The present invention relates to a device and method for supporting improved communication speed in a wireless power transmission system. The present specification provides a method comprising the steps of: generating wireless power at an operating frequency; configuring n, as the number of cycles per bit, which is used for transmitting one bit at the operating frequency; aligning each bit of the data with the n cycles; causing the operating frequency to transition between differential biphases according to the value of said each bit during the n cycles; and transmitting the wireless power to a wireless power receiving device on the basis of magnetic coupling at the transitioning operating frequency.