  Full-duplex communication has the potential to substantially increase the
throughput in wireless networks. However, the benefits of full-duplex are still
not well understood. In this paper, we characterize the full-duplex rate gains
in both single-channel and multi-channel use cases. For the single-channel
case, we quantify the rate gain as a function of the remaining
self-interference and SNR values. We also provide a sufficient condition under
which the sum of uplink and downlink rates on a full-duplex channel is concave
in the transmission power levels. Building on these results, we consider the
multi-channel case. For that case, we introduce a new realistic model of a
small form-factor (e.g., smartphone) full-duplex receiver and demonstrate its
accuracy via measurements. We study the problem of jointly allocating power
levels to different channels and selecting the frequency of maximum
self-interference suppression, where the objective is maximizing the sum of the
rates over uplink and downlink OFDM channels. We develop a polynomial time
algorithm which is nearly optimal in practice under very mild restrictions. To
reduce the running time, we develop an efficient nearly-optimal algorithm under
the high SINR approximation. Finally, we demonstrate via numerical evaluations
the capacity gains in the different use cases and obtain insights into the
impact of the remaining self-interference and wireless channel states on the
performance.
