Resource Scheduling and Modulation and Coding Scheme Selection with Reduced Complexity for LTE

Abstract

Long term evolution (LTE), a very widely deployed cellular technology supports a good number of users simultaneously in a cell. Different algorithms are used at the eNodeB to allocate the radio resources to different users. The algorithm also selects the modulation and coding scheme (MCS) level for every user. The possible number of resource blocks and the possible number of MCS levels are fairly high for each user. Since the allocation decisions need to be made quickly in real time, it is too complex to consider all those possibilities and so, limited ranges of possibilities are currently used for simplicity. The use of limited ranges aggravates the optimization. In this dissertation, a method is proposed that takes all those possibilities into account to allocate resources and MCS but it has much lower computational complexity for its process. The proposed method can be viable due to its lower complexity while it can be more optimal due to the consideration of broader ranges of possibilities. There are variables to adjust the intended level of ranges and complexity within the proposed method. Simulations have been performed for different levels of complexities of the proposed method to roughly demonstrate their relative processing period and impact on data rate. The Thesis has depicted that the computational complexity is reduced. Initially, the computational time for resource allocation to a single user for 800 TTI is 1.6s means 2ms in each TTI. Numerical Analysis shows that the Iteration reduction can provide sufficient flexibility to decide within .8ms by abandoning users in different TTI. So, it seems a sharp computational complexity reduction through abandoning users and advantageous selection of MCS and SBs.