The capability of error correction codes is largely dependent on the calculation of soft decision values. In this letter, linear-dispersion (LD) code is applied to single-carrier frequency-division multiple access (SC-FDMA) and the closedform expression of soft decision values is derived. It is shown that the calculation of soft decision values generally depends on both time and space within an SC-FDMA symbol, as opposed to single-antenna transmission. In addition, a sufficient condition to guarantee the independence from time and space is presented. Index Terms-SC-FDMA, DFTS-OFDM, linear dispersion code, MIMO, soft decision value, LLR, MMSE.