In an embodiment an interference cancellation method includes generating, by a first device, a first packet, wherein the first packet comprises a first group of elements, a second group of elements, and user data, the first group of elements being different from the second group of elements and sending, by the first device, the first packet to a second device by using at least one pair of subcarriers, wherein two subcarriers in the at least one pair of subcarriers are symmetrical with respect to a direct current subcarrier, and wherein the first packet is usable by the second device to cancel interference in the user data based on the first group of elements and the second group of elements.