A receiver convolutes each of a real component and an imaginary component of each polarization of a polarization-multiplexed reception signal with an impulse response for compensating for frequency characteristics of the receiver and a complex impulse response for wavelength dispersion compensation, and generates, as input signals, the convoluted real component and imaginary component of each polarization and phase conjugations thereof, for each polarization. The receiver generates, for each polarization, a first addition signal obtained by multiplying each of the real component and the imaginary component of each polarization by a complex impulse response, thereafter adding together the multiplied real component and imaginary component, and applying a phase rotation for frequency offset compensation to the added components, and a second addition signal obtained by multiplying each of the phase conjugation of the real component of and the phase conjugation of the imaginary component of each polarization by a complex impulse response, thereafter adding together the multiplied phase conjugations, and applying a phase rotation opposite to the phase rotation for frequency offset compensation to the added phase conjugations, and adds or subtracts a transmission data bias correction signal to or from a signal obtained by adding together the generated first addition signal and second addition signal.