positions from the origin (A.sup.2 +B.sup.2 / 2) is no greater than the square of the distance from the origin to the position of the furthest mapped data point;
- (b) assigning a binary "1" to the existence of a data point at one of said pair of positions and a binary "0" to the existence of a date point at the other of said pair of positions;
- (c) shifting a single data point from a normal position to assume either of said pair of positions to define said secondary channel, the other data points being kept at their normal positions.
- 2. The method in accordance with claim 1 wherein said pair of positions lie on a line passing through the origin of the complex plane.
- 3. The method in accordance with claim 2 wherein said shifted data point normal position also lies on said line.
- 4. The method in accordance with claim 3 wherein said line comprises an axis of said complex plane.
- 5. The method in accordance with claim 1 wherein one of said pair of positions comprises the origin of the complex plane.
RELATED APPLICATIONS
This is a continuation-in-part application to application Ser. No. 565,523 filed Dec. 28, 1983 now abandoned which is a continuation of application Ser. No. 299,660 filed Sept. 8, 1981, now abandoned.
US Referenced Citations (5)
Continuations (1)
|
Number |
Date |
Country |
Parent |
299660 |
Sep 1981 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
565523 |
Dec 1983 |
|