Search Space Allocation Schemes Review for Control Channels in LTE and LTE-Advanced

The search space allocation scheme is a very important operation done to schedule users in the resources of the control channels PDCCH and enhanced PDCCH. However, the standard scheme has many drawbacks as it allocates each user a contiguous number of candidates to blindly search for its control information. This paper reviews some of the proposed designs in literature for the search space allocation scheme and compares them to provide a thorough performance analysis. Simulation results showed some comparisons between the proposed schemes in literature and the standard scheme using three different metrics. Finally, the scattered design was proved to be of the best overall performance although some schemes have comparable performance in the blocking probability metric.