New partial response signaling systems and methods for high spectral efficiency communications are described. In a first implementation, a communication system includes a partial response signaling transmitter and a nonlinear satellite transponder. The partial response signaling transmitter includes a partial response transmit filter configured to convert complex-valued data symbols to a transmit signal using a partial response pulse shaping function; and a modulator configured to modulate the transmit signal onto a carrier wave. The transponder receives and non-linearly amplifies the modulated transmit signal for broadcast to receivers. In a second implementation, a receiver includes circuitry for downconverting a received input signal; a partial response filter with a partial response impulse function for filtering the downconverted signal; circuitry for downsampling the partial response filtered signal; circuitry for equalizing the downsampled signal; and a linear and non-linear interference cancellation module including circuitry for removing linear and non-linear ISI in the input signal.