In this paper, a sub-optimal Rake receiver combined with a Wiener Filter is investigated for use in an indoor environment. Inner-Chip-interference is dominant when the application is indoors, so the inner-chip-interference rejection function becomes critical for the receiver. Pilot symbols in each slot are used for channel estimation and weight calculation of Rake combining through Wiener Filter. Compared to conventional combining which uses maximum ratio combining, Wiener combining using IRC (Interference rejection combining) achieves better ICI (Inner-chip-Interference) rejection. This paper clarified that the sub optimal Rake receiver using Wiener Filter is 4 dB better than the conventional Rake receiver under the indoor application.