Patent ID: 8279959

Claim:
A method for use in a communication transmitter that is adapted to produce a communication signal for transmission of a binary data sequence via a channel to a communication receiver, the method comprising: generating a first real-valued baseband message signal (m 1 (t) signal) that follows a first trajectory through an amplitude trellis, wherein the binary data sequence is trellis encoded to correspond to the first trajectory, and the first trajectory passes through a first particular sequence of trellis states, Q 0 ,Q 1 . . . Q k , at discrete times, kT, where k is an integer counting variable and T is a symbol interval duration; transforming the m 1 (t) signal into a first compact pulse shape (CPS) encoded partial response signal (x I (t) signal) wherein x I ⁡ ( t ) = ∑ j = 1 L + 1 ⁢ p Q ( k - j + 1 ) , ⁢ Q ( k - j + 2 ) ⁡ ( t - k ⁢ ⁢ T + j ⁢ ⁢ T - T ) , for at least a two discrete sample times, t, in each of a plurality of symbol intervals, including a k th symbol interval (kT≦t<(k+1)T), where L is a positive integer and L≦7, p Q (k−j+1), Q (k−j+2) (t)=m Q (k−j+1), Q (k−j+2) (t) h(t) is a compact pulse shape whose length is no longer than (L+1)T, m Q (k−j+1), Q (k−j+2) (t) is a state transition signal of the m 1 (t) signal from a state Q(k−j+1) to a state Q(k−j+2), h(t) is a finite impulse response filter whose impulse response has a length no longer than LT and j is an integer; and processing the x I (t) signal to generate the communication signal therefrom; wherein neither h(t) nor the processing, alone or in combination with any subsequent receive equalization, are designed to cause zero intersymbol interference or a fixed relationship of intersymbol interference to exist at discrete sampling points of a received and sampled version of the communication signal ({circumflex over (x)} I (kT+Δ) signal) as observed in the receiver prior to any subsequent trellis decoding, where Δ is an optional receiver variable selectable in the receiver to compensate a time shift introduced between the transmitter and receiver.