A method for a terminal, in a wireless communication system, receiving a downlink signal from a cell in which a plurality of beams are multiplexed according to an embodiment of the present invention comprises the steps of: generating a quasi-orthogonal scrambling sequence that is used for scrambling the downlink signal; and receiving the downlink signal through one or more beams of the plurality of multiplexed beams using the generated quasi-orthogonal scrambling sequence, wherein the terminal can initialise the quasi-orthogonal scrambling sequence using a beam-specific parameter corresponding to one or more beams for transmitting the downlink signal when generating the quasi-orthogonal scrambling sequence.