[MU-MIMO] Feedback reduction by multiuser diversity
We describe the throughput performance of user scheduling system when multiuser diversity is applied to the network. If the number of scheduling users is K in the user scheduling network, the required feedback bits is reduced from B to B – log2 K where B is the number of feedback bits and K is the number of active users in the network. The channel model of the uplink multiuser MIMO system is given by y_k = H_k * x_k + n_k where H_k is the wireless fading channel vector for user k, x_k is the scalar transmit signal, and n_k is the noise signal vector.