  This paper investigates the capacity problem for some multiple-access
scenarios with cooperative transmitters. First, a general Multiple-Access
Channel (MAC) with common information, i.e., a scenario where p transmitters
send private messages and also a common message to q receivers and each
receiver decodes all of the messages, is considered. The capacity region of the
discrete memoryless channel is characterized. Then, the general Gaussian fading
MAC with common information wherein partial Channel State Information (CSI) is
available at the transmitters (CSIT) and perfect CSI is available at the
receivers (CSIR) is investigated. A coding theorem is proved for this model
that yields an exact characterization of the throughput capacity region.
Finally, a two-transmitter/one-receiver Gaussian fading MAC with conferencing
encoders with partial CSIT and perfect CSIR is studied and its capacity region
is determined. For the Gaussian fading models with CSIR only (transmitters have
no access to CSIT), some numerical examples and simulation results are provided
for Rayleigh fading.
