QoS guaranteed resource block allocation algorithm for LTE systems

Using conventional resource allocation algorithms in OFDM systems, each user can employ different Modulation and Coding Scheme (MCS) on allocated subcarriers to achieve good throughput. However, in the downlink transmission of LTE systems, the minimum allocation unit for one user is Scheduling Block (SB) and all SB assigned to one user must adopt the same MCS. Therefore, the application of conventional resource allocation algorithms in LTE results in degraded performance since MCS must be chosen according to the worst SB. To solve this problem, a QoS guaranteed resource block allocation algorithm is proposed for LTE systems, which takes into account both the constraint on MCS and the requirement of Quality of Services (QoS). The proposed algorithm firstly estimates the number of SB required by each user and then allocates SBs to users according to their priorities. Simulation results show that compared to conventional schemes, the proposed algorithm can achieve high throughput as well as significant improvement in guaranteeing users´ QoS requirements.