— This paper addresses advanced radio resource management (RRM) algorithms for multiple-input multipleoutput (MIMO) transmission schemes in downlink OFDMA systems. The analysis covers the main RRM mechanisms including MIMO rank adaptation and time-frequency packet scheduling. The UTRAN Long Term Evolution (LTE) system is used as case study. System-level performance analysis is presented for 2x2 and 4x4 spatial-multiplexing, single-user MIMO transmission schemes in typical Macro- and Micro-Cell scenarios including the effects of limited and imperfect CQI feedback from the terminals. We show that time-frequency domain RRM schemes can be successfully adapted and optimized for operations with high-rate adaptive MIMO transmission schemes.
István Z. Kovács, Markku Kuusela, El