A power and bit allocation algorithm of changeable BER for MIMO OFDM system

A novel power and bit allocation algorithm for MIMO OFDM system with changeable BER is proposed. This algorithm is based on the waterfilling theorem and calculates the approximate upper bound of the BER in each subchannel, and then the bit and power can be allocated according to the variable BER. This approach maximizes the frequency efficiency under the average power constraint. The theoretic analysis and simulation results show that the frequency efficiency is greater than the algorithm with the fixed BER.