Abstract

The method and apparatus disclosed for more efficient use of the bandwidth of a communication channel includes steps of generating a single sideband signal, including inputting a digital signal into an N-tap Hilbert transform filter, modulating the output of the ((N-1)/2)th tap of the filter onto a first carrier signal, and modulating the output of the Nth tap of the filter onto a second carrier signal. The second carrier signal has the same frequency as, and is separated by 90 degrees in phase from, the first carrier signal. The modulated first and second carrier signals are combined to produce a single sideband signal. A second signal is similarly processed to produce a second single sideband signal. The two single sideband signals may be combined on a single output line. Each single sideband modulation process may be preceded by the steps of receiving an analog signal, sampling the signal to produce a digital signal, and compressing in time the digital signal to produce a compressed signal, wherein each compressed signal is input to the corresponding single sideband signal generator.