Performance analysis on carrier scheduling schemes in the long-term evolution-advanced system with carrier aggregation

Carrier aggregation (CA) is one of the promising techniques for the further advancements of the third-generation (3G) long-term evolution (LTE) system, referred to as LTE-Advanced. When CA is applied, a well-designed carrier scheduling (CS) scheme is essential to the LTE-Advanced system. Joint user scheduling (JUS) and separated random user scheduling (SRUS) are two straightforward CS schemes. JUS is optimal in performance but with very high complexity, whereas SRUS is contrary. Consequently, the authors propose a novel CS scheme, termed as 'separated burst-level scheduling' (SBLS). In SBLS, the connected component carrier (CC) of one user can be changed in burst level, whereas in SRUS, it is fixed. Meanwhile, SBLS limits the users to receive from only one of the CCs simultaneously, which is the same as that in SRUS. In this way, SBLS is expected to achieve higher resource utilisation than SRUS but with acceptable complexity increase. There are two factors that are important to the performance of SBLS, namely the dispatching granularity and the dispatching policy. The authors' analysis is verified by system-level simulations. The simulation results also show that the resultant performance gain of SBLS over SRUS is notable and increasing dispatching granularity will quickly deteriorate the performance of SBLS.