Distributed antenna system (DAS) or distributed multiple-input multiple-output (MIMO) can enhance the cellular throughput performance, thanks to the largely separated multiple remote antenna units (RAU) which can experience the different large scale fading and the small scale fading. So far, much research work has been published in the DAS. However, to the authors' best knowledge, there is no research work which deals with the impact of the large scale fading effect on the throughput performance when practical data modulation, adaptive modulation, and signal detection schemes are used. How the bits should be allocated to the different RAUs is an important research topic in the DAS. In this paper, we consider two bit allocation methods: statistical channel based allocation and instantaneous channel based allocation. How the bits are allocated to each RAU are expressed by using simple equations based on statistical and instantaneous channel. Using numerical computation, how the large scale fading and bit allocation methods affect the throughput performance of distributed MIMO system are evaluated.