Patent ID: 6252910
Filing Date: 2001-06-26
Classification: H04L,H04W

Abstract:
A method of transmitting N information signals over a single pre-defined frequency channel having a bandwidth of BWc, each of the N information signals being transmitted on a single sub-channel of bandwidth BWsc, comprising:a. modulating each of N information signals to form N modulated signals, each having a bandwidth equal to or less than (BWc-BW.sub.GB)/N, wherein BW.sub.GB corresponds to the collective bandwidth of guardbands inserted between adjacent sub-channels and inserted at each end of the bandwidth of the pre-defined frequency channel, each modulated information signal having a center frequency of F.sub.c, wherein said modulating is accomplished using differential modulation, and wherein each of the N modulated signals is comprised of symbols, the value of each symbol being determined by reference to a preceding symbol;b. off setting the center frequency of each modulated signal by a frequency offset individual to that modulated signal, the frequency offset being different for each modulated signal;c. combining the modulated signals to form a composite signal; andd. transmitting the composite signal to a terminal.