The purpose of the present invention is to provide a high-power-efficiency and low-design-cost transmission device by implementing, with a constant clock, delta-sigma modulation maintaining a zero current switching property in an amplifier. This delta-sigma modulator comprises: a pulse phase signal generation unit for generating a pulse phase signal from a phase signal; a delta-sigma modulation unit for generating a pulse amplitude signal obtained by delta-sigma modulating an amplitude signal with a constant clock; a phase sorting unit for outputting a control signal on the basis of the phase signal; a delay switching unit for delaying the pulse amplitude signal on the basis of the control signal; and a mixing unit for outputting a pulse string obtained by multiplying together the delayed pulse amplitude signal and the pulse phase signal.

This application provides an encoding method and an encoding apparatus based on a polar code, to improve compression performance of a source sequence of a limited length. The method includes: obtaining a source bit sequence; encoding the source bit sequence by using a polar code generation matrix that is based on sub-block column transformation, to obtain a first bit sequence, where the polar code generation matrix that is based on the sub-block column transformation is determined based on a first polar code generation matrix and a transformation matrix, and the transformation matrix may achieve effect of performing sub-block column transformation on the first polar code generation matrix; and compressing the first bit sequence, to obtain a compressed bit sequence.