Optimal Zero-Forcing Transceiver Design for Maximizing Bit Rate Subject to a Total Transmit Power Constraint

In this paper, we design the optimal zero-forcing transceiver that maximizes the transmission bit rate for multiple-input multiple-output (MIMO) channels. The transmission bit rate is maximized subject to a total power constraint for a given error rate. Instead of using the same input constella-tion size for all subchannels as in earlier designs, the bit al-location is also taken into consideration. The bit allocation and the zero-forcing transceiver are jointly designed for bit rate maximization. The optimal transceiver is obtained in a closed form. The bits are allocated according to the sub-channel signal to noise ratios. The larger the signal to noise ratio is, the more the number of bits are allocated. In the simulation, we have demonstrated that a higher bit rate can be achieved compared to previously reported methods. 1