1. A method of decoding a video signal having a current block to be decoded with a decoding apparatus, comprising: obtaining, from the video signal, residual samples of a current block and index information for specifying a temporal motion vector candidate of the current block; obtaining a spatial motion vector candidate from a spatial neighboring block of the current block; selecting, based on the index information, a collocated picture relating to the temporal motion vector candidate of the current block; obtaining the temporal motion vector candidate from a collocated block included in the selected collocated picture; generating a motion vector candidate list including the spatial motion vector candidate and the temporal motion vector candidate; deriving a motion vector predictor based on the motion vector candidate list and a candidate index of the current block, the candidate index specifying one of motion vector candidates included in the motion vector candidate list; deriving a motion vector of the current block using the motion vector predictor and a motion vector difference, the motion vector difference being representative of a difference between the motion vector and the motion vector predictor; obtaining prediction samples of the current block by using the motion vector; and reconstructing the current block by using the residual samples and the prediction samples.