Efficient resource allocation for orthogonal transmission in broadcast channels

The allocation of network resources for spectral efficiency maximization in a broadcast channel under the practical restrictions of orthogonal transmission and the use of squared QAM constellations is addressed. Given a total transmit power constraint and (possibly) different per-user quality of service requirements in the form of target uncoded bit error rates, efficient power and bit loading algorithms are proposed to maximize a weighted sum of the users' rates that tightly match the performance of the optimal but computationally prohibitive allocation strategy.