A novel scheduling algorithm for multiuser MIMO systems with channel decomposition

In multiuser MIMO systems, the base station offers access to a group of users simultaneously. When the number of users is larger than the maximum that the system can support simultaneously, the base station selects a subset of users based on the scheduling policy, to maximize the system throughput. The scheduling policy used must improve the capacity and it should reduce the complexity. As the data transmitted to each user are different, it is necessary to avoid the inter-user interference. So a technique known as transmit pre-processing technique is used. It is the technique, which decomposes the multiuser MIMO downlink channel into multiple parallel independent single-user MIMO channels. As the pre-processing technique decomposes the channel, it offers the advantage which is interference mitigation. The optimal scheduling algorithm (exhaustive search) offers better performance but it is much complex. The Greedy algorithm offers comparable performance with reduced complexity. So a novel scheduling algorithm named as Modified Greedy algorithm is proposed to enhance the capacity. Simulation result shows that the Modified Greedy algorithm achieves higher capacity than the other scheduling schemes.