  With the advancement of battery technology, energy harvesting communication
systems attracted great research attention in recent years. However, energy
harvesting communication systems with multiple transmitters and multiple
receivers have not been considered yet. In this paper, the problem of
broadcasting in a communication system with multiple energy harvesting
transmitters and multiple receivers is studied. First, regarding the
transmitters as a 'hole transmitter' [1], the optimal total transmission power
is obtained and the optimal power allocation policy in [2] is extended to our
system setup, with the aim of minimizing the transmission completion time.
Then, a simpler power allocation policy is developed to allocate the optimal
total transmission power to the data transmissions. As transmitter switching
can provide flexibility and robustness to an energy harvesting communication
system, especially when a transmitter is broken or the energy harvested by a
transmitter is insufficient, a transmitter switching policy is further
developed to choose a suitable transmitter to work whenever necessary. The
results show that the proposed power allocation policy performs close to the
optimal one and outperforms some heuristic ones in terms of transmission
completion time. Besides, the proposed transmitter switching policy outperforms
some heuristic ones in terms of number of switches.
