  This paper investigates downlink transmission over a quasi-static fading
Gaussian broadcast channel (BC), to model delay-sensitive applications over
slowly time-varying fading channels. System performance is characterized by
outage achievable rate regions. In contrast to most previous work, here the
problem is studied under the key assumption that the transmitter only knows the
probability distributions of the fading coefficients, but not their
realizations. For scalar-input channels, two coding schemes are proposed. The
first scheme is called blind dirty paper coding (B-DPC), which utilizes a
robustness property of dirty paper coding to perform precoding at the
transmitter. The second scheme is called statistical superposition coding
(S-SC), in which each receiver adaptively performs successive decoding with the
process statistically governed by the realized fading. Both B-DPC and S-SC
schemes lead to the same outage achievable rate region, which always dominates
that of time-sharing, irrespective of the particular fading distributions. The
S-SC scheme can be extended to BCs with multiple transmit antennas.
