In this paper, power coverage characteristic and multipath diversity scheme for downlink simulcast distributed antenna system (DAS) are investigated based on a wideband channel measurement at 6 GHz for indoor scenario. With measured path loss (PL), power coverage property is analyzed. Compared with centralized antenna system (CAS), DAS can introduce 5–17 dB PL gain, and achieve a higher coverage ratio. Then, we propose a multipath diversity algorithm to improve the received power through introducing differential delay and phase rotation simultaneously at the transmitter (Tx). Based on the measured data, it has 1.67 dB power gain in line of sight (LOS) case averagely, better than the scheme without transmission control and multipath antenna diversity (MAD) algorithm.