Viterbo and Hottinen (2008). A scheduling strategy is introduced where the users transmit in different time, frequency or code slots and accordingly refer to the channel quality. The proposed scheduling strategy will be used to solve the problem of combinatorial optimization. The Hungarian algorithm is proposed to perform the multiuser scheduling with the Minimum Mean Square Error (MMSE) receiver detection. It is possible to improve the capacity of the multiuser system in different time-frequency-code (TFC) slots because each user will use different channel condition. The capacity can be enhanced by allocating different groups of users. The user pairing starts by assuming the number of paired users that will access two TFC slots in order to double their rate. Then, the single user will use only one TFC slot as a compensation and allow to double the transmit power. A higher modulation can be employed by the unpaired users by transmitting the double transmit power. Hence, their spectral efficiency can be doubled and compensated for their usage of one TFC slot only. The proposed strategy has improved the performance of multiuser system, where the strategies of efficiently exploiting the channel, interference diversity and joint optimisation have been utilised to improve the multiuse system.

The effort for improving the throughput and users fairness has been done by Han, Tao, and Cui (2009), where a user pairing method is introduced for the V-MIMO on the third generation (3G) Long Term Evolution (LTE). The spatial diversity can be rendered by taking into account the large scale and small scale fading. The pairing algorithm which is based on the simplified SNIR-based pairing scheduling (SSNIR-PS) has been proposed to implement the user pairing and improve the fairness of the paired users. The proposed pairing scheduling is aimed to approach the near-optimal throughput performance with lower computational complexity. By assuming two receiver antennas are presented at based station, the user pairing starts by choosing the first user equipment. The first user equipment is selected by performing the scheduling algorithm which is round-robin. Then, the next user equipment that would be paired with the selected first use