Patent ID: 6278732
Filing Date: 2001-08-21
Classification: H04L

Abstract:
Apparatus for demodulating a signal having been modulated during a series of signaling intervals, the modulated signal includes at least first and second modulating pulses, said pulses representing binary data bits, and said first and second modulating pulses having first and second shapes and energy levels, respectively, said shapes being different from one another and said pulses existing simultaneously in time and frequency and being substantially nonorthogonal in at least some of said signaling intervals such that cross-correlation between said pulses is substantially non-zero, said apparatus comprising:a) filters connected to receive said first and second modulating pulses, each of said filters being substantially matched to the shape of one of said first and second modulating pulses; andb) an equalizer connected to receive the outputs of said filters and being operable to compensate for at lest one of inter-symbol interference and cross-symbol interference among said modulating pulses to determine said binary data bits wherein a symbol represents a selected number of said binary data bits.