Opportunistic Scheduling for Multiantenna Cellular: Interference Limited Regime

Modern cellular networks employ high frequency reuse and smaller cell sizes. In such a situation, the interference to a user from an adjacent cell can dominate the power of the thermal noise experienced at the user´s receiver. For a K user SISO system with interference insignificant compared to the noise, the optimal throughput scaling is log log K [P. Viswanath et al., 2002], Treating interference as noise, we show that SISO opportunistic scheduling to a single user within a particular cell yields log K throughput scaling while the interference dominates and then transitions to the more familiar log log K regime as the number of users increases and the interference can be opportunistically selected away. For MISO and SIMO systems, opportunistically selecting the best user results in a log K scaling in the interference limited regime. The parameter a varies depending on the number of transmit and receive antennas and the number of interfering cells.