Patent ID: 11863366
Assignee: CABLE TELEVISION LABORATORIES, INC.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method of modulating, by a transmitter, a series of input digital symbols of a first modulation scheme, comprising the steps of:
receiving a sequential series of samples of the digital symbols in a time domain of the first modulation scheme, such that its dual is a second modulation scheme in a frequency domain;
applying a 90 degree rotational operation to the second modulation scheme to generate a rotational modulation format, wherein the 90 degree rotational operation is an inverse Fast Fourier transform, and wherein the generated rotational modulation format comprises one of binary phase shift keying and duobinary modulation;
modulating the series of digital symbols with the generated rotational modulation format; and
outputting the modulated series of digital symbols to a receiver.