Delay-limited capacity and maximum throughput of spatially correlated multiple antenna systems under average and peak-power constraints

Abstract

The delay-limited capacity is defined as the transmission rate that can be guaranteed in all fading states under finite long-term power constraints. For the single-input single-output Rayleigh fading channel it is zero. In contrast it is greater than zero in multiple antenna channels but depends on the properties of the fading channel, e.g. on the spatial correlation. In this work, we prove that the delay-limited capacity is Schur-concave with respect to the spatial correlation. In addition to the average power constraint, we apply a peak-power constraint which limits the kurtosis of the input signal. We derive the delay-limited capacity for this general class of multiple antenna channels with correlation under peak-power and long-term power constraint. Without the stringent delay constraint, the maximum throughput is defined as the transmission rate times successful transmission probability. When the transmitter is uninformed, the maximum throughput is achieved for small SNR by using only one transmit antenna and for high SNR by using all available transmit antennas. When the transmitter has perfect channel knowledge, the optimal power allocation under long-term power constraint is analyzed and the impact of correlation is discussed by numerical simulations.